sh: Generic kgdb stub support.

This migrates from the old bitrotted kgdb stub implementation and moves
to the generic stub. In the process support for SH-2/SH-2A is also added,
which the old stub never provided.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/Kconfig

@@ -27,6 +27,7 @@ config SUPERH32
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_DYNAMIC_FTRACE
+	select HAVE_ARCH_KGDB
 
 config SUPERH64
 	def_bool y if CPU_SH5

arch/sh/Kconfig.debug

@@ -98,19 +98,6 @@ config IRQSTACKS
 	  for handling hard and soft interrupts.  This can help avoid
 	  overflowing the process kernel stacks.
 
-config SH_KGDB
-	bool "Include KGDB kernel debugger"
-	select FRAME_POINTER
-	select DEBUG_INFO
-	depends on CPU_SH3 || CPU_SH4
-	help
-	  Include in-kernel hooks for kgdb, the Linux kernel source level
-	  debugger.  See <http://kgdb.sourceforge.net/> for more information.
-	  Unless you are intending to debug the kernel, say N here.
-
-menu "KGDB configuration options"
-	depends on SH_KGDB
-
 config MORE_COMPILE_OPTIONS
 	bool "Add any additional compile options"
 	help
@@ -122,62 +109,6 @@ config COMPILE_OPTIONS
 	string "Additional compile arguments"
 	depends on MORE_COMPILE_OPTIONS
 
-config KGDB_NMI
-	def_bool n
-	prompt "Enter KGDB on NMI"
-
-config SH_KGDB_CONSOLE
-	def_bool n
-	prompt "Console messages through GDB"
-	depends on !SERIAL_SH_SCI_CONSOLE && SERIAL_SH_SCI=y
-	select SERIAL_CORE_CONSOLE
-
-config KGDB_SYSRQ
-	def_bool y
-	prompt "Allow SysRq 'G' to enter KGDB"
-	depends on MAGIC_SYSRQ
-
-comment "Serial port setup"
-
-config KGDB_DEFPORT
-	int "Port number (ttySCn)"
-	default "1"
-
-config KGDB_DEFBAUD
-	int "Baud rate"
-	default "115200"
-
-choice
-	prompt "Parity"
-	depends on SH_KGDB
-	default KGDB_DEFPARITY_N
-
-config KGDB_DEFPARITY_N
-	bool "None"
-
-config KGDB_DEFPARITY_E
-	bool "Even"
-
-config KGDB_DEFPARITY_O
-	bool "Odd"
-
-endchoice
-
-choice
-	prompt "Data bits"
-	depends on SH_KGDB
-	default KGDB_DEFBITS_8
-
-config KGDB_DEFBITS_8
-	bool "8"
-
-config KGDB_DEFBITS_7
-	bool "7"
-
-endchoice
-
-endmenu
-
 if SUPERH64
 
 config SH64_SR_WATCH

arch/sh/include/asm/kgdb.h

-/*
- * May be copied or modified under the terms of the GNU General Public
- * License.  See linux/COPYING for more information.
- *
- * Based on original code by Glenn Engel, Jim Kingdon,
- * David Grothe <dave@gcom.com>, Tigran Aivazian, <tigran@sco.com> and
- * Amit S. Kale <akale@veritas.com>
- * 
- * Super-H port based on sh-stub.c (Ben Lee and Steve Chamberlain) by
- * Henry Bell <henry.bell@st.com>
- * 
- * Header file for low-level support for remote debug using GDB. 
- *
- */
-
-#ifndef __KGDB_H
-#define __KGDB_H
+#ifndef __ASM_SH_KGDB_H
+#define __ASM_SH_KGDB_H
 
+#include <asm/cacheflush.h>
 #include <asm/ptrace.h>
 
 /* Same as pt_regs but has vbr in place of syscall_nr */
@@ -30,40 +16,26 @@ struct kgdb_regs {
         unsigned long vbr;
 };
 
-/* State info */
-extern char kgdb_in_gdb_mode;
-extern int kgdb_nofault;	/* Ignore bus errors (in gdb mem access) */
-extern char in_nmi;		/* Debounce flag to prevent NMI reentry*/
+enum regnames {
+	GDB_R0, GDB_R1, GDB_R2, GDB_R3, GDB_R4, GDB_R5, GDB_R6, GDB_R7,
+	GDB_R8, GDB_R9, GDB_R10, GDB_R11, GDB_R12, GDB_R13, GDB_R14, GDB_R15,
 
-/* SCI */
-extern int kgdb_portnum;
-extern int kgdb_baud;
-extern char kgdb_parity;
-extern char kgdb_bits;
+	GDB_PC, GDB_PR, GDB_SR, GDB_GBR, GDB_MACH, GDB_MACL, GDB_VBR,
+};
 
-/* Init and interface stuff */
-extern int kgdb_init(void);
-extern int (*kgdb_getchar)(void);
-extern void (*kgdb_putchar)(int);
+#define NUMREGBYTES    ((GDB_VBR + 1) * 4)
 
-/* Trap functions */
-typedef void (kgdb_debug_hook_t)(struct pt_regs *regs);
-typedef void (kgdb_bus_error_hook_t)(void);
-extern kgdb_debug_hook_t  *kgdb_debug_hook;
-extern kgdb_bus_error_hook_t *kgdb_bus_err_hook;
+static inline void arch_kgdb_breakpoint(void)
+{
+	__asm__ __volatile__ ("trapa #0x3c\n");
+}
 
-/* Console */
-struct console;
-void kgdb_console_write(struct console *co, const char *s, unsigned count);
-extern int kgdb_console_setup(struct console *, char *);
+/* State info */
+extern char in_nmi;		/* Debounce flag to prevent NMI reentry*/
 
