diff options
| author | Frédéric Desbiens <[email protected]> | 2026-03-04 08:36:53 +0100 |
|---|---|---|
| committer | GitHub <[email protected]> | 2026-03-04 08:36:53 +0100 |
| commit | 385d39f421f61f9857ff1d31479a4a5547452437 (patch) | |
| tree | a58a778362cd46eb51fdf1d587abe48663ee41ef | |
| parent | b3e8a9aa2074c553e39605271e6267c1a29ccd9a (diff) | |
| parent | 49439bfa9c67fee51852a0e55df3a96aad785a8f (diff) | |
Merge pull request #502 from quintauris-tech/riscv32-clang-portv6.5.0.202601_pre
Added a RV32 Clang port
28 files changed, 4101 insertions, 0 deletions
diff --git a/cmake/riscv32-clang-unknown-elf.cmake b/cmake/riscv32-clang-unknown-elf.cmake new file mode 100644 index 00000000..eb520962 --- /dev/null +++ b/cmake/riscv32-clang-unknown-elf.cmake @@ -0,0 +1,29 @@ +# Toolchain settings +set(CMAKE_C_COMPILER clang-18) +set(CMAKE_CXX_COMPILER clang++-18) +#set(AS llvm-as) +#set(AR llvm-ar) +#set(OBJCOPY llvm-objcopy) +#set(OBJDUMP llvm-objdump-18) +#set(SIZE llvm-size) + +set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER) +set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY) +set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY) +set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY) + +# this makes the test compiles use static library option so that we don't need to pre-set linker flags and scripts +set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY) + +set(CMAKE_C_FLAGS "${CFLAGS}" CACHE INTERNAL "c compiler flags") +set(CMAKE_CXX_FLAGS "${CXXFLAGS}" CACHE INTERNAL "cxx compiler flags") +set(CMAKE_ASM_FLAGS "${ASFLAGS} -D__ASSEMBLER__" CACHE INTERNAL "asm compiler flags") +set(CMAKE_EXE_LINKER_FLAGS "${LDFLAGS}" CACHE INTERNAL "exe link flags") + +SET(CMAKE_C_FLAGS_DEBUG "--target=riscv32 -march=rv32im_zicsr_zicntr -mabi=ilp32 -g" CACHE INTERNAL "c debug compiler flags") +SET(CMAKE_CXX_FLAGS_DEBUG "--target=riscv32 -march=rv32im_zicsr_zicntr -mabi=ilp32 -g" CACHE INTERNAL "cxx debug compiler flags") +SET(CMAKE_ASM_FLAGS_DEBUG "--target=riscv32 -march=rv32im_zicsr_zicntr -mabi=ilp32 -g" CACHE INTERNAL "asm debug compiler flags") + +SET(CMAKE_C_FLAGS_RELEASE "--target=riscv32 -march=rv32im_zicsr_zicntr -mabi=ilp32 -O3" CACHE INTERNAL "c release compiler flags") +SET(CMAKE_CXX_FLAGS_RELEASE "--target=riscv32 -march=rv32im_zicsr_zicntr -mabi=ilp32 -O3" CACHE INTERNAL "cxx release compiler flags") +SET(CMAKE_ASM_FLAGS_RELEASE "--target=riscv32 -march=rv32im_zicsr_zicntr -mabi=ilp32" CACHE INTERNAL "asm release compiler flags") diff --git a/cmake/riscv32_clang.cmake b/cmake/riscv32_clang.cmake new file mode 100644 index 00000000..97acd832 --- /dev/null +++ b/cmake/riscv32_clang.cmake @@ -0,0 +1,18 @@ +# Name of the target +set(CMAKE_SYSTEM_NAME Generic) +set(CMAKE_SYSTEM_PROCESSOR risc-v32) + +IF(DEFINED $ENV{GCC_INSTALL_PREFIX}) + SET(GCC_INSTALL_PREFIX "$ENV{GCC_INSTALL_PREFIX}" CACHE INTERNAL "" FORCE) +ELSE() + SET(GCC_INSTALL_PREFIX "/opt/riscv_rv32ima" CACHE INTERNAL "" FORCE) +ENDIF() + +set(THREADX_ARCH "risc-v32") +set(THREADX_TOOLCHAIN "clang") +set(ARCH_FLAGS "--sysroot=${GCC_INSTALL_PREFIX}/riscv32-unknown-elf --target=riscv32 -g -march=rv32ima_zicsr -mabi=ilp32") +set(CFLAGS "${ARCH_FLAGS}") +set(ASFLAGS "${ARCH_FLAGS}") +set(LDFLAGS "--no-dynamic-linker -m elf32lriscv -static -nostdlib") + +include(${CMAKE_CURRENT_LIST_DIR}/riscv32-clang-unknown-elf.cmake) diff --git a/ports/risc-v32/clang/CMakeLists.txt b/ports/risc-v32/clang/CMakeLists.txt new file mode 100644 index 00000000..9b725103 --- /dev/null +++ b/ports/risc-v32/clang/CMakeLists.txt @@ -0,0 +1,19 @@ + +target_sources(${PROJECT_NAME} + PRIVATE + # {{BEGIN_TARGET_SOURCES}} + ${CMAKE_CURRENT_LIST_DIR}/src/tx_initialize_low_level.S + ${CMAKE_CURRENT_LIST_DIR}/src/tx_thread_context_restore.S + ${CMAKE_CURRENT_LIST_DIR}/src/tx_thread_context_save.S + ${CMAKE_CURRENT_LIST_DIR}/src/tx_thread_interrupt_control.S + ${CMAKE_CURRENT_LIST_DIR}/src/tx_thread_schedule.S + ${CMAKE_CURRENT_LIST_DIR}/src/tx_thread_stack_build.S + ${CMAKE_CURRENT_LIST_DIR}/src/tx_thread_system_return.S + ${CMAKE_CURRENT_LIST_DIR}/src/tx_timer_interrupt.S + # {{END_TARGET_SOURCES}} +) + +target_include_directories(${PROJECT_NAME} + PUBLIC + ${CMAKE_CURRENT_LIST_DIR}/inc +) diff --git a/ports/risc-v32/clang/example_build/qemu_virt/board.c b/ports/risc-v32/clang/example_build/qemu_virt/board.c new file mode 100644 index 00000000..47f828d4 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/board.c @@ -0,0 +1,42 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + +#include "plic.h" +#include "hwtimer.h" +#include "uart.h" +#include <stdint.h> +#include <stddef.h> + +void *memset(void *des, int c,size_t n) +{ + if((des == NULL) || n <=0) + return (void*)des; + char* t = (char*)des; + int i; + for(i=0;i<n;i++) + t[i]=c; + return t; +} + + +int board_init(void) +{ + int ret; + ret = plic_init(); + if(ret) + return ret; + ret = uart_init(); + if(ret) + return ret; + ret = hwtimer_init(); + if(ret) + return ret; + return 0; +} diff --git a/ports/risc-v32/clang/example_build/qemu_virt/build_libthreadx.sh b/ports/risc-v32/clang/example_build/qemu_virt/build_libthreadx.sh new file mode 100755 index 00000000..ff84c974 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/build_libthreadx.sh @@ -0,0 +1,7 @@ +#!/bin/bash + +pushd ../../../../../ +#cmake -Bbuild -GNinja -DCMAKE_TOOLCHAIN_FILE=cmake/riscv32_clang.cmake . +cmake -Bbuild -DCMAKE_TOOLCHAIN_FILE=cmake/riscv32_clang.cmake . +cmake --build ./build/ +popd diff --git a/ports/risc-v32/clang/example_build/qemu_virt/build_threadx_sample.sh b/ports/risc-v32/clang/example_build/qemu_virt/build_threadx_sample.sh new file mode 100755 index 00000000..a1b3cb88 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/build_threadx_sample.sh @@ -0,0 +1,19 @@ +#!/bin/bash + +DIRNAME=$(dirname "$0") +BASEDIR=$DIRNAME/../../../../.. + +mkdir -p build + +CC=clang-18 +LD=ld.lld-18 + +$CC -I $BASEDIR/ports/risc-v32/clang/inc -I $BASEDIR/build/custom_inc -g --sysroot=/opt/riscv_rv32ima/riscv32-unknown-elf --target=riscv32 -march=rv32ima_zicsr -mabi=ilp32 -o build/entry.obj -c entry.s +$CC -DTX_INCLUDE_USER_DEFINE_FILE -I $BASEDIR/ports/risc-v32/clang/inc -I $BASEDIR/build/custom_inc -isystem $BASEDIR/common/inc -g --sysroot=/opt/riscv_rv32ima/riscv32-unknown-elf --target=riscv32 -march=rv32ima_zicsr -mabi=ilp32 -D__ASSEMBLER__ -o build/tx_initialize_low_level.obj -c tx_initialize_low_level.S +$CC -DTX_INCLUDE_USER_DEFINE_FILE -I $BASEDIR/ports/risc-v32/clang/inc -I $BASEDIR/build/custom_inc -isystem $BASEDIR/common/inc -g --sysroot=/opt/riscv_rv32ima/riscv32-unknown-elf --target=riscv32 -march=rv32ima_zicsr -mabi=ilp32 -o build/board.obj -c board.c +$CC -DTX_INCLUDE_USER_DEFINE_FILE -I $BASEDIR/ports/risc-v32/clang/inc -I $BASEDIR/build/custom_inc -isystem $BASEDIR/common/inc -g --sysroot=/opt/riscv_rv32ima/riscv32-unknown-elf --target=riscv32 -march=rv32ima_zicsr -mabi=ilp32 -o build/hwtimer.obj -c hwtimer.c +$CC -DTX_INCLUDE_USER_DEFINE_FILE -I $BASEDIR/ports/risc-v32/clang/inc -I $BASEDIR/build/custom_inc -isystem $BASEDIR/common/inc -g --sysroot=/opt/riscv_rv32ima/riscv32-unknown-elf --target=riscv32 -march=rv32ima_zicsr -mabi=ilp32 -o build/plic.obj -c plic.c +$CC -DTX_INCLUDE_USER_DEFINE_FILE -I $BASEDIR/ports/risc-v32/clang/inc -I $BASEDIR/build/custom_inc -isystem $BASEDIR/common/inc -g --sysroot=/opt/riscv_rv32ima/riscv32-unknown-elf --target=riscv32 -march=rv32ima_zicsr -mabi=ilp32 -o build/trap.obj -c trap.c +$CC -DTX_INCLUDE_USER_DEFINE_FILE -I $BASEDIR/ports/risc-v32/clang/inc -I $BASEDIR/build/custom_inc -isystem $BASEDIR/common/inc -g --sysroot=/opt/riscv_rv32ima/riscv32-unknown-elf --target=riscv32 -march=rv32ima_zicsr -mabi=ilp32 -o build/uart.obj -c uart.c +$CC -DTX_INCLUDE_USER_DEFINE_FILE -I $BASEDIR/ports/risc-v32/clang/inc -I $BASEDIR/build/custom_inc -isystem $BASEDIR/common/inc -g --sysroot=/opt/riscv_rv32ima/riscv32-unknown-elf --target=riscv32 -march=rv32ima_zicsr -mabi=ilp32 -o build/demo_threadx.obj -c demo_threadx.c +$LD -Tlink.lds --no-dynamic-linker -m elf32lriscv -static -nostdlib -o build/demo_threadx.elf --Map=build/demo_threadx.map build/entry.obj build/tx_initialize_low_level.obj build/board.obj build/hwtimer.obj build/plic.obj build/trap.obj build/uart.obj build/demo_threadx.obj $BASEDIR/build/libthreadx.a diff --git a/ports/risc-v32/clang/example_build/qemu_virt/csr.h b/ports/risc-v32/clang/example_build/qemu_virt/csr.h new file mode 100644 index 00000000..0c163404 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/csr.h @@ -0,0 +1,343 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + + +#ifndef RISCV_CSR_H +#define RISCV_CSR_H + + +// Machine Status Register, mstatus +#define MSTATUS_MPP_MASK (3L << 11) // previous mode. +#define MSTATUS_MPP_M (3L << 11) +#define MSTATUS_MPP_S (1L << 11) +#define MSTATUS_MPP_U (0L << 11) +#define MSTATUS_MIE (1L << 3) // machine-mode interrupt enable. +#define MSTATUS_MPIE (1L << 7) +#define MSTATUS_FS (1L << 13) + +// Machine-mode Interrupt Enable +#define MIE_MTIE (1L << 7) +#define MIE_MSIE (1L << 3) +#define MIE_MEIE (1L << 11) +#define MIE_STIE (1L << 5) // supervisor timer +#define MIE_SSIE (1L << 1) +#define MIE_SEIE (1L << 9) + +// Supervisor Status Register, sstatus +#define SSTATUS_SPP (1L << 8) // Previous mode, 1=Supervisor, 0=User +#define SSTATUS_SPIE (1L << 5) // Supervisor Previous Interrupt Enable +#define SSTATUS_UPIE (1L << 4) // User Previous Interrupt Enable +#define SSTATUS_SIE (1L << 1) // Supervisor Interrupt Enable +#define SSTATUS_UIE (1L << 0) // User Interrupt Enable +#define SSTATUS_SPIE (1L << 5) +#define SSTATUS_UPIE (1L << 4) + +// Supervisor Interrupt Enable +#define SIE_SEIE (1L << 9) // external +#define SIE_STIE (1L << 5) // timer +#define SIE_SSIE (1L << 1) // software + +#ifndef __ASSEMBLER__ + +#include <stdint.h> + +static inline uint32_t riscv_get_core() +{ + uint32_t x; + asm volatile("csrr %0, mhartid" : "=r" (x) ); + return x; +} + +static inline uint32_t riscv_get_mstatus() +{ + uint32_t x; + asm volatile("csrr %0, mstatus" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_mstatus(uint32_t x) +{ + asm volatile("csrw mstatus, %0" : : "r" (x)); +} + +static inline void riscv_writ_mepc(uint32_t x) +{ + asm volatile("csrw mepc, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_sstatus() +{ + uint32_t x; + asm volatile("csrr %0, sstatus" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_sstatus(uint32_t x) +{ + asm volatile("csrw sstatus, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_sip() +{ + uint32_t x; + asm volatile("csrr %0, sip" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_sip(uint32_t x) +{ + asm volatile("csrw sip, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_sie() +{ + uint32_t x; + asm volatile("csrr %0, sie" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_sie(uint32_t x) +{ + asm volatile("csrw sie, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_mie() +{ + uint32_t x; + asm volatile("csrr %0, mie" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_mie(uint32_t x) +{ + asm volatile("csrw mie, %0" : : "r" (x)); +} + +static inline void riscv_writ_sepc(uint32_t x) +{ + asm volatile("csrw sepc, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_sepc() +{ + uint32_t x; + asm volatile("csrr %0, sepc" : "=r" (x) ); + return x; +} + +static inline uint32_t riscv_get_medeleg() +{ + uint32_t x; + asm volatile("csrr %0, medeleg" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_medeleg(uint32_t x) +{ + asm volatile("csrw medeleg, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_mideleg() +{ + uint32_t x; + asm volatile("csrr %0, mideleg" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_mideleg(uint32_t x) +{ + asm volatile("csrw mideleg, %0" : : "r" (x)); +} + +static inline void riscv_writ_stvec(uint32_t x) +{ + asm volatile("csrw stvec, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_stvec() +{ + uint32_t x; + asm volatile("csrr %0, stvec" : "=r" (x) ); + return x; +} + +static inline uint32_t riscv_get_stimecmp() +{ + uint32_t x; + asm volatile("csrr %0, 0x14d" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_stimecmp(uint32_t x) +{ + asm volatile("csrw 0x14d, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_menvcfg() +{ + uint32_t x; + asm volatile("csrr %0, 0x30a" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_menvcfg(uint32_t x) +{ + asm volatile("csrw 0x30a, %0" : : "r" (x)); +} + +static inline void riscv_writ_pmpcfg0(uint32_t x) +{ + asm volatile("csrw pmpcfg0, %0" : : "r" (x)); +} + +static inline void riscv_writ_pmpaddr0(uint32_t x) +{ + asm volatile("csrw pmpaddr0, %0" : : "r" (x)); +} + +static inline void riscv_writ_satp(uint32_t x) +{ + asm volatile("csrw satp, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_satp() +{ + uint32_t x; + asm volatile("csrr %0, satp" : "=r" (x) ); + return x; +} + +static inline uint32_t riscv_get_scause() +{ + uint32_t x; + asm volatile("csrr %0, scause" : "=r" (x) ); + return x; +} + +static inline uint32_t riscv_get_stval() +{ + uint32_t x; + asm volatile("csrr %0, stval" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_mcounteren(uint32_t x) +{ + asm volatile("csrw mcounteren, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_mcounteren() +{ + uint32_t x; + asm volatile("csrr %0, mcounteren" : "=r" (x) ); + return x; +} + +static inline uint32_t riscv_get_time() +{ + uint32_t x; + asm volatile("csrr %0, time" : "=r" (x) ); + return x; +} + +static inline void riscv_sintr_on() +{ + uint32_t sstatus = riscv_get_sstatus(); + sstatus |= SSTATUS_SIE; + riscv_writ_sstatus(sstatus); +} + +static inline void riscv_sintr_off() +{ + uint32_t sstatus = riscv_get_sstatus(); + sstatus &= (~SSTATUS_SIE); + riscv_writ_sstatus(sstatus); +} + +static inline int riscv_sintr_get() +{ + uint32_t x = riscv_get_sstatus(); + return (x & SSTATUS_SIE) != 0; +} + +static inline void riscv_sintr_restore(int x) +{ + if(x) + riscv_sintr_on(); + else + riscv_sintr_off(); +} + +static inline void riscv_mintr_on() +{ + uint32_t mstatus = riscv_get_mstatus(); + mstatus |= MSTATUS_MIE; + riscv_writ_mstatus(mstatus); +} + +static inline void riscv_mintr_off() +{ + uint32_t mstatus = riscv_get_mstatus(); + mstatus &= (~MSTATUS_MIE); + riscv_writ_mstatus(mstatus); +} + +static inline int riscv_mintr_get() +{ + uint32_t x = riscv_get_mstatus(); + return (x & MSTATUS_MIE) != 0; +} + +static inline void riscv_mintr_restore(int x) +{ + if(x) + riscv_mintr_on(); + else + riscv_mintr_off(); +} + +static inline uint32_t riscv_get_sp() +{ + uint32_t x; + asm volatile("mv %0, sp" : "=r" (x) ); + return x; +} + +// read and write tp, the thread pointer, which xv6 uses to hold +// this core's hartid (core number), the index into cpus[]. +static