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/*
ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT 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/RT 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/>.
*/
/**
* @addtogroup ARMCM3_CORE
* @{
*/
#include <ch.h>
#include <nvic.h>
/**
* The default implementation of this function is void so no messages are
* actually printed.
* @note The function is declared as a weak symbol, it is possible to redefine
* it in your application code.
* @param msg pointer to the message string
*/
__attribute__((weak))
void sys_puts(char *msg) {
}
/**
* Halts the system.
* @note The function is declared as a weak symbol, it is possible to redefine
* it in your application code.
*/
__attribute__((weak))
void sys_halt(void) {
sys_disable_all();
while (TRUE) {
}
}
/**
* Start a thread by invoking its work function.
* If the work function returns @p chThdExit() is automatically invoked.
*/
__attribute__((naked, weak))
void threadstart(void) {
asm volatile ("blx r1 \n\t" \
"bl chThdExit");
}
/**
* System Timer vector.
* This interrupt is used as system tick.
* @note The timer is initialized in the board setup code.
*/
SYS_IRQ_HANDLER void SysTickVector(void) {
chSysIRQEnterI();
chSysLockI();
chSysTimerHandlerI();
chSysUnlockI();
chSysIRQExitI();
}
/**
* The SVC vector is used for commanded context switch.
*/
__attribute__((naked))
void SVCallVector(Thread *otp, Thread *ntp) {
/* { r0 = otp, r1 = ntp } */
/* get the BASEPRI in r3 */
/* get the PSP in r12 */
/* push the registers on the PSP stack */
/* stores the modified PSP into the thread context */
/* fetches the PSP position from the new thread context */
/* pop the registers from the PSP stack */
/* set the PSP from r12 */
/* set the BASEPRI from R3 */
#ifdef CH_CURRP_REGISTER_CACHE
asm volatile ("mrs r3, BASEPRI \n\t" \
"mrs r12, PSP \n\t" \
"stmdb r12!, {r3-r6,r8-r11, lr} \n\t" \
"str r12, [r0, #16] \n\t" \
"ldr r12, [r1, #16] \n\t" \
"ldmia r12!, {r3-r6,r8-r11, lr} \n\t" \
"msr PSP, r12 \n\t" \
"msr BASEPRI, r3 \n\t" \
"bx lr ");
#else
asm volatile ("mrs r3, BASEPRI \n\t" \
"mrs r12, PSP \n\t" \
"stmdb r12!, {r3-r11, lr} \n\t" \
"str r12, [r0, #16] \n\t" \
"ldr r12, [r1, #16] \n\t" \
"ldmia r12!, {r3-r11, lr} \n\t" \
"msr PSP, r12 \n\t" \
"msr BASEPRI, r3 \n\t" \
"bx lr ");
#endif
}
#ifdef CH_CURRP_REGISTER_CACHE
#define PUSH_CONTEXT(sp) { \
register uint32_t tmp asm ("r3") = BASEPRI_USER; \
asm volatile ("mrs %0, PSP \n\t" \
"stmdb %0!, {r3-r6,r8-r11, lr}" : \
"=r" (sp) : "r" (sp), "r" (tmp)); \
}
#define POP_CONTEXT(sp) { \
asm volatile ("ldmia %0!, {r3-r6,r8-r11, lr} \n\t" \
"msr PSP, %0 \n\t" \
"msr BASEPRI, r3 \n\t" \
"bx lr" : "=r" (sp) : "r" (sp)); \
}
#else
#define PUSH_CONTEXT(sp) { \
register uint32_t tmp asm ("r3") = BASEPRI_USER; \
asm volatile ("mrs %0, PSP \n\t" \
"stmdb %0!, {r3-r11,lr}" : \
"=r" (sp) : "r" (sp), "r" (tmp)); \
}
#define POP_CONTEXT(sp) { \
asm volatile ("ldmia %0!, {r3-r11, lr} \n\t" \
"msr PSP, %0 \n\t" \
"msr BASEPRI, r3 \n\t" \
"bx lr" : "=r" (sp) : "r" (sp)); \
}
#endif
/**
* Preemption invoked context switch.
*/
__attribute__((naked))
void PendSVVector(void) {
Thread *otp;
register struct intctx *sp_thd asm("r12");
chSysLockI();
asm volatile ("push {lr}");
if (!chSchRescRequiredI()) {
chSysUnlockI();
asm volatile ("pop {pc}");
}
asm volatile ("pop {lr}");
PUSH_CONTEXT(sp_thd);
(otp = currp)->p_ctx.r13 = sp_thd;
(currp = fifo_remove((void *)&rlist))->p_state = PRCURR;
chSchReadyI(otp);
#ifdef CH_USE_ROUNDROBIN
/* set the round-robin time quantum */
rlist.r_preempt = CH_TIME_QUANTUM;
#endif
#ifdef CH_USE_TRACE
chDbgTrace(otp, currp);
#endif
sp_thd = currp->p_ctx.r13;
POP_CONTEXT(sp_thd);
}
/** @} */
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