diff options
Diffstat (limited to 'ports/arm11/gnu/src/tx_thread_context_save.S')
| -rw-r--r-- | ports/arm11/gnu/src/tx_thread_context_save.S | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/ports/arm11/gnu/src/tx_thread_context_save.S b/ports/arm11/gnu/src/tx_thread_context_save.S new file mode 100644 index 00000000..8a072cf5 --- /dev/null +++ b/ports/arm11/gnu/src/tx_thread_context_save.S @@ -0,0 +1,210 @@ +@/**************************************************************************/ +@/* */ +@/* Copyright (c) Microsoft Corporation. All rights reserved. */ +@/* */ +@/* This software is licensed under the Microsoft Software License */ +@/* Terms for Microsoft Azure RTOS. Full text of the license can be */ +@/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */ +@/* and in the root directory of this software. */ +@/* */ +@/**************************************************************************/ +@ +@ +@/**************************************************************************/ +@/**************************************************************************/ +@/** */ +@/** ThreadX Component */ +@/** */ +@/** Thread */ +@/** */ +@/**************************************************************************/ +@/**************************************************************************/ +@ +@ +@#define TX_SOURCE_CODE +@ +@ +@/* Include necessary system files. */ +@ +@#include "tx_api.h" +@#include "tx_thread.h" +@#include "tx_timer.h" +@ +#ifdef TX_ENABLE_FIQ_SUPPORT +DISABLE_INTS = 0xC0 @ IRQ & FIQ interrupts disabled +#else +DISABLE_INTS = 0x80 @ IRQ interrupts disabled +#endif +@ + .global _tx_thread_system_state + .global _tx_thread_current_ptr + .global _tx_irq_processing_return + .global _tx_execution_isr_enter +@ +@ +@/* No 16-bit Thumb mode veneer code is needed for _tx_thread_context_save +@ since it will never be called 16-bit mode. */ +@ + .arm + .text + .align 2 +@/**************************************************************************/ +@/* */ +@/* FUNCTION RELEASE */ +@/* */ +@/* _tx_thread_context_save ARM11/GNU */ +@/* 6.0.1 */ +@/* AUTHOR */ +@/* */ +@/* William E. Lamie, Microsoft Corporation */ +@/* */ +@/* 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 */ +@/* */ +@/* 06-30-2020 William E. Lamie Initial Version 6.0.1 */ +@/* */ +@/**************************************************************************/ +@VOID _tx_thread_context_save(VOID) +@{ + .global _tx_thread_context_save + .type _tx_thread_context_save,function +_tx_thread_context_save: +@ +@ /* Upon entry to this routine, it is assumed that IRQ interrupts are locked +@ out, we are in IRQ mode, and all registers are intact. */ +@ +@ /* Check for a nested interrupt condition. */ +@ if (_tx_thread_system_state++) +@ { +@ + STMDB sp!, {r0-r3} @ Save some working registers +#ifdef TX_ENABLE_FIQ_SUPPORT + MRS r0, CPSR @ Pickup the CPSR + ORR r0, r0, #DISABLE_INTS @ Build disable interrupt CPSR + MSR CPSR_cxsf, r0 @ Disable interrupts +#endif + LDR r3, =_tx_thread_system_state @ Pickup address of system state variable + LDR r2, [r3] @ Pickup system state + CMP r2, #0 @ Is this the first interrupt? + BEQ __tx_thread_not_nested_save @ Yes, not a nested context save +@ +@ /* Nested interrupt condition. */ +@ + ADD r2, r2, #1 @ Increment the interrupt counter + STR r2, [r3] @ Store it back in the variable +@ +@ /* Save the rest of the scratch registers on the stack and return to the +@ calling ISR. */ +@ + MRS r0, SPSR @ Pickup saved SPSR + SUB lr, lr, #4 @ Adjust point of interrupt + STMDB sp!, {r0, r10, r12, lr} @ Store other registers +@ +@ /* Return to the ISR. */ +@ + MOV r10, #0 @ Clear stack limit + +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY +@ +@ /* Call the ISR enter function to indicate an ISR is executing. */ +@ + PUSH {lr} @ Save ISR lr + BL _tx_execution_isr_enter @ Call the ISR enter function + POP {lr} @ Recover ISR lr +#endif + + B __tx_irq_processing_return @ Continue IRQ processing +@ +__tx_thread_not_nested_save: +@ } +@ +@ /* Otherwise, not nested, check to see if a thread was running. */ +@ else if (_tx_thread_current_ptr) +@ { +@ + ADD r2, r2, #1 @ Increment the interrupt counter + STR r2, [r3] @ Store it back in the variable + LDR r1, =_tx_thread_current_ptr @ Pickup address of current thread ptr + LDR r0, [r1] @ Pickup current thread pointer + CMP r0, #0 @ Is it NULL? + BEQ __tx_thread_idle_system_save @ If so, interrupt occurred in + @ scheduling loop - nothing needs saving! +@ +@ /* Save minimal context of interrupted thread. */ +@ + MRS r2, SPSR @ Pickup saved SPSR + SUB lr, lr, #4 @ Adjust point of interrupt + STMDB sp!, {r2, r10, r12, lr} @ Store other registers +@ +@ /* Save the current stack pointer in the thread's control block. */ +@ _tx_thread_current_ptr -> tx_thread_stack_ptr = sp; +@ +@ /* Switch to the system stack. */ +@ sp = _tx_thread_system_stack_ptr@ +@ + MOV r10, #0 @ Clear stack limit + +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY +@ +@ /* Call the ISR enter function to indicate an ISR is executing. */ +@ + PUSH {lr} @ Save ISR lr + BL _tx_execution_isr_enter @ Call the ISR enter function + POP {lr} @ Recover ISR lr +#endif + + B __tx_irq_processing_return @ Continue IRQ processing +@ +@ } +@ else +@ { +@ +__tx_thread_idle_system_save: +@ +@ /* Interrupt occurred in the scheduling loop. */ +@ +@ /* Not much to do here, just adjust the stack pointer, and return to IRQ +@ processing. */ +@ + MOV r10, #0 @ Clear stack limit + +#ifdef TX_ENABLE_EXECUTION_CHANGE_NOTIFY +@ +@ /* Call the ISR enter function to indicate an ISR is executing. */ +@ + PUSH {lr} @ Save ISR lr + BL _tx_execution_isr_enter @ Call the ISR enter function + POP {lr} @ Recover ISR lr +#endif + + ADD sp, sp, #16 @ Recover saved registers + B __tx_irq_processing_return @ Continue IRQ processing +@ +@ } +@} + + + |