/**
* @file
*
* @brief ARM7M CPU Context Switch
*/
/*
* Copyright (c) 2011-2014 Sebastian Huber. All rights reserved.
*
* embedded brains GmbH
* Obere Lagerstr. 30
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/score/armv7m.h>
#include <rtems/score/percpu.h>
#ifdef ARM_MULTILIB_ARCH_V7M
void __attribute__((naked)) _CPU_Context_switch(
Context_Control *executing,
Context_Control *heir
)
{
__asm__ volatile (
"movw r2, #:lower16:_Per_CPU_Information\n"
"movt r2, #:upper16:_Per_CPU_Information\n"
"ldr r3, [r2, %[isrpcpuoff]]\n"
"stm r0, {r4-r11, lr}\n"
#ifdef ARM_MULTILIB_VFP
"add r4, r0, %[d8off]\n"
"vstm r4, {d8-d15}\n"
#endif
"str sp, [r0, %[spctxoff]]\n"
"str r3, [r0, %[isrctxoff]]\n"
"ldr r3, [r1, %[isrctxoff]]\n"
"ldr sp, [r1, %[spctxoff]]\n"
#ifdef ARM_MULTILIB_VFP
"add r4, r1, %[d8off]\n"
"vldm r4, {d8-d15}\n"
#endif
"ldm r1, {r4-r11, lr}\n"
"str r3, [r2, %[isrpcpuoff]]\n"
"bx lr\n"
:
: [spctxoff] "J" (offsetof(Context_Control, register_sp)),
#ifdef ARM_MULTILIB_VFP
[d8off] "J" (ARM_CONTEXT_CONTROL_D8_OFFSET),
#endif
[isrctxoff] "J" (offsetof(Context_Control, isr_nest_level)),
[isrpcpuoff] "J" (offsetof(Per_CPU_Control, isr_nest_level))
);
}
#endif /* ARM_MULTILIB_ARCH_V7M */
