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/*
* FreeRTOS Kernel V10.3.0
* 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.
*
* http://www.FreeRTOS.org
* http://aws.amazon.com/freertos
*
* 1 tab == 4 spaces!
*/
#include <FreeRTOSConfig.h>
RSEG CODE:CODE(2)
thumb
EXTERN vPortYieldFromISR
EXTERN pxCurrentTCB
EXTERN vTaskSwitchContext
PUBLIC vSetMSP
PUBLIC xPortPendSVHandler
PUBLIC vPortSVCHandler
PUBLIC vPortStartFirstTask
PUBLIC ulSetInterruptMaskFromISR
PUBLIC vClearInterruptMaskFromISR
/*-----------------------------------------------------------*/
vSetMSP
msr msp, r0
bx lr
/*-----------------------------------------------------------*/
xPortPendSVHandler:
mrs r0, psp
ldr r3, =pxCurrentTCB /* Get the location of the current TCB. */
ldr r2, [r3]
subs r0, r0, #32 /* Make space for the remaining low registers. */
str r0, [r2] /* Save the new top of stack. */
stmia r0!, {r4-r7} /* Store the low registers that are not saved automatically. */
mov r4, r8 /* Store the high registers. */
mov r5, r9
mov r6, r10
mov r7, r11
stmia r0!, {r4-r7}
push {r3, r14}
cpsid i
bl vTaskSwitchContext
cpsie i
pop {r2, r3} /* lr goes in r3. r2 now holds tcb pointer. */
ldr r1, [r2]
ldr r0, [r1] /* The first item in pxCurrentTCB is the task top of stack. */
adds r0, r0, #16 /* Move to the high registers. */
ldmia r0!, {r4-r7} /* Pop the high registers. */
mov r8, r4
mov r9, r5
mov r10, r6
mov r11, r7
msr psp, r0 /* Remember the new top of stack for the task. */
subs r0, r0, #32 /* Go back for the low registers that are not automatically restored. */
ldmia r0!, {r4-r7} /* Pop low registers. */
bx r3
/*-----------------------------------------------------------*/
vPortSVCHandler;
/* This function is no longer used, but retained for backward
compatibility. */
bx lr
/*-----------------------------------------------------------*/
vPortStartFirstTask
/* The MSP stack is not reset as, unlike on M3/4 parts, there is no vector
table offset register that can be used to locate the initial stack value.
Not all M0 parts have the application vector table at address 0. */
ldr r3, =pxCurrentTCB /* Obtain location of pxCurrentTCB. */
ldr r1, [r3]
ldr r0, [r1] /* The first item in pxCurrentTCB is the task top of stack. */
adds r0, #32 /* Discard everything up to r0. */
msr psp, r0 /* This is now the new top of stack to use in the task. */
movs r0, #2 /* Switch to the psp stack. */
msr CONTROL, r0
isb
pop {r0-r5} /* Pop the registers that are saved automatically. */
mov lr, r5 /* lr is now in r5. */
pop {r3} /* The return address is now in r3. */
pop {r2} /* Pop and discard the XPSR. */
cpsie i /* The first task has its context and interrupts can be enabled. */
bx r3 /* Jump to the user defined task code. */
/*-----------------------------------------------------------*/
ulSetInterruptMaskFromISR
mrs r0, PRIMASK
cpsid i
bx lr
/*-----------------------------------------------------------*/
vClearInterruptMaskFromISR
msr PRIMASK, r0
bx lr
END
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