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