| /* SPDX-License-Identifier: GPL-2.0 */ | |
| /* | |
| * ARM KGDB support | |
| * | |
| * Author: Deepak Saxena <dsaxena@mvista.com> | |
| * | |
| * Copyright (C) 2002 MontaVista Software Inc. | |
| * | |
| */ | |
| #ifndef __ARM_KGDB_H__ | |
| #define __ARM_KGDB_H__ | |
| #include <linux/ptrace.h> | |
| #include <asm/opcodes.h> | |
| /* | |
| * GDB assumes that we're a user process being debugged, so | |
| * it will send us an SWI command to write into memory as the | |
| * debug trap. When an SWI occurs, the next instruction addr is | |
| * placed into R14_svc before jumping to the vector trap. | |
| * This doesn't work for kernel debugging as we are already in SVC | |
| * we would loose the kernel's LR, which is a bad thing. This | |
| * is bad thing. | |
| * | |
| * By doing this as an undefined instruction trap, we force a mode | |
| * switch from SVC to UND mode, allowing us to save full kernel state. | |
| * | |
| * We also define a KGDB_COMPILED_BREAK which can be used to compile | |
| * in breakpoints. This is important for things like sysrq-G and for | |
| * the initial breakpoint from trap_init(). | |
| * | |
| * Note to ARM HW designers: Add real trap support like SH && PPC to | |
| * make our lives much much simpler. :) | |
| */ | |
| #define BREAK_INSTR_SIZE 4 | |
| #define GDB_BREAKINST 0xef9f0001 | |
| #define KGDB_BREAKINST 0xe7ffdefe | |
| #define KGDB_COMPILED_BREAK 0xe7ffdeff | |
| #define CACHE_FLUSH_IS_SAFE 1 | |
| #ifndef __ASSEMBLY__ | |
| static inline void arch_kgdb_breakpoint(void) | |
| { | |
| asm(__inst_arm(0xe7ffdeff)); | |
| } | |
| extern void kgdb_handle_bus_error(void); | |
| extern int kgdb_fault_expected; | |
| #endif /* !__ASSEMBLY__ */ | |
| /* | |
| * From Kevin Hilman: | |
| * | |
| * gdb is expecting the following registers layout. | |
| * | |
| * r0-r15: 1 long word each | |
| * f0-f7: unused, 3 long words each !! | |
| * fps: unused, 1 long word | |
| * cpsr: 1 long word | |
| * | |
| * Even though f0-f7 and fps are not used, they need to be | |
| * present in the registers sent for correct processing in | |
| * the host-side gdb. | |
| * | |
| * In particular, it is crucial that CPSR is in the right place, | |
| * otherwise gdb will not be able to correctly interpret stepping over | |
| * conditional branches. | |
| */ | |
| #define _GP_REGS 16 | |
| #define _FP_REGS 8 | |
| #define _EXTRA_REGS 2 | |
| #define GDB_MAX_REGS (_GP_REGS + (_FP_REGS * 3) + _EXTRA_REGS) | |
| #define DBG_MAX_REG_NUM (_GP_REGS + _FP_REGS + _EXTRA_REGS) | |
| #define KGDB_MAX_NO_CPUS 1 | |
| #define BUFMAX 400 | |
| #define NUMREGBYTES (GDB_MAX_REGS << 2) | |
| #define NUMCRITREGBYTES (32 << 2) | |
| #define _R0 0 | |
| #define _R1 1 | |
| #define _R2 2 | |
| #define _R3 3 | |
| #define _R4 4 | |
| #define _R5 5 | |
| #define _R6 6 | |
| #define _R7 7 | |
| #define _R8 8 | |
| #define _R9 9 | |
| #define _R10 10 | |
| #define _FP 11 | |
| #define _IP 12 | |
| #define _SPT 13 | |
| #define _LR 14 | |
| #define _PC 15 | |
| #define _CPSR (GDB_MAX_REGS - 1) | |
| /* | |
| * So that we can denote the end of a frame for tracing, | |
| * in the simple case: | |
| */ | |
| #define CFI_END_FRAME(func) __CFI_END_FRAME(_PC, _SPT, func) | |
| #endif /* __ASM_KGDB_H__ */ |