-/* Prototypes for jmp fns */
-#define _JBLEN 9
-typedef        int jmp_buf[_JBLEN];
-extern void    longjmp(jmp_buf __jmpb, int __retval);
-extern int     setjmp(jmp_buf __jmpb);
+#define BUFMAX                 2048
 
-/* Forced breakpoint */
-#define breakpoint()	__asm__ __volatile__("trapa   #0x3c")
+#define CACHE_FLUSH_IS_SAFE	1
+#define BREAK_INSTR_SIZE	2
 
-#endif
+#endif /* __ASM_SH_KGDB_H */

arch/sh/include/asm/system.h

@@ -175,6 +175,8 @@ asmlinkage void name##_trap_handler(unsigned int vec, struct pt_regs *regs)
 BUILD_TRAP_HANDLER(address_error);
 BUILD_TRAP_HANDLER(debug);
 BUILD_TRAP_HANDLER(bug);
+BUILD_TRAP_HANDLER(breakpoint);
+BUILD_TRAP_HANDLER(singlestep);
 BUILD_TRAP_HANDLER(fpu_error);
 BUILD_TRAP_HANDLER(fpu_state_restore);
 

arch/sh/kernel/Makefile_32

@@ -19,7 +19,7 @@ obj-$(CONFIG_VSYSCALL)		+= vsyscall/
 obj-$(CONFIG_SMP)		+= smp.o
 obj-$(CONFIG_CF_ENABLER)	+= cf-enabler.o
 obj-$(CONFIG_SH_STANDARD_BIOS)	+= sh_bios.o
-obj-$(CONFIG_SH_KGDB)		+= kgdb_stub.o kgdb_jmp.o
+obj-$(CONFIG_KGDB)		+= kgdb.o
 obj-$(CONFIG_SH_CPU_FREQ)	+= cpufreq.o
 obj-$(CONFIG_MODULES)		+= sh_ksyms_32.o module.o
 obj-$(CONFIG_EARLY_PRINTK)	+= early_printk.o

arch/sh/kernel/cpu/sh3/entry.S

@@ -52,7 +52,7 @@
  *	syscall #
  *
  */
-#if defined(CONFIG_KGDB_NMI)
+#if defined(CONFIG_KGDB)
 NMI_VEC = 0x1c0			! Must catch early for debounce
 #endif
 
@@ -307,7 +307,7 @@ skip_restore:
 6:	or	k0, k2			! Set the IMASK-bits
 	ldc	k2, ssr
 	!
-#if defined(CONFIG_KGDB_NMI)
+#if defined(CONFIG_KGDB)
 	! Clear in_nmi
 	mov.l	6f, k0
 	mov	#0, k1
@@ -320,7 +320,7 @@ skip_restore:
 
 	.align	2
 5:	.long	0x00001000	! DSP
-#ifdef CONFIG_KGDB_NMI
+#ifdef CONFIG_KGDB
 6:	.long	in_nmi
 #endif
 7:	.long	0x30000000
@@ -377,7 +377,7 @@ tlb_miss:
 	.balign 	512,0,512
 interrupt:
 	mov.l	3f, k3
-#if defined(CONFIG_KGDB_NMI)
+#if defined(CONFIG_KGDB)
 	mov.l	2f, k2
 	! Debounce (filter nested NMI)
 	mov.l	@k2, k0
@@ -394,7 +394,7 @@ interrupt:
 5:	.long	NMI_VEC
 6:	.long	in_nmi
 0:
-#endif /* defined(CONFIG_KGDB_NMI) */
+#endif /* defined(CONFIG_KGDB) */
 	bra	handle_exception
 	 mov	#-1, k2		! interrupt exception marker
 

arch/sh/kernel/cpu/sh3/ex.S

@@ -26,7 +26,7 @@
 #define	fpu_error_trap_handler		exception_error
 #endif
 
-#if !defined(CONFIG_KGDB_NMI)
+#if !defined(CONFIG_KGDB)
 #define kgdb_handle_exception		exception_error
 #endif
 

arch/sh/kernel/debugtraps.S

@@ -3,7 +3,7 @@
  *
  * Debug trap jump tables for SuperH
  *
- *  Copyright (C) 2006  Paul Mundt
+ *  Copyright (C) 2006 - 2008  Paul Mundt
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file "COPYING" in the main directory of this archive
@@ -12,12 +12,13 @@
 #include <linux/sys.h>
 #include <linux/linkage.h>
 
-#if !defined(CONFIG_SH_KGDB)
-#define kgdb_handle_exception	debug_trap_handler
+#if !defined(CONFIG_KGDB)
+#define breakpoint_trap_handler		debug_trap_handler
+#define singlestep_trap_handler		debug_trap_handler
 #endif
 
 #if !defined(CONFIG_SH_STANDARD_BIOS)
-#define sh_bios_handler		debug_trap_handler
+#define sh_bios_handler			debug_trap_handler
 #endif
 
 	.data
@@ -35,7 +36,7 @@ ENTRY(debug_trap_table)
 	.long debug_trap_handler	/* 0x39 */
 	.long debug_trap_handler	/* 0x3a */
 	.long debug_trap_handler	/* 0x3b */
-	.long kgdb_handle_exception	/* 0x3c */
-	.long debug_trap_handler	/* 0x3d */
+	.long breakpoint_trap_handler	/* 0x3c */
+	.long singlestep_trap_handler	/* 0x3d */
 	.long bug_trap_handler		/* 0x3e */
 	.long sh_bios_handler		/* 0x3f */

arch/sh/kernel/entry-common.S

@@ -308,15 +308,19 @@ ENTRY(system_call)
 	mov.l	1f, r9
 	mov.l	@r9, r8		! Read from TRA (Trap Address) Register
 #endif
+
+	mov	#OFF_TRA, r10
+	add	r15, r10
+	mov.l	r8, @r10		! set TRA value to tra
+
 	/*
 	 * Check the trap type
 	 */
 	mov	#((0x20 << 2) - 1), r9
 	cmp/hi	r9, r8
 	bt/s	debug_trap		! it's a debug trap..
-	 mov	#OFF_TRA, r9
-	add	r15, r9
-	mov.l	r8, @r9			! set TRA value to tra
+	 nop
+
 #ifdef CONFIG_TRACE_IRQFLAGS
 	mov.l	5f, r10
 	jsr	@r10

