/* * 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> /* * 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(".word 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 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__ */