/*
* $Id$
*
* This file contains all assembly code for the ARM implementation
* of RTEMS.
*
* 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
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
*/
#include <rtems/asm.h>
#include <rtems/score/cpu_asm.h>
/*
* void _CPU_Context_switch( run_context, heir_context )
* void _CPU_Context_restore( run_context, heir_context )
*
* This routine performs a normal non-FP 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.
*
*/
.globl _CPU_Context_switch
_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
/*
* void _CPU_Context_restore( new_context )
*
* This function copies the restores the registers from where r0 points.
* It must match _CPU_Context_switch()
*
*/
.globl _CPU_Context_restore
_CPU_Context_restore:
mov r1, r0
b _restore
/* FIXME: _Exception_Handler_Undef_Swi is untested */
.globl _Exception_Handler_Undef_Swi
_Exception_Handler_Undef_Swi:
/* FIXME: This should use load and store multiple instructions */
sub r13,r13,#SIZE_REGS
str r4, [r13, #REG_R4]
str r5, [r13, #REG_R5]
str r6, [r13, #REG_R6]
str r7, [r13, #REG_R7]
str r8, [r13, #REG_R8]
str r9, [r13, #REG_R9]
str r10, [r13, #REG_R10]
str r11, [r13, #REG_R11]
str sp, [r13, #REG_SP]
str lr, [r13, #REG_LR]
mrs r0, cpsr /* read the status */
and r0, r0,#0x1f /* we keep the mode as exception number */
str r0, [r13, #REG_PC] /* we store it in a free place */
mov r0, r13 /* put frame address in r0 (C arg 1) */
ldr r1, =SWI_Handler
ldr lr, =_go_back_1
ldr pc,[r1] /* call handler */
_go_back_1:
ldr r4, [r13, #REG_R4]
ldr r5, [r13, #REG_R5]
ldr r6, [r13, #REG_R6]
ldr r7, [r13, #REG_R7]
ldr r8, [r13, #REG_R8]
ldr r9, [r13, #REG_R9]
ldr r10, [r13, #REG_R10]
ldr r11, [r13, #REG_R11]
ldr sp, [r13, #REG_SP]
ldr lr, [r13, #REG_LR]
add r13,r13,#SIZE_REGS
movs pc,r14 /* return */
/* FIXME: _Exception_Handler_Abort is untested */
.globl _Exception_Handler_Abort
_Exception_Handler_Abort:
/* FIXME: This should use load and store multiple instructions */
sub r13,r13,#SIZE_REGS
str r4, [r13, #REG_R4]
str r5, [r13, #REG_R5]
str r6, [r13, #REG_R6]
str r7, [r13, #REG_R7]
str r8, [r13, #REG_R8]
str r9, [r13, #REG_R9]
str sp, [r13, #REG_R11]
str lr, [r13, #REG_SP]
str lr, [r13, #REG_LR]
mrs r0, cpsr /* read the status */
and r0, r0,#0x1f /* we keep the mode as exception number */
str r0, [r13, #REG_PC] /* we store it in a free place */
mov r0, r13 /* put frame address in ro (C arg 1) */
ldr r1, =_currentExcHandler
ldr lr, =_go_back_2
ldr pc,[r1] /* call handler */
_go_back_2:
ldr r4, [r13, #REG_R4]
ldr r5, [r13, #REG_R5]
ldr r6, [r13, #REG_R6]
ldr r7, [r13, #REG_R7]
ldr r8, [r13, #REG_R8]
ldr r9, [r13, #REG_R9]
ldr r10, [r13, #REG_R10]
ldr sp, [r13, #REG_R11]
ldr lr, [r13, #REG_SP]
ldr lr, [r13, #REG_LR]
add r13,r13,#SIZE_REGS
subs pc,r14,#4 /* return */
#define ABORT_REGS_OFFS 32-REG_R4
#define ABORT_SIZE_REGS SIZE_REGS+ABORT_REGS_OFFS
.globl _exc_data_abort
_exc_data_abort:
sub sp, sp, #ABORT_SIZE_REGS /* reserve register frame */
stmia sp, {r0-r11}
add sp, sp, #ABORT_REGS_OFFS /* the Context_Control structure starts by CPSR, R4, ... */
str ip, [sp, #REG_PC] /* store R12 (ip) somewhere, oh hackery, hackery, hack */
str lr, [sp, #REG_LR]
mov r1, lr
ldr r0, [r1, #-8] /* r0 = bad instruction */
mrs r1, spsr /* r1 = spsr */
mov r2, r13 /* r2 = exception frame of Context_Control type */
bl do_data_abort
ldr lr, [sp, #REG_LR]
ldr ip, [sp, #REG_PC] /* restore R12 (ip) */
sub sp, sp, #ABORT_REGS_OFFS
ldmia sp, {r0-r11}
add sp, sp, #ABORT_SIZE_REGS
subs pc, r14, #4 /* return to the instruction */
/* _AFTER_ the aborted one */
