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/***************************************************************************
* Copyright (c) 2024 Microsoft Corporation
* Copyright (c) 2026-present Eclipse ThreadX contributors
*
* 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 */
/** */
/**************************************************************************/
/**************************************************************************/
/* #define TX_SOURCE_CODE */
/* Include necessary system files. */
/* #include "tx_api.h"
#include "tx_initialize.h"
#include "tx_thread.h"
#include "tx_timer.h" */
EXTERN _tx_thread_system_stack_ptr
EXTERN _tx_initialize_unused_memory
EXTERN _tx_thread_context_save
EXTERN _tx_thread_context_restore
EXTERN _tx_timer_interrupt
RSEG FREE_MEM:DATA
PUBLIC __tx_free_memory_start
__tx_free_memory_start:
DS32 4
SECTION `.text`:CODE:REORDER:NOROOT(2)
CODE
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_initialize_low_level RISC-V32/IAR */
/* 6.1 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* Tom van Leeuwen, Technolution B.V. */
/* */
/* 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 */
/**************************************************************************/
/* VOID _tx_initialize_low_level(VOID)
{ */
PUBLIC _tx_initialize_low_level
_tx_initialize_low_level:
sw sp, _tx_thread_system_stack_ptr, t0 ; Save system stack pointer
la t0, __tx_free_memory_start ; Pickup first free address
sw t0, _tx_initialize_unused_memory, t1 ; Save unused memory address
ret
/* Define the actual timer interrupt/exception handler. */
PUBLIC _tx_timer_interrupt_handler
PUBLIC __minterrupt_000007
EXTWEAK __require_minterrupt_vector_table
_tx_timer_interrupt_handler:
__minterrupt_000007:
REQUIRE __require_minterrupt_vector_table
/* Before calling _tx_thread_context_save, we have to allocate an interrupt
stack frame and save the current value of x1 (ra). */
#if __iar_riscv_base_isa == rv32e
addi sp, sp, -260 ; Allocate space for all registers - with floating point enabled
#else
addi sp, sp, -128 ; Allocate space for all registers - without floating point enabled
#endif
sw x1, 0x70(sp) ; Store RA
call _tx_thread_context_save ; Call ThreadX context save
/* Call the ThreadX timer routine. */
call _tx_timer_interrupt ; Call timer interrupt handler
/* Timer interrupt processing is done, jump to ThreadX context restore. */
j _tx_thread_context_restore ; Jump to ThreadX context restore function. Note: this does not return!
END
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