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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011 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/>.
*/
/**
* @file ARMCMx/chcore_v7m.c
* @brief ARMv7-M architecture port code.
*
* @addtogroup ARMCMx_V7M_CORE
* @{
*/
#include "ch.h"
#if !CH_OPTIMIZE_SPEED
void _port_lock(void) {
register uint32_t tmp asm ("r3") = CORTEX_BASEPRI_KERNEL;
asm volatile ("msr BASEPRI, %0" : : "r" (tmp));
}
void _port_unlock(void) {
register uint32_t tmp asm ("r3") = CORTEX_BASEPRI_DISABLED;
asm volatile ("msr BASEPRI, %0" : : "r" (tmp));
}
#endif
/**
* @brief System Timer vector.
* @details This interrupt is used as system tick.
* @note The timer must be initialized in the startup code.
*/
void SysTickVector(void) {
chSysLockFromIsr();
chSysTimerHandlerI();
if (chSchIsRescRequiredExI())
SCB_ICSR = ICSR_PENDSVSET;
chSysUnlockFromIsr();
}
#define PUSH_CONTEXT(sp, prio) { \
asm volatile ("mrs %0, PSP \n\t" \
"stmdb %0!, {r3-r11,lr}" : \
"=r" (sp) : "r" (sp), "r" (prio)); \
}
#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)); \
}
/**
* @brief SVC vector.
* @details The SVC vector is used for commanded context switch. Structures
* @p intctx are saved and restored from the process stacks of the
* switched threads.
*
* @param[in] ntp the thread to be switched it
* @param[in] otp the thread to be switched out
*/
#if !defined(__DOXYGEN__)
__attribute__((naked))
#endif
void SVCallVector(Thread *ntp, Thread *otp) {
register struct intctx *sp_thd asm("r2");
register uint32_t prio asm ("r3");
asm volatile ("mrs r3, BASEPRI" : "=r" (prio) : );
PUSH_CONTEXT(sp_thd, prio)
otp->p_ctx.r13 = sp_thd;
sp_thd = ntp->p_ctx.r13;
POP_CONTEXT(sp_thd)
}
/**
* @brief Preemption code.
*/
#if !defined(__DOXYGEN__)
__attribute__((naked))
#endif
void PendSVVector(void) {
register struct intctx *sp_thd asm("r2");
register uint32_t prio asm ("r3");
Thread *otp, *ntp;
chSysLockFromIsr();
prio = CORTEX_BASEPRI_DISABLED;
PUSH_CONTEXT(sp_thd, prio)
(otp = currp)->p_ctx.r13 = sp_thd;
ntp = fifo_remove(&rlist.r_queue);
setcurrp(ntp);
ntp->p_state = THD_STATE_CURRENT;
chSchReadyI(otp);
#if CH_TIME_QUANTUM > 0
/* Set the round-robin time quantum.*/
rlist.r_preempt = CH_TIME_QUANTUM;
#endif
chDbgTrace(otp);
sp_thd = ntp->p_ctx.r13;
POP_CONTEXT(sp_thd)
}
/** @} */
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