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/*
* FreeRTOS Kernel V10.4.3 LTS Patch 3
* Copyright (C) 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* https://www.FreeRTOS.org
* https://github.com/FreeRTOS
*
* 1 tab == 4 spaces!
*/
.file "portASM.S"
#include "FreeRTOSConfig.h"
#include "ISR_Support.h"
.extern pxCurrentTCB
.extern vTaskSwitchContext
.extern vPortCentralInterruptHandler
.extern xTaskIncrementTick
.extern vPortAPICErrorHandler
.extern pucPortTaskFPUContextBuffer
.extern ulPortYieldPending
.global vPortStartFirstTask
.global vPortCentralInterruptWrapper
.global vPortAPICErrorHandlerWrapper
.global vPortTimerHandler
.global vPortYieldCall
.global vPortAPICSpuriousHandler
.text
/*-----------------------------------------------------------*/
.align 4
.func vPortYieldCall
vPortYieldCall:
/* Save general purpose registers. */
pusha
.if configSUPPORT_FPU == 1
/* If the task has a buffer allocated to save the FPU context then save
the FPU context now. */
movl pucPortTaskFPUContextBuffer, %eax
test %eax, %eax
je 1f
fnsave ( %eax )
fwait
1:
/* Save the address of the FPU context, if any. */
push pucPortTaskFPUContextBuffer
.endif /* configSUPPORT_FPU */
/* Find the TCB. */
movl pxCurrentTCB, %eax
/* Stack location is first item in the TCB. */
movl %esp, (%eax)
call vTaskSwitchContext
/* Find the location of pxCurrentTCB again - a callee saved register could
be used in place of eax to prevent this second load, but that then relies
on the compiler and other asm code. */
movl pxCurrentTCB, %eax
movl (%eax), %esp
.if configSUPPORT_FPU == 1
/* Restore address of task's FPU context buffer. */
pop pucPortTaskFPUContextBuffer
/* If the task has a buffer allocated in which its FPU context is saved,
then restore it now. */
movl pucPortTaskFPUContextBuffer, %eax
test %eax, %eax
je 1f
frstor ( %eax )
1:
.endif
popa
iret
.endfunc
/*-----------------------------------------------------------*/
.align 4
.func vPortStartFirstTask
vPortStartFirstTask:
/* Find the TCB. */
movl pxCurrentTCB, %eax
/* Stack location is first item in the TCB. */
movl (%eax), %esp
/* Restore FPU context flag. */
.if configSUPPORT_FPU == 1
pop pucPortTaskFPUContextBuffer
.endif /* configSUPPORT_FPU */
/* Restore general purpose registers. */
popa
iret
.endfunc
/*-----------------------------------------------------------*/
.align 4
.func vPortAPICErrorHandlerWrapper
vPortAPICErrorHandlerWrapper:
pusha
call vPortAPICErrorHandler
popa
/* EOI. */
movl $0x00, (0xFEE000B0)
iret
.endfunc
/*-----------------------------------------------------------*/
.align 4
.func vPortTimerHandler
vPortTimerHandler:
/* Save general purpose registers. */
pusha
/* Interrupts are not nested, so save the rest of the task context. */
.if configSUPPORT_FPU == 1
/* If the task has a buffer allocated to save the FPU context then save the
FPU context now. */
movl pucPortTaskFPUContextBuffer, %eax
test %eax, %eax
je 1f
fnsave ( %eax ) /* Save FLOP context into ucTempFPUBuffer array. */
fwait
1:
/* Save the address of the FPU context, if any. */
push pucPortTaskFPUContextBuffer
.endif /* configSUPPORT_FPU */
/* Find the TCB. */
movl pxCurrentTCB, %eax
/* Stack location is first item in the TCB. */
movl %esp, (%eax)
/* Switch stacks. */
movl ulTopOfSystemStack, %esp
movl %esp, %ebp
/* Increment nesting count. */
add $1, ulInterruptNesting
call xTaskIncrementTick
sti
/* Is a switch to another task required? */
test %eax, %eax
je _skip_context_switch
cli
call vTaskSwitchContext
_skip_context_switch:
cli
/* Decrement the variable used to determine if a switch to a system
stack is necessary. */
sub $1, ulInterruptNesting
/* Stack location is first item in the TCB. */
movl pxCurrentTCB, %eax
movl (%eax), %esp
.if configSUPPORT_FPU == 1
/* Restore address of task's FPU context buffer. */
pop pucPortTaskFPUContextBuffer
/* If the task has a buffer allocated in which its FPU context is saved,
then restore it now. */
movl pucPortTaskFPUContextBuffer, %eax
test %eax, %eax
je 1f
frstor ( %eax )
1:
.endif
popa
/* EOI. */
movl $0x00, (0xFEE000B0)
iret
.endfunc
/*-----------------------------------------------------------*/
.if configUSE_COMMON_INTERRUPT_ENTRY_POINT == 1
.align 4
.func vPortCentralInterruptWrapper
vPortCentralInterruptWrapper:
portFREERTOS_INTERRUPT_ENTRY
movl $0xFEE00170, %eax /* Highest In Service Register (ISR) long word. */
movl $8, %ecx /* Loop counter. */
next_isr_long_word:
test %ecx, %ecx /* Loop counter reached 0? */
je wrapper_epilogue /* Looked at all ISR registers without finding a bit set. */
sub $1, %ecx /* Sub 1 from loop counter. */
movl (%eax), %ebx /* Load next ISR long word. */
sub $0x10, %eax /* Point to next ISR long word in case no bits are set in the current long word. */
test %ebx, %ebx /* Are there any bits set? */
je next_isr_long_word /* Look at next ISR long word if no bits were set. */
sti
bsr %ebx, %ebx /* A bit was set, which one? */
movl $32, %eax /* Destination operand for following multiplication. */
mul %ecx /* Calculate base vector for current register, 32 vectors per register. */
add %ebx, %eax /* Add bit offset into register to get final vector number. */
push %eax /* Vector number is function parameter. */
call vPortCentralInterruptHandler
pop %eax /* Remove parameter. */
wrapper_epilogue:
portFREERTOS_INTERRUPT_EXIT
.endfunc
.endif /* configUSE_COMMON_INTERRUPT_ENTRY_POINT */
/*-----------------------------------------------------------*/
.align 4
.func vPortAPISpuriousHandler
vPortAPICSpuriousHandler:
iret
.endfunc
.end
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