arch/sh/kernel/kgdb.c

+/*
+ * SuperH KGDB support
+ *
+ * Copyright (C) 2008  Paul Mundt
+ *
+ * Single stepping taken from the old stub by Henry Bell and Jeremy Siegel.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/kgdb.h>
+#include <linux/kdebug.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <asm/cacheflush.h>
+
+char in_nmi = 0;	/* Set during NMI to prevent re-entry */
+
+/* Macros for single step instruction identification */
+#define OPCODE_BT(op)		(((op) & 0xff00) == 0x8900)
+#define OPCODE_BF(op)		(((op) & 0xff00) == 0x8b00)
+#define OPCODE_BTF_DISP(op)	(((op) & 0x80) ? (((op) | 0xffffff80) << 1) : \
+				 (((op) & 0x7f ) << 1))
+#define OPCODE_BFS(op)		(((op) & 0xff00) == 0x8f00)
+#define OPCODE_BTS(op)		(((op) & 0xff00) == 0x8d00)
+#define OPCODE_BRA(op)		(((op) & 0xf000) == 0xa000)
+#define OPCODE_BRA_DISP(op)	(((op) & 0x800) ? (((op) | 0xfffff800) << 1) : \
+				 (((op) & 0x7ff) << 1))
+#define OPCODE_BRAF(op)		(((op) & 0xf0ff) == 0x0023)
+#define OPCODE_BRAF_REG(op)	(((op) & 0x0f00) >> 8)
+#define OPCODE_BSR(op)		(((op) & 0xf000) == 0xb000)
+#define OPCODE_BSR_DISP(op)	(((op) & 0x800) ? (((op) | 0xfffff800) << 1) : \
+				 (((op) & 0x7ff) << 1))
+#define OPCODE_BSRF(op)		(((op) & 0xf0ff) == 0x0003)
+#define OPCODE_BSRF_REG(op)	(((op) >> 8) & 0xf)
+#define OPCODE_JMP(op)		(((op) & 0xf0ff) == 0x402b)
+#define OPCODE_JMP_REG(op)	(((op) >> 8) & 0xf)
+#define OPCODE_JSR(op)		(((op) & 0xf0ff) == 0x400b)
+#define OPCODE_JSR_REG(op)	(((op) >> 8) & 0xf)
+#define OPCODE_RTS(op)		((op) == 0xb)
+#define OPCODE_RTE(op)		((op) == 0x2b)
+
+#define SR_T_BIT_MASK           0x1
+#define STEP_OPCODE             0xc33d
+
+/* Calculate the new address for after a step */
+static short *get_step_address(struct pt_regs *linux_regs)
+{
+	opcode_t op = __raw_readw(linux_regs->pc);
+	long addr;
+
+	/* BT */
+	if (OPCODE_BT(op)) {
+		if (linux_regs->sr & SR_T_BIT_MASK)
+			addr = linux_regs->pc + 4 + OPCODE_BTF_DISP(op);
+		else
+			addr = linux_regs->pc + 2;
+	}
+
+	/* BTS */
+	else if (OPCODE_BTS(op)) {
+		if (linux_regs->sr & SR_T_BIT_MASK)
+			addr = linux_regs->pc + 4 + OPCODE_BTF_DISP(op);
+		else
+			addr = linux_regs->pc + 4;	/* Not in delay slot */
+	}
+
+	/* BF */
+	else if (OPCODE_BF(op)) {
+		if (!(linux_regs->sr & SR_T_BIT_MASK))
+			addr = linux_regs->pc + 4 + OPCODE_BTF_DISP(op);
+		else
+			addr = linux_regs->pc + 2;
+	}
+
+	/* BFS */
+	else if (OPCODE_BFS(op)) {
+		if (!(linux_regs->sr & SR_T_BIT_MASK))
+			addr = linux_regs->pc + 4 + OPCODE_BTF_DISP(op);
+		else
+			addr = linux_regs->pc + 4;	/* Not in delay slot */
+	}
+
+	/* BRA */
+	else if (OPCODE_BRA(op))
+		addr = linux_regs->pc + 4 + OPCODE_BRA_DISP(op);
+
+	/* BRAF */
+	else if (OPCODE_BRAF(op))
+		addr = linux_regs->pc + 4
+		    + linux_regs->regs[OPCODE_BRAF_REG(op)];
+
+	/* BSR */
+	else if (OPCODE_BSR(op))
+		addr = linux_regs->pc + 4 + OPCODE_BSR_DISP(op);
+
+	/* BSRF */
+	else if (OPCODE_BSRF(op))
+		addr = linux_regs->pc + 4
+		    + linux_regs->regs[OPCODE_BSRF_REG(op)];
+
+	/* JMP */
+	else if (OPCODE_JMP(op))
+		addr = linux_regs->regs[OPCODE_JMP_REG(op)];
+
+	/* JSR */
+	else if (OPCODE_JSR(op))
+		addr = linux_regs->regs[OPCODE_JSR_REG(op)];
+
+	/* RTS */
+	else if (OPCODE_RTS(op))
+		addr = linux_regs->pr;
+
+	/* RTE */
+	else if (OPCODE_RTE(op))
+		addr = linux_regs->regs[15];
+
+	/* Other */
+	else
+		addr = linux_regs->pc + instruction_size(op);
+
+	flush_icache_range(addr, addr + instruction_size(op));
+	return (short *)addr;
+}
+
+/*
+ * Replace the instruction immediately after the current instruction
+ * (i.e. next in the expected flow of control) with a trap instruction,
+ * so that returning will cause only a single instruction to be executed.