inline uint32_t riscv_get_tp() +{ + uint32_t x; + asm volatile("mv %0, tp" : "=r" (x) ); + return x; +} + +static inline void riscv_writ_tp(uint32_t x) +{ + asm volatile("mv tp, %0" : : "r" (x)); +} + +static inline uint32_t riscv_get_ra() +{ + uint32_t x; + asm volatile("mv %0, ra" : "=r" (x) ); + return x; +} + +// flush the TLB. +static inline void sfence_vma() +{ + // the zero, zero means flush all TLB entries. + asm volatile("sfence.vma zero, zero"); +} + +#endif // __ASSEMBLER__ + +#endif diff --git a/ports/risc-v32/clang/example_build/qemu_virt/demo_threadx.c b/ports/risc-v32/clang/example_build/qemu_virt/demo_threadx.c new file mode 100644 index 00000000..a5955b29 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/demo_threadx.c @@ -0,0 +1,397 @@ +/* This is a small demo of the high-performance ThreadX kernel. It includes examples of eight + threads of different priorities, using a message queue, semaphore, mutex, event flags group, + byte pool, and block pool. */ + +#include "tx_api.h" +#include "uart.h" + +#define DEMO_STACK_SIZE 1024 +#define DEMO_BYTE_POOL_SIZE 9120 +#define DEMO_BLOCK_POOL_SIZE 100 +#define DEMO_QUEUE_SIZE 100 + +char *_to_str(ULONG val) +{ + static char buf[11]; /* 10 digits max + '\0' */ + char *p = buf + sizeof(buf) - 1; + + *p = '\0'; + do { + *--p = '0' + (val % 10); + val /= 10; + } while (val); + + return p; +} + +/* Define the ThreadX object control blocks... */ + +TX_THREAD thread_0; +TX_THREAD thread_1; +TX_THREAD thread_2; +TX_THREAD thread_3; +TX_THREAD thread_4; +TX_THREAD thread_5; +TX_THREAD thread_6; +TX_THREAD thread_7; +TX_QUEUE queue_0; +TX_SEMAPHORE semaphore_0; +TX_MUTEX mutex_0; +TX_EVENT_FLAGS_GROUP event_flags_0; +TX_BYTE_POOL byte_pool_0; +TX_BLOCK_POOL block_pool_0; + + +/* Define the counters used in the demo application... */ + +ULONG thread_0_counter; +ULONG thread_1_counter; +ULONG thread_1_messages_sent; +ULONG thread_2_counter; +ULONG thread_2_messages_received; +ULONG thread_3_counter; +ULONG thread_4_counter; +ULONG thread_5_counter; +ULONG thread_6_counter; +ULONG thread_7_counter; + + +/* Define thread prototypes. */ + +void thread_0_entry(ULONG thread_input); +void thread_1_entry(ULONG thread_input); +void thread_2_entry(ULONG thread_input); +void thread_3_and_4_entry(ULONG thread_input); +void thread_5_entry(ULONG thread_input); +void thread_6_and_7_entry(ULONG thread_input); + + +/* Define main entry point. */ + +int main() +{ + + /* Enter the ThreadX kernel. */ + tx_kernel_enter(); +} + + +/* Define what the initial system looks like. */ + +void tx_application_define(void *first_unused_memory) +{ + CHAR *pointer = TX_NULL; + + /* Create a byte memory pool from which to allocate the thread stacks. */ + tx_byte_pool_create(&byte_pool_0, "byte pool 0", first_unused_memory, DEMO_BYTE_POOL_SIZE); + + /* Put system definition stuff in here, e.g. thread creates and other assorted + create information. */ + + /* Allocate the stack for thread 0. */ + tx_byte_allocate(&byte_pool_0, (VOID **) &pointer, DEMO_STACK_SIZE, TX_NO_WAIT); + + /* Create the main thread. */ + tx_thread_create(&thread_0, "thread 0", thread_0_entry, 0, + pointer, DEMO_STACK_SIZE, + 1, 1, TX_NO_TIME_SLICE, TX_AUTO_START); + + + /* Allocate the stack for thread 1. */ + tx_byte_allocate(&byte_pool_0, (VOID **) &pointer, DEMO_STACK_SIZE, TX_NO_WAIT); + + /* Create threads 1 and 2. These threads pass information through a ThreadX + message queue. It is also interesting to note that these threads have a time + slice. */ + tx_thread_create(&thread_1, "thread 1", thread_1_entry, 1, + pointer, DEMO_STACK_SIZE, + 16, 16, 4, TX_AUTO_START); + + /* Allocate the stack for thread 2. */ + tx_byte_allocate(&byte_pool_0, (VOID **) &pointer, DEMO_STACK_SIZE, TX_NO_WAIT); + + tx_thread_create(&thread_2, "thread 2", thread_2_entry, 2, + pointer, DEMO_STACK_SIZE, + 16, 16, 4, TX_AUTO_START); + + /* Allocate the stack for thread 3. */ + tx_byte_allocate(&byte_pool_0, (VOID **) &pointer, DEMO_STACK_SIZE, TX_NO_WAIT); + + /* Create threads 3 and 4. These threads compete for a ThreadX counting semaphore. + An interesting thing here is that both threads share the same instruction area. */ + tx_thread_create(&thread_3, "thread 3", thread_3_and_4_entry, 3, + pointer, DEMO_STACK_SIZE, + 8, 8, TX_NO_TIME_SLICE, TX_AUTO_START); + + /* Allocate the stack for thread 4. */ + tx_byte_allocate(&byte_pool_0, (VOID **) &pointer, DEMO_STACK_SIZE, TX_NO_WAIT); + + tx_thread_create(&thread_4, "thread 4", thread_3_and_4_entry, 4, + pointer, DEMO_STACK_SIZE, + 8, 8, TX_NO_TIME_SLICE, TX_AUTO_START); + + /* Allocate the stack for thread 5. */ + tx_byte_allocate(&byte_pool_0, (VOID **) &pointer, DEMO_STACK_SIZE, TX_NO_WAIT); + + /* Create thread 5. This thread simply pends on an event flag which will be set + by thread_0. */ + tx_thread_create(&thread_5, "thread 5", thread_5_entry, 5, + pointer, DEMO_STACK_SIZE, + 4, 4, TX_NO_TIME_SLICE, TX_AUTO_START); + + /* Allocate the stack for thread 6. */ + tx_byte_allocate(&byte_pool_0, (VOID **) &pointer, DEMO_STACK_SIZE, TX_NO_WAIT); + + /* Create threads 6 and 7. These threads compete for a ThreadX mutex. */ + tx_thread_create(&thread_6, "thread 6", thread_6_and_7_entry, 6, + pointer, DEMO_STACK_SIZE, + 8, 8, TX_NO_TIME_SLICE, TX_AUTO_START); + + /* Allocate the stack for thread 7. */ + tx_byte_allocate(&byte_pool_0, (VOID **) &pointer, DEMO_STACK_SIZE, TX_NO_WAIT); + + tx_thread_create(&thread_7, "thread 7", thread_6_and_7_entry, 7, + pointer, DEMO_STACK_SIZE, + 8, 8, TX_NO_TIME_SLICE, TX_AUTO_START); + + /* Allocate the message queue. */ + tx_byte_allocate(&byte_pool_0, (VOID **) &pointer, DEMO_QUEUE_SIZE*sizeof(ULONG), TX_NO_WAIT); + + /* Create the message queue shared by threads 1 and 2. */ + tx_queue_create(&queue_0, "queue 0", TX_1_ULONG, pointer, DEMO_QUEUE_SIZE*sizeof(ULONG)); + + /* Create the semaphore used by threads 3 and 4. */ + tx_semaphore_create(&semaphore_0, "semaphore 0", 1); + + /* Create the event flags group used by threads 1 and 5. */ + tx_event_flags_create(&event_flags_0, "event flags 0"); + + /* Create the mutex used by thread 6 and 7 without priority inheritance. */ + tx_mutex_create(&mutex_0, "mutex 0", TX_NO_INHERIT); + + /* Allocate the memory for a small block pool. */ + tx_byte_allocate(&byte_pool_0, (VOID **) &pointer, DEMO_BLOCK_POOL_SIZE, TX_NO_WAIT); + + /* Create a block memory pool to allocate a message buffer from. */ + tx_block_pool_create(&block_pool_0, "block pool 0", sizeof(ULONG), pointer, DEMO_BLOCK_POOL_SIZE); + + /* Allocate a block and release the block memory. */ + tx_block_allocate(&block_pool_0, (VOID **) &pointer, TX_NO_WAIT); + + /* Release the block back to the pool. */ + tx_block_release(pointer); +} + + + +/* Define the test threads. */ + +void thread_0_entry(ULONG thread_input) +{ + +UINT status; + + + /* This thread simply sits in while-forever-sleep loop. */ + while(1) + { + puts("[Thread] : thread_0_entry is here!"); + + /* Increment the thread counter. */ + thread_0_counter++; + + /* Sleep for 10 ticks. */ + tx_thread_sleep(10); + + /* Set event flag 0 to wakeup thread 5. */ + status = tx_event_flags_set(&event_flags_0, 0x1, TX_OR); + + /* Check status. */ + if (status != TX_SUCCESS) + break; + } +} + + +void thread_1_entry(ULONG thread_input) +{ + +UINT status; + + /* This thread simply sends messages to a queue shared by thread 2. */ + while(1) + { + puts("[Thread] : thread_1_entry is here!"); + /* Increment the thread counter. */ + thread_1_counter++; + + /* Send message to queue 0. */ + status = tx_queue_send(&queue_0, &thread_1_messages_sent, TX_WAIT_FOREVER); + + tx_thread_sleep(2); + + /* Check completion status. */ + if (status != TX_SUCCESS) { + puts("[Thread 1] ERROR: Failed to send message!"); + break; + } + + /* Increment the message sent. */ + thread_1_messages_sent++; + } +} + + + +void thread_2_entry(ULONG thread_input) +{ + +ULONG received_message; +UINT status; + + /* This thread retrieves messages placed on the queue by thread 1. */ + while(1) + { + puts("[Thread] : thread_2_entry is here!"); + /* Increment the thread counter. */ + thread_2_counter++; + + /* Retrieve a message from the queue. */ + status = tx_queue_receive(&queue_0, &received_message, TX_WAIT_FOREVER); + + tx_thread_sleep(2); + + /* Check completion status and make sure the message is what we + expected. */ + if ((status != TX_SUCCESS) || (received_message != thread_2_messages_received)){ + puts("[Thread 2] ERROR: Failed to receive message ! Expected # "); + uart_puts(_to_str(thread_2_messages_received)); + puts(", but got # "); + uart_puts(_to_str(received_message)); + break; + } + + /* Otherwise, all is okay. Increment the received message count. */ + thread_2_messages_received++; + } +} + + +void thread_3_and_4_entry(ULONG thread_input) +{ + +UINT status; + + + /* This function is executed from thread 3 and thread 4. As the loop + below shows, these function compete for ownership of semaphore_0. */ + while(1) + { + puts("[Thread] : thread_3_and_4_entry is here!"); + + + /* Increment the thread counter. */ + if (thread_input == 3) + thread_3_counter++; + else + thread_4_counter++; + + /* Get the semaphore with suspension. */ + status = tx_semaphore_get(&semaphore_0, TX_WAIT_FOREVER); + + /* Check status. */ + if (status != TX_SUCCESS) + break; + + /* Sleep for 2 ticks to hold the semaphore. */ + tx_thread_sleep(2); + + /* Release the semaphore. */ + status = tx_semaphore_put(&semaphore_0); + + /* Check status. */ + if (status != TX_SUCCESS) + break; + } +} + + +void thread_5_entry(ULONG thread_input) +{ + +UINT status; +ULONG actual_flags; + + + /* This thread simply waits for an event in a forever loop. */ + while(1) + { + puts("[Thread] : thread_5_entry is here!"); + + /* Increment the thread counter. */ + thread_5_counter++; + + /* Wait for event flag 0. */ + status = tx_event_flags_get(&event_flags_0, 0x1, TX_OR_CLEAR, + &actual_flags, TX_WAIT_FOREVER); + + /* Check status. */ + if ((status != TX_SUCCESS) || (actual_flags != 0x1)) + break; + } +} + + +void thread_6_and_7_entry(ULONG thread_input) +{ + +UINT status; + + + /* This function is executed from thread 6 and thread 7. As the loop + below shows, these function compete for ownership of mutex_0. */ + while(1) + { + puts("[Thread] : thread_6_and_7_entry is here!"); + + /* Increment the thread counter. */ + if (thread_input == 6) + thread_6_counter++; + else + thread_7_counter++; + + /* Get the mutex with suspension. */ + status = tx_mutex_get(&mutex_0, TX_WAIT_FOREVER); + + /* Check status. */ + if (status != TX_SUCCESS) + break; + + /* Get the mutex again with suspension. This shows + that an owning thread may retrieve the mutex it + owns multiple times. */ + status = tx_mutex_get(&mutex_0, TX_WAIT_FOREVER); + + /* Check status. */ + if (status != TX_SUCCESS) + break; + + /* Sleep for 2 ticks to hold the mutex. */ + tx_thread_sleep(2); + + /* Release the mutex. */ + status = tx_mutex_put(&mutex_0); + + /* Check status. */ + if (status != TX_SUCCESS) + break; + + /* Release the mutex again. This will actually + release ownership since it was obtained twice. */ + status = tx_mutex_put(&mutex_0); + + /* Check status. */ + if (status != TX_SUCCESS) + break; + } +} diff --git a/ports/risc-v32/clang/example_build/qemu_virt/entry.s b/ports/risc-v32/clang/example_build/qemu_virt/entry.s new file mode 100644 index 00000000..9b202ca1 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/entry.s @@ -0,0 +1,58 @@ + +.section .text +.align 4 +.global _start +.extern main +.extern _sysstack_start +.extern _bss_start +.extern _bss_end +_start: + csrr t0, mhartid + bne t0, zero, 1f + li x1, 0 + li x2, 0 + li x3, 0 + li x4, 0 + li x5, 0 + li x6, 0 + li x7, 0 + li x8, 0 + li x9, 0 + li x10, 0 + li x11, 0 + li x12, 0 + li x13, 0 + li x14, 0 + li x15, 0 + li x16, 0 + li x17, 0 + li x18, 0 + li x19, 0 + li x20, 0 + li x21, 0 + li x22, 0 + li x23, 0 + li x24, 0 + li x25, 0 + li x26, 0 + li x27, 0 + li x28, 0 + li x29, 0 + li x30, 0 + li x31, 0 + la t0, _sysstack_start + li t1, 0x1000 + add sp, t0, t1 + la t0, _bss_start + la t1, _bss_end +_bss_clean_start: + bgeu t0, t1, _bss_clean_end + sb zero, 0(t0) + addi t0, t0, 1 + j _bss_clean_start +_bss_clean_end: + call main +1: + /* todo smp */ + wfi + j 1b diff --git a/ports/risc-v32/clang/example_build/qemu_virt/hwtimer.c b/ports/risc-v32/clang/example_build/qemu_virt/hwtimer.c new file mode 100644 index 00000000..b5335cf3 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/hwtimer.c @@ -0,0 +1,35 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + +#include "tx_port.h" +#include "csr.h" +#include "hwtimer.h" + +#define CLINT (0x02000000L) +#define CLINT_TIME (CLINT+0xBFF8) +#define CLINT_TIMECMP(hart_id) (CLINT+0x4000+8*(hart_id)) + + +int hwtimer_init(void) +{ + int hart = riscv_get_core(); + uint64_t time = *((uint64_t*)CLINT_TIME); + *((uint64_t*)CLINT_TIMECMP(hart)) = time + TICKNUM_PER_TIMER; + return 0; +} + +int hwtimer_handler(void) +{ + int hart = riscv_get_core(); + uint64_t time = *((uint64_t*)CLINT_TIME); + *((uint64_t*)CLINT_TIMECMP(hart)) = time + TICKNUM_PER_TIMER; + return 0; +} + diff --git a/ports/risc-v32/clang/example_build/qemu_virt/hwtimer.h b/ports/risc-v32/clang/example_build/qemu_virt/hwtimer.h new file mode 100644 index 00000000..e27a7578 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/hwtimer.h @@ -0,0 +1,23 @@ + +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + +#ifndef RISCV_HWTIMER_H +#define RISCV_HWTIMER_H + +#include <stdint.h> + +#define TICKNUM_PER_SECOND 10000000 +#define TICKNUM_PER_TIMER (TICKNUM_PER_SECOND / 10) + +int hwtimer_init(void); +int hwtimer_handler(void); + +#endif diff --git a/ports/risc-v32/clang/example_build/qemu_virt/link.lds b/ports/risc-v32/clang/example_build/qemu_virt/link.lds new file mode 100644 index 00000000..522f90d9 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/link.lds @@ -0,0 +1,49 @@ +OUTPUT_ARCH( "riscv" ) +ENTRY( _start ) + +SECTIONS +{ + /* + * ensure that entry.S / _entry is at 0x80000000, + * where qemu's -kernel jumps. + */ + . = 0x80000000; + + .text : { + *(.text .text.*) + . = ALIGN(0x1000); + PROVIDE(etext = .); + } + + .rodata : { + . = ALIGN(16); + *(.srodata .srodata.*) /* do not need to distinguish this from .rodata */ + . = ALIGN(16); + *(.rodata .rodata.*) + } + + .data : { + . = ALIGN(16); + *(.sdata .sdata.*) /* do not need to distinguish this from .data */ + . = ALIGN(16); + *(.data .data.*) + } + + .bss : { + . = ALIGN(16); + _bss_start = .; + *(.sbss .sbss.*) /* do not need to distinguish this from .bss */ + . = ALIGN(16); + *(.bss .bss.