From 5cbad0ebf45c5417104b383dc0e34f64fa7f2473 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Wed, 20 Feb 2008 13:33:40 -0600 Subject: kgdb: support for ARCH=arm This patch adds the ARCH=arm specific a kgdb backend, originally written by Deepak Saxena and George Davis . Geoff Levand , Nicolas Pitre, Manish Lachwani, and Jason Wessel have contributed various fixups here as well. The KGDB patch makes one change to the core ARM architecture such that the traps are initialized early for use with the debugger or other subsystems. [ mingo@elte.hu: small cleanups. ] [ ben-linux@fluff.org: fixed early_trap_init ] Signed-off-by: Jason Wessel Acked-by: Deepak Saxena --- include/asm-arm/kgdb.h | 104 ++++++++++++++++++++++++++++++++++++++++++++++++ include/asm-arm/traps.h | 2 + 2 files changed, 106 insertions(+) create mode 100644 include/asm-arm/kgdb.h (limited to 'include') diff --git a/include/asm-arm/kgdb.h b/include/asm-arm/kgdb.h new file mode 100644 index 00000000000..67af4b84198 --- /dev/null +++ b/include/asm-arm/kgdb.h @@ -0,0 +1,104 @@ +/* + * ARM KGDB support + * + * Author: Deepak Saxena + * + * Copyright (C) 2002 MontaVista Software Inc. + * + */ + +#ifndef __ARM_KGDB_H__ +#define __ARM_KGDB_H__ + +#include + +/* + * 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__ */ diff --git a/include/asm-arm/traps.h b/include/asm-arm/traps.h index f1541afcf85..aa399aec568 100644 --- a/include/asm-arm/traps.h +++ b/include/asm-arm/traps.h @@ -24,4 +24,6 @@ static inline int in_exception_text(unsigned long ptr) ptr < (unsigned long)&__exception_text_end; } +extern void __init early_trap_init(void); + #endif -- cgit v1.2.3 From 17ce452f7ea3df760b7f9f42453b6f6acd765217 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Wed, 23 Jul 2008 11:30:15 -0500 Subject: kgdb, powerpc: arch specific powerpc kgdb support This patch removes the old kgdb reminants from ARCH=powerpc and implements the new style arch specific stub for the common kgdb core interface. It is possible to have xmon and kgdb in the same kernel, but you cannot use both at the same time because there is only one set of debug hooks. The arch specific kgdb implementation saves the previous state of the debug hooks and restores them if you unconfigure the kgdb I/O driver. Kgdb should have no impact on a kernel that has no kgdb I/O driver configured. Signed-off-by: Jason Wessel --- include/asm-powerpc/kgdb.h | 92 +++++++++++++++++++++++++--------------------- 1 file changed, 50 insertions(+), 42 deletions(-) (limited to 'include') diff --git a/include/asm-powerpc/kgdb.h b/include/asm-powerpc/kgdb.h index b617dac8296..1399caf719a 100644 --- a/include/asm-powerpc/kgdb.h +++ b/include/asm-powerpc/kgdb.h @@ -1,57 +1,65 @@ /* - * kgdb.h: Defines and declarations for serial line source level - * remote debugging of the Linux kernel using gdb. + * include/asm-powerpc/kgdb.h * + * The PowerPC (32/64) specific defines / externs for KGDB. Based on + * the previous 32bit and 64bit specific files, which had the following + * copyrights: + * + * PPC64 Mods (C) 2005 Frank Rowand (frowand@mvista.com) + * PPC Mods (C) 2004 Tom Rini (trini@mvista.com) + * PPC Mods (C) 2003 John Whitney (john.whitney@timesys.com) * PPC Mods (C) 1998 Michael Tesch (tesch@cs.wisc.edu) * + * * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) + * Author: Tom Rini + * + * 2006 (c) MontaVista Software, Inc. This file is licensed under + * the terms of the GNU General Public License version 2. This program + * is licensed "as is" without any warranty of any kind, whether express + * or implied. */ #ifdef __KERNEL__ -#ifndef _PPC_KGDB_H -#define _PPC_KGDB_H +#ifndef __POWERPC_KGDB_H__ +#define __POWERPC_KGDB_H__ #ifndef __ASSEMBLY__ -/* Things specific to the gen550 backend. */ -struct uart_port; - -extern void gen550_progress(char *, unsigned short); -extern void gen550_kgdb_map_scc(void); -extern void gen550_init(int, struct uart_port *); - -/* Things specific to the pmac backend. */ -extern void zs_kgdb_hook(int tty_num); - -/* To init the kgdb engine. (called by serial hook)*/ -extern void set_debug_traps(void); - -/* To enter the debugger explicitly. */ -extern void breakpoint(void); - -/* For taking exceptions - * these are defined in traps.c - */ -extern int (*debugger)(struct pt_regs *regs); -extern int (*debugger_bpt)(struct pt_regs *regs); -extern int (*debugger_sstep)(struct pt_regs *regs); -extern int (*debugger_iabr_match)(struct pt_regs *regs); -extern int (*debugger_dabr_match)(struct pt_regs *regs); -extern void (*debugger_fault_handler)(struct pt_regs *regs); - -/* What we bring to the party */ -int kgdb_bpt(struct pt_regs *regs); -int kgdb_sstep(struct pt_regs *regs); -void kgdb(struct pt_regs *regs); -int kgdb_iabr_match(struct pt_regs *regs); -int kgdb_dabr_match(struct pt_regs *regs); +#define BREAK_INSTR_SIZE 4 +#define BUFMAX ((NUMREGBYTES * 2) + 512) +#define OUTBUFMAX ((NUMREGBYTES * 2) + 512) +static inline void arch_kgdb_breakpoint(void) +{ + asm(".long 0x7d821008"); /* twge r2, r2 */ +} +#define CACHE_FLUSH_IS_SAFE 1 +/* The number bytes of registers we have to save depends on a few + * things. For 64bit we default to not including vector registers and + * vector state registers. */ +#ifdef CONFIG_PPC64 /* - * external low-level support routines (ie macserial.c) + * 64 bit (8 byte) registers: + * 32 gpr, 32 fpr, nip, msr, link, ctr + * 32 bit (4 byte) registers: + * ccr, xer, fpscr */ -extern void kgdb_interruptible(int); /* control interrupts from serial */ -extern void putDebugChar(char); /* write a single character */ -extern char getDebugChar(void); /* read and return a single char */ - +#define NUMREGBYTES ((68 * 8) + (3 * 4)) +#define NUMCRITREGBYTES 184 +#else /* CONFIG_PPC32 */ +/* On non-E500 family PPC32 we determine the size by picking the last + * register we need, but on E500 we skip sections so we list what we + * need to store, and add it up. */ +#ifndef CONFIG_E500 +#define MAXREG (PT_FPSCR+1) +#else +/* 32 GPRs (8 bytes), nip, msr, ccr, link, ctr, xer, acc (8 bytes), spefscr*/ +#define MAXREG ((32*2)+6+2+1) +#endif +#define NUMREGBYTES (MAXREG * sizeof(int)) +/* CR/LR, R1, R2, R13-R31 inclusive. */ +#define NUMCRITREGBYTES (23 * sizeof(int)) +#endif /* 32/64 */ #endif /* !(__ASSEMBLY__) */ -#endif /* !(_PPC_KGDB_H) */ +#endif /* !__POWERPC_KGDB_H__ */ #endif /* __KERNEL__ */ -- cgit v1.2.3