+ * Note that this model is slightly broken for instructions with delay
+ * slots (e.g. B[TF]S, BSR, BRA etc), where both the branch and the
+ * instruction in the delay slot will be executed.
+ */
+
+static unsigned long stepped_address;
+static opcode_t stepped_opcode;
+
+static void do_single_step(struct pt_regs *linux_regs)
+{
+	/* Determine where the target instruction will send us to */
+	unsigned short *addr = get_step_address(linux_regs);
+
+	stepped_address = (int)addr;
+
+	/* Replace it */
+	stepped_opcode = __raw_readw((long)addr);
+	*addr = STEP_OPCODE;
+
+	/* Flush and return */
+	flush_icache_range((long)addr, (long)addr +
+			   instruction_size(stepped_opcode));
+}
+
+/* Undo a single step */
+static void undo_single_step(struct pt_regs *linux_regs)
+{
+	/* If we have stepped, put back the old instruction */
+	/* Use stepped_address in case we stopped elsewhere */
+	if (stepped_opcode != 0) {
+		__raw_writew(stepped_opcode, stepped_address);
+		flush_icache_range(stepped_address, stepped_address + 2);
+	}
+
+	stepped_opcode = 0;
+}
+
+void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+	int i;
+
+	for (i = 0; i < 16; i++)
+		gdb_regs[GDB_R0 + i] = regs->regs[i];
+
+	gdb_regs[GDB_PC] = regs->pc;
+	gdb_regs[GDB_PR] = regs->pr;
+	gdb_regs[GDB_SR] = regs->sr;
+	gdb_regs[GDB_GBR] = regs->gbr;
+	gdb_regs[GDB_MACH] = regs->mach;
+	gdb_regs[GDB_MACL] = regs->macl;
+
+	__asm__ __volatile__ ("stc vbr, %0" : "=r" (gdb_regs[GDB_VBR]));
+}
+
+void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+	int i;
+
+	for (i = 0; i < 16; i++)
+		regs->regs[GDB_R0 + i] = gdb_regs[GDB_R0 + i];
+
+	regs->pc = gdb_regs[GDB_PC];
+	regs->pr = gdb_regs[GDB_PR];
+	regs->sr = gdb_regs[GDB_SR];
+	regs->gbr = gdb_regs[GDB_GBR];
+	regs->mach = gdb_regs[GDB_MACH];
+	regs->macl = gdb_regs[GDB_MACL];
+
+	__asm__ __volatile__ ("ldc %0, vbr" : : "r" (gdb_regs[GDB_VBR]));
+}
+
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+	gdb_regs[GDB_R15] = p->thread.sp;
+	gdb_regs[GDB_PC] = p->thread.pc;
+}
+
+int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
+			       char *remcomInBuffer, char *remcomOutBuffer,
+			       struct pt_regs *linux_regs)
+{
+	unsigned long addr;
+	char *ptr;
+
+	/* Undo any stepping we may have done */
+	undo_single_step(linux_regs);
+
+	switch (remcomInBuffer[0]) {
+	case 'c':
+	case 's':
+		/* try to read optional parameter, pc unchanged if no parm */
+		ptr = &remcomInBuffer[1];
+		if (kgdb_hex2long(&ptr, &addr))
+			linux_regs->pc = addr;
+	case 'D':
+	case 'k':
+		atomic_set(&kgdb_cpu_doing_single_step, -1);
+
+		if (remcomInBuffer[0] == 's') {
+			do_single_step(linux_regs);
+			kgdb_single_step = 1;
+
+			atomic_set(&kgdb_cpu_doing_single_step,
+				   raw_smp_processor_id());
+		}
+
+		return 0;
+	}
+
+	/* this means that we do not want to exit from the handler: */
+	return -1;
+}
+
+/*
+ * The primary entry points for the kgdb debug trap table entries.
+ */
+BUILD_TRAP_HANDLER(singlestep)
+{
+	unsigned long flags;
+	TRAP_HANDLER_DECL;
+
+	local_irq_save(flags);
+	regs->pc -= instruction_size(__raw_readw(regs->pc - 4));
+	kgdb_handle_exception(vec >> 2, SIGTRAP, 0, regs);
+	local_irq_restore(flags);
+}
+
+
+BUILD_TRAP_HANDLER(breakpoint)
+{
+	unsigned long flags;
+	TRAP_HANDLER_DECL;
+
+	local_irq_save(flags);
+	kgdb_handle_exception(vec >> 2, SIGTRAP, 0, regs);
+	local_irq_restore(flags);
+}
+
+int kgdb_arch_init(void)
+{
+	return 0;
+}
+
+void kgdb_arch_exit(void)
+{
+}
+
+struct kgdb_arch arch_kgdb_ops = {
+	/* Breakpoint instruction: trapa #0x3c */
+#ifdef CONFIG_CPU_LITTLE_ENDIAN
+	.gdb_bpt_instr		= { 0x3c, 0xc3 },
+#else
+	.gdb_bpt_instr		= { 0xc3, 0x3c },
+#endif
+};