*) + _bss_end = .; + } + + .stack : { + . = ALIGN(4096); + _sysstack_start = .; + . += 0x1000; + _sysstack_end = .; + } + + PROVIDE(_end = .); +} diff --git a/ports/risc-v32/clang/example_build/qemu_virt/plic.c b/ports/risc-v32/clang/example_build/qemu_virt/plic.c new file mode 100644 index 00000000..01e5c71a --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/plic.c @@ -0,0 +1,72 @@ +#include "plic.h" +#include <stddef.h> +irq_callback callbacks[MAX_CALLBACK_NUM]; + +void plic_irq_enable(int irqno) +{ + int hart = riscv_get_core(); + *(uint32_t*)PLIC_MENABLE(hart) = (*(uint32_t*)PLIC_MENABLE(hart) | (1 << irqno)); + return; +} + +void plic_irq_disable(int irqno) +{ + int hart = riscv_get_core(); + *(uint32_t*)PLIC_MENABLE(hart) = (*(uint32_t*)PLIC_MENABLE(hart) & (~(1 << irqno))); + return; +} + +void plic_prio_set(int irqno, int prio) +{ + PLIC_SET_PRIO(irqno, prio); +} + +int plic_prio_get(int irqno) +{ + return PLIC_GET_PRIO(irqno); +} + +int plic_register_callback(int irqno, irq_callback callback) +{ + if(!(irqno >=0 && irqno < MAX_CALLBACK_NUM)) + return -1; + callbacks[irqno] = callback; + return 0; +} + +int plic_unregister_callback(int irqno) +{ + return plic_register_callback(irqno, NULL); +} + +int plic_init(void) +{ + for(int i=0;i<MAX_CALLBACK_NUM;i++) + { + callbacks[i] = NULL; + } + return 0; +} + +int plic_claim(void) +{ + int hart = riscv_get_core(); + return (*(uint32_t*)PLIC_MCLAIM(hart)); +} + +void plic_complete(int irqno) +{ + int hart = riscv_get_core(); + *(uint32_t*)(PLIC_MCOMPLETE(hart)) = (uint32_t)irqno; + return; +} + +int plic_irq_intr(void) +{ + int ret = -1; + int irqno = plic_claim(); + if(callbacks[irqno] != NULL) + ret = (callbacks[irqno])(irqno); + plic_complete(irqno); + return ret; +} diff --git a/ports/risc-v32/clang/example_build/qemu_virt/plic.h b/ports/risc-v32/clang/example_build/qemu_virt/plic.h new file mode 100644 index 00000000..899bfb90 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/plic.h @@ -0,0 +1,49 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + +#ifndef RISCV_PLIC_H +#define RISCV_PLIC_H + +#include "csr.h" +#include <stdint.h> + +#define PLIC 0x0c000000L +#define PLIC_PRIORITY (PLIC + 0x0) +#define PLIC_PENDING (PLIC + 0x1000) +#define PLIC_MENABLE(hart) (PLIC + 0x2000 + (hart)*0x100) +#define PLIC_SENABLE(hart) (PLIC + 0x2080 + (hart)*0x100) +#define PLIC_MPRIORITY(hart) (PLIC + 0x200000 + (hart)*0x2000) +#define PLIC_SPRIORITY(hart) (PLIC + 0x201000 + (hart)*0x2000) +#define PLIC_MCLAIM(hart) (PLIC + 0x200004 + (hart)*0x2000) +#define PLIC_SCLAIM(hart) (PLIC + 0x201004 + (hart)*0x2000) +#define PLIC_MCOMPLETE(hart) (PLIC + 0x200004 + (hart)*0x2000) +#define PLIC_SCOMPLETE(hart) (PLIC + 0x201004 + (hart)*0x2000) + + +#define PLIC_GET_PRIO(irqno) (*(uint32_t *)(PLIC_PRIORITY + (irqno)*4)) +#define PLIC_SET_PRIO(irqno, prio) (*(uint32_t *)(PLIC_PRIORITY + (irqno)*4) = (prio)) + +#define MAX_CALLBACK_NUM 128 +typedef int (*irq_callback)(int irqno); + +void plic_irq_enable(int irqno); +void plic_irq_disable(int irqno); +int plic_prio_get(int irqno); +void plic_prio_set(int irqno, int prio); +int plic_register_callback(int irqno, irq_callback callback); +int plic_unregister_callback(int irqno); +int plic_init(void); +int plic_claim(void); +void plic_complete(int irqno); + +int plic_irq_intr(void); + +#endif + diff --git a/ports/risc-v32/clang/example_build/qemu_virt/trap.c b/ports/risc-v32/clang/example_build/qemu_virt/trap.c new file mode 100644 index 00000000..a2733e02 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/trap.c @@ -0,0 +1,67 @@ +#include "csr.h" +#include <stdint.h> +#include "uart.h" +#include "hwtimer.h" +#include "plic.h" +#include <tx_port.h> +#include <tx_api.h> + +#define OS_IS_INTERUPT(mcause) (mcause & 0x80000000u) +#define OS_IS_EXCEPTION(mcause) (~(OS_IS_INTERUPT)) +#define OS_IS_TICK_INT(mcause) (mcause == 0x80000007u) +#define OS_IS_SOFT_INT(mcause) (mcause == 0x80000003u) +#define OS_IS_EXT_INT(mcause) (mcause == 0x8000000bu) +#define OS_IS_TRAP_USER(mcause) (mcause == 0x0000000bu) +extern void _tx_timer_interrupt(void); + +extern int uart_putc(int ch); + +static void print_hex(uintptr_t val) +{ + char digits[] = "0123456789ABCDEF"; + uart_putc('0'); + uart_putc('x'); + for(int i = (sizeof(uintptr_t)*2) - 1; i >= 0; i--) { + int d = (val >> (i*4)) & 0xF; + uart_putc(digits[d]); + } + uart_putc('\n'); +} + +void trap_handler(uintptr_t mcause, uintptr_t mepc, uintptr_t mtval) +{ + // uart_puts("DEBUG : threadx/ports/risc-v32/gnu/example_build/qemu_virt/trap.c, trap_handler\n"); + if(OS_IS_INTERUPT(mcause)) + { + if(OS_IS_TICK_INT(mcause)) + { + hwtimer_handler(); + _tx_timer_interrupt(); + } + else if(OS_IS_EXT_INT(mcause)) + { + int ret = plic_irq_intr(); + if(ret) + { + puts("[INTERRUPT]: handler irq error!"); + while(1) ; + } + } + else + { + puts("[INTERRUPT]: now can't deal with the interrupt!"); + while(1) ; + } + } + else + { + puts("[EXCEPTION] : Unkown Error!!"); + puts("mcause:"); + print_hex(mcause); + puts("mepc:"); + print_hex(mepc); + puts("mtval:"); + print_hex(mtval); + while(1) ; + } +} diff --git a/ports/risc-v32/clang/example_build/qemu_virt/tx_initialize_low_level.S b/ports/risc-v32/clang/example_build/qemu_virt/tx_initialize_low_level.S new file mode 100644 index 00000000..4cbfcf65 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/tx_initialize_low_level.S @@ -0,0 +1,177 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + +#include "csr.h" +#include "tx_port.h" + + .section .text + .align 4 +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* trap_entry RISC-V32/GNU */ +/* 6.4.x */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function is responsible for riscv processor trap handle */ +/* It will do the contex save and call c trap_handler and do contex */ +/* load */ +/* */ +/* INPUT */ +/* */ +/* None */ +/* */ +/* OUTPUT */ +/* */ +/* None */ +/* */ +/* CALLS */ +/* */ +/* trap_handler */ +/* */ +/* CALLED BY */ +/* */ +/* hardware exception */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 02-02-2026 Francisco Merino Adapted for RV32 Clang */ +/* */ +/**************************************************************************/ + + +/**************************************************************************/ +/**************************************************************************/ +/** */ +/** ThreadX Component */ +/** */ +/** Initialize */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + .global trap_entry + .extern trap_handler + .extern _tx_thread_context_restore + trap_entry: +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + addi sp, sp, -65*4 // Allocate space for all registers - with floating point enabled +#else + addi sp, sp, -32*4 // Allocate space for all registers - without floating point enabled +#endif + + sw x1, 28*4(sp) // Store RA, 28*4(because call will override ra [ra is a calle register in riscv]) + + call _tx_thread_context_save + + csrr a0, mcause + csrr a1, mepc + csrr a2, mtval + addi sp, sp, -4 + sw ra, 0(sp) + call trap_handler + lw ra, 0(sp) + addi sp, sp, 4 + call _tx_thread_context_restore + // it will nerver return +_err: + wfi + j _err + .section .text +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_initialize_low_level RISC-V32/GNU */ +/* 6.4.x */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function is responsible for any low-level processor */ +/* initialization, including setting up interrupt vectors, setting */ +/* up a periodic timer interrupt source, saving the system stack */ +/* pointer for use in ISR processing later, and finding the first */ +/* available RAM memory address for tx_application_define. */ +/* */ +/* INPUT */ +/* */ +/* None */ +/* */ +/* OUTPUT */ +/* */ +/* None */ +/* */ +/* CALLS */ +/* */ +/* None */ +/* */ +/* CALLED BY */ +/* */ +/* _tx_initialize_kernel_enter ThreadX entry function */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 26-02-2026 Francisco Merino Adapted for RV32 Clang */ +/* */ +/**************************************************************************/ +/* VOID _tx_initialize_low_level(VOID) +{ */ +// .global _tx_initialize_low_level + .weak _tx_initialize_low_level + .extern _end + .extern board_init +_tx_initialize_low_level: + +/* debug print + .section .rodata +debug_str_init: + .string "DEBUG : threadx/ports/risc-v32/gnu/example_build/qemu_virt/tx_initialize_low_level.S, _tx_initialize_low_level\n" +*/ + .section .text + + la t0, _tx_thread_system_stack_ptr + sw sp, 0(t0) // Save system stack pointer + + la t0, _end // Pickup first free address + la t1, _tx_initialize_unused_memory + sw t0, 0(t1) // Save unused memory address + li t0, MSTATUS_MIE + csrrc zero, mstatus, t0 // clear MSTATUS_MIE bit + li t0, (MSTATUS_MPP_M | MSTATUS_MPIE ) + csrrs zero, mstatus, t0 // set MSTATUS_MPP, MPIE bit + li t0, (MIE_MTIE | MIE_MSIE | MIE_MEIE) + csrrs zero, mie, t0 // set mie +#ifdef __riscv_flen + li t0, MSTATUS_FS + csrrs zero, mstatus, t0 // set MSTATUS_FS bit to open f/d isa in riscv + fscsr x0 +#endif + addi sp, sp, -4 + sw ra, 0(sp) + call board_init +/* debug print + la a0, debug_str_init + call uart_puts +*/ + lw ra, 0(sp) + addi sp, sp, 4 + la t0, trap_entry + csrw mtvec, t0 + ret diff --git a/ports/risc-v32/clang/example_build/qemu_virt/uart.c b/ports/risc-v32/clang/example_build/qemu_virt/uart.c new file mode 100644 index 00000000..a175b7d2 --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/uart.c @@ -0,0 +1,102 @@ +#include "uart.h" +#include "csr.h" +#include "plic.h" +#include <stdint.h> + +// the UART control registers are memory-mapped +// at address UART0. this macro returns the +// address of one of the registers. +#define Reg(reg) ((volatile unsigned char *)(UART0 + (reg))) + +// the UART control registers. +// some have different meanings for +// read vs write. +// see http://byterunner.com/16550.html +#define RHR 0 // receive holding register (for input bytes) +#define THR 0 // transmit holding register (for output bytes) +#define IER 1 // interrupt enable register +#define IER_RX_ENABLE (1<<0) +#define IER_TX_ENABLE (1<<1) +#define FCR 2 // FIFO control register +#define FCR_FIFO_ENABLE (1<<0) +#define FCR_FIFO_CLEAR (3<<1) // clear the content of the two FIFOs +#define ISR 2 // interrupt status register +#define LCR 3 // line control register +#define LCR_EIGHT_BITS (3<<0) +#define LCR_BAUD_LATCH (1<<7) // special mode to set baud rate +#define LSR 5 // line status register +#define LSR_RX_READY (1<<0) // input is waiting to be read from RHR +#define LSR_TX_IDLE (1<<5) // THR can accept another character to send + +#define ReadReg(reg) (*(Reg(reg))) +#define WriteReg(reg, v) (*(Reg(reg)) = (v)) + +int uart_init(void) +{ + // disable interrupts. + WriteReg(IER, 0x00); + + // special mode to set baud rate. + WriteReg(LCR, LCR_BAUD_LATCH); + + // LSB for baud rate of 38.4K. + WriteReg(0, 0x03); + + // MSB for baud rate of 38.4K. + WriteReg(1, 0x00); + + // leave set-baud mode, + // and set word length to 8 bits, no parity. + WriteReg(LCR, LCR_EIGHT_BITS); + + // reset and enable FIFOs. + WriteReg(FCR, FCR_FIFO_ENABLE | FCR_FIFO_CLEAR); + + // enable transmit and receive interrupts. + // WriteReg(IER, IER_TX_ENABLE | IER_RX_ENABLE); + + //enable UART0 in PLIC + plic_irq_enable(UART0_IRQ); + + //set UART0 priority in PLIC + plic_prio_set(UART0_IRQ, 1); + + //register callback for UART0 + //plic_register_callback(UART0_IRQ, uart_intr); + puts("[UART0] : Uart Init Done, this is Test output!"); + return 0; +} + +void uart_putc_nolock(int ch) +{ + // wait for Transmit Holding Empty to be set in LSR. + while((ReadReg(LSR) & LSR_TX_IDLE) == 0) + ; + WriteReg(THR, ch); + return; +} + +int uart_putc(int ch) +{ + int intr_enable = riscv_mintr_get(); + riscv_mintr_off(); + uart_putc_nolock(ch); + riscv_mintr_restore(intr_enable); + return 1; +} + +int uart_puts(const char* str) +{ + int i; + int intr_enable = riscv_mintr_get(); + riscv_mintr_off(); + for(i=0;str[i]!=0;i++) + { + uart_putc_nolock(str[i]); + } + uart_putc_nolock('\n'); + riscv_mintr_restore(intr_enable); + return i; +} + + diff --git a/ports/risc-v32/clang/example_build/qemu_virt/uart.h b/ports/risc-v32/clang/example_build/qemu_virt/uart.h new file mode 100644 index 00000000..19e8f73d --- /dev/null +++ b/ports/risc-v32/clang/example_build/qemu_virt/uart.h @@ -0,0 +1,22 @@ +/*************************************************************************** + * Copyright (c) 2024 Microsoft Corporation + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + +#ifndef RISCV_UART_H +#define RISCV_UART_H + +#define UART0 0x10000000L +#define UART0_IRQ 10 + +#define puts uart_puts +int uart_init(void); +int uart_putc(int ch); +void uart_putc_nolock(int ch); +int uart_puts(const char* str); +#endif diff --git a/ports/risc-v32/clang/inc/tx_port.h b/ports/risc-v32/clang/inc/tx_port.h new file mode 100644 index 00000000..ece70953 --- /dev/null +++ b/ports/risc-v32/clang/inc/tx_port.h @@ -0,0 +1,291 @@ +/*************************************************************************** + * Copyright (c) 2025 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + + +/**************************************************************************/ +/**************************************************************************/ +/** */ +/** ThreadX Component */ +/** */ +/** Port Specific */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + + +/**************************************************************************/ +/* */ +/* PORT SPECIFIC C INFORMATION RELEASE */ +/* */ +/* tx_port.h RISC-V32/GNU */ +/* 6.4.x */ +/* */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This file contains data type definitions that make the ThreadX */ +/* real-time kernel function identically on a variety of different */ +/* processor architectures. For example, the size or number of bits */ +/* in an "int" data type vary between microprocessor architectures and */ +/* even C compilers for the same microprocessor. ThreadX does not */ +/* directly use native C data types. Instead, ThreadX creates its */ +/* own special types that can be mapped to actual data types by this */ +/* file to guarantee consistency in the interface and functionality. */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 02-26-2026 Francisco Merino Initial Version 6.4.x */ +/* */ +/**************************************************************************/ + +#ifndef TX_PORT_H +#define TX_PORT_H + +#ifndef __ASSEMBLER__ + +/* Include for memset. */ +#include <string.h> + + +/* Determine if the optional ThreadX user define file should be used. */ + +#ifdef TX_INCLUDE_USER_DEFINE_FILE + + +/* Yes, include the user defines in tx_user.h. The defines in this file may + alternately be defined on the command line. */ + +#include "tx_user.h" +#endif /* TX_INCLUDE_USER_DEFINE_FILE */ + +#endif /* __ASSEMBLER__ */ + + +/* Define