coreboot-kgpe-d16/payloads/libpayload/arch/arm/exception_asm.S

125 lines
3.2 KiB
ArmAsm

/*
*
* Copyright 2013 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
.text
.align 6
.arm
.global exception_table
exception_table:
b 1f
b 2f
b 3f
b 4f
b 5f
b 6f
b 7f
b 8f
1:
mov sp, #0
b exception_common
/* Undefined Instruction (CAREFUL: the PC offset is specific to thumb mode!) */
2:
sub lr, lr, #2
mov sp, #1
b exception_common
/* Software Interrupt (no PC offset necessary) */
3:
mov sp, #2
b exception_common
/* Prefetch Abort */
4:
sub lr, lr, #4
mov sp, #3
b exception_common
/* Data Abort */
5:
sub lr, lr, #8
mov sp, #4
b exception_common
/* (not used) */
6:
mov sp, #5
b exception_common
/* Interrupt */
7:
sub lr, lr, #4
mov sp, #6
b exception_common
/* Fast Interrupt */
8:
sub lr, lr, #4
mov sp, #7
b exception_common
exception_common:
str sp, exception_idx
ldr sp, exception_state_ptr
stmia sp!, { r0 - r12 } /* Save regs from bottom to top */
stmia sp, { sp, lr }^ /* Save banked SP/LR (no writeback) */
str lr, [sp, #(4 * 2)] /* Save PC to &regs[13] + 2 */
mrs r0, SPSR
str r0, [sp, #(4 * 3)] /* Save SPSR to &regs[13] + 3 */
ldr sp, exception_stack_end /* Point SP to the stack for C code */
ldr r0, exception_idx
blx exception_dispatch
ldr sp, exception_state_ptr
ldr r0, [sp, #(4 * 16)] /* Load SPSR from &regs[0] + 16... */
msr SPSR_cxsf, r0 /* ...and get it out of the way */
ldmia sp!, { r0 - r12 } /* Restore regs from bottom to top */
ldmia sp, { sp, lr }^ /* Restore SP/LR to banked location */
add sp, sp, #8 /* Adjust SP (no writeback allowed) */
ldmia sp!, { pc }^ /* Do exception return (mode switch) */
.align 2
.global exception_stack_end
exception_stack_end:
.word 0
.global exception_state_ptr
exception_state_ptr:
.word 0
exception_idx:
.word 0
.thumb
.global set_vbar
.thumb_func
set_vbar:
mcr p15, 0, r0, c12, c0, 0
bx lr