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/*
* Copyright (c) 2008 Travis Geiselbrecht
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files
* (the "Software"), to deal in the Software without restriction,
* including without limitation the rights to use, copy, modify, merge,
* publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include <asm.h>
/* context switch frame is as follows:
* ulr
* usp
* lr
* r11
* r10
* r9
* r8
* r7
* r6
* r5
* r4
*/
/* arm_context_switch(addr_t *old_sp, addr_t new_sp) */
FUNCTION(arm_context_switch)
/* save all the usual registers + user regs */
/* the spsr is saved and restored in the iframe by exceptions.S */
sub r3, sp, #(11*4) /* can't use sp in user mode stm */
mov r12, lr
stmia r3, { r4-r11, r12, r13, r14 }^
/* save old sp */
str r3, [r0]
/* clear any exlusive locks that the old thread holds */
#if ARM_ISA_ARMV7
/* can clear it directly */
.word 0xf57ff01f // clrex
#elif ARM_ISA_ARMV6
/* have to do a fake strex to clear it */
ldr r0, =strex_spot
strex r3, r2, [r0]
#endif
/* load new regs */
ldmia r1, { r4-r11, r12, r13, r14 }^
mov lr, r12 /* restore lr */
add sp, r1, #(11*4) /* restore sp */
bx lr
.ltorg
FUNCTION(arm_save_mode_regs)
mrs r1, cpsr
#if ARM_ISA_ARMv6
cps #0x11 /* fiq */
str r13, [r0], #4
str r14, [r0], #4
cps #0x12 /* irq */
str r13, [r0], #4
str r14, [r0], #4
cps #0x13 /* svc */
str r13, [r0], #4
str r14, [r0], #4
cps #0x17 /* abt */
str r13, [r0], #4
str r14, [r0], #4
cps #0x1b /* und */
str r13, [r0], #4
str r14, [r0], #4
cps #0x1f /* sys */
str r13, [r0], #4
str r14, [r0], #4
#else
// XXX implement
b .
#endif
msr cpsr_c, r1
bx lr
.data
strex_spot:
.word 0