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/***************************************************************************
* 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
**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** ThreadX Component */
/** */
/** Initialize */
/** */
/**************************************************************************/
/**************************************************************************/
.section .data
.global __tx_free_memory_start
__tx_free_memory_start:
.section .text
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_initialize_low_level RISC-V64/GNU */
/* 6.2.1 */
/* AUTHOR */
/* */
/* Scott Larson, Microsoft Corporation */
/* */
/* 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 */
/* */
/* 03-08-2023 Scott Larson Initial Version 6.2.1 */
/* */
/**************************************************************************/
/* VOID _tx_initialize_low_level(VOID)
{ */
.global _tx_initialize_low_level
.weak _tx_initialize_low_level
_tx_initialize_low_level:
sd sp, _tx_thread_system_stack_ptr, t0 // Save system stack pointer
la t0, __tx_free_memory_start // Pickup first free address
sd t0, _tx_initialize_unused_memory, t1 // Save unused memory address
#ifdef __riscv_flen
fscsr x0
#endif
ret
/* Define the actual timer interrupt/exception handler. */
.global timer1_plic_IRQHandler
//.global __minterrupt_000007
//EXTWEAK __require_minterrupt_vector_table
timer1_plic_IRQHandler:
//__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 defined(__riscv_float_abi_single) || defined(__riscv_float_abi_double)
// addi sp, sp, -520 // Allocate space for all registers - with floating point enabled
//#else
// addi sp, sp, -256 // Allocate space for all registers - without floating point enabled
//#endif
// sd x1, 224(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
call timer1_interrupt
ret
/* 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!
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