251 lines
5.0 KiB
ArmAsm
251 lines
5.0 KiB
ArmAsm
/*
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* arch/sh/kernel/cpu/sh2a/entry.S
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*
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* The SH-2A exception entry
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*
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* Copyright (C) 2008 Yoshinori Sato
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* Based on arch/sh/kernel/cpu/sh2/entry.S
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/linkage.h>
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#include <asm/asm-offsets.h>
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#include <asm/thread_info.h>
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#include <cpu/mmu_context.h>
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#include <asm/unistd.h>
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#include <asm/errno.h>
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#include <asm/page.h>
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/* Offsets to the stack */
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OFF_R0 = 0 /* Return value. New ABI also arg4 */
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OFF_R1 = 4 /* New ABI: arg5 */
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OFF_R2 = 8 /* New ABI: arg6 */
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OFF_R3 = 12 /* New ABI: syscall_nr */
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OFF_R4 = 16 /* New ABI: arg0 */
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OFF_R5 = 20 /* New ABI: arg1 */
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OFF_R6 = 24 /* New ABI: arg2 */
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OFF_R7 = 28 /* New ABI: arg3 */
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OFF_SP = (15*4)
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OFF_PC = (16*4)
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OFF_SR = (16*4+2*4)
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OFF_TRA = (16*4+6*4)
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#include <asm/entry-macros.S>
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ENTRY(exception_handler)
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! stack
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! r0 <- point sp
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! r1
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! pc
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! sr
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! r0 = temporary
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! r1 = vector (pseudo EXPEVT / INTEVT / TRA)
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mov.l r2,@-sp
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cli
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mov.l $cpu_mode,r2
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bld.b #6,@(0,r2) !previus SR.MD
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bst.b #6,@(4*4,r15) !set cpu mode to SR.MD
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bt 1f
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! switch to kernel mode
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bset.b #6,@(0,r2) !set SR.MD
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mov.l $current_thread_info,r2
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mov.l @r2,r2
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mov #(THREAD_SIZE >> 8),r0
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shll8 r0
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add r2,r0 ! r0 = kernel stack tail
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mov r15,r2 ! r2 = user stack top
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mov r0,r15 ! switch kernel stack
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mov.l r1,@-r15 ! TRA
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sts.l macl, @-r15
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sts.l mach, @-r15
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stc.l gbr, @-r15
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mov.l @(4*4,r2),r0
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mov.l r0,@-r15 ! original SR
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sts.l pr,@-r15
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mov.l @(3*4,r2),r0
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mov.l r0,@-r15 ! original PC
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mov r2,r0
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add #(3+2)*4,r0 ! rewind r0 - r3 + exception frame
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lds r0,pr ! pr = original SP
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movmu.l r3,@-r15 ! save regs
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mov r2,r8 ! r8 = previus stack top
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mov r1,r9 ! r9 = interrupt vector
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! restore previous stack
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mov.l @r8+,r2
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mov.l @r8+,r0
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mov.l @r8+,r1
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bra 2f
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movml.l r2,@-r15
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1:
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! in kernel exception
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mov r15,r2
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add #-((OFF_TRA + 4) - OFF_PC) + 5*4,r15
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movmu.l r3,@-r15
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mov r2,r8 ! r8 = previous stack top
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mov r1,r9 ! r9 = interrupt vector
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! restore exception frame & regs
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mov.l @r8+,r2 ! old R2
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mov.l @r8+,r0 ! old R0
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mov.l @r8+,r1 ! old R1
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mov.l @r8+,r10 ! old PC
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mov.l @r8+,r11 ! old SR
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movml.l r2,@-r15
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mov.l r10,@(OFF_PC,r15)
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mov.l r11,@(OFF_SR,r15)
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mov.l r8,@(OFF_SP,r15) ! save old sp
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mov r15,r8
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add #OFF_TRA + 4,r8
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mov.l r9,@-r8
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sts.l macl,@-r8
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sts.l mach,@-r8
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stc.l gbr,@-r8
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add #-4,r8
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sts.l pr,@-r8
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2:
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! dispatch exception / interrupt
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mov #64,r8
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cmp/hs r8,r9
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bt interrupt_entry ! vec >= 64 is interrupt
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mov #32,r8
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cmp/hs r8,r9
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bt trap_entry ! 64 > vec >= 32 is trap
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mov.l 4f,r8
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mov r9,r4
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shll2 r9
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add r9,r8
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mov.l @r8,r8 ! exception handler address
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tst r8,r8
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bf 3f
