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;/*
; FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd.
;
;
; ***************************************************************************
; * *
; * FreeRTOS tutorial books are available in pdf and paperback. *
; * Complete, revised, and edited pdf reference manuals are also *
; * available. *
; * *
; * Purchasing FreeRTOS documentation will not only help you, by *
; * ensuring you get running as quickly as possible and with an *
; * in-depth knowledge of how to use FreeRTOS, it will also help *
; * the FreeRTOS project to continue with its mission of providing *
; * professional grade, cross platform, de facto standard solutions *
; * for microcontrollers - completely free of charge! *
; * *
; * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
; * *
; * Thank you for using FreeRTOS, and thank you for your support! *
; * *
; ***************************************************************************
;
;
; This file is part of the FreeRTOS distribution.
;
; FreeRTOS is free software; you can redistribute it and/or modify it under
; the terms of the GNU General Public License (version 2) as published by the
; Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
; >>>NOTE<<< The modification to the GPL is included to allow you to
; distribute a combined work that includes FreeRTOS without being obliged to
; provide the source code for proprietary components outside of the FreeRTOS
; kernel. FreeRTOS is distributed in the hope that it will be useful, but
; WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
; or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
; more details. You should have received a copy of the GNU General Public
; License and the FreeRTOS license exception along with FreeRTOS; if not it
; can be viewed here: http://www.freertos.org/a00114.html and also obtained
; by writing to Richard Barry, contact details for whom are available on the
; FreeRTOS WEB site.
;
; 1 tab == 4 spaces!
;
; http://www.FreeRTOS.org - Documentation, latest information, license and
; contact details.
;
; http://www.SafeRTOS.com - A version that is certified for use in safety
; critical systems.
;
; http://www.OpenRTOS.com - Commercial support, development, porting,
; licensing and training services.
;*/
.extern pxCurrentTCB
.extern vTaskSwitchContext
.extern ulMaxSyscallInterruptPriorityConst
.global PendSV_Handler
.global SVC_Handler
.global vPortStartFirstTask
.global vPortEnableVFP
;-----------------------------------------------------------
.section .text
.thumb
.align 4
PendSV_Handler: .type func
mrs r0, psp
;Get the location of the current TCB.
ldr.w r3, =pxCurrentTCB
ldr r2, [r3]
;Is the task using the FPU context? If so, push high vfp registers.
tst r14, #0x10
it eq
vstmdbeq r0!, {s16-s31}
;Save the core registers.
stmdb r0!, {r4-r11, r14}
;Save the new top of stack into the first member of the TCB.
str r0, [r2]
stmdb sp!, {r3, r14}
ldr.w r0, =ulMaxSyscallInterruptPriorityConst
msr basepri, r0
bl vTaskSwitchContext
mov r0, #0
msr basepri, r0
ldmia sp!, {r3, r14}
;The first item in pxCurrentTCB is the task top of stack.
ldr r1, [r3]
ldr r0, [r1]
;Pop the core registers.
ldmia r0!, {r4-r11, r14}
;Is the task using the FPU context? If so, pop the high vfp registers too.
tst r14, #0x10
it eq
vldmiaeq r0!, {s16-s31}
msr psp, r0
bx r14
.size PendSV_Handler, $-PendSV_Handler
.endsec
;-----------------------------------------------------------
.section .text
.thumb
.align 4
SVC_Handler: .type func
;Get the location of the current TCB.
ldr.w r3, =pxCurrentTCB
ldr r1, [r3]
ldr r0, [r1]
;Pop the core registers.
ldmia r0!, {r4-r11, r14}
msr psp, r0
mov r0, #0
msr basepri, r0
bx r14
.size SVC_Handler, $-SVC_Handler
.endsec
;-----------------------------------------------------------
.section .text
.thumb
.align 4
vPortStartFirstTask .type func
;Use the NVIC offset register to locate the stack.
ldr.w r0, =0xE000ED08
ldr r0, [r0]
ldr r0, [r0]
;Set the msp back to the start of the stack.
msr msp, r0
;Call SVC to start the first task.
cpsie i
svc 0
.size vPortStartFirstTask, $-vPortStartFirstTask
.endsec
;-----------------------------------------------------------
.section .text
.thumb
.align 4
vPortEnableVFP .type func
;The FPU enable bits are in the CPACR.
ldr.w r0, =0xE000ED88
ldr r1, [r0]
;Enable CP10 and CP11 coprocessors, then save back.
orr r1, r1, #( 0xf << 20 )
str r1, [r0]
bx r14
.size vPortEnableVFP, $-vPortEnableVFP
.endsec
.end