ThreadX basic types for this port. */ + +#define VOID void + +#ifndef __ASSEMBLER__ +typedef char CHAR; +typedef unsigned char UCHAR; +typedef int INT; +typedef unsigned int UINT; +typedef long LONG; +typedef unsigned long ULONG; +typedef unsigned long long ULONG64; +typedef short SHORT; +typedef unsigned short USHORT; +#define ULONG64_DEFINED +#endif /* __ASSEMBLER__ */ + + + + +/* Define the priority levels for ThreadX. Legal values range + from 32 to 1024 and MUST be evenly divisible by 32. */ + +#ifndef TX_MAX_PRIORITIES +#define TX_MAX_PRIORITIES 32 +#endif + + +/* Define the minimum stack for a ThreadX thread on this processor. If the size supplied during + thread creation is less than this value, the thread create call will return an error. */ + +#ifndef TX_MINIMUM_STACK +#define TX_MINIMUM_STACK 1024 /* Minimum stack size for this port */ +#endif + + +/* Define the system timer thread's default stack size and priority. These are only applicable + if TX_TIMER_PROCESS_IN_ISR is not defined. */ + +#ifndef TX_TIMER_THREAD_STACK_SIZE +#define TX_TIMER_THREAD_STACK_SIZE 1024 /* Default timer thread stack size */ +#endif + +#ifndef TX_TIMER_THREAD_PRIORITY +#define TX_TIMER_THREAD_PRIORITY 0 /* Default timer thread priority */ +#endif + + +/* Define various constants for the ThreadX RISC-V port. */ + +#define TX_INT_DISABLE 0x00000000 /* Disable interrupts value */ +#define TX_INT_ENABLE 0x00000008 /* Enable interrupt value */ + + +/* Define the clock source for trace event entry time stamp. The following two item are port specific. + For example, if the time source is at the address 0x0a800024 and is 16-bits in size, the clock + source constants would be: + +#define TX_TRACE_TIME_SOURCE *((ULONG *) 0x0a800024) +#define TX_TRACE_TIME_MASK 0x0000FFFFUL + +*/ + +#ifndef TX_TRACE_TIME_SOURCE +#define TX_TRACE_TIME_SOURCE ++_tx_trace_simulated_time +#endif +#ifndef TX_TRACE_TIME_MASK +#define TX_TRACE_TIME_MASK 0xFFFFFFFFUL +#endif + + +/* Define the port specific options for the _tx_build_options variable. This variable indicates + how the ThreadX library was built. */ + +#define TX_PORT_SPECIFIC_BUILD_OPTIONS 0 + + +/* Define the in-line initialization constant so that modules with in-line + initialization capabilities can prevent their initialization from being + a function call. */ + +#define TX_INLINE_INITIALIZATION + + +/* Determine whether or not stack checking is enabled. By default, ThreadX stack checking is + disabled. When the following is defined, ThreadX thread stack checking is enabled. If stack + checking is enabled (TX_ENABLE_STACK_CHECKING is defined), the TX_DISABLE_STACK_FILLING + define is negated, thereby forcing the stack fill which is necessary for the stack checking + logic. */ + +#ifdef TX_ENABLE_STACK_CHECKING +#undef TX_DISABLE_STACK_FILLING +#endif + + +/* Define the TX_THREAD control block extensions for this port. The main reason + for the multiple macros is so that backward compatibility can be maintained with + existing ThreadX kernel awareness modules. */ + +#define TX_THREAD_EXTENSION_0 +#define TX_THREAD_EXTENSION_1 +#define TX_THREAD_EXTENSION_2 +#define TX_THREAD_EXTENSION_3 + + +/* Define the port extensions of the remaining ThreadX objects. */ + +#define TX_BLOCK_POOL_EXTENSION +#define TX_BYTE_POOL_EXTENSION +#define TX_EVENT_FLAGS_GROUP_EXTENSION +#define TX_MUTEX_EXTENSION +#define TX_QUEUE_EXTENSION +#define TX_SEMAPHORE_EXTENSION +#define TX_TIMER_EXTENSION + + +/* Define the user extension field of the thread control block. Nothing + additional is needed for this port so it is defined as white space. */ + +#ifndef TX_THREAD_USER_EXTENSION +#define TX_THREAD_USER_EXTENSION +#endif + + +/* Define the macros for processing extensions in tx_thread_create, tx_thread_delete, + tx_thread_shell_entry, and tx_thread_terminate. */ + +#define TX_THREAD_CREATE_EXTENSION(thread_ptr) +#define TX_THREAD_DELETE_EXTENSION(thread_ptr) +#define TX_THREAD_COMPLETED_EXTENSION(thread_ptr) +#define TX_THREAD_TERMINATED_EXTENSION(thread_ptr) + + +/* Define the ThreadX object creation extensions for the remaining objects. */ + +#define TX_BLOCK_POOL_CREATE_EXTENSION(pool_ptr) +#define TX_BYTE_POOL_CREATE_EXTENSION(pool_ptr) +#define TX_EVENT_FLAGS_GROUP_CREATE_EXTENSION(group_ptr) +#define TX_MUTEX_CREATE_EXTENSION(mutex_ptr) +#define TX_QUEUE_CREATE_EXTENSION(queue_ptr) +#define TX_SEMAPHORE_CREATE_EXTENSION(semaphore_ptr) +#define TX_TIMER_CREATE_EXTENSION(timer_ptr) + + +/* Define the ThreadX object deletion extensions for the remaining objects. */ + +#define TX_BLOCK_POOL_DELETE_EXTENSION(pool_ptr) +#define TX_BYTE_POOL_DELETE_EXTENSION(pool_ptr) +#define TX_EVENT_FLAGS_GROUP_DELETE_EXTENSION(group_ptr) +#define TX_MUTEX_DELETE_EXTENSION(mutex_ptr) +#define TX_QUEUE_DELETE_EXTENSION(queue_ptr) +#define TX_SEMAPHORE_DELETE_EXTENSION(semaphore_ptr) +#define TX_TIMER_DELETE_EXTENSION(timer_ptr) + + +/* Define ThreadX interrupt lockout and restore macros for protection on + access of critical kernel information. The restore interrupt macro must + restore the interrupt posture of the running thread prior to the value + present prior to the disable macro. In most cases, the save area macro + is used to define a local function save area for the disable and restore + macros. */ + +/* Expose helper used to perform an atomic read/modify/write of mstatus. + The helper composes and returns the posture per ThreadX contract. */ +#ifndef __ASSEMBLER__ +UINT _tx_thread_interrupt_control(UINT new_posture); +#endif + +#ifdef TX_DISABLE_INLINE + +#define TX_INTERRUPT_SAVE_AREA register UINT interrupt_save; + +#define TX_DISABLE __asm__ volatile("csrrci %0, mstatus, 8" : "=r" (interrupt_save) :: "memory"); +#define TX_RESTORE { \ + unsigned long _temp_mstatus; \ + __asm__ volatile( \ + "csrc mstatus, 8\n" \ + "andi %0, %1, 8\n" \ + "csrs mstatus, %0" \ + : "=&r" (_temp_mstatus) \ + : "r" (interrupt_save) \ + : "memory"); \ + } + +#else + +#define TX_INTERRUPT_SAVE_AREA register UINT interrupt_save; + +#define TX_DISABLE interrupt_save = _tx_thread_interrupt_control(TX_INT_DISABLE); +#define TX_RESTORE _tx_thread_interrupt_control(interrupt_save); + +#endif /* TX_DISABLE_INLINE */ + + +/* Define the interrupt lockout macros for each ThreadX object. */ + +#define TX_BLOCK_POOL_DISABLE TX_DISABLE +#define TX_BYTE_POOL_DISABLE TX_DISABLE +#define TX_EVENT_FLAGS_GROUP_DISABLE TX_DISABLE +#define TX_MUTEX_DISABLE TX_DISABLE +#define TX_QUEUE_DISABLE TX_DISABLE +#define TX_SEMAPHORE_DISABLE TX_DISABLE + + +/* Define the version ID of ThreadX. This may be utilized by the application. */ + +#ifndef __ASSEMBLER__ +#ifdef TX_THREAD_INIT +CHAR _tx_version_id[] = + "Copyright (c) 2024 Microsoft Corporation. * ThreadX RISC-V32/GNU Version 6.4.2 *"; +#else +extern CHAR _tx_version_id[]; +#endif /* TX_THREAD_INIT */ +#endif /* __ASSEMBLER__ */ + +#endif /* TX_PORT_H */
\ No newline at end of file diff --git a/ports/risc-v32/clang/readme_threadx.txt b/ports/risc-v32/clang/readme_threadx.txt new file mode 100644 index 00000000..53ffcf23 --- /dev/null +++ b/ports/risc-v32/clang/readme_threadx.txt @@ -0,0 +1,442 @@ + Eclipse Foundation's RTOS, ThreadX for RISC-V32 + + Using the Clang Tools + + +1. Building the ThreadX run-time Library + +Prerequisites +- Install a RISC-V32 bare-metal Clang toolchain +- Install a RISC-V32 bare-metal GNU toolchain with riscv32-unknown-elf prefix. + Common source: https://github.com/riscv-collab/riscv-gnu-toolchain + +The GNU toolchain is needed because the Clang toolchain does not include some +standard headers and libraries, i.e. "string.h". + +Verify the Clang toolchain: + clang --version + +Verify the GCC toolchain: + riscv32-unknown-elf-gcc --version + riscv32-unknown-elf-objdump --version + +CMake-based build (recommended) + +From the ThreadX top-level directory: + + Set environment variable "GCC_INSTALL_PREFIX" with the location of the + GNU toolchain, i.e., export GCC_INSTALL_PREFIX=/opt/riscv_rv32ima + + cmake -Bbuild -GNinja -DCMAKE_TOOLCHAIN_FILE=cmake/riscv32_clang.cmake . + cmake --build ./build/ + +This uses cmake/riscv32_clang.cmake and ports/risc-v32/clang/CMakeLists.txt to +configure the cross-compiler flags and produce the ThreadX run-time library +and example binaries. + +Example build script + +The example demonstration contains a build script. See: + + ports/risc-v32/clang/example_build/qemu_virt/build_libthreadx.sh + +This script builds the library and the demo application kernel.elf. + + +2. Demonstration System (QEMU) + +The provided example is targeted at QEMU's virt platform. After building the +example, the produced kernel.elf can be executed in QEMU: + + qemu-system-riscv32 -nographic -smp 1 -bios none -m 128M -machine virt -kernel kernel.elf + +Typical QEMU features used: +- Single-core CPU +- UART serial console +- PLIC (Platform-Level Interrupt Controller) +- CLINT (Core-Local Interruptor) for timer + + +3. System Initialization + +Entry Point + +The example startup code begins at the _start label in entry.s. This startup +code performs hardware initialization including: +- Check hart ID (only hart 0 continues; others enter WFI loop) +- Zero general-purpose registers +- Set up initial stack pointer +- Clear BSS section +- Jump to main() + +Low-Level Port Initialization (tx_initialize_low_level.S) + +The _tx_initialize_low_level function: +- Saves the system stack pointer to _tx_thread_system_stack_ptr +- Records first free RAM address from __tx_free_memory_start symbol +- Initializes floating-point control/status register (FCSR) if floating point enabled + +Board Initialization (board.c) + +After tx_initialize_low_level returns, main() calls board_init() to: +- Initialize PLIC (Platform-Level Interrupt Controller) +- Initialize UART +- Initialize hardware timer (CLINT) +- Set trap vector (mtvec) to point to trap handler + + +4. Register Usage and Stack Frames + +The RISC-V32 ABI defines t0-t6 and a0-a7 as caller-saved (scratch) registers. +All other registers used by a function must be preserved by the function. + +ThreadX takes advantage of this: when a context switch happens during a +function call, only the non-scratch registers need to be saved. + +Stack Frame Types + +Two types of stack frames exist: + +A. Interrupt Frame (stack type = 1) + Created when an interrupt occurs during thread execution. + Saves all registers including caller-saved registers. + Size: 65*4 = 260 bytes (with FP), or 32*4 = 128 bytes (without FP) + +B. Solicited Frame (stack type = 0) + Created when a thread voluntarily yields via ThreadX service calls. + Saves only callee-saved registers (s0-s11) and mstatus. + Size: 29*4 = 116 bytes (with FP), or 16*4 = 64 bytes (without FP) + + +Stack Layout for Interrupt Frame (with FP enabled): + + Index Offset Register Description + ───────────────────────────────────────────────── + 0 0x00 -- Stack type (1 = interrupt) + 1 0x04 s11 Preserved register + 2 0x08 s10 Preserved register + 3 0x0C s9 Preserved register + 4 0x10 s8 Preserved register + 5 0x14 s7 Preserved register + 6 0x18 s6 Preserved register + 7 0x1C s5 Preserved register + 8 0x20 s4 Preserved register + 9 0x24 s3 Preserved register + 10 0x28 s2 Preserved register + 11 0x2C s1 Preserved register + 12 0x30 s0 Preserved register + 13 0x34 t6 Scratch register + 14 0x38 t5 Scratch register + 15 0x3C t4 Scratch register + 16 0x40 t3 Scratch register + 17 0x44 t2 Scratch register + 18 0x48 t1 Scratch register + 19 0x4C t0 Scratch register + 20 0x50 a7 Argument register + 21 0x54 a6 Argument register + 22 0x58 a5 Argument register + 23 0x5C a4 Argument register + 24 0x60 a3 Argument register + 25 0x64 a2 Argument register + 26 0x68 a1 Argument register + 27 0x6C a0 Argument register + 28 0x70 ra Return address + 29 0x74 -- Reserved + 30 0x78 mepc Machine exception PC + 31-46 0x7C-0xB8 fs0-fs7 Preserved FP registers* + 47-62 0xBC-0xF8 ft0-ft11 Scratch FP registers* + 63 0xFC fcsr FP control/status register + ───────────────────────────────────────────────── + *Note: In ilp32d ABI, FP registers are 8 bytes each, but current + port implementation uses 4-byte indexing which may cause + overlap if fsd/fld are used. + + +5. Interrupt Handling + +Machine Mode Operation + +ThreadX operates in machine mode (M-mode), the highest privilege level. +All interrupts and exceptions trap to machine mode. + +Interrupt Sources + +1. Machine Timer Interrupt (MTI): + - Triggered by CLINT when mtime >= mtimecmp + - Handled by _tx_timer_interrupt (src/tx_timer_interrupt.S) + - Called from trap handler in trap.c + +2. External Interrupts (MEI): + - Routed through PLIC + - Handler in trap.c calls registered ISR callbacks + +3. Software Interrupts (MSI): + - Supported but not actively used in this port + +Interrupt Flow + +1. Hardware trap entry (automatic): + - mepc <- PC (address of interrupted instruction) + - mcause <- exception/interrupt code + - mstatus.MPIE <- mstatus.MIE (save interrupt-enable state) + - mstatus.MIE <- 0 (disable interrupts) + - mstatus.MPP <- Machine mode + - PC <- mtvec (points to trap_entry in entry.s) + +2. Trap entry (entry.s): + - Allocates interrupt stack frame (32*4 or 65*4 bytes depending on FP) + - Saves RA (x1) on stack + - Calls _tx_thread_context_save + +3. Context save (_tx_thread_context_save.S): + - Increments _tx_thread_system_state (nested interrupt counter) + - If nested interrupt: saves remaining registers and returns to ISR + - If first interrupt: saves full context, switches to system stack + +4. Trap handler (trap.c): + - Examines mcause to determine interrupt type + - Dispatches to appropriate handler (_tx_timer_interrupt or PLIC handler) + - Returns to context restore + +5. Context restore (_tx_thread_context_restore.S): + - Decrements _tx_thread_system_state + - Checks if preemption needed + - Restores thread context or switches to next ready thread via scheduler + - Returns to interrupted thread or executes new thread + + +Interrupt Control Macros + +TX_DISABLE and TX_RESTORE macros atomically manage the MIE bit in mstatus: + + TX_DISABLE: Saves and clears MIE bit via csrrci (CSR read-clear immediate) + TX_RESTORE: Restores only MIE bit via csrrs (CSR read-set) + Other mstatus bits remain unchanged + +These are defined in ports/risc-v32/gnu/inc/tx_port.h and use the +_tx_thread_interrupt_control() function. + + +6. Thread Scheduling and Context Switching + +Thread Scheduler (src/tx_thread_schedule.S) + +The scheduler: +1. Enables interrupts while waiting for next thread +2. Spins until _tx_thread_execute_ptr becomes non-NULL +3. Disables interrupts (critical section) +4. Sets _tx_thread_current_ptr = _tx_thread_execute_ptr +5. Increments thread's run count +6. Switches to thread's stack +7. Determines stack