arch/sh/kernel/kgdb_jmp.S

-#include <linux/linkage.h>
-
-ENTRY(setjmp)
-	add	#(9*4), r4
-	sts.l	pr, @-r4
-	mov.l	r15, @-r4
-	mov.l	r14, @-r4
-	mov.l	r13, @-r4
-	mov.l	r12, @-r4
-	mov.l	r11, @-r4
-	mov.l	r10, @-r4
-	mov.l	r9, @-r4
-	mov.l	r8, @-r4
-	rts
-	 mov	#0, r0
-
-ENTRY(longjmp)
-	mov.l	@r4+, r8
-	mov.l	@r4+, r9
-	mov.l	@r4+, r10
-	mov.l	@r4+, r11
-	mov.l	@r4+, r12
-	mov.l	@r4+, r13
-	mov.l	@r4+, r14
-	mov.l	@r4+, r15
-	lds.l	@r4+, pr
-	mov	r5, r0
-	tst	r0, r0
-	bf	1f
-	mov	#1, r0	! in case val==0
-1:	rts
-	 nop
-

arch/sh/kernel/kgdb_stub.c

-/*
- * May be copied or modified under the terms of the GNU General Public
- * License.  See linux/COPYING for more information.
- *
- * Contains extracts from code by Glenn Engel, Jim Kingdon,
- * David Grothe <dave@gcom.com>, Tigran Aivazian <tigran@sco.com>,
- * Amit S. Kale <akale@veritas.com>,  William Gatliff <bgat@open-widgets.com>,
- * Ben Lee, Steve Chamberlain and Benoit Miller <fulg@iname.com>.
- *
- * This version by Henry Bell <henry.bell@st.com>
- * Minor modifications by Jeremy Siegel <jsiegel@mvista.com>
- *
- * Contains low-level support for remote debug using GDB.
- *
- * To enable debugger support, two things need to happen. A call to
- * set_debug_traps() is necessary in order to allow any breakpoints
- * or error conditions to be properly intercepted and reported to gdb.
- * A breakpoint also needs to be generated to begin communication.  This
- * is most easily accomplished by a call to breakpoint() which does
- * a trapa if the initialisation phase has been successfully completed.
- *
- * In this case, set_debug_traps() is not used to "take over" exceptions;
- * other kernel code is modified instead to enter the kgdb functions here
- * when appropriate (see entry.S for breakpoint traps and NMI interrupts,
- * see traps.c for kernel error exceptions).
- *
- * The following gdb commands are supported:
- *
- *    Command       Function                               Return value
- *
- *    g             return the value of the CPU registers  hex data or ENN
- *    G             set the value of the CPU registers     OK or ENN
- *
- *    mAA..AA,LLLL  Read LLLL bytes at address AA..AA      hex data or ENN
- *    MAA..AA,LLLL: Write LLLL bytes at address AA.AA      OK or ENN
- *    XAA..AA,LLLL: Same, but data is binary (not hex)     OK or ENN
- *
- *    c             Resume at current address              SNN   ( signal NN)
- *    cAA..AA       Continue at address AA..AA             SNN
- *    CNN;          Resume at current address with signal  SNN
- *    CNN;AA..AA    Resume at address AA..AA with signal   SNN
- *
- *    s             Step one instruction                   SNN
- *    sAA..AA       Step one instruction from AA..AA       SNN
- *    SNN;          Step one instruction with signal       SNN
- *    SNNAA..AA     Step one instruction from AA..AA w/NN  SNN
- *
- *    k             kill (Detach GDB)
- *
- *    d             Toggle debug flag
- *    D             Detach GDB
- *
- *    Hct           Set thread t for operations,           OK or ENN
- *                  c = 'c' (step, cont), c = 'g' (other
- *                  operations)
- *
- *    qC            Query current thread ID                QCpid
- *    qfThreadInfo  Get list of current threads (first)    m<id>
- *    qsThreadInfo   "    "  "     "      "   (subsequent)
- *    qOffsets      Get section offsets                  Text=x;Data=y;Bss=z
- *
- *    TXX           Find if thread XX is alive             OK or ENN
- *    ?             What was the last sigval ?             SNN   (signal NN)
- *    O             Output to GDB console
- *
- * Remote communication protocol.
- *
- *    A debug packet whose contents are <data> is encapsulated for
- *    transmission in the form:
- *
- *       $ <data> # CSUM1 CSUM2
- *
- *       <data> must be ASCII alphanumeric and cannot include characters
- *       '$' or '#'.  If <data> starts with two characters followed by
- *       ':', then the existing stubs interpret this as a sequence number.
- *
- *       CSUM1 and CSUM2 are ascii hex representation of an 8-bit
- *       checksum of <data>, the most significant nibble is sent first.
- *       the hex digits 0-9,a-f are used.
- *
- *    Receiver responds with:
- *
- *       +       - if CSUM is correct and ready for next packet
- *       -       - if CSUM is incorrect
- *
- * Responses can be run-length encoded to save space.  A '*' means that
