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/*
* arch/mips/kernel/gdb-low.S
*
* gdb-low.S contains the low-level trap handler for the GDB stub.
*
* Copyright (C) 1995 Andreas Busse
*/
#include <linux/sys.h>
#include <asm/asm.h>
#include <asm/mipsregs.h>
#include <asm/mipsconfig.h>
#include <asm/regdef.h>
#include <asm/stackframe.h>
#include <asm/gdb-stub.h>
/*
* The low level trap handler
*/
.align 5
NESTED(trap_low, GDB_FR_SIZE, sp)
.set noat
.set noreorder
mfc0 k0,CP0_STATUS
sll k0,3 /* extract cu0 bit */
bltz k0,1f
move k1,sp
/*
* Called from user mode, new stack
*/
lui k1,%hi(kernelsp)
lw k1,%lo(kernelsp)(k1)
1:
move k0,sp
subu sp,k1,GDB_FR_SIZE
sw k0,GDB_FR_REG29(sp)
sw v0,GDB_FR_REG2(sp)
/*
* First save the CP0 and special registers
*/
mfc0 v0,CP0_STATUS
sw v0,GDB_FR_STATUS(sp)
mfc0 v0,CP0_CAUSE
sw v0,GDB_FR_CAUSE(sp)
mfc0 v0,CP0_EPC
sw v0,GDB_FR_EPC(sp)
mfc0 v0,CP0_BADVADDR
sw v0,GDB_FR_BADVADDR(sp)
mfhi v0
sw v0,GDB_FR_HI(sp)
mflo v0
sw v0,GDB_FR_LO(sp)
/*
* Now the integer registers
*/
sw zero,GDB_FR_REG0(sp) /* I know... */
sw $1,GDB_FR_REG1(sp)
/* v0 already saved */
sw v1,GDB_FR_REG3(sp)
sw a0,GDB_FR_REG4(sp)
sw a1,GDB_FR_REG5(sp)
sw a2,GDB_FR_REG6(sp)
sw a3,GDB_FR_REG7(sp)
sw t0,GDB_FR_REG8(sp)
sw t1,GDB_FR_REG9(sp)
sw t2,GDB_FR_REG10(sp)
sw t3,GDB_FR_REG11(sp)
sw t4,GDB_FR_REG12(sp)
sw t5,GDB_FR_REG13(sp)
sw t6,GDB_FR_REG14(sp)
sw t7,GDB_FR_REG15(sp)
sw s0,GDB_FR_REG16(sp)
sw s1,GDB_FR_REG17(sp)
sw s2,GDB_FR_REG18(sp)
sw s3,GDB_FR_REG19(sp)
sw s4,GDB_FR_REG20(sp)
sw s5,GDB_FR_REG21(sp)
sw s6,GDB_FR_REG22(sp)
sw s7,GDB_FR_REG23(sp)
sw t8,GDB_FR_REG24(sp)
sw t9,GDB_FR_REG25(sp)
sw k0,GDB_FR_REG26(sp)
sw k1,GDB_FR_REG27(sp)
sw gp,GDB_FR_REG28(sp)
/* sp already saved */
sw fp,GDB_FR_REG30(sp)
sw ra,GDB_FR_REG31(sp)
STI /* disable interrupts */
/*
* Followed by the floating point registers
*/
mfc0 v0,CP0_STATUS /* FPU enabled? */
srl v0,v0,16
andi v0,v0,(ST0_CU1 >> 16)
beqz v0,2f /* disabled, skip */
nop