frame type and restores context: + - Interrupt frame: full context restored, returns via mret + - Solicited frame: minimal context restored, returns via ret + +Initial Thread Stack Frame (src/tx_thread_stack_build.S) + +New threads start with a fake interrupt frame containing: +- All registers initialized to 0 +- ra (x1) = 0 +- mepc = entry function pointer +- Stack type = 1 (interrupt frame) +- Floating-point registers initialized based on ABI + + +7. Port Configuration and Macros + +Default Configurations (in ports/risc-v32/gnu/inc/tx_port.h): + + TX_MINIMUM_STACK 1024 /* Minimum thread stack size */ + TX_TIMER_THREAD_STACK_SIZE 1024 /* Timer thread stack size */ + TX_TIMER_THREAD_PRIORITY 0 /* Timer thread priority */ + TX_MAX_PRIORITIES 32 /* Must be multiple of 32 */ + +These can be overridden in tx_user.h or on the compiler command line. + + +8. Build Configuration + +CMake Toolchain File: cmake/riscv32_gnu.cmake + +Compiler Flags: + -march=rv32gc RV32 with IMAFD+C extensions + -mabi=ilp32d 32-bit integers/pointers, double-precision FP in registers + -mcmodel=medany ±2GB addressability + -D__ASSEMBLER__ For assembly files + +ABI Selection + +The port uses ilp32d ABI which includes: +- 32-bit integers and pointers +- Double-precision floating-point arguments in registers +- Floating-point registers f0-f31 + +When building with floating-point ABI: +- FP registers and FCSR are saved/restored in context switches +- Stack frames expand from 32*REGBYTES to 65*REGBYTES +- Conditional compilation uses __riscv_float_abi_double / __riscv_float_abi_single + + +9. File Organization + +Port-specific files (ports/risc-v32/gnu/): + +Core assembly files (src/): + - tx_initialize_low_level.S Initial setup and system state + - tx_thread_context_save.S Save context on interrupt entry + - tx_thread_context_restore.S Restore context on interrupt exit + - tx_thread_schedule.S Thread scheduler + - tx_thread_system_return.S Solicited context save for voluntary yield + - tx_thread_stack_build.S Build initial stack frame for new thread + - tx_thread_interrupt_control.S Interrupt enable/disable control + - tx_timer_interrupt.S Timer interrupt handler + +Header file (inc/): + - tx_port.h Port-specific defines and macros + +Example files (example_build/qemu_virt/): + - entry.s Startup code, trap entry point + - board.c, uart.c, hwtimer.c Platform-specific initialization + - plic.c PLIC interrupt controller driver + - trap.c Trap/exception dispatcher + - link.lds Linker script for QEMU virt + - build_libthreadx.sh Build script + + +10. Linker Script Requirements + +The linker script must provide: + +1. Entry point: + ENTRY(_start) + +2. Memory layout: + - .text section (code) + - .rodata section (read-only data) + - .data section (initialized data) + - .bss section (uninitialized data) + +3. Symbols: + - _end: First free memory address (used by ThreadX allocation) + - _bss_start, _bss_end: For zero initialization + - Initial stack space (example: 4KB) + +4. Alignment: + - 16-byte alignment throughout (RISC-V requirement) + +Example from QEMU virt build: + + SECTIONS + { + . = 0x80000000; /* QEMU virt base address */ + + .text : { *(.text .text.*) } + .rodata : { *(.rodata .rodata.*) } + .data : { *(.data .data.*) } + .bss : { *(.bss .bss.*) } + + .stack : { + . = ALIGN(4096); + _sysstack_start = .; + . += 0x1000; /* 4KB initial stack */ + _sysstack_end = .; + } + + PROVIDE(_end = .); + } + + +11. Floating-Point Support + +When building with ilp32d ABI and FP enabled: + +- FP registers f0-f31 and FCSR are saved/restored during context switches +- Stack frames increase from 32*REGBYTES to 65*REGBYTES (128 to 260 bytes) +- MSTATUS.FS (floating-point state) field is set to indicate dirty FP state + +Stack frame differences: +- Without FP: 32*4 = 128 bytes (interrupt), 16*4 = 64 bytes (solicited) +- With FP: 65*4 = 260 bytes (interrupt), 29*4 = 116 bytes (solicited) + + +12. Performance and Debugging + +Performance Optimization + +Build optimizations: +- Use -O2 or -O3 for production (example uses -O0 for debugging) +- Enable -Wl,--gc-sections to remove unused code +- Define TX_DISABLE_ERROR_CHECKING to remove parameter checks +- Consider -flto for link-time optimization + +Debugging with QEMU and GDB + +Start QEMU in debug mode: + qemu-system-riscv32 -nographic -smp 1 -bios none -m 128M \ + -machine virt -kernel kernel.elf -s -S + + -s: Enable GDB server on TCP port 1234 + -S: Pause at startup waiting for GDB + +Connect GDB: + riscv32-unknown-elf-gdb kernel.elf + (gdb) target remote :1234 + (gdb) break main + (gdb) continue + +Useful GDB commands: + (gdb) info registers # View general registers + (gdb) info all-registers # Include CSR and FP registers + (gdb) p/x $mstatus # View machine status register + (gdb) x/32xw $sp # Examine stack memory + (gdb) p *_tx_thread_current_ptr # View current thread control block + + +13. Platform-Specific Notes (QEMU virt) + +PLIC Configuration + +The PLIC (Platform-Level Interrupt Controller) is memory-mapped at 0x0C000000: + +- Enables up to 1024 interrupt sources +- Supports priority levels 0-7 (0 = disabled) +- Requires per-hart priority threshold and enable register configuration + +Example PLIC usage (from plic.c): + plic_irq_enable(irq_number); # Enable specific interrupt + plic_prio_set(irq_number, priority);# Set priority level + +CLINT Configuration + +The CLINT (Core-Local Interruptor) is memory-mapped at 0x02000000: + +- CLINT_MSIP(hartid): 0x0000 + 4*hartid (software interrupt) +- CLINT_MTIMECMP(hartid): 0x4000 + 8*hartid (timer compare) +- CLINT_MTIME: 0xBFF8 (timer value, read-only) + +Timer frequency is platform-dependent (example uses 10MHz). + +Multi-Core Considerations + +The current port is single-core focused: +- Only hart 0 continues from reset; others enter WFI loop +- _tx_thread_system_state is a global variable +- No per-hart data structures + + +14. Revision History + +For generic code revision information, refer to readme_threadx_generic.txt. + +The following details the revision history for this RISC-V32 GNU port: + +01-26-2026 Akif Ejaz Brief rewrite with accurate + technical details matching implementation, + register naming per RISC-V ABI, and + complete interrupt flow documentation + (Adapted from RISC-V64 port) + + +Copyright (c) 1996-2026 Microsoft Corporation + +https://azure.com/rtos diff --git a/ports/risc-v32/clang/src/tx_initialize_low_level.S b/ports/risc-v32/clang/src/tx_initialize_low_level.S new file mode 100644 index 00000000..6414e1be --- /dev/null +++ b/ports/risc-v32/clang/src/tx_initialize_low_level.S @@ -0,0 +1,118 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + + +/**************************************************************************/ +/**************************************************************************/ +/** */ +/** ThreadX Component */ +/** */ +/** Initialize */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + + .section .data + .global __tx_free_memory_start +__tx_free_memory_start: + + + .section .text +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_initialize_low_level RISC-V32/GNU */ +/* 6.4.x */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function is responsible for any low-level processor */ +/* initialization, including setting up interrupt vectors, setting */ +/* up a periodic timer interrupt source, saving the system stack */ +/* pointer for use in ISR processing later, and finding the first */ +/* available RAM memory address for tx_application_define. */ +/* */ +/* INPUT */ +/* */ +/* None */ +/* */ +/* OUTPUT */ +/* */ +/* None */ +/* */ +/* CALLS */ +/* */ +/* None */ +/* */ +/* CALLED BY */ +/* */ +/* _tx_initialize_kernel_enter ThreadX entry function */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 26-02-2026 Francisco Merino Initial Version 6.4.x */ +/* */ +/**************************************************************************/ +/* VOID _tx_initialize_low_level(VOID) +{ */ +// .global _tx_initialize_low_level + .weak _tx_initialize_low_level +_tx_initialize_low_level: + + /* Save the system stack pointer. */ + /* _tx_thread_system_stack_ptr = sp; */ + + la t0, _tx_thread_system_stack_ptr // Pickup address of system stack ptr + sw sp, 0(t0) // Save system stack pointer + + /* Pickup first free address. */ + /* _tx_initialize_unused_memory(__tx_free_memory_start); */ + + la t0, __tx_free_memory_start // Pickup first free address + la t1, _tx_initialize_unused_memory // Pickup address of unused memory + sw t0, 0(t1) // Save unused memory address + + /* Initialize floating point control/status register if floating point is enabled. */ +#ifdef __riscv_flen + li t0, 0 + csrw fcsr, t0 // Clear FP control/status register +#endif + + ret + +/* Timer Interrupt Handler Note: + Platform-specific implementations must provide their own timer ISR. + The timer interrupt handler should follow this execution flow: + + 1. Disable interrupts (if not done by hardware exception entry) + 2. Allocate interrupt stack frame (65*4 bytes with FP, 32*4 bytes without) + 3. Save RA (x1) on the stack at offset 28*4 + 4. Call _tx_thread_context_save to save thread context + 5. Call _tx_timer_interrupt to process the timer tick + 6. Call _tx_thread_context_restore to resume execution (does not return) + + Example (for CLINT timer): + + _tx_timer_interrupt_handler: + addi sp, sp, -32*4 + sw ra, 28*4(sp) + call _tx_thread_context_save + call _tx_timer_interrupt + j _tx_thread_context_restore + + The port assumes Machine mode (M-mode) execution. + For Supervisor mode (S-mode), use sstatus and SIE/SPIE instead of mstatus. + See the RISC-V Privileged Specification for more details. */
\ No newline at end of file diff --git a/ports/risc-v32/clang/src/tx_thread_context_restore.S b/ports/risc-v32/clang/src/tx_thread_context_restore.S new file mode 100644 index 00000000..8fa108b4 --- /dev/null +++ b/ports/risc-v32/clang/src/tx_thread_context_restore.S @@ -0,0 +1,416 @@ +/*************************************************************************** + * Copyright (c) 2025 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + + +/**************************************************************************/ +/**************************************************************************/ +/** */ +/** ThreadX Component */ +/** */ +/** Thread */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + + .section .text +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_thread_context_restore RISC-V32/GNU */ +/* 6.4.x */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function restores the interrupt context if it is processing a */ +/* nested interrupt. If not, it returns to the interrupt thread if no */ +/* preemption is necessary. Otherwise, if preemption is necessary or */ +/* if no thread was running, the function returns to the scheduler. */ +/* */ +/* INPUT */ +/* */ +/* None */ +/* */ +/* OUTPUT */ +/* */ +/* None */ +/* */ +/* CALLS */ +/* */ +/* _tx_thread_schedule Thread scheduling routine */ +/* */ +/* CALLED BY */ +/* */ +/* ISRs Interrupt Service Routines */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 26-02-2026 Francisco Merino Initial Version 6.4.x */ +/* */ +/**************************************************************************/ +/* VOID _tx_thread_context_restore(VOID) +{ */ + .global _tx_thread_context_restore +_tx_thread_context_restore: + + /* Lockout interrupts. */ + + csrci mstatus, 0x08 // Disable interrupts (MIE bit 3) + +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY + call _tx_execution_isr_exit // Call the ISR execution exit function +#endif + + /* Determine if interrupts are nested. */ + /* if (--_tx_thread_system_state) + { */ + + la t0, _tx_thread_system_state // Pickup addr of nested interrupt count + lw t1, 0(t0) // Pickup nested interrupt count + addi t1, t1, -1 // Decrement the nested interrupt counter + sw t1, 0(t0) // Store new nested count + beqz t1, _tx_thread_not_nested_restore // If 0, not nested restore + + /* Interrupts are nested. */ + + /* Just recover the saved registers and return to the point of + interrupt. */ + + /* Recover floating point registers. */ +#if defined(__riscv_float_abi_single) + flw f0, 31*4(sp) // Recover ft0 + flw f1, 32*4(sp) // Recover ft1 + flw f2, 33*4(sp) // Recover ft2 + flw f3, 34*4(sp) // Recover ft3 + flw f4, 35*4(sp) // Recover ft4 + flw f5, 36*4(sp) // Recover ft5 + flw f6, 37*4(sp) // Recover ft6 + flw f7, 38*4(sp) // Recover ft7 + flw f10, 41*4(sp) // Recover fa0 + flw f11, 42*4(sp) // Recover fa1 + flw f12, 43*4(sp) // Recover fa2 + flw f13, 44*4(sp) // Recover fa3 + flw f14, 45*4(sp) // Recover fa4 + flw f15, 46*4(sp) // Recover fa5 + flw f16, 47*4(sp) // Recover fa6 + flw f17, 48*4(sp) // Recover fa7 + flw f28, 59*4(sp) // Recover ft8 + flw f29, 60*4(sp) // Recover ft9 + flw f30, 61*4(sp) // Recover ft10 + flw f31, 62*4(sp) // Recover ft11 + lw t0, 63*4(sp) // Recover fcsr + csrw fcsr, t0 // Restore fcsr +#elif defined(__riscv_float_abi_double) + fld f0, 31*4(sp) // Recover ft0 + fld f1, 32*4(sp) // Recover ft1 + fld f2, 33*4(sp) // Recover ft2 + fld f3, 34*4(sp) // Recover ft3 + fld f4, 35*4(sp) // Recover ft4 + fld f5, 36*4(sp) // Recover ft5 + fld f6, 37*4(sp) // Recover ft6 + fld f7, 38*4(sp) // Recover ft7 + fld f10, 41*4(sp) // Recover fa0 + fld f11, 42*4(sp) // Recover fa1 + fld f12, 43*4(sp) // Recover fa2 + fld f13, 44*4(sp) // Recover fa3 + fld f14, 45*4(sp) // Recover fa4 + fld f15, 46*4(sp) // Recover fa5 + fld f16, 47*4(sp) // Recover fa6 + fld f17, 48*4(sp) // Recover fa7 + fld f28, 59*4(sp) // Recover ft8 + fld f29, 60*4(sp) // Recover ft9 + fld f30, 61*4(sp) // Recover ft10 + fld f31, 62*4(sp) // Recover ft11 + lw t0, 63*4(sp) // Recover fcsr + csrw fcsr, t0 // Restore fcsr +#endif + + /* Recover standard registers. */ + + /* Restore registers, + Skip global pointer because that does not change. + Also skip the saved registers since they have been restored by any function we called, + except s0 since we use it ourselves. */ + + lw t0, 30*4(sp) // Recover mepc + csrw mepc, t0 // Setup mepc + + /* Compose mstatus via read/modify/write to avoid clobbering unrelated bits. + Set MPIE and restore MPP to Machine, preserve other fields. */ + + csrr t1, mstatus + + /* Clear MPP/MPIE/MIE bits in t1 then set desired values. */ + + li t2, 0x1888 // MPP(0x1800) | MPIE(0x80) | MIE(0x08) + li t3, 0x1800 // Set MPP to Machine mode (bits 12:11) + + /* Construct new mstatus in t1: clear mask bits, set MPP/MPIE and optionally FP bit, + preserve everything except the bits we will modify. */ + + li t4, ~0x1888 // Clear mask for MPP/MPIE/MIE + and t1, t1, t4 + or t1, t1, t3 + +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + li t0, 0x2000 // Set FS bits (bits 14:13 to 01) for