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mov.l 8f,r8 ! unhandled exception
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3:
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mov.l 5f,r10
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jmp @r8
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lds r10,pr
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interrupt_entry:
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mov r9,r4
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mov r15,r5
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mov.l 7f,r8
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mov.l 6f,r9
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jmp @r8
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lds r9,pr
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.align 2
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4: .long exception_handling_table
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5: .long ret_from_exception
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6: .long ret_from_irq
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7: .long do_IRQ
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8: .long exception_error
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trap_entry:
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mov #0x30,r8
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cmp/ge r8,r9 ! vector 0x20-0x2f is systemcall
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bt 1f
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add #-0x10,r9 ! convert SH2 to SH3/4 ABI
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1:
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shll2 r9 ! TRA
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bra system_call ! jump common systemcall entry
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mov r9,r8
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#if defined(CONFIG_SH_STANDARD_BIOS)
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/* Unwind the stack and jmp to the debug entry */
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ENTRY(sh_bios_handler)
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mov r15,r0
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add #(22-4)*4-4,r0
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ldc.l @r0+,gbr
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lds.l @r0+,mach
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lds.l @r0+,macl
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mov r15,r0
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mov.l @(OFF_SP,r0),r1
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mov.l @(OFF_SR,r2),r3
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mov.l r3,@-r1
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mov.l @(OFF_SP,r2),r3
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mov.l r3,@-r1
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mov r15,r0
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add #(22-4)*4-8,r0
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mov.l 1f,r2
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mov.l @r2,r2
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stc sr,r3
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mov.l r2,@r0
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mov.l r3,@(4,r0)
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mov.l r1,@(8,r0)
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movml.l @r15+,r14
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add #8,r15
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lds.l @r15+, pr
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mov.l @r15+,r15
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rte
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nop
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.align 2
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1: .long gdb_vbr_vector
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#endif /* CONFIG_SH_STANDARD_BIOS */
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ENTRY(address_error_trap_handler)
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mov r15,r4 ! regs
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mov.l @(OFF_PC,r15),r6 ! pc
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mov.l 1f,r0
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jmp @r0
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mov #0,r5 ! writeaccess is unknown
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.align 2
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1: .long do_address_error
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restore_all:
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stc sr,r0
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or #0xf0,r0
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ldc r0,sr ! all interrupt block (same BL = 1)
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! restore special register
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! overlap exception frame
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mov r15,r0
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add #17*4,r0
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lds.l @r0+,pr
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add #4,r0
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ldc.l @r0+,gbr
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lds.l @r0+,mach
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lds.l @r0+,macl
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mov r15,r0
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mov.l $cpu_mode,r2
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bld.b #6,@(OFF_SR,r15)
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bst.b #6,@(0,r2) ! save CPU mode
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mov.l @(OFF_SR,r0),r1
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shll2 r1
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shlr2 r1 ! clear MD bit
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mov.l @(OFF_SP,r0),r2
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add #-8,r2
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mov.l r2,@(OFF_SP,r0) ! point exception frame top
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mov.l r1,@(4,r2) ! set sr
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mov.l @(OFF_PC,r0),r1
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mov.l r1,@r2 ! set pc
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get_current_thread_info r0, r1
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mov.l $current_thread_info,r1
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mov.l r0,@r1
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movml.l @r15+,r14
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mov.l @r15,r15
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rte
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nop
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.align 2
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$current_thread_info:
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.long __current_thread_info
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$cpu_mode:
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.long __cpu_mode
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! common exception handler
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#include "../../entry-common.S"
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.data
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! cpu operation mode
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! bit30 = MD (compatible SH3/4)
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__cpu_mode:
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.long 0x40000000
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.section .bss
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__current_thread_info:
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.long 0
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ENTRY(exception_handling_table)
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.space 4*32
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