swc1 $0,GDB_FR_FPR0(sp)
swc1 $1,GDB_FR_FPR1(sp)
swc1 $2,GDB_FR_FPR2(sp)
swc1 $3,GDB_FR_FPR3(sp)
swc1 $4,GDB_FR_FPR4(sp)
swc1 $5,GDB_FR_FPR5(sp)
swc1 $6,GDB_FR_FPR6(sp)
swc1 $7,GDB_FR_FPR7(sp)
swc1 $8,GDB_FR_FPR8(sp)
swc1 $9,GDB_FR_FPR9(sp)
swc1 $10,GDB_FR_FPR10(sp)
swc1 $11,GDB_FR_FPR11(sp)
swc1 $12,GDB_FR_FPR12(sp)
swc1 $13,GDB_FR_FPR13(sp)
swc1 $14,GDB_FR_FPR14(sp)
swc1 $15,GDB_FR_FPR15(sp)
swc1 $16,GDB_FR_FPR16(sp)
swc1 $17,GDB_FR_FPR17(sp)
swc1 $18,GDB_FR_FPR18(sp)
swc1 $19,GDB_FR_FPR19(sp)
swc1 $20,GDB_FR_FPR20(sp)
swc1 $21,GDB_FR_FPR21(sp)
swc1 $22,GDB_FR_FPR22(sp)
swc1 $23,GDB_FR_FPR23(sp)
swc1 $24,GDB_FR_FPR24(sp)
swc1 $25,GDB_FR_FPR25(sp)
swc1 $26,GDB_FR_FPR26(sp)
swc1 $27,GDB_FR_FPR27(sp)
swc1 $28,GDB_FR_FPR28(sp)
swc1 $29,GDB_FR_FPR29(sp)
swc1 $30,GDB_FR_FPR30(sp)
swc1 $31,GDB_FR_FPR31(sp)
/*
* FPU control registers
*/
mfc1 v0,CP1_STATUS
sw v0,GDB_FR_FSR(sp)
mfc1 v0,CP1_REVISION
sw v0,GDB_FR_FIR(sp)
/*
* Current stack frame ptr
*/
2:
sw sp,GDB_FR_FRP(sp)
/*
* CP0 registers (R4000/R4400 unused registers skipped)
*/
mfc0 v0,CP0_INDEX
sw v0,GDB_FR_CP0_INDEX(sp)
mfc0 v0,CP0_RANDOM
sw v0,GDB_FR_CP0_RANDOM(sp)
mfc0 v0,CP0_ENTRYLO0
sw v0,GDB_FR_CP0_ENTRYLO0(sp)
mfc0 v0,CP0_ENTRYLO1
sw v0,GDB_FR_CP0_ENTRYLO1(sp)
mfc0 v0,CP0_PAGEMASK
sw v0,GDB_FR_CP0_PAGEMASK(sp)
mfc0 v0,CP0_WIRED
sw v0,GDB_FR_CP0_WIRED(sp)
mfc0 v0,CP0_ENTRYHI
sw v0,GDB_FR_CP0_ENTRYHI(sp)
mfc0 v0,CP0_PRID
sw v0,GDB_FR_CP0_PRID(sp)
.set at
/*
* Continue with the higher level handler
*/
move a0,sp
jal handle_exception
nop
/*
* Restore all writable registers, in reverse order
*/
.set noat
lw v0,GDB_FR_CP0_ENTRYHI(sp)
lw v1,GDB_FR_CP0_WIRED(sp)
mtc0 v0,CP0_ENTRYHI
mtc0 v1,CP0_WIRED
lw v0,GDB_FR_CP0_PAGEMASK(sp)
lw v1,GDB_FR_CP0_ENTRYLO1(sp)
mtc0 v0,CP0_PAGEMASK
mtc0 v1,CP0_ENTRYLO1
lw v0,GDB_FR_CP0_ENTRYLO0(sp)
lw v1,GDB_FR_CP0_INDEX(sp)
mtc0 v0,CP0_ENTRYLO0
mtc0 v1,CP0_INDEX
/*
* Next, the floating point registers
*/
mfc0 v0,CP0_STATUS /* check if the FPU is enabled */
srl v0,v0,16