FP state + or t1, t1, t0 +#endif + csrw mstatus, t1 // Update mstatus safely + + lw ra, 28*4(sp) // Recover return address + lw t0, 19*4(sp) // Recover t0 + lw t1, 18*4(sp) // Recover t1 + lw t2, 17*4(sp) // Recover t2 + lw s0, 12*4(sp) // Recover s0 + lw a0, 27*4(sp) // Recover a0 + lw a1, 26*4(sp) // Recover a1 + lw a2, 25*4(sp) // Recover a2 + lw a3, 24*4(sp) // Recover a3 + lw a4, 23*4(sp) // Recover a4 + lw a5, 22*4(sp) // Recover a5 + lw a6, 21*4(sp) // Recover a6 + lw a7, 20*4(sp) // Recover a7 + lw t3, 16*4(sp) // Recover t3 + lw t4, 15*4(sp) // Recover t4 + lw t5, 14*4(sp) // Recover t5 + lw t6, 13*4(sp) // Recover t6 + +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + addi sp, sp, 65*4 // Recover stack frame - with floating point enabled +#else + addi sp, sp, 32*4 // Recover stack frame - without floating point enabled +#endif + mret // Return to point of interrupt + + /* } */ +_tx_thread_not_nested_restore: + /* Determine if a thread was interrupted and no preemption is required. */ + /* else if (((_tx_thread_current_ptr) && (_tx_thread_current_ptr == _tx_thread_execute_ptr) + || (_tx_thread_preempt_disable)) + { */ + + la t0, _tx_thread_current_ptr // Pickup current thread pointer address + lw t1, 0(t0) // Pickup current thread pointer + + beqz t1, _tx_thread_idle_system_restore // If NULL, idle system restore + + + la t0, _tx_thread_preempt_disable // Pickup preempt disable flag address + lw t2, 0(t0) // Pickup preempt disable flag (UINT) + + bgtz t2, _tx_thread_no_preempt_restore // If set, restore interrupted thread + + + la t0, _tx_thread_execute_ptr // Pickup thread execute pointer address + lw t2, 0(t0) // Pickup thread execute pointer + + bne t1, t2, _tx_thread_preempt_restore // If higher-priority thread is ready, preempt + + +_tx_thread_no_preempt_restore: + /* Restore interrupted thread or ISR. */ + + /* Pickup the saved stack pointer. */ + /* sp = _tx_thread_current_ptr -> tx_thread_stack_ptr; */ + + lw sp, 8(t1) // Switch back to thread's stack + + /* Recover floating point registers. */ +#if defined(__riscv_float_abi_single) + flw f0, 31*4(sp) // Recover ft0 + flw f1, 32*4(sp) // Recover ft1 + flw f2, 33*4(sp) // Recover ft2 + flw f3, 34*4(sp) // Recover ft3 + flw f4, 35*4(sp) // Recover ft4 + flw f5, 36*4(sp) // Recover ft5 + flw f6, 37*4(sp) // Recover ft6 + flw f7, 38*4(sp) // Recover ft7 + flw f10, 41*4(sp) // Recover fa0 + flw f11, 42*4(sp) // Recover fa1 + flw f12, 43*4(sp) // Recover fa2 + flw f13, 44*4(sp) // Recover fa3 + flw f14, 45*4(sp) // Recover fa4 + flw f15, 46*4(sp) // Recover fa5 + flw f16, 47*4(sp) // Recover fa6 + flw f17, 48*4(sp) // Recover fa7 + flw f28, 59*4(sp) // Recover ft8 + flw f29, 60*4(sp) // Recover ft9 + flw f30, 61*4(sp) // Recover ft10 + flw f31, 62*4(sp) // Recover ft11 + lw t0, 63*4(sp) // Recover fcsr + csrw fcsr, t0 // Restore fcsr +#elif defined(__riscv_float_abi_double) + fld f0, 31*4(sp) // Recover ft0 + fld f1, 32*4(sp) // Recover ft1 + fld f2, 33*4(sp) // Recover ft2 + fld f3, 34*4(sp) // Recover ft3 + fld f4, 35*4(sp) // Recover ft4 + fld f5, 36*4(sp) // Recover ft5 + fld f6, 37*4(sp) // Recover ft6 + fld f7, 38*4(sp) // Recover ft7 + fld f10, 41*4(sp) // Recover fa0 + fld f11, 42*4(sp) // Recover fa1 + fld f12, 43*4(sp) // Recover fa2 + fld f13, 44*4(sp) // Recover fa3 + fld f14, 45*4(sp) // Recover fa4 + fld f15, 46*4(sp) // Recover fa5 + fld f16, 47*4(sp) // Recover fa6 + fld f17, 48*4(sp) // Recover fa7 + fld f28, 59*4(sp) // Recover ft8 + fld f29, 60*4(sp) // Recover ft9 + fld f30, 61*4(sp) // Recover ft10 + fld f31, 62*4(sp) // Recover ft11 + lw t0, 63*4(sp) // Recover fcsr + csrw fcsr, t0 // Restore fcsr +#endif + + /* Recover the saved context and return to the point of interrupt. */ + + /* Recover standard registers. */ + /* Restore registers, + Skip global pointer because that does not change */ + + lw t0, 30*4(sp) // Recover mepc + csrw mepc, t0 // Setup mepc + + /* Compose mstatus via read/modify/write to avoid clobbering unrelated bits. */ + + csrr t1, mstatus + li t2, 0x1888 // MPP(0x1800) | MPIE(0x80) | MIE(0x08) + li t3, 0x1800 // Set MPP to Machine mode + li t4, ~0x1888 // Clear mask for MPP/MPIE/MIE + and t1, t1, t4 + or t1, t1, t3 + +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + li t0, 0x2000 // Set FS bits for FP state + or t1, t1, t0 +#endif + csrw mstatus, t1 // Update mstatus safely + + lw ra, 28*4(sp) // Recover return address + lw t0, 19*4(sp) // Recover t0 + lw t1, 18*4(sp) // Recover t1 + lw t2, 17*4(sp) // Recover t2 + lw s0, 12*4(sp) // Recover s0 + lw a0, 27*4(sp) // Recover a0 + lw a1, 26*4(sp) // Recover a1 + lw a2, 25*4(sp) // Recover a2 + lw a3, 24*4(sp) // Recover a3 + lw a4, 23*4(sp) // Recover a4 + lw a5, 22*4(sp) // Recover a5 + lw a6, 21*4(sp) // Recover a6 + lw a7, 20*4(sp) // Recover a7 + lw t3, 16*4(sp) // Recover t3 + lw t4, 15*4(sp) // Recover t4 + lw t5, 14*4(sp) // Recover t5 + lw t6, 13*4(sp) // Recover t6 + +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + addi sp, sp, 65*4 // Recover stack frame - with floating point enabled +#else + addi sp, sp, 32*4 // Recover stack frame - without floating point enabled +#endif + mret // Return to point of interrupt + + /* } + else + { */ +_tx_thread_preempt_restore: + /* Instead of directly activating the thread again, ensure we save the + entire stack frame by saving the remaining registers. */ + + lw t0, 8(t1) // Pickup thread's stack pointer + ori t3, zero, 1 // Build interrupt stack type + sw t3, 0(t0) // Store stack type + + /* Store floating point preserved registers. */ +#ifdef __riscv_float_abi_single + fsw f8, 39*4(t0) // Store fs0 + fsw f9, 40*4(t0) // Store fs1 + fsw f18, 49*4(t0) // Store fs2 + fsw f19, 50*4(t0) // Store fs3 + fsw f20, 51*4(t0) // Store fs4 + fsw f21, 52*4(t0) // Store fs5 + fsw f22, 53*4(t0) // Store fs6 + fsw f23, 54*4(t0) // Store fs7 + fsw f24, 55*4(t0) // Store fs8 + fsw f25, 56*4(t0) // Store fs9 + fsw f26, 57*4(t0) // Store fs10 + fsw f27, 58*4(t0) // Store fs11 +#elif defined(__riscv_float_abi_double) + fsd f8, 39*4(t0) // Store fs0 + fsd f9, 40*4(t0) // Store fs1 + fsd f18, 49*4(t0) // Store fs2 + fsd f19, 50*4(t0) // Store fs3 + fsd f20, 51*4(t0) // Store fs4 + fsd f21, 52*4(t0) // Store fs5 + fsd f22, 53*4(t0) // Store fs6 + fsd f23, 54*4(t0) // Store fs7 + fsd f24, 55*4(t0) // Store fs8 + fsd f25, 56*4(t0) // Store fs9 + fsd f26, 57*4(t0) // Store fs10 + fsd f27, 58*4(t0) // Store fs11 +#endif + + /* Store standard preserved registers. */ + + sw x9, 11*4(t0) // Store s1 + sw x18, 10*4(t0) // Store s2 + sw x19, 9*4(t0) // Store s3 + sw x20, 8*4(t0) // Store s4 + sw x21, 7*4(t0) // Store s5 + sw x22, 6*4(t0) // Store s6 + sw x23, 5*4(t0) // Store s7 + sw x24, 4*4(t0) // Store s8 + sw x25, 3*4(t0) // Store s9 + sw x26, 2*4(t0) // Store s10 + sw x27, 1*4(t0) // Store s11 + // Note: s0 is already stored! + + /* Save the remaining time-slice and disable it. */ + /* if (_tx_timer_time_slice) + { */ + + la t0, _tx_timer_time_slice // Pickup time slice variable address + lw t2, 0(t0) // Pickup time slice + beqz t2, _tx_thread_dont_save_ts // If 0, skip time slice processing + + /* _tx_thread_current_ptr -> tx_thread_time_slice = _tx_timer_time_slice + _tx_timer_time_slice = 0; */ + + sw t2, 24(t1) // Save current time slice + sw x0, 0(t0) // Clear global time slice + + + /* } */ +_tx_thread_dont_save_ts: + /* Clear the current task pointer. */ + /* _tx_thread_current_ptr = TX_NULL; */ + + /* Return to the scheduler. */ + /* _tx_thread_schedule(); */ + + la t0, _tx_thread_current_ptr // Pickup current thread pointer address + sw x0, 0(t0) // Clear current thread pointer + + /* } */ + +_tx_thread_idle_system_restore: + /* Just return back to the scheduler! */ + j _tx_thread_schedule // Return to scheduler + +/* } */ diff --git a/ports/risc-v32/clang/src/tx_thread_context_save.S b/ports/risc-v32/clang/src/tx_thread_context_save.S new file mode 100644 index 00000000..8801374e --- /dev/null +++ b/ports/risc-v32/clang/src/tx_thread_context_save.S @@ -0,0 +1,277 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + + +/**************************************************************************/ +/**************************************************************************/ +/** */ +/** ThreadX Component */ +/** */ +/** Thread */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + + .section .text +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_thread_context_save RISC-V32/GNU */ +/* 6.4.x */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function saves the context of an executing thread in the */ +/* beginning of interrupt processing. The function also ensures that */ +/* the system stack is used upon return to the calling ISR. */ +/* */ +/* INPUT */ +/* */ +/* None */ +/* */ +/* OUTPUT */ +/* */ +/* None */ +/* */ +/* CALLS */ +/* */ +/* None */ +/* */ +/* CALLED BY */ +/* */ +/* ISRs */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 26-02-2026 Francisco Merino Initial Version 6.4.x */ +/* */ +/**************************************************************************/ +/* VOID _tx_thread_context_save(VOID) +{ */ + .global _tx_thread_context_save +_tx_thread_context_save: + + /* Upon entry to this routine, RA/x1 has been saved on the stack + and the stack has been already allocated for the entire context: + addi sp, sp, -32*4 (or -65*4) + sw ra, 28*4(sp) + */ + + sw t0, 19*4(sp) // Store t0 + sw t1, 18*4(sp) // Store t1 + + /* Check for a nested interrupt. */ + /* if (_tx_thread_system_state++) + { */ + + la t0, _tx_thread_system_state // Pickup addr of system state var + lw t1, 0(t0) // Pickup system state + addi t1, t1, 1 // Increment system state + sw t1, 0(t0) // Store system state + li t0, 1 + bgt t1, t0, _tx_thread_nested_save // If it's more than 1, nested interrupt + + /* First level interrupt, save the rest of the scratch registers and + check for a thread to preempt. */ + + sw t2, 17*4(sp) // Store t2 + sw s0, 12*4(sp) // Store s0 + sw a0, 27*4(sp) // Store a0 + sw a1, 26*4(sp) // Store a1 + sw a2, 25*4(sp) // Store a2 + sw a3, 24*4(sp) // Store a3 + sw a4, 23*4(sp) // Store a4 + sw a5, 22*4(sp) // Store a5 + sw a6, 21*4(sp) // Store a6 + sw a7, 20*4(sp) // Store a7 + sw t3, 16*4(sp) // Store t3 + sw t4, 15*4(sp) // Store t4 + sw t5, 14*4(sp) // Store t5 + sw t6, 13*4(sp) // Store t6 + + /* Save floating point registers. */ +#if defined(__riscv_float_abi_single) + fsw f0, 31*4(sp) // Store ft0 + fsw f1, 32*4(sp) // Store ft1 + fsw f2, 33*4(sp) // Store ft2 + fsw f3, 34*4(sp) // Store ft3 + fsw f4, 35*4(sp) // Store ft4 + fsw f5, 36*4(sp) // Store ft5 + fsw f6, 37*4(sp) // Store ft6 + fsw f7, 38*4(sp) // Store ft7 + fsw f10, 41*4(sp) // Store fa0 + fsw f11, 42*4(sp) // Store fa1 + fsw f12, 43*4(sp) // Store fa2 + fsw f13, 44*4(sp) // Store fa3 + fsw f14, 45*4(sp) // Store fa4 + fsw f15, 46*4(sp) // Store fa5 + fsw f16, 47*4(sp) // Store fa6 + fsw f17, 48*4(sp) // Store fa7 + fsw f28, 59*4(sp) // Store ft8 + fsw f29, 60*4(sp) // Store ft9 + fsw f30, 61*4(sp) // Store ft10 + fsw f31, 62*4(sp) // Store ft11 + csrr t0, fcsr + sw t0, 63*4(sp) // Store fcsr +#elif defined(__riscv_float_abi_double) + fsd f0, 31*4(sp) // Store ft0 + fsd f1, 32*4(sp) // Store ft1 + fsd f2, 33*4(sp) // Store ft2 + fsd f3, 34*4(sp) // Store ft3 + fsd f4, 35*4(sp) // Store ft4 + fsd f5, 36*4(sp) // Store ft5 + fsd f6, 37*4(sp) // Store ft6 + fsd f7, 38*4(sp) // Store ft7 + fsd f10, 41*4(sp) // Store fa0 + fsd f11, 42*4(sp) // Store fa1 + fsd f12, 43*4(sp) // Store fa2 + fsd f13, 44*4(sp) // Store fa3 + fsd f14, 45*4(sp) // Store fa4 + fsd f15, 46*4(sp) // Store fa5 + fsd f16, 47*4(sp) // Store fa6 + fsd f17, 48*4(sp) // Store fa7 + fsd f28, 59*4(sp) // Store ft8 + fsd f29, 60*4(sp) // Store ft9 + fsd f30, 61*4(sp) // Store ft10 + fsd f31, 62*4(sp) // Store ft11 + csrr t0, fcsr + sw t0, 63*4(sp) // Store fcsr +#endif + + csrr t0, mepc + sw t0, 30*4(sp) // Save it on the stack + + /* Save mstatus. */ + csrr t0, mstatus + sw t0, 29*4(sp) + + la t1, _tx_thread_current_ptr // Pickup address of current thread ptr + lw t2, 0(t1) // Pickup current thread pointer + beqz t2, _tx_thread_idle_system_save // If NULL, idle system was interrupted + + /* Save the current thread's stack pointer and switch to the system stack. */ + /* _tx_thread_current_ptr -> tx_thread_stack_ptr = sp; + sp = _tx_thread_system_stack_ptr; */ + + sw sp, 8(t2) // Save stack pointer + la t0, _tx_thread_system_stack_ptr + lw sp, 0(t0) // Switch to system stack + + /* Call the ISR execution exit function if enabled. */ +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY + call _tx_execution_isr_enter // Call the ISR execution enter function +#endif + + ret // Return to ISR + +_tx_thread_nested_save: + + /* Nested interrupt! Just save the scratch registers and return to the ISR. */ + + sw t2, 17*4(sp) // Store t2 + sw s0, 12*4(sp) // Store s0 + sw a0, 27*4(sp) // Store a0 + sw a1, 26*4(sp) // Store a1 + sw a2, 25*4(sp) // Store a2 + sw a3, 24*4(sp) // Store a3 + sw a4, 23*4(sp) // Store a4 + sw a5, 22*4(sp) // Store a5 + sw a6, 21*4(sp) // Store a6 + sw a7, 20*4(sp) // Store a7 + sw t3, 16*4(sp) // Store t3 + sw t4, 15*4(sp) // Store t4 + sw t5, 14*4(sp) // Store t5 + sw t6, 13*4(sp) // Store t6 + + /* Save floating point registers. */ +#if defined(__riscv_float_abi_single) + fsw f0, 31*4(sp) // Store ft0 + fsw f1, 32*4(sp) // Store ft1 + fsw f2, 33*4(sp) // Store ft2 + fsw f3, 34*4(sp) // Store ft3 + fsw f4, 35*4(sp) // Store ft4 + fsw f5, 36*4(sp) // Store ft5 + fsw f6, 37*4(sp) // Store ft6 + fsw f7, 38*4(sp) // Store ft7 + fsw f10, 41*4(sp) // Store fa0 + fsw f11, 42*4(sp) // Store fa1 + fsw f12, 43*4(sp) // Store fa2 + fsw f13, 44*4(sp) // Store fa3 + fsw f14, 45*4(sp) // Store fa4 + fsw f15, 46*4(sp) // Store fa5 + fsw f16, 47*4(sp) // Store fa6 + fsw f17, 48*4(sp) // Store fa7 + fsw f28, 59*4(sp) // Store ft8 + fsw f29, 60*4(sp) // Store ft9 + fsw f30, 61*4(sp) // Store ft10 + fsw f31, 62*4(sp) // Store ft11 + csrr t0, fcsr + sw t0, 63*4(sp) // Store fcsr +#elif defined(__riscv_float_abi_double) + fsd f0, 31*4(sp) // Store ft0 + fsd f1, 32*4(sp) // Store ft1 + fsd f2, 33*4(sp) // Store ft2 + fsd f3, 34*4(sp) // Store ft3 + fsd f4, 35*4(sp) // Store ft4 + fsd f5, 36*4(sp) // Store ft5 + fsd f6, 37*4(sp) // Store ft6 + fsd f7, 38*4(sp) // Store ft7 + fsd f10, 41*4(sp) // Store fa0 + fsd f11, 42*4(sp) // Store fa1 + fsd f12, 43*4(sp) // Store fa2 + fsd f13, 44*4(sp) // Store fa3 + fsd f14, 45*4(sp) // Store fa4 + fsd f15, 46*4(sp) // Store fa5 + fsd f16, 47*4(sp) // Store fa6 + fsd f17, 48*4(sp) // Store fa7 + fsd f28, 59*4(sp) // Store ft8 + fsd f29, 60*4(sp) // Store ft9 + fsd f30, 61*4(sp) // Store ft10 + fsd f31, 62*4(sp) // Store ft11 + csrr t0, fcsr + sw t0, 63*4(sp) // Store