- * the next character is an ASCII encoding giving a repeat count which
- * stands for that many repetitions of the character preceding the '*'.
- * The encoding is n+29, yielding a printable character where n >=3
- * (which is where RLE starts to win).  Don't use an n > 126.
- *
- * So "0* " means the same as "0000".
- */
-
-#include <linux/string.h>
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/smp.h>
-#include <linux/spinlock.h>
-#include <linux/delay.h>
-#include <linux/linkage.h>
-#include <linux/init.h>
-#include <linux/console.h>
-#include <linux/sysrq.h>
-#include <linux/module.h>
-#include <asm/system.h>
-#include <asm/cacheflush.h>
-#include <asm/current.h>
-#include <asm/signal.h>
-#include <asm/pgtable.h>
-#include <asm/ptrace.h>
-#include <asm/kgdb.h>
-#include <asm/io.h>
-
-/* Function pointers for linkage */
-kgdb_debug_hook_t *kgdb_debug_hook;
-kgdb_bus_error_hook_t *kgdb_bus_err_hook;
-
-int (*kgdb_getchar)(void);
-EXPORT_SYMBOL_GPL(kgdb_getchar);
-void (*kgdb_putchar)(int);
-EXPORT_SYMBOL_GPL(kgdb_putchar);
-
-static void put_debug_char(int c)
-{
-	if (!kgdb_putchar)
-		return;
-	(*kgdb_putchar)(c);
-}
-static int get_debug_char(void)
-{
-	if (!kgdb_getchar)
-		return -1;
-	return (*kgdb_getchar)();
-}
-
-/* Num chars in in/out bound buffers, register packets need NUMREGBYTES * 2 */
-#define BUFMAX 1024
-#define NUMREGBYTES (MAXREG*4)
-#define OUTBUFMAX (NUMREGBYTES*2+512)
-
-enum {
-	R0 = 0, R1,  R2,  R3,   R4,   R5,  R6, R7,
-	R8, R9, R10, R11, R12,  R13,  R14, R15,
-	PC, PR, GBR, VBR, MACH, MACL, SR,
-	/*  */
-	MAXREG
-};
-
-static unsigned int registers[MAXREG];
-struct kgdb_regs trap_registers;
-
-char kgdb_in_gdb_mode;
-char in_nmi;			/* Set during NMI to prevent reentry */
-int kgdb_nofault;		/* Boolean to ignore bus errs (i.e. in GDB) */
-
-/* Default values for SCI (can override via kernel args in setup.c) */
-#ifndef CONFIG_KGDB_DEFPORT
-#define CONFIG_KGDB_DEFPORT 1
-#endif
-
-#ifndef CONFIG_KGDB_DEFBAUD
-#define CONFIG_KGDB_DEFBAUD 115200
-#endif
-
-#if defined(CONFIG_KGDB_DEFPARITY_E)
-#define CONFIG_KGDB_DEFPARITY 'E'
-#elif defined(CONFIG_KGDB_DEFPARITY_O)
-#define CONFIG_KGDB_DEFPARITY 'O'
-#else /* CONFIG_KGDB_DEFPARITY_N */
-#define CONFIG_KGDB_DEFPARITY 'N'
-#endif
-
-#ifdef CONFIG_KGDB_DEFBITS_7
-#define CONFIG_KGDB_DEFBITS '7'
-#else /* CONFIG_KGDB_DEFBITS_8 */
-#define CONFIG_KGDB_DEFBITS '8'
-#endif
-
-/* SCI/UART settings, used in kgdb_console_setup() */
-int  kgdb_portnum = CONFIG_KGDB_DEFPORT;
-EXPORT_SYMBOL_GPL(kgdb_portnum);
-int  kgdb_baud = CONFIG_KGDB_DEFBAUD;
-EXPORT_SYMBOL_GPL(kgdb_baud);
-char kgdb_parity = CONFIG_KGDB_DEFPARITY;
-EXPORT_SYMBOL_GPL(kgdb_parity);
-char kgdb_bits = CONFIG_KGDB_DEFBITS;
-EXPORT_SYMBOL_GPL(kgdb_bits);
-
-/* Jump buffer for setjmp/longjmp */
-static jmp_buf rem_com_env;
-
-/* TRA differs sh3/4 */
-#if defined(CONFIG_CPU_SH3)
-#define TRA 0xffffffd0
-#elif defined(CONFIG_CPU_SH4)
-#define TRA 0xff000020
-#endif
-
-/* Macros for single step instruction identification */
-#define OPCODE_BT(op)         (((op) & 0xff00) == 0x8900)
-#define OPCODE_BF(op)         (((op) & 0xff00) == 0x8b00)
-#define OPCODE_BTF_DISP(op)   (((op) & 0x80) ? (((op) | 0xffffff80) << 1) : \
-			      (((op) & 0x7f ) << 1))
-#define OPCODE_BFS(op)        (((op) & 0xff00) == 0x8f00)
-#define OPCODE_BTS(op)        (((op) & 0xff00) == 0x8d00)
-#define OPCODE_BRA(op)        (((op) & 0xf000) == 0xa000)
-#define OPCODE_BRA_DISP(op)   (((op) & 0x800) ? (((op) | 0xfffff800) << 1) : \
-			      (((op) & 0x7ff) << 1))
-#define OPCODE_BRAF(op)       (((op) & 0xf0ff) == 0x0023)
-#define OPCODE_BRAF_REG(op)   (((op) & 0x0f00) >> 8)
-#define OPCODE_BSR(op)        (((op) & 0xf000) == 0xb000)
-#define OPCODE_BSR_DISP(op)   (((op) & 0x800) ? (((op) | 0xfffff800) << 1) : \
-			      (((op) & 0x7ff) << 1))
-#define OPCODE_BSRF(op)       (((op) & 0xf0ff) == 0x0003)
-#define OPCODE_BSRF_REG(op)   (((op) >> 8) & 0xf)
-#define OPCODE_JMP(op)        (((op) & 0xf0ff) == 0x402b)
-#define OPCODE_JMP_REG(op)    (((op) >> 8) & 0xf)
-#define OPCODE_JSR(op)        (((op) & 0xf0ff) == 0x400b)
-#define OPCODE_JSR_REG(op)    (((op) >> 8) & 0xf)
-#define OPCODE_RTS(op)        ((op) == 0xb)
-#define OPCODE_RTE(op)        ((op) == 0x2b)
-
-#define SR_T_BIT_MASK           0x1
-#define STEP_OPCODE             0xc320
-#define BIOS_CALL_TRAP          0x3f
-
-/* Exception codes as per SH-4 core manual */
-#define ADDRESS_ERROR_LOAD_VEC   7
-#define ADDRESS_ERROR_STORE_VEC  8
-#define TRAP_VEC                 11