andi v0,v0,(ST0_CU1 >> 16)
beqz v0,3f /* disabled, skip */
nop
lwc1 $31,GDB_FR_FPR31(sp)
lwc1 $30,GDB_FR_FPR30(sp)
lwc1 $29,GDB_FR_FPR29(sp)
lwc1 $28,GDB_FR_FPR28(sp)
lwc1 $27,GDB_FR_FPR27(sp)
lwc1 $26,GDB_FR_FPR26(sp)
lwc1 $25,GDB_FR_FPR25(sp)
lwc1 $24,GDB_FR_FPR24(sp)
lwc1 $23,GDB_FR_FPR23(sp)
lwc1 $22,GDB_FR_FPR22(sp)
lwc1 $21,GDB_FR_FPR21(sp)
lwc1 $20,GDB_FR_FPR20(sp)
lwc1 $19,GDB_FR_FPR19(sp)
lwc1 $18,GDB_FR_FPR18(sp)
lwc1 $17,GDB_FR_FPR17(sp)
lwc1 $16,GDB_FR_FPR16(sp)
lwc1 $15,GDB_FR_FPR15(sp)
lwc1 $14,GDB_FR_FPR14(sp)
lwc1 $13,GDB_FR_FPR13(sp)
lwc1 $12,GDB_FR_FPR12(sp)
lwc1 $11,GDB_FR_FPR11(sp)
lwc1 $10,GDB_FR_FPR10(sp)
lwc1 $9,GDB_FR_FPR9(sp)
lwc1 $8,GDB_FR_FPR8(sp)
lwc1 $7,GDB_FR_FPR7(sp)
lwc1 $6,GDB_FR_FPR6(sp)
lwc1 $5,GDB_FR_FPR5(sp)
lwc1 $4,GDB_FR_FPR4(sp)
lwc1 $3,GDB_FR_FPR3(sp)
lwc1 $2,GDB_FR_FPR2(sp)
lwc1 $1,GDB_FR_FPR1(sp)
lwc1 $0,GDB_FR_FPR0(sp)
/*
* Now the CP0 and integer registers
*/
3:
mfc0 t0,CP0_STATUS
ori t0,0x1f
xori t0,0x1f
mtc0 t0,CP0_STATUS
lw v0,GDB_FR_STATUS(sp)
lw v1,GDB_FR_EPC(sp)
mtc0 v0,CP0_STATUS
mtc0 v1,CP0_EPC
lw v0,GDB_FR_HI(sp)
lw v1,GDB_FR_LO(sp)
mthi v0
mtlo v0
lw ra,GDB_FR_REG31(sp)
lw fp,GDB_FR_REG30(sp)
lw gp,GDB_FR_REG28(sp)
lw k1,GDB_FR_REG27(sp)
lw k0,GDB_FR_REG26(sp)
lw t9,GDB_FR_REG25(sp)
lw t8,GDB_FR_REG24(sp)
lw s7,GDB_FR_REG23(sp)
lw s6,GDB_FR_REG22(sp)
lw s5,GDB_FR_REG21(sp)
lw s4,GDB_FR_REG20(sp)
lw s3,GDB_FR_REG19(sp)
lw s2,GDB_FR_REG18(sp)
lw s1,GDB_FR_REG17(sp)
lw s0,GDB_FR_REG16(sp)
lw t7,GDB_FR_REG15(sp)
lw t6,GDB_FR_REG14(sp)
lw t5,GDB_FR_REG13(sp)
lw t4,GDB_FR_REG12(sp)
lw t3,GDB_FR_REG11(sp)
lw t2,GDB_FR_REG10(sp)
lw t1,GDB_FR_REG9(sp)
lw t0,GDB_FR_REG8(sp)
lw a3,GDB_FR_REG7(sp)
lw a2,GDB_FR_REG6(sp)
lw a1,GDB_FR_REG5(sp)
lw a0,GDB_FR_REG4(sp)
lw v1,GDB_FR_REG3(sp)
lw v0,GDB_FR_REG2(sp)
lw $1,GDB_FR_REG1(sp)
lw sp,GDB_FR_REG29(sp) /* Deallocate stack */
.set mips3
eret
.set mips0
.set at
.set reorder
END(trap_low)
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