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/*
ChibiOS - Copyright (C) 2006..2015 Giovanni Di Sirio.
This file is part of ChibiOS.
ChibiOS 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 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 nilcore_v7m.c
* @brief ARMv7-M architecture port code.
*
* @addtogroup ARMCMx_V7M_CORE
* @{
*/
#include "nil.h"
/*===========================================================================*/
/* Module local definitions. */
/*===========================================================================*/
/*===========================================================================*/
/* Module exported variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local types. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local variables. */
/*===========================================================================*/
/*===========================================================================*/
/* Module local functions. */
/*===========================================================================*/
/*===========================================================================*/
/* Module interrupt handlers. */
/*===========================================================================*/
#if (CORTEX_SIMPLIFIED_PRIORITY == FALSE) || defined(__DOXYGEN__)
/**
* @brief SVC vector.
* @details The SVC vector is used for exception mode re-entering after a
* context switch.
* @note The PendSV vector is only used in advanced kernel mode.
*/
/*lint -save -e9075 [8.4] All symbols are invoked from asm context.*/
void SVC_Handler(void) {
/*lint -restore*/
struct port_extctx *ctxp;
#if CORTEX_USE_FPU == TRUE
/* Enforcing unstacking of the FP part of the context.*/
FPU->FPCCR &= ~FPU_FPCCR_LSPACT_Msk;
#endif
/* The port_extctx structure is pointed by the PSP register.*/
ctxp = (struct port_extctx *)__get_PSP();
/* Discarding the current exception context and positioning the stack to
point to the real one.*/
ctxp++;
/* Restoring real position of the original stack frame.*/
__set_PSP((uint32_t)ctxp);
/* Restoring the normal interrupts status.*/
port_unlock_from_isr();
}
#endif /* CORTEX_SIMPLIFIED_PRIORITY == FALSE */
#if (CORTEX_SIMPLIFIED_PRIORITY == TRUE) || defined(__DOXYGEN__)
/**
* @brief PendSV vector.
* @details The PendSV vector is used for exception mode re-entering after a
* context switch.
* @note The PendSV vector is only used in compact kernel mode.
*/
/*lint -save -e9075 [8.4] All symbols are invoked from asm context.*/
void PendSV_Handler(void) {
/*lint -restore*/
struct port_extctx *ctxp;
#if CORTEX_USE_FPU == TRUE
/* Enforcing unstacking of the FP part of the context.*/
FPU->FPCCR &= ~FPU_FPCCR_LSPACT_Msk;
#endif
/* The port_extctx structure is pointed by the PSP register.*/
ctxp = (struct port_extctx *)__get_PSP();
/* Discarding the current exception context and positioning the stack to
point to the real one.*/
ctxp++;
/* Writing back the modified PSP value.*/
__set_PSP((uint32_t)ctxp);
}
#endif /* CORTEX_SIMPLIFIED_PRIORITY == TRUE */
/*===========================================================================*/
/* Module exported functions. */
/*===========================================================================*/
/**
* @brief Exception exit redirection to _port_switch_from_isr().
*/
void _port_irq_epilogue(void) {
port_lock_from_isr();
if ((SCB->ICSR & SCB_ICSR_RETTOBASE_Msk) != 0U) {
struct port_extctx *ctxp;
#if CORTEX_USE_FPU == TRUE
/* Enforcing a lazy FPU state save by accessing the FPCSR register.*/
(void) __get_FPSCR();
#endif
/* The port_extctx structure is pointed by the PSP register.*/
ctxp = (struct port_extctx *)__get_PSP();
/* Adding an artificial exception return context, there is no need to
populate it fully.*/
ctxp--;
/* Setting up a fake XPSR register value.*/
ctxp->xpsr = (regarm_t)0x01000000;
/* Writing back the modified PSP value.*/
__set_PSP((uint32_t)ctxp);
/* The exit sequence is different depending on if a preemption is
required or not.*/
if (chSchIsRescRequiredI()) {
/* Preemption is required we need to enforce a context switch.*/
ctxp->pc = (regarm_t)_port_switch_from_isr;
}
else {
/* Preemption not required, we just need to exit the exception
atomically.*/
ctxp->pc = (regarm_t)_port_exit_from_isr;
}
/* Note, returning without unlocking is intentional, this is done in
order to keep the rest of the context switch atomic.*/
return;
}
port_unlock_from_isr();
}
/** @} */
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