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/*
ChibiOS/NIL - Copyright (C) 2013,2014 Giovanni Di Sirio.
This file is part of ChibiOS/NIL.
ChibiOS/NIL is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/NIL 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
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file ARMCMx/compilers/GCC/nilcoreasm_v6m.s
* @brief ARMv6-M architecture port low level code.
*
* @addtogroup ARMCMx_GCC_CORE
* @{
*/
#define _FROM_ASM_
#include "nilconf.h"
#include "nilcore.h"
#if !defined(FALSE) || defined(__DOXYGEN__)
#define FALSE 0
#endif
#if !defined(TRUE) || defined(__DOXYGEN__)
#define TRUE 1
#endif
#if !defined(__DOXYGEN__)
.set CONTEXT_OFFSET, 0
.set SCB_ICSR, 0xE000ED04
.set ICSR_PENDSVSET, 0x10000000
.set ICSR_NMIPENDSET, 0x80000000
.cpu cortex-m0
.fpu softvfp
.thumb
.text
/*--------------------------------------------------------------------------*
* Performs a context switch between two threads.
*--------------------------------------------------------------------------*/
.thumb_func
.globl _port_switch
_port_switch:
push {r4, r5, r6, r7, lr}
mov r4, r8
mov r5, r9
mov r6, r10
mov r7, r11
push {r4, r5, r6, r7}
mov r3, sp
str r3, [r1, #CONTEXT_OFFSET]
ldr r3, [r0, #CONTEXT_OFFSET]
mov sp, r3
pop {r4, r5, r6, r7}
mov r8, r4
mov r9, r5
mov r10, r6
mov r11, r7
pop {r4, r5, r6, r7, pc}
/*--------------------------------------------------------------------------*
* Start a thread by invoking its work function.
*
* Threads execution starts here, the code leaves the system critical zone
* and then jumps into the thread function passed in register R4. The
* register R5 contains the thread parameter. The function chThdExit() is
* called on thread function return.
*--------------------------------------------------------------------------*/
.thumb_func
.globl _port_thread_start
_port_thread_start:
cpsie i
mov r0, r5
blx r4
mov r3, #0
bl chSysHalt
/*--------------------------------------------------------------------------*
* Post-IRQ switch code.
*
* Exception handlers return here for context switching.
*--------------------------------------------------------------------------*/
.thumb_func
.globl _port_switch_from_isr
_port_switch_from_isr:
bl chSchRescheduleS
.globl _port_exit_from_isr
_port_exit_from_isr:
ldr r2, .L2
ldr r3, .L3
str r3, [r2, #0]
#if CORTEX_ALTERNATE_SWITCH
cpsie i
#endif
.L1: b .L1
.align 2
.L2: .word SCB_ICSR
#if CORTEX_ALTERNATE_SWITCH
.L3: .word ICSR_PENDSVSET
#else
.L3: .word ICSR_NMIPENDSET
#endif
#endif /* !defined(__DOXYGEN__) */
/** @} */
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