| /* |
| * 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 |
| |
| |