fcsr +#endif + + csrr t0, mepc + sw t0, 30*4(sp) // Save it on stack + + csrr t0, mstatus + sw t0, 29*4(sp) + + /* Call the ISR execution exit function if enabled. */ +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY + call _tx_execution_isr_enter // Call the ISR execution enter function +#endif + + ret // Return to ISR + +_tx_thread_idle_system_save: + + +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY + call _tx_execution_isr_enter // Call the ISR execution enter function +#endif + + /* Interrupt occurred in the scheduling loop. */ + + /* } +} */ +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + addi sp, sp, 65*4 // Recover stack frame - with floating point enabled +#else + addi sp, sp, 32*4 // Recover the reserved stack space +#endif + ret // Return to calling ISR diff --git a/ports/risc-v32/clang/src/tx_thread_interrupt_control.S b/ports/risc-v32/clang/src/tx_thread_interrupt_control.S new file mode 100644 index 00000000..867174ad --- /dev/null +++ b/ports/risc-v32/clang/src/tx_thread_interrupt_control.S @@ -0,0 +1,94 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + + +/**************************************************************************/ +/**************************************************************************/ +/** */ +/** ThreadX Component */ +/** */ +/** Thread */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + + + .section .text +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_thread_interrupt_control RISC-V32/GNU */ +/* 6.4.x */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function is responsible for changing the interrupt lockout */ +/* posture of the system. */ +/* */ +/* INPUT */ +/* */ +/* new_posture New interrupt lockout posture */ +/* */ +/* OUTPUT */ +/* */ +/* old_posture Old interrupt lockout posture */ +/* */ +/* CALLS */ +/* */ +/* None */ +/* */ +/* CALLED BY */ +/* */ +/* Application Code */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 26-02-2026 Francisco Merino Initial Version 6.4.x */ +/* */ +/**************************************************************************/ +/* UINT _tx_thread_interrupt_control(UINT new_posture) +{ */ + .global _tx_thread_interrupt_control +_tx_thread_interrupt_control: + + /* Pickup current interrupt posture. */ + + csrr a1, mstatus // Pickup mstatus + andi a1, a1, 0x08 // Mask out all but MIE + + /* Check for the new posture. */ + + beqz a0, _tx_thread_interrupt_disable // If 0, disable interrupts + + /* Enable interrupts. */ + + csrsi mstatus, 0x08 // Enable interrupts (MIE bit 3) + j _tx_thread_interrupt_control_exit // Return to caller + +_tx_thread_interrupt_disable: + + /* Disable interrupts. */ + + csrci mstatus, 0x08 // Disable interrupts (MIE bit 3) + +_tx_thread_interrupt_control_exit: + + /* Return the old interrupt posture. */ + + mv a0, a1 // Setup return value + ret // Return to caller + +/* } */ diff --git a/ports/risc-v32/clang/src/tx_thread_schedule.S b/ports/risc-v32/clang/src/tx_thread_schedule.S new file mode 100644 index 00000000..3e6d3506 --- /dev/null +++ b/ports/risc-v32/clang/src/tx_thread_schedule.S @@ -0,0 +1,324 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + + +/**************************************************************************/ +/**************************************************************************/ +/** */ +/** ThreadX Component */ +/** */ +/** Thread */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + + + .section .text +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_thread_schedule RISC-V32/GNU */ +/* 6.4.x */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function waits for a thread control block pointer to appear in */ +/* the _tx_thread_execute_ptr variable. Once a thread pointer appears */ +/* in the variable, the corresponding thread is resumed. */ +/* */ +/* INPUT */ +/* */ +/* None */ +/* */ +/* OUTPUT */ +/* */ +/* None */ +/* */ +/* CALLS */ +/* */ +/* None */ +/* */ +/* CALLED BY */ +/* */ +/* _tx_initialize_kernel_enter ThreadX entry function */ +/* _tx_thread_system_return Return to system from thread */ +/* _tx_thread_context_restore Restore thread's context */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 23-12-2025 Akif Ejaz Initial Version 6.4.x */ +/* */ +/**************************************************************************/ +/* VOID _tx_thread_schedule(VOID) +{ */ + .global _tx_thread_schedule +_tx_thread_schedule: + + /* Enable interrupts. */ + + csrsi mstatus, 0x08 // Enable interrupts (MIE bit 3) + + /* Wait for a thread to execute. */ + /* do + { */ +_tx_thread_schedule_loop: + + la t0, _tx_thread_execute_ptr // Pickup address of execute ptr + lw t1, 0(t0) // Pickup execute pointer + bnez t1, _tx_thread_ready_to_run // If non-NULL, a thread is ready to run + +#ifndef TX_NO_WFI + wfi // Wait for interrupt +#endif + j _tx_thread_schedule_loop // Check again + + /* } + while (_tx_thread_execute_ptr == TX_NULL); */ + +_tx_thread_ready_to_run: + + /* At this point, t1 contains the pointer to the thread to execute. + Lockout interrupts. */ + + csrci mstatus, 0x08 // Disable interrupts (MIE bit 3) + + /* Check _tx_thread_execute_ptr again, in case an interrupt occurred + between the check and the disable. */ + + lw t1, 0(t0) // Pickup execute pointer + beqz t1, _tx_thread_schedule_loop // If NULL, go back to wait loop + + /* Yes! We have a thread to execute. */ + /* _tx_thread_current_ptr = _tx_thread_execute_ptr; */ + + la t0, _tx_thread_current_ptr // Pickup address of current thread + sw t1, 0(t0) // Setup current thread pointer + + /* Increment the run count for this thread. */ + /* _tx_thread_current_ptr -> tx_thread_run_count++; */ + + lw t2, 4(t1) // Pickup run count + addi t2, t2, 1 // Increment run count + sw t2, 4(t1) // Store run count + + /* Setup time-slice values. */ + /* _tx_timer_time_slice = _tx_thread_current_ptr -> tx_thread_time_slice; */ + + lw t2, 24(t1) // Pickup thread time-slice + la t3, _tx_timer_time_slice // Pickup address of time-slice + sw t2, 0(t3) // Setup time-slice + + /* Call the thread execution enter function if enabled. */ +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY + + call _tx_execution_thread_enter // Call the thread execution enter function +#endif + + /* Switch to the thread's stack. */ + /* sp = _tx_thread_current_ptr -> tx_thread_stack_ptr; */ + + lw sp, 8(t1) // Switch to thread stack + + /* Determine the type of stack frame. */ + /* if (*sp) + { */ + + lw t0, 0(sp) // Pickup stack type + beqz t0, _tx_thread_solicited_return // If 0, solicited return + + /* Recover floating point registers. */ +#if defined(__riscv_float_abi_single) + flw f0, 31*4(sp) // Recover ft0 + flw f1, 32*4(sp) // Recover ft1 + flw f2, 33*4(sp) // Recover ft2 + flw f3, 34*4(sp) // Recover ft3 + flw f4, 35*4(sp) // Recover ft4 + flw f5, 36*4(sp) // Recover ft5 + flw f6, 37*4(sp) // Recover ft6 + flw f7, 38*4(sp) // Recover ft7 + flw f8, 39*4(sp) // Recover fs0 + flw f9, 40*4(sp) // Recover fs1 + flw f10, 41*4(sp) // Recover fa0 + flw f11, 42*4(sp) // Recover fa1 + flw f12, 43*4(sp) // Recover fa2 + flw f13, 44*4(sp) // Recover fa3 + flw f14, 45*4(sp) // Recover fa4 + flw f15, 46*4(sp) // Recover fa5 + flw f16, 47*4(sp) // Recover fa6 + flw f17, 48*4(sp) // Recover fa7 + flw f18, 49*4(sp) // Recover fs2 + flw f19, 50*4(sp) // Recover fs3 + flw f20, 51*4(sp) // Recover fs4 + flw f21, 52*4(sp) // Recover fs5 + flw f22, 53*4(sp) // Recover fs6 + flw f23, 54*4(sp) // Recover fs7 + flw f24, 55*4(sp) // Recover fs8 + flw f25, 56*4(sp) // Recover fs9 + flw f26, 57*4(sp) // Recover fs10 + flw f27, 58*4(sp) // Recover fs11 + flw f28, 59*4(sp) // Recover ft8 + flw f29, 60*4(sp) // Recover ft9 + flw f30, 61*4(sp) // Recover ft10 + flw f31, 62*4(sp) // Recover ft11 + lw t0, 63*4(sp) // Recover fcsr + csrw fcsr, t0 // Restore fcsr +#elif defined(__riscv_float_abi_double) + fld f0, 31*4(sp) // Recover ft0 + fld f1, 32*4(sp) // Recover ft1 + fld f2, 33*4(sp) // Recover ft2 + fld f3, 34*4(sp) // Recover ft3 + fld f4, 35*4(sp) // Recover ft4 + fld f5, 36*4(sp) // Recover ft5 + fld f6, 37*4(sp) // Recover ft6 + fld f7, 38*4(sp) // Recover ft7 + fld f8, 39*4(sp) // Recover fs0 + fld f9, 40*4(sp) // Recover fs1 + fld f10, 41*4(sp) // Recover fa0 + fld f11, 42*4(sp) // Recover fa1 + fld f12, 43*4(sp) // Recover fa2 + fld f13, 44*4(sp) // Recover fa3 + fld f14, 45*4(sp) // Recover fa4 + fld f15, 46*4(sp) // Recover fa5 + fld f16, 47*4(sp) // Recover fa6 + fld f17, 48*4(sp) // Recover fa7 + fld f18, 49*4(sp) // Recover fs2 + fld f19, 50*4(sp) // Recover fs3 + fld f20, 51*4(sp) // Recover fs4 + fld f21, 52*4(sp) // Recover fs5 + fld f22, 53*4(sp) // Recover fs6 + fld f23, 54*4(sp) // Recover fs7 + fld f24, 55*4(sp) // Recover fs8 + fld f25, 56*4(sp) // Recover fs9 + fld f26, 57*4(sp) // Recover fs10 + fld f27, 58*4(sp) // Recover fs11 + fld f28, 59*4(sp) // Recover ft8 + fld f29, 60*4(sp) // Recover ft9 + fld f30, 61*4(sp) // Recover ft10 + fld f31, 62*4(sp) // Recover ft11 + lw t0, 63*4(sp) // Recover fcsr + csrw fcsr, t0 // Restore fcsr +#endif + + /* Recover standard registers. */ + + lw t0, 30*4(sp) // Recover mepc + csrw mepc, t0 // Setup mepc + + li t0, 0x1880 // Prepare mstatus: MPP=Machine(0x1800) | MPIE(0x80) +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + li t1, 0x2000 // Set FS bits for FP state + or t0, t0, t1 +#endif + csrw mstatus, t0 // Set mstatus + + lw ra, 28*4(sp) // Recover return address + lw t0, 19*4(sp) // Recover t0 + lw t1, 18*4(sp) // Recover t1 + lw t2, 17*4(sp) // Recover t2 + lw s0, 12*4(sp) // Recover s0 + lw x9, 11*4(sp) // Recover s1 + lw a0, 27*4(sp) // Recover a0 + lw a1, 26*4(sp) // Recover a1 + lw a2, 25*4(sp) // Recover a2 + lw a3, 24*4(sp) // Recover a3 + lw a4, 23*4(sp) // Recover a4 + lw a5, 22*4(sp) // Recover a5 + lw a6, 21*4(sp) // Recover a6 + lw a7, 20*4(sp) // Recover a7 + lw t3, 16*4(sp) // Recover t3 + lw t4, 15*4(sp) // Recover t4 + lw t5, 14*4(sp) // Recover t5 + lw t6, 13*4(sp) // Recover t6 + lw x18, 10*4(sp) // Recover s2 + lw x19, 9*4(sp) // Recover s3 + lw x20, 8*4(sp) // Recover s4 + lw x21, 7*4(sp) // Recover s5 + lw x22, 6*4(sp) // Recover s6 + lw x23, 5*4(sp) // Recover s7 + lw x24, 4*4(sp) // Recover s8 + lw x25, 3*4(sp) // Recover s9 + lw x26, 2*4(sp) // Recover s10 + lw x27, 1*4(sp) // Recover s11 + +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + addi sp, sp, 65*4 // Recover stack frame - with floating point enabled +#else + addi sp, sp, 32*4 // Recover stack frame - without floating point enabled +#endif + mret // Return to thread + +_tx_thread_solicited_return: + + /* Recover floating point registers. */ +#if defined(__riscv_float_abi_single) + flw f8, 15*4(sp) // Recover fs0 + flw f9, 16*4(sp) // Recover fs1 + flw f18, 17*4(sp) // Recover fs2 + flw f19, 18*4(sp) // Recover fs3 + flw f20, 19*4(sp) // Recover fs4 + flw f21, 20*4(sp) // Recover fs5 + flw f22, 21*4(sp) // Recover fs6 + flw f23, 22*4(sp) // Recover fs7 + flw f24, 23*4(sp) // Recover fs8 + flw f25, 24*4(sp) // Recover fs9 + flw f26, 25*4(sp) // Recover fs10 + flw f27, 26*4(sp) // Recover fs11 + lw t0, 27*4(sp) // Recover fcsr + csrw fcsr, t0 // Restore fcsr +#elif defined(__riscv_float_abi_double) + fld f8, 15*4(sp) // Recover fs0 + fld f9, 16*4(sp) // Recover fs1 + fld f18, 17*4(sp) // Recover fs2 + fld f19, 18*4(sp) // Recover fs3 + fld f20, 19*4(sp) // Recover fs4 + fld f21, 20*4(sp) // Recover fs5 + fld f22, 21*4(sp) // Recover fs6 + fld f23, 22*4(sp) // Recover fs7 + fld f24, 23*4(sp) // Recover fs8 + fld f25, 24*4(sp) // Recover fs9 + fld f26, 25*4(sp) // Recover fs10 + fld f27, 26*4(sp) // Recover fs11 + lw t0, 27*4(sp) // Recover fcsr + csrw fcsr, t0 // Restore fcsr +#endif + + /* Recover standard registers. */ + + lw t0, 14*4(sp) // Recover mstatus + csrw mstatus, t0 // Restore mstatus + + lw ra, 13*4(sp) // Recover return address + lw s0, 12*4(sp) // Recover s0 + lw s1, 11*4(sp) // Recover s1 + lw x18, 10*4(sp) // Recover s2 + lw x19, 9*4(sp) // Recover s3 + lw x20, 8*4(sp) // Recover s4 + lw x21, 7*4(sp) // Recover s5 + lw x22, 6*4(sp) // Recover s6 + lw x23, 5*4(sp) // Recover s7 + lw x24, 4*4(sp) // Recover s8 + lw x25, 3*4(sp) // Recover s9 + lw x26, 2*4(sp) // Recover s10 + lw x27, 1*4(sp) // Recover s11 + +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + addi sp, sp, 29*4 // Recover stack frame - with floating point enabled +#else + addi sp, sp, 16*4 // Recover stack frame - without floating point enabled +#endif + ret // Return to thread + +/* } */ diff --git a/ports/risc-v32/clang/src/tx_thread_stack_build.S b/ports/risc-v32/clang/src/tx_thread_stack_build.S new file mode 100644 index 00000000..20ceed2f --- /dev/null +++ b/ports/risc-v32/clang/src/tx_thread_stack_build.S @@ -0,0 +1,227 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + + +/**************************************************************************/ +/**************************************************************************/ +/** */ +/** ThreadX Component */ +/** */ +/** Thread */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + + + .section .text +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_thread_stack_build RISC-V32/GNU */ +/* 6.4.x */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function builds a stack frame on the supplied thread's stack. */ +/* The stack frame results in a fake interrupt return to the supplied */ +/* function pointer. */ +/* */ +/* INPUT */ +/* */ +/* thread_ptr Pointer to thread control blk */ +/* function_ptr Pointer to return function */ +/* */ +/* OUTPUT */ +/* */ +/* None */ +/* */ +/* CALLS */ +/* */ +/* None */ +/* */ +/* CALLED BY */ +/* */ +/* _tx_thread_create Create thread service */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 26-02-2026 Francisco Merino Initial Version 6.4.x */ +/* */ +/**************************************************************************/ +/* VOID _tx_thread_stack_build(TX_THREAD *thread_ptr, VOID (*function_ptr)(VOID)) +{ */ + .global _tx_thread_stack_build +_tx_thread_stack_build: + + /* Build a fake interrupt frame. The form of the fake interrupt stack + on the RISC-V should look like the following after it is built: + Reg Index + Stack Top: 1 0 Interrupt stack frame type + x27 1 Initial s11 + x26 2 Initial s10 + x25 3 Initial s9 + x24 4 Initial s8 + x23 5 Initial s7 + x22 6 Initial s6 + x21 7 Initial s5 + x20 8 Initial s4 + x19 9 Initial s3 + x18 10 Initial s2 + x9 11 Initial s1 + x8 12 Initial s0 + x31 13 Initial t6 + x30 14 Initial t5 + x29 15 Initial t4 + x28 16 Initial t3 + x7 17 Initial t2 + x6 18 Initial t1 + x5 19 Initial t0 + x17 20 Initial a7 + x16 21 Initial a6 + x15 22 Initial a5 + x14 23 Initial a4 + x13 24 Initial a3 + x12 25 Initial a2 + x11 26 Initial a1 + x10 27 Initial a0 + x1 28 Initial