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/**
* @file cpu_asm.S
*
* This file contains the implementation of exception handlers.
*/
/*
* RTEMS GBA BSP
*
* Copyright (c) 2002 by Advent Networks, Inc.
* Jay Monkman <jmonkman@adventnetworks.com>
*
* COPYRIGHT (c) 2000 Canon Research Centre France SA.
* Emmanuel Raguet, mailto:raguet@crf.canon.fr
*
* Copyright (c) 2004
* Markku Puro <markku.puro@kopteri.net>
*
* The license and distribution terms for this file may be
* found in found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* $Id$
*/
#define __asm__
#include <rtems/asm.h>
#include <rtems/score/cpu_asm.h>
#include <asm_macros.h>
/* @cond INCLUDE_ASM */
/**
* This routine performs a normal non-FP context.
* function void _CPU_Context_switch( run_context, heir_context )
* R0 = run_context R1 = heir_context
*
* This function copies the current registers to where r0 points, then
* restores the ones from where r1 points.
*
* Using the ldm/stm opcodes save 2-3 us on 100 MHz ARM9TDMI with
* a 16 bit data bus.
*
*/
.align
/* .section .iwram */
PUBLIC_ARM_FUNCTION(_CPU_Context_switch)
/* Start saving context */
mrs r2, cpsr
stmia r0, {r2, r4, r5, r6, r7, r8, r9, r10, r11, r13, r14}
/* Start restoring context */
_restore:
ldmia r1, {r2, r4, r5, r6, r7, r8, r9, r10, r11, r13, r14}
msr cpsr, r2
mov pc, lr
LABEL_END(_CPU_Context_switch)
/**
* This function copies the restores the registers from where r0 points.
* function void _CPU_Context_restore( new_context )
* It must match _CPU_Context_switch()
*
*/
PUBLIC_ARM_FUNCTION(_CPU_Context_restore)
mov r1, r0
b _restore
LABEL_END(_CPU_Context_restore)
/**
* function _Exception_Handler_Undef_Swi
* Can't use exception vectors in GBA
* @todo _Exception_Handler_Undef_Swi: Unused handler needed by ../score/cpu_asm.S
*
*/
.global _Exception_Handler_Undef_Swi
_Exception_Handler_Undef_Swi:
mov pc, lr
/**
* function _Exception_Handler_Abort
* Can't use exception vectors in GBA
* @todo _Exception_Handler_Abort: Unused handler needed by ../score/cpu_asm.S
*
*/
.global _Exception_Handler_Abort
_Exception_Handler_Abort:
mov pc, lr
/* @endcond */
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