-#define INVALID_INSN_VEC         12
-#define INVALID_SLOT_VEC         13
-#define NMI_VEC                  14
-#define USER_BREAK_VEC           15
-#define SERIAL_BREAK_VEC         58
-
-/* Misc static */
-static int stepped_address;
-static short stepped_opcode;
-static char in_buffer[BUFMAX];
-static char out_buffer[OUTBUFMAX];
-
-static void kgdb_to_gdb(const char *s);
-
-/* Convert ch to hex */
-static int hex(const char ch)
-{
-	if ((ch >= 'a') && (ch <= 'f'))
-		return (ch - 'a' + 10);
-	if ((ch >= '0') && (ch <= '9'))
-		return (ch - '0');
-	if ((ch >= 'A') && (ch <= 'F'))
-		return (ch - 'A' + 10);
-	return (-1);
-}
-
-/* Convert the memory pointed to by mem into hex, placing result in buf.
-   Returns a pointer to the last char put in buf (null) */
-static char *mem_to_hex(const char *mem, char *buf, const int count)
-{
-	int i;
-	int ch;
-	unsigned short s_val;
-	unsigned long l_val;
-
-	/* Check for 16 or 32 */
-	if (count == 2 && ((long) mem & 1) == 0) {
-		s_val = *(unsigned short *) mem;
-		mem = (char *) &s_val;
-	} else if (count == 4 && ((long) mem & 3) == 0) {
-		l_val = *(unsigned long *) mem;
-		mem = (char *) &l_val;
-	}
-	for (i = 0; i < count; i++) {
-		ch = *mem++;
-		buf = pack_hex_byte(buf, ch);
-	}
-	*buf = 0;
-	return (buf);
-}
-
-/* Convert the hex array pointed to by buf into binary, to be placed in mem.
-   Return a pointer to the character after the last byte written */
-static char *hex_to_mem(const char *buf, char *mem, const int count)
-{
-	int i;
-	unsigned char ch;
-
-	for (i = 0; i < count; i++) {
-		ch = hex(*buf++) << 4;
-		ch = ch + hex(*buf++);
-		*mem++ = ch;
-	}
-	return (mem);
-}
-
-/* While finding valid hex chars, convert to an integer, then return it */
-static int hex_to_int(char **ptr, int *int_value)
-{
-	int num_chars = 0;
-	int hex_value;
-
-	*int_value = 0;
-
-	while (**ptr) {
-		hex_value = hex(**ptr);
-		if (hex_value >= 0) {
-			*int_value = (*int_value << 4) | hex_value;
-			num_chars++;
-		} else
-			break;
-		(*ptr)++;
-	}
-	return num_chars;
-}
-
-/*  Copy the binary array pointed to by buf into mem.  Fix $, #,
-    and 0x7d escaped with 0x7d.  Return a pointer to the character
-    after the last byte written. */
-static char *ebin_to_mem(const char *buf, char *mem, int count)
-{
-	for (; count > 0; count--, buf++) {
-		if (*buf == 0x7d)
-			*mem++ = *(++buf) ^ 0x20;
-		else
-			*mem++ = *buf;
-	}
-	return mem;
-}
-
-/* Scan for the start char '$', read the packet and check the checksum */
-static void get_packet(char *buffer, int buflen)
-{
-	unsigned char checksum;
-	unsigned char xmitcsum;
-	int i;
-	int count;
-	char ch;
-
-	do {
-		/* Ignore everything until the start character */
-		while ((ch = get_debug_char()) != '$');
-
-		checksum = 0;
-		xmitcsum = -1;
-		count = 0;
-
-		/* Now, read until a # or end of buffer is found */
-		while (count < (buflen - 1)) {
-			ch = get_debug_char();
-
-			if (ch == '#')
-				break;
-
-			checksum = checksum + ch;
-			buffer[count] = ch;
-			count = count + 1;
-		}
-
-		buffer[count] = 0;
-
-		/* Continue to read checksum following # */
-		if (ch == '#') {
-			xmitcsum = hex(get_debug_char()) << 4;
-			xmitcsum += hex(get_debug_char());
-
-			/* Checksum */
-			if (checksum != xmitcsum)
-				put_debug_char('-');	/* Failed checksum */
-			else {
-				/* Ack successful transfer */
-				put_debug_char('+');
-
-				/* If a sequence char is present, reply
-				   the sequence ID */
-				if (buffer[2] == ':') {
-					put_debug_char(buffer[0]);
-					put_debug_char(buffer[1]);
-
-					/* Remove sequence chars from buffer */
-					count = strlen(buffer);
-					for (i = 3; i <= count; i++)
-						buffer[i - 3] = buffer[i];
-				}
-			}
-		}
-	}
-	while (checksum != xmitcsum);	/* Keep trying while we fail */
-}
-
-/* Send the packet in the buffer with run-length encoding */
-static void put_packet(char *buffer)
-{
-	int checksum;
-	char *src;
-	int runlen;
-	int encode;
-
-	do {
-		src = buffer;
-		put_debug_char('$');
-		checksum = 0;
-
-		/* Continue while we still have chars left */
-		while (*src) {
-			/* Check for runs up to 99 chars long */
-			for (runlen = 1; runlen < 99; runlen++) {
-				if (src[0] != src[runlen])
-					break;
-			}
-
-			if (runlen > 3) {
-				/* Got a useful amount, send encoding */
-				encode = runlen + ' ' - 4;
-				put_debug_char(*src);   checksum += *src;
-				put_debug_char('*');    checksum += '*';
-				put_debug_char(encode); checksum += encode;
