| 0,0 → 1,199 |
|---|
| # |
| # Copyright (c) 2009 Vineeth Pillai |
| # All rights reserved. |
| # |
| # Redistribution and use in source and binary forms, with or without |
| # modification, are permitted provided that the following conditions |
| # are met: |
| # |
| # - Redistributions of source code must retain the above copyright |
| # notice, this list of conditions and the following disclaimer. |
| # - 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. |
| # - 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 ``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 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 |
| |
| .global irq_exception_entry |
| .global fiq_exception_entry |
| .global data_abort_exception_entry |
| .global prefetch_abort_exception_entry |
| .global undef_instr_exception_entry |
| .global swi_exception_entry |
| .global reset_exception_entry |
| |
| |
| # Switches to kernel stack and saves all registers there. |
| # |
| # The stack frame created by the function looks like: |
| # |
| # |_________________| |
| # | | |
| # | SPSR | |
| # | | |
| # |_________________| |
| # | Stack Pointer | |
| # | of | |
| # | Previous Mode | |
| # |_________________| |
| # | Return address | |
| # | of | |
| # | Previous Mode | |
| # |_________________| |
| # | R0 - R12 | |
| # | of | |
| # | Previous Mode | |
| # |_________________| |
| # | Return address | |
| # | from | |
| # |Exception Handler| |
| # |_________________| |
| # | | |
| # |
| # |
| |
| .macro SAVE_REGS_TO_STACK |
| stmfd r13!, {r0-r3} |
| mov r3, sp |
| add sp, sp, #16 |
| mrs r1, cpsr |
| bic r1, r1, #0x1f |
| mrs r2, spsr |
| and r0, r2, #0x1f |
| cmp r0, #0x10 |
| bne 1f |
| |
| # prev mode was usermode |
| mov r0, lr |
| |
| # Switch to supervisor mode |
| orr r1, r1, #0x13 |
| msr cpsr_c, r1 |
| |
| # Load sp with [supervisor_sp] |
| ldr r13, =supervisor_sp |
| ldr r13, [r13] |
| |
| # Populate the stack frame |
| msr spsr, r2 |
| mov lr, r0 |
| stmfd r13!, {lr} |
| stmfd r13!, {r4-r12} |
| ldmfd r3!, {r4-r7} |
| stmfd r13!, {r4-r7} |
| stmfd r13!, {r13, lr}^ |
| stmfd r13!, {r2} |
| b 2f |
| |
| # mode was not usermode |
| 1: |
| # Switch to previous mode which is undoubtedly the supervisor mode |
| orr r1, r1, r0 |
| mov r0, lr |
| msr cpsr_c, r1 |
| |
| # Populate the stack frame |
| mov r1, sp |
| stmfd r13!, {r0} |
| stmfd r13!, {r4-r12} |
| |
| # Store r0-r3 in r4-r7 and then push it on to stack |
| ldmfd r3!, {r4-r7} |
| stmfd r13!, {r4-r7} |
| |
| # Push return address and stack pointer on to stack |
| stmfd r13!, {lr} |
| stmfd r13!, {r1} |
| mov lr, r0 |
| msr spsr, r2 |
| stmfd r13!, {r2} |
| 2: |
| .endm |
| |
| .macro LOAD_REGS_FROM_STACK |
| ldmfd r13!, {r0} |
| msr spsr, r0 |
| and r0, r0, #0x1f |
| cmp r0, #0x10 |
| bne 1f |
| |
| # return to user mode |
| ldmfd r13!, {r13, lr}^ |
| b 2f |
| |
| # return to non-user mode |
| 1: |
| ldmfd r13!, {r1, lr} |
| |
| 2: |
| ldmfd r13!, {r0-r12, pc}^ |
| .endm |
| |
| reset_exception_entry: |
| SAVE_REGS_TO_STACK |
| mov r0, #0 |
| mov r1, r13 |
| bl exc_dispatch |
| LOAD_REGS_FROM_STACK |
| |
| irq_exception_entry: |
| sub lr, lr, #4 |
| SAVE_REGS_TO_STACK |
| mov r0, #5 |
| mov r1, r13 |
| bl exc_dispatch |
| LOAD_REGS_FROM_STACK |
| |
| fiq_exception_entry: |
| sub lr, lr, #4 |
| SAVE_REGS_TO_STACK |
| mov r0, #6 |
| mov r1, r13 |
| bl exc_dispatch |
| LOAD_REGS_FROM_STACK |
| |
| undef_instr_exception_entry: |
| SAVE_REGS_TO_STACK |
| mov r0, #1 |
| mov r1, r13 |
| bl exc_dispatch |
| LOAD_REGS_FROM_STACK |
| |
| prefetch_abort_exception_entry: |
| sub lr, lr, #4 |
| SAVE_REGS_TO_STACK |
| mov r0, #3 |
| mov r1, r13 |
| bl exc_dispatch |
| LOAD_REGS_FROM_STACK |
| |
| data_abort_exception_entry: |
| sub lr, lr, #8 |
| SAVE_REGS_TO_STACK |
| mov r0, #4 |
| mov r1, r13 |
| bl exc_dispatch |
| LOAD_REGS_FROM_STACK |
| |
| swi_exception_entry: |
| ldr r13, =exc_stack |
| SAVE_REGS_TO_STACK |
| mov r0, #2 |
| mov r1, r13 |
| bl exc_dispatch |
| LOAD_REGS_FROM_STACK |
| |