/* * 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/errno.h> #include <asm/irqflags.h> #include <asm/mipsregs.h> #include <asm/regdef.h> #include <asm/stackframe.h> #include <asm/gdb-stub.h> #ifdef CONFIG_32BIT #define DMFC0 mfc0 #define DMTC0 mtc0 #define LDC1 lwc1 #define SDC1 lwc1 #endif #ifdef CONFIG_64BIT #define DMFC0 dmfc0 #define DMTC0 dmtc0 #define LDC1 ldc1 #define SDC1 ldc1 #endif /* * [jsun] We reserves about 2x GDB_FR_SIZE in stack. The lower (addressed) * part is used to store registers and passed to exception handler. * The upper part is reserved for "call func" feature where gdb client * saves some of the regs, setups call frame and passes args. * * A trace shows about 200 bytes are used to store about half of all regs. * The rest should be big enough for frame setup and passing args. */ /* * 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, go somewhere else. */ mfc0 k0, CP0_CAUSE andi k0, k0, 0x7c #ifdef CONFIG_64BIT dsll k0, k0, 1 #endif PTR_L k1, saved_vectors(k0) jr k1 nop 1: move k0, sp PTR_SUBU sp, k1, GDB_FR_SIZE*2 # see comment above LONG_S k0, GDB_FR_REG29(sp) LONG_S $2, GDB_FR_REG2(sp) /* * First save the CP0 and special registers */ mfc0 v0, CP0_STATUS LONG_S v0, GDB_FR_STATUS(sp) mfc0 v0, CP0_CAUSE LONG_S v0, GDB_FR_CAUSE(sp) DMFC0 v0, CP0_EPC LONG_S v0, GDB_FR_EPC(sp) DMFC0 v0, CP0_BADVADDR LONG_S v0, GDB_FR_BADVADDR(sp) mfhi v0 LONG_S v0, GDB_FR_HI(sp) mflo v0 LONG_S v0, GDB_FR_LO(sp) /* * Now the integer registers */ LONG_S zero, GDB_FR_REG0(sp) /* I know... */ LONG_S $1, GDB_FR_REG1(sp) /* v0 already saved */ LONG_S $3, GDB_FR_REG3(sp) LONG_S $4, GDB_FR_REG4(sp) LONG_S $5, GDB_FR_REG5(sp) LONG_S $6, GDB_FR_REG6(sp) LONG_S $7, GDB_FR_REG7(sp) LONG_S $8, GDB_FR_REG8(sp) LONG_S $9, GDB_FR_REG9(sp) LONG_S $10, GDB_FR_REG10(sp) LONG_S $11, GDB_FR_REG11(sp) LONG_S $12, GDB_FR_REG12(sp) LONG_S $13, GDB_FR_REG13(sp) LONG_S $14, GDB_FR_REG14(sp) LONG_S $15, GDB_FR_REG15(sp) LONG_S $16, GDB_FR_REG16(sp) LONG_S $17, GDB_FR_REG17(sp) LONG_S $18, GDB_FR_REG18(sp) LONG_S $19, GDB_FR_REG19(sp) LONG_S $20, GDB_FR_REG20(sp) LONG_S $21, GDB_FR_REG21(sp) LONG_S $22, GDB_FR_REG22(sp) LONG_S $23, GDB_FR_REG23(sp) LONG_S $24, GDB_FR_REG24(sp) LONG_S $25, GDB_FR_REG25(sp) LONG_S $26, GDB_FR_REG26(sp) LONG_S $27, GDB_FR_REG27(sp) LONG_S $28, GDB_FR_REG28(sp) /* sp already saved */ LONG_S $30, GDB_FR_REG30(sp) LONG_S $31, GDB_FR_REG31(sp) CLI /* disable interrupts */ TRACE_IRQS_OFF /* * 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 SDC1 $0, GDB_FR_FPR0(sp) SDC1 $1, GDB_FR_FPR1(sp) SDC1 $2, GDB_FR_FPR2(sp) SDC1 $3, GDB_FR_FPR3(sp) SDC1 $4, GDB_FR_FPR4(sp) SDC1 $5, GDB_FR_FPR5(sp) SDC1 $6, GDB_FR_FPR6(sp) SDC1 $7, GDB_FR_FPR7(sp) SDC1 $8, GDB_FR_FPR8(sp) SDC1 $9, GDB_FR_FPR9(sp) SDC1 $10, GDB_FR_FPR10(sp) SDC1 $11, GDB_FR_FPR11(sp) SDC1 $12, GDB_FR_FPR12(sp) SDC1 $13, GDB_FR_FPR13(sp) SDC1 $14, GDB_FR_FPR14(sp) SDC1 $15, GDB_FR_FPR15(sp) SDC1 $16, GDB_FR_FPR16(sp) SDC1 $17, GDB_FR_FPR17(sp) SDC1 $18, GDB_FR_FPR18(sp) SDC1 $19, GDB_FR_FPR19(sp) SDC1 $20, GDB_FR_FPR20(sp) SDC1 $21, GDB_FR_FPR21(sp) SDC1 $22, GDB_FR_FPR22(sp) SDC1 $23, GDB_FR_FPR23(sp) SDC1 $24, GDB_FR_FPR24(sp) SDC1 $25, GDB_FR_FPR25(sp) SDC1 $26, GDB_FR_FPR26(sp) SDC1 $27, GDB_FR_FPR27(sp) SDC1 $28, GDB_FR_FPR28(sp) SDC1 $29, GDB_FR_FPR29(sp) SDC1 $30, GDB_FR_FPR30(sp) SDC1 $31, GDB_FR_FPR31(sp) /* * FPU control registers */ cfc1 v0, CP1_STATUS LONG_S v0, GDB_FR_FSR(sp) cfc1 v0, CP1_REVISION LONG_S v0, GDB_FR_FIR(sp) /* * Current stack frame ptr */ 2: LONG_S sp, GDB_FR_FRP(sp) /* * CP0 registers (R4000/R4400 unused registers skipped) */ mfc0 v0, CP0_INDEX LONG_S v0, GDB_FR_CP0_INDEX(sp) mfc0 v0, CP0_RANDOM LONG_S v0, GDB_FR_CP0_RANDOM(sp) DMFC0 v0, CP0_ENTRYLO0 LONG_S v0, GDB_FR_CP0_ENTRYLO0(sp) DMFC0 v0, CP0_ENTRYLO1 LONG_S v0, GDB_FR_CP0_ENTRYLO1(sp) DMFC0 v0, CP0_CONTEXT LONG_S v0, GDB_FR_CP0_CONTEXT(sp) mfc0 v0, CP0_PAGEMASK LONG_S v0, GDB_FR_CP0_PAGEMASK(sp) mfc0 v0, CP0_WIRED LONG_S v0, GDB_FR_CP0_WIRED(sp) DMFC0 v0, CP0_ENTRYHI LONG_S v0, GDB_FR_CP0_ENTRYHI(sp) mfc0 v0, CP0_PRID LONG_S 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 LONG_L v0, GDB_FR_CP0_ENTRYHI(sp) LONG_L v1, GDB_FR_CP0_WIRED(sp) DMTC0 v0, CP0_ENTRYHI mtc0 v1, CP0_WIRED LONG_L v0, GDB_FR_CP0_PAGEMASK(sp) LONG_L v1, GDB_FR_CP0_ENTRYLO1(sp) mtc0 v0, CP0_PAGEMASK DMTC0 v1, CP0_ENTRYLO1 LONG_L v0, GDB_FR_CP0_ENTRYLO0(sp) LONG_L v1, GDB_FR_CP0_INDEX(sp) DMTC0 v0, CP0_ENTRYLO0 LONG_L v0, GDB_FR_CP0_CONTEXT(sp) mtc0 v1, CP0_INDEX DMTC0 v0, CP0_CONTEXT /* * 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 LDC1 $31, GDB_FR_FPR31(sp) LDC1 $30, GDB_FR_FPR30(sp) LDC1 $29, GDB_FR_FPR29(sp) LDC1 $28, GDB_FR_FPR28(sp) LDC1 $27, GDB_FR_FPR27(sp) LDC1 $26, GDB_FR_FPR26(sp) LDC1 $25, GDB_FR_FPR25(sp) LDC1 $24, GDB_FR_FPR24(sp) LDC1 $23, GDB_FR_FPR23(sp) LDC1 $22, GDB_FR_FPR22(sp) LDC1 $21, GDB_FR_FPR21(sp) LDC1 $20, GDB_FR_FPR20(sp) LDC1 $19, GDB_FR_FPR19(sp) LDC1 $18, GDB_FR_FPR18(sp) LDC1 $17, GDB_FR_FPR17(sp) LDC1 $16, GDB_FR_FPR16(sp) LDC1 $15, GDB_FR_FPR15(sp) LDC1 $14, GDB_FR_FPR14(sp) LDC1 $13, GDB_FR_FPR13(sp) LDC1 $12, GDB_FR_FPR12(sp) LDC1 $11, GDB_FR_FPR11(sp) LDC1 $10, GDB_FR_FPR10(sp) LDC1 $9, GDB_FR_FPR9(sp) LDC1 $8, GDB_FR_FPR8(sp) LDC1 $7, GDB_FR_FPR7(sp) LDC1 $6, GDB_FR_FPR6(sp) LDC1 $5, GDB_FR_FPR5(sp) LDC1 $4, GDB_FR_FPR4(sp) LDC1 $3, GDB_FR_FPR3(sp) LDC1 $2, GDB_FR_FPR2(sp) LDC1 $1, GDB_FR_FPR1(sp) LDC1 $0, GDB_FR_FPR0(sp) /* * Now the CP0 and integer registers */ 3: #ifdef CONFIG_MIPS_MT_SMTC /* Read-modify write of Status must be atomic */ mfc0 t2, CP0_TCSTATUS ori t1, t2, TCSTATUS_IXMT mtc0 t1, CP0_TCSTATUS andi t2, t2, TCSTATUS_IXMT _ehb DMT 9 # dmt t1 jal mips_ihb nop #endif /* CONFIG_MIPS_MT_SMTC */ mfc0 t0, CP0_STATUS ori t0, 0x1f xori t0, 0x1f mtc0 t0, CP0_STATUS #ifdef CONFIG_MIPS_MT_SMTC andi t1, t1, VPECONTROL_TE beqz t1, 9f nop EMT # emt 9: mfc0 t1, CP0_TCSTATUS xori t1, t1, TCSTATUS_IXMT or t1, t1, t2 mtc0 t1, CP0_TCSTATUS _ehb #endif /* CONFIG_MIPS_MT_SMTC */ LONG_L v0, GDB_FR_STATUS(sp) LONG_L v1, GDB_FR_EPC(sp) mtc0 v0, CP0_STATUS DMTC0 v1, CP0_EPC LONG_L v0, GDB_FR_HI(sp) LONG_L v1, GDB_FR_LO(sp) mthi v0 mtlo v1 LONG_L $31, GDB_FR_REG31(sp) LONG_L $30, GDB_FR_REG30(sp) LONG_L $28, GDB_FR_REG28(sp) LONG_L $27, GDB_FR_REG27(sp) LONG_L $26, GDB_FR_REG26(sp) LONG_L $25, GDB_FR_REG25(sp) LONG_L $24, GDB_FR_REG24(sp) LONG_L $23, GDB_FR_REG23(sp) LONG_L $22, GDB_FR_REG22(sp) LONG_L $21, GDB_FR_REG21(sp) LONG_L $20, GDB_FR_REG20(sp) LONG_L $19, GDB_FR_REG19(sp) LONG_L $18, GDB_FR_REG18(sp) LONG_L $17, GDB_FR_REG17(sp) LONG_L $16, GDB_FR_REG16(sp) LONG_L $15, GDB_FR_REG15(sp) LONG_L $14, GDB_FR_REG14(sp) LONG_L $13, GDB_FR_REG13(sp) LONG_L $12, GDB_FR_REG12(sp) LONG_L $11, GDB_FR_REG11(sp) LONG_L $10, GDB_FR_REG10(sp) LONG_L $9, GDB_FR_REG9(sp) LONG_L $8, GDB_FR_REG8(sp) LONG_L $7, GDB_FR_REG7(sp) LONG_L $6, GDB_FR_REG6(sp) LONG_L $5, GDB_FR_REG5(sp) LONG_L $4, GDB_FR_REG4(sp) LONG_L $3, GDB_FR_REG3(sp) LONG_L $2, GDB_FR_REG2(sp) LONG_L $1, GDB_FR_REG1(sp) #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX) LONG_L k0, GDB_FR_EPC(sp) LONG_L $29, GDB_FR_REG29(sp) /* Deallocate stack */ jr k0 rfe #else LONG_L sp, GDB_FR_REG29(sp) /* Deallocate stack */ .set mips3 eret .set mips0 #endif .set at .set reorder END(trap_low) LEAF(kgdb_read_byte) 4: lb t0, (a0) sb t0, (a1) li v0, 0 jr ra .section __ex_table,"a" PTR 4b, kgdbfault .previous END(kgdb_read_byte) LEAF(kgdb_write_byte) 5: sb a0, (a1) li v0, 0 jr ra .section __ex_table,"a" PTR 5b, kgdbfault .previous END(kgdb_write_byte) .type kgdbfault@function .ent kgdbfault kgdbfault: li v0, -EFAULT jr ra .end kgdbfault