ra + -- 29 reserved + mepc 30 Initial mepc +If floating point support: + f0 31 Initial ft0 + f1 32 Initial ft1 + f2 33 Initial ft2 + f3 34 Initial ft3 + f4 35 Initial ft4 + f5 36 Initial ft5 + f6 37 Initial ft6 + f7 38 Initial ft7 + f8 39 Initial fs0 + f9 40 Initial fs1 + f10 41 Initial fa0 + f11 42 Initial fa1 + f12 43 Initial fa2 + f13 44 Initial fa3 + f14 45 Initial fa4 + f15 46 Initial fa5 + f16 47 Initial fa6 + f17 48 Initial fa7 + f18 49 Initial fs2 + f19 50 Initial fs3 + f20 51 Initial fs4 + f21 52 Initial fs5 + f22 53 Initial fs6 + f23 54 Initial fs7 + f24 55 Initial fs8 + f25 56 Initial fs9 + f26 57 Initial fs10 + f27 58 Initial fs11 + f28 59 Initial ft8 + f29 60 Initial ft9 + f30 61 Initial ft10 + f31 62 Initial ft11 + fscr 63 Initial fscr + + Stack Bottom: (higher memory address) */ + + lw t0, 16(a0) // Pickup end of stack area + li t1, ~15 // Build 16-byte alignment mask + and t0, t0, t1 // Make sure 16-byte alignment + + /* Actually build the stack frame. */ + +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + addi t0, t0, -65*4 +#else + addi t0, t0, -32*4 // Allocate space for the stack frame +#endif + li t1, 1 // Build stack type + sw t1, 0*4(t0) // Place stack type on the top + sw zero, 1*4(t0) // Initial s11 + sw zero, 2*4(t0) // Initial s10 + sw zero, 3*4(t0) // Initial s9 + sw zero, 4*4(t0) // Initial s8 + sw zero, 5*4(t0) // Initial s7 + sw zero, 6*4(t0) // Initial s6 + sw zero, 7*4(t0) // Initial s5 + sw zero, 8*4(t0) // Initial s4 + sw zero, 9*4(t0) // Initial s3 + sw zero, 10*4(t0) // Initial s2 + sw zero, 11*4(t0) // Initial s1 + sw zero, 12*4(t0) // Initial s0 + sw zero, 13*4(t0) // Initial t6 + sw zero, 14*4(t0) // Initial t5 + sw zero, 15*4(t0) // Initial t4 + sw zero, 16*4(t0) // Initial t3 + sw zero, 17*4(t0) // Initial t2 + sw zero, 18*4(t0) // Initial t1 + sw zero, 19*4(t0) // Initial t0 + sw zero, 20*4(t0) // Initial a7 + sw zero, 21*4(t0) // Initial a6 + sw zero, 22*4(t0) // Initial a5 + sw zero, 23*4(t0) // Initial a4 + sw zero, 24*4(t0) // Initial a3 + sw zero, 25*4(t0) // Initial a2 + sw zero, 26*4(t0) // Initial a1 + sw zero, 27*4(t0) // Initial a0 + sw zero, 28*4(t0) // Initial ra + sw a1, 30*4(t0) // Initial mepc (thread entry point) +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + sw zero, 31*4(t0) // Initial ft0 + sw zero, 32*4(t0) // Initial ft1 + sw zero, 33*4(t0) // Initial ft2 + sw zero, 34*4(t0) // Initial ft3 + sw zero, 35*4(t0) // Initial ft4 + sw zero, 36*4(t0) // Initial ft5 + sw zero, 37*4(t0) // Initial ft6 + sw zero, 38*4(t0) // Initial ft7 + sw zero, 39*4(t0) // Initial fs0 + sw zero, 40*4(t0) // Initial fs1 + sw zero, 41*4(t0) // Initial fa0 + sw zero, 42*4(t0) // Initial fa1 + sw zero, 43*4(t0) // Initial fa2 + sw zero, 44*4(t0) // Initial fa3 + sw zero, 45*4(t0) // Initial fa4 + sw zero, 46*4(t0) // Initial fa5 + sw zero, 47*4(t0) // Initial fa6 + sw zero, 48*4(t0) // Initial fa7 + sw zero, 49*4(t0) // Initial fs2 + sw zero, 50*4(t0) // Initial fs3 + sw zero, 51*4(t0) // Initial fs4 + sw zero, 52*4(t0) // Initial fs5 + sw zero, 53*4(t0) // Initial fs6 + sw zero, 54*4(t0) // Initial fs7 + sw zero, 55*4(t0) // Initial fs8 + sw zero, 56*4(t0) // Initial fs9 + sw zero, 57*4(t0) // Initial fs10 + sw zero, 58*4(t0) // Initial fs11 + sw zero, 59*4(t0) // Initial ft8 + sw zero, 60*4(t0) // Initial ft9 + sw zero, 61*4(t0) // Initial ft10 + sw zero, 62*4(t0) // Initial ft11 + csrr a1, fcsr // Read fcsr for initial value + sw a1, 63*4(t0) // Initial fcsr + sw zero, 64*4(t0) // Reserved word (0) +#else + sw zero, 31*4(t0) // Reserved word (0) +#endif + + /* Setup stack pointer. */ + /* thread_ptr -> tx_thread_stack_ptr = t0; */ + + sw t0, 8(a0) // Save stack pointer in thread's + ret // control block and return +/* } */ diff --git a/ports/risc-v32/clang/src/tx_thread_system_return.S b/ports/risc-v32/clang/src/tx_thread_system_return.S new file mode 100644 index 00000000..e8fe5617 --- /dev/null +++ b/ports/risc-v32/clang/src/tx_thread_system_return.S @@ -0,0 +1,174 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + + +/**************************************************************************/ +/**************************************************************************/ +/** */ +/** ThreadX Component */ +/** */ +/** Thread */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + + + .section .text +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_thread_system_return RISC-V32/GNU */ +/* 6.4.x */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function is target processor specific. It is used to transfer */ +/* control from a thread back to the system. Only a minimal context */ +/* is saved since the compiler assumes temp registers are going to get */ +/* slicked by a function call anyway. */ +/* */ +/* INPUT */ +/* */ +/* None */ +/* */ +/* OUTPUT */ +/* */ +/* None */ +/* */ +/* CALLS */ +/* */ +/* _tx_thread_schedule Thread scheduling loop */ +/* */ +/* CALLED BY */ +/* */ +/* ThreadX components */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 26-02-2026 Francisco Merino Initial Version 6.4.x */ +/* */ +/**************************************************************************/ +/* VOID _tx_thread_system_return(VOID) +{ */ + .global _tx_thread_system_return +_tx_thread_system_return: + + /* Save minimal context on the stack. */ + /* sp -= sizeof(stack_frame); */ + +#if defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double) + addi sp, sp, -29*4 // Allocate space on the stack - with floating point enabled +#else + addi sp, sp, -16*4 // Allocate space on the stack - without floating point enabled +#endif + + /* Store floating point preserved registers. */ +#if defined(__riscv_float_abi_single) + fsw f8, 15*4(sp) // Store fs0 + fsw f9, 16*4(sp) // Store fs1 + fsw f18, 17*4(sp) // Store fs2 + fsw f19, 18*4(sp) // Store fs3 + fsw f20, 19*4(sp) // Store fs4 + fsw f21, 20*4(sp) // Store fs5 + fsw f22, 21*4(sp) // Store fs6 + fsw f23, 22*4(sp) // Store fs7 + fsw f24, 23*4(sp) // Store fs8 + fsw f25, 24*4(sp) // Store fs9 + fsw f26, 25*4(sp) // Store fs10 + fsw f27, 26*4(sp) // Store fs11 + csrr t0, fcsr + sw t0, 27*4(sp) // Store fcsr +#elif defined(__riscv_float_abi_double) + fsd f8, 15*4(sp) // Store fs0 + fsd f9, 16*4(sp) // Store fs1 + fsd f18, 17*4(sp) // Store fs2 + fsd f19, 18*4(sp) // Store fs3 + fsd f20, 19*4(sp) // Store fs4 + fsd f21, 20*4(sp) // Store fs5 + fsd f22, 21*4(sp) // Store fs6 + fsd f23, 22*4(sp) // Store fs7 + fsd f24, 23*4(sp) // Store fs8 + fsd f25, 24*4(sp) // Store fs9 + fsd f26, 25*4(sp) // Store fs10 + fsd f27, 26*4(sp) // Store fs11 + csrr t0, fcsr + sw t0, 27*4(sp) // Store fcsr +#endif + + sw zero, 0(sp) // Solicited stack type + sw ra, 13*4(sp) // Save return address + sw s0, 12*4(sp) // Save s0 + sw s1, 11*4(sp) // Save s1 + sw s2, 10*4(sp) // Save s2 + sw s3, 9*4(sp) // Save s3 + sw s4, 8*4(sp) // Save s4 + sw s5, 7*4(sp) // Save s5 + sw s6, 6*4(sp) // Save s6 + sw s7, 5*4(sp) // Save s7 + sw s8, 4*4(sp) // Save s8 + sw s9, 3*4(sp) // Save s9 + sw s10, 2*4(sp) // Save s10 + sw s11, 1*4(sp) // Save s11 + csrr t0, mstatus // Pickup mstatus + sw t0, 14*4(sp) // Save mstatus + + + /* Lockout interrupts. will be enabled in _tx_thread_schedule */ + + csrci mstatus, 0x08 // Disable interrupts (MIE bit 3) + +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY + + call _tx_execution_thread_exit // Call the thread execution exit function +#endif + + la t0, _tx_thread_current_ptr // Pickup address of pointer + lw t1, 0(t0) // Pickup current thread pointer + la t2, _tx_thread_system_stack_ptr // Pickup stack pointer address + + /* Save current stack and switch to system stack. */ + /* _tx_thread_current_ptr -> tx_thread_stack_ptr = SP; + SP = _tx_thread_system_stack_ptr; */ + + sw sp, 8(t1) // Save stack pointer + lw sp, 0(t2) // Switch to system stack + + /* Determine if the time-slice is active. */ + /* if (_tx_timer_time_slice) + { */ + + la t4, _tx_timer_time_slice // Pickup time slice variable addr + lw t3, 0(t4) // Pickup time slice value + la t2, _tx_thread_schedule // Pickup address of scheduling loop + beqz t3, _tx_thread_dont_save_ts // If no time-slice, don't save it + + /* Save time-slice for the thread and clear the current time-slice. */ + /* _tx_thread_current_ptr -> tx_thread_time_slice = _tx_timer_time_slice; + _tx_timer_time_slice = 0; */ + + sw t3, 24(t1) // Save current time-slice for thread + sw zero, 0(t4) // Clear time-slice variable + + /* } */ +_tx_thread_dont_save_ts: + + /* Clear the current thread pointer. */ + /* _tx_thread_current_ptr = TX_NULL; */ + + sw x0, 0(t0) // Clear current thread pointer + jr t2 // Return to thread scheduler + +/* } */ diff --git a/ports/risc-v32/clang/src/tx_timer_interrupt.S b/ports/risc-v32/clang/src/tx_timer_interrupt.S new file mode 100644 index 00000000..b32256ba --- /dev/null +++ b/ports/risc-v32/clang/src/tx_timer_interrupt.S @@ -0,0 +1,210 @@ +/*************************************************************************** + * Copyright (c) 2026 Quintauris + * + * This program and the accompanying materials are made available under the + * terms of the MIT License which is available at + * https://opensource.org/licenses/MIT. + * + * SPDX-License-Identifier: MIT + **************************************************************************/ + + +/**************************************************************************/ +/**************************************************************************/ +/** */ +/** ThreadX Component */ +/** */ +/** Timer */ +/** */ +/**************************************************************************/ +/**************************************************************************/ + + .section .text + .align 4 +/**************************************************************************/ +/* */ +/* FUNCTION RELEASE */ +/* */ +/* _tx_timer_interrupt RISC-V32/GNU */ +/* 6.2.1 */ +/* AUTHOR */ +/* */ +/* Francisco Merino, Quintauris */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function processes the hardware timer interrupt. This */ +/* processing includes incrementing the system clock and checking for */ +/* time slice and/or timer expiration. If either is found, the */ +/* interrupt context save/restore functions are called along with the */ +/* expiration functions. */ +/* */ +/* INPUT */ +/* */ +/* None */ +/* */ +/* OUTPUT */ +/* */ +/* None */ +/* */ +/* CALLS */ +/* */ +/* _tx_timer_expiration_process Timer expiration processing */ +/* _tx_thread_time_slice Time slice interrupted thread */ +/* */ +/* CALLED BY */ +/* */ +/* interrupt vector */ +/* */ +/* RELEASE HISTORY */ +/* */ +/* DATE NAME DESCRIPTION */ +/* */ +/* 01-20-2023 Akif Ejaz Initial Version 6.2.1 */ +/* */ +/**************************************************************************/ +/* VOID _tx_timer_interrupt(VOID) +{ */ + .global _tx_timer_interrupt +_tx_timer_interrupt: + + /* Increment the system clock. */ + /* _tx_timer_system_clock++; */ + + la t0, _tx_timer_system_clock // Pickup address of system clock + lw t1, 0(t0) // Pickup system clock + la t2, _tx_timer_time_slice // Pickup address of time slice + lw t3, 0(t2) // Pickup time slice + addi t1, t1, 1 // Increment system clock + sw t1, 0(t0) // Store new system clock + li t6, 0 // Clear local expired flag + + /* Test for time-slice expiration. */ + /* if (_tx_timer_time_slice) + { */ + + beqz t3, _tx_timer_no_time_slice // If 0, skip time slice processing + addi t3, t3, -1 // Decrement the time slice + + /* Decrement the time_slice. */ + /* _tx_timer_time_slice--; */ + + sw t3, 0(t2) // Store new time slice + + /* Check for expiration. */ + /* if (_tx_timer_time_slice == 0) */ + + bgtz t3, _tx_timer_no_time_slice // If not 0, has not expired yet + li t1, 1 // Build expired flag + + /* Set the time-slice expired flag. */ + /* _tx_timer_expired_time_slice = TX_TRUE; */ + + la t4, _tx_timer_expired_time_slice // Get address of expired flag + sw t1, 0(t4) // Set expired flag (UINT) + ori t6, t6, 1 // Set local expired flag + + /* } */ + +_tx_timer_no_time_slice: + + /* Test for timer expiration. */ + /* if (*_tx_timer_current_ptr) + { */ + + la t0, _tx_timer_current_ptr // Pickup address of current ptr + lw t1, 0(t0) // Pickup current pointer (word) + lw t3, 0(t1) // Pickup the current timer entry (word) + la t2, _tx_timer_expired // Pickup address of timer expired flag + li t4, 1 // Build TX_TRUE flag + beqz t3, _tx_timer_no_timer // If NULL, no timer has expired + + /* Set expiration flag. */ + /* _tx_timer_expired = TX_TRUE; */ + + ori t6, t6, 2 // Set local expired flag + sw t4, 0(t2) // Set expired flag in memory (UINT) + j _tx_timer_done // Finished timer processing + + + /* } + else + { */ +_tx_timer_no_timer: + + /* No timer expired, increment the timer pointer. */ + /* _tx_timer_current_ptr++; */ + + /* Check for wrap-around. */ + /* if (_tx_timer_current_ptr == _tx_timer_list_end) */ + + la t2, _tx_timer_list_end // Pickup address of list end pointer + lw t3, 0(t2) // Pickup actual list end + addi t1, t1, 4 // Point to next timer entry + sw t1, 0(t0) // Store new timer pointer + bne t1, t3, _tx_timer_skip_wrap // If not same, good pointer + + /* Wrap to beginning of list. */ + /* _tx_timer_current_ptr = _tx_timer_list_start; */ + + la t2, _tx_timer_list_start // Pickup address of list start pointer + lw t4, 0(t2) // Pickup start of the list + sw t4, 0(t0) // Store new timer pointer + + +_tx_timer_skip_wrap: + /* } */ + +_tx_timer_done: + + + /* See if anything has expired. */ + /* if ((_tx_timer_expired_time_slice) || (_tx_timer_expired)) + { */ + + beqz t6, _tx_timer_nothing_expired // If nothing expired skip the rest + addi sp, sp, -16 // Allocate some storage on the stack + sw t6, 0(sp) // Save local expired flag + sw ra, 4(sp) // Save ra + + /* Did a timer expire? */ + /* if (_tx_timer_expired) + { */ + + andi t2, t6, 2 // Isolate the timer expired bit + beqz t2, _tx_timer_dont_activate // No, timer not expired + + /* Call the timer expiration processing. */ + /* _tx_timer_expiration_process(void); */ + + call _tx_timer_expiration_process // Call _tx_timer_expiration_process + lw t6, 0(sp) // Recover local expired flag + + /* } */ +_tx_timer_dont_activate: + + /* Did time slice expire? */ + /* if (_tx_timer_expired_time_slice) + { */ + + andi t2, t6, 1 // Is the timer expired bit set? + beqz t2, _tx_timer_not_ts_expiration // If not, skip time slice processing + + /* Time slice interrupted thread. */ + /* _tx_thread_time_slice(); */ + + call _tx_thread_time_slice // Call time slice + + /* } */ + +_tx_timer_not_ts_expiration: + + lw ra, 4(sp) // Recover ra + addi sp, sp, 16 // Recover stack space + /* } */ + +_tx_timer_nothing_expired: + + ret + +/* } */
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