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/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012 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 PPC/chcore.c
* @brief PowerPC architecture port code.
*
* @addtogroup PPC_CORE
* @{
*/
#include "ch.h"
/**
* @brief Kernel port layer initialization.
* @details IVOR4 and IVOR10 initialization.
*/
void port_init(void) {
#if PPC_SUPPORTS_IVORS
/* The CPU support IVOR registers, the kernel requires IVOR4 and IVOR10
and the initialization is performed here.*/
asm volatile ("li %r3, IVOR4@l \t\n"
"mtIVOR4 %r3 \t\n"
"li %r3, IVOR10@l \t\n"
"mtIVOR10 %r3");
#endif
}
/**
* @brief Halts the system.
* @details This function is invoked by the operating system when an
* unrecoverable error is detected (for example because a programming
* error in the application code that triggers an assertion while
* in debug mode).
*/
void port_halt(void) {
port_disable();
while (TRUE) {
}
}
/**
* @brief Performs a context switch between two threads.
* @details This is the most critical code in any port, this function
* is responsible for the context switch between 2 threads.
* @note The implementation of this code affects <b>directly</b> the context
* switch performance so optimize here as much as you can.
*
* @param[in] ntp the thread to be switched in
* @param[in] otp the thread to be switched out
*/
void port_switch(Thread *ntp, Thread *otp) {
(void)otp;
(void)ntp;
asm ("subi %sp, %sp, 80"); /* Size of the intctx structure. */
asm ("mflr %r0");
asm ("stw %r0, 84(%sp)"); /* LR into the caller frame. */
asm ("mfcr %r0");
asm ("stw %r0, 0(%sp)"); /* CR. */
asm ("stmw %r14, 4(%sp)"); /* GPR14...GPR31. */
asm ("stw %sp, 12(%r4)"); /* Store swapped-out stack. */
asm ("lwz %sp, 12(%r3)"); /* Load swapped-in stack. */
asm ("lmw %r14, 4(%sp)"); /* GPR14...GPR31. */
asm ("lwz %r0, 0(%sp)"); /* CR. */
asm ("mtcr %r0");
asm ("lwz %r0, 84(%sp)"); /* LR from the caller frame. */
asm ("mtlr %r0");
asm ("addi %sp, %sp, 80"); /* Size of the intctx structure. */
}
/**
* @brief Start a thread by invoking its work function.
* @details If the work function returns @p chThdExit() is automatically
* invoked.
*/
void _port_thread_start(void) {
chSysUnlock();
asm ("mr %r3, %r31"); /* Thread parameter. */
asm ("mtctr %r30");
asm ("bctrl"); /* Invoke thread function. */
asm ("bl chThdExit"); /* Thread termination on exit. */
}
/** @} */
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