-				src += runlen;
-			} else {
-				/* Otherwise just send the current char */
-				put_debug_char(*src);   checksum += *src;
-				src += 1;
-			}
-		}
-
-		/* '#' Separator, put high and low components of checksum */
-		put_debug_char('#');
-		put_debug_char(hex_asc_hi(checksum));
-		put_debug_char(hex_asc_lo(checksum));
-	}
-	while ((get_debug_char()) != '+');	/* While no ack */
-}
-
-/* A bus error has occurred - perform a longjmp to return execution and
-   allow handling of the error */
-static void kgdb_handle_bus_error(void)
-{
-	longjmp(rem_com_env, 1);
-}
-
-/* Translate SH-3/4 exception numbers to unix-like signal values */
-static int compute_signal(const int excep_code)
-{
-	int sigval;
-
-	switch (excep_code) {
-
-	case INVALID_INSN_VEC:
-	case INVALID_SLOT_VEC:
-		sigval = SIGILL;
-		break;
-	case ADDRESS_ERROR_LOAD_VEC:
-	case ADDRESS_ERROR_STORE_VEC:
-		sigval = SIGSEGV;
-		break;
-
-	case SERIAL_BREAK_VEC:
-	case NMI_VEC:
-		sigval = SIGINT;
-		break;
-
-	case USER_BREAK_VEC:
-	case TRAP_VEC:
-		sigval = SIGTRAP;
-		break;
-
-	default:
-		sigval = SIGBUS;	/* "software generated" */
-		break;
-	}
-
-	return (sigval);
-}
-
-/* Make a local copy of the registers passed into the handler (bletch) */
-static void kgdb_regs_to_gdb_regs(const struct kgdb_regs *regs,
-				  int *gdb_regs)
-{
-	gdb_regs[R0] = regs->regs[R0];
-	gdb_regs[R1] = regs->regs[R1];
-	gdb_regs[R2] = regs->regs[R2];
-	gdb_regs[R3] = regs->regs[R3];
-	gdb_regs[R4] = regs->regs[R4];
-	gdb_regs[R5] = regs->regs[R5];
-	gdb_regs[R6] = regs->regs[R6];
-	gdb_regs[R7] = regs->regs[R7];
-	gdb_regs[R8] = regs->regs[R8];
-	gdb_regs[R9] = regs->regs[R9];
-	gdb_regs[R10] = regs->regs[R10];
-	gdb_regs[R11] = regs->regs[R11];
-	gdb_regs[R12] = regs->regs[R12];
-	gdb_regs[R13] = regs->regs[R13];
-	gdb_regs[R14] = regs->regs[R14];
-	gdb_regs[R15] = regs->regs[R15];
-	gdb_regs[PC] = regs->pc;
-	gdb_regs[PR] = regs->pr;
-	gdb_regs[GBR] = regs->gbr;
-	gdb_regs[MACH] = regs->mach;
-	gdb_regs[MACL] = regs->macl;
-	gdb_regs[SR] = regs->sr;
-	gdb_regs[VBR] = regs->vbr;
-}
-
-/* Copy local gdb registers back to kgdb regs, for later copy to kernel */
-static void gdb_regs_to_kgdb_regs(const int *gdb_regs,
-				  struct kgdb_regs *regs)
-{
-	regs->regs[R0] = gdb_regs[R0];
-	regs->regs[R1] = gdb_regs[R1];
-	regs->regs[R2] = gdb_regs[R2];
-	regs->regs[R3] = gdb_regs[R3];
-	regs->regs[R4] = gdb_regs[R4];
-	regs->regs[R5] = gdb_regs[R5];
-	regs->regs[R6] = gdb_regs[R6];
-	regs->regs[R7] = gdb_regs[R7];
-	regs->regs[R8] = gdb_regs[R8];
-	regs->regs[R9] = gdb_regs[R9];
-	regs->regs[R10] = gdb_regs[R10];
-	regs->regs[R11] = gdb_regs[R11];
-	regs->regs[R12] = gdb_regs[R12];
-	regs->regs[R13] = gdb_regs[R13];
-	regs->regs[R14] = gdb_regs[R14];
-	regs->regs[R15] = gdb_regs[R15];
-	regs->pc = gdb_regs[PC];
-	regs->pr = gdb_regs[PR];
-	regs->gbr = gdb_regs[GBR];
-	regs->mach = gdb_regs[MACH];
-	regs->macl = gdb_regs[MACL];
-	regs->sr = gdb_regs[SR];
-	regs->vbr = gdb_regs[VBR];
-}
-
-/* Calculate the new address for after a step */
-static short *get_step_address(void)
-{
-	short op = *(short *) trap_registers.pc;
-	long addr;
-
-	/* BT */
-	if (OPCODE_BT(op)) {
-		if (trap_registers.sr & SR_T_BIT_MASK)
-			addr = trap_registers.pc + 4 + OPCODE_BTF_DISP(op);
-		else
-			addr = trap_registers.pc + 2;
-	}
-
-	/* BTS */
-	else if (OPCODE_BTS(op)) {
-		if (trap_registers.sr & SR_T_BIT_MASK)
-			addr = trap_registers.pc + 4 + OPCODE_BTF_DISP(op);
-		else
-			addr = trap_registers.pc + 4;	/* Not in delay slot */
-	}
-
-	/* BF */
-	else if (OPCODE_BF(op)) {
-		if (!(trap_registers.sr & SR_T_BIT_MASK))
-			addr = trap_registers.pc + 4 + OPCODE_BTF_DISP(op);
-		else
-			addr = trap_registers.pc + 2;
-	}
-
-	/* BFS */
-	else if (OPCODE_BFS(op)) {
-		if (!(trap_registers.sr & SR_T_BIT_MASK))
-			addr = trap_registers.pc + 4 + OPCODE_BTF_DISP(op);
-		else
-			addr = trap_registers.pc + 4;	/* Not in delay slot */
-	}
-
-	/* BRA */
-	else if (OPCODE_BRA(op))
-		addr = trap_registers.pc + 4 + OPCODE_BRA_DISP(op);
-
-	/* BRAF */
-	else if (OPCODE_BRAF(op))
-		addr = trap_registers.pc + 4
-		    + trap_registers.regs[OPCODE_BRAF_REG(op)];
-
-	/* BSR */
-	else if (OPCODE_BSR(op))
-		addr = trap_registers.pc + 4 + OPCODE_BSR_DISP(op);
-
-	/* BSRF */
-	else if (OPCODE_BSRF(op))
-		addr = trap_registers.pc + 4
-		    + trap_registers.regs[OPCODE_BSRF_REG(op)];
-
-	/* JMP */
-	else if (OPCODE_JMP(op))
-		addr = trap_registers.regs[OPCODE_JMP_REG(op)];
-
-	/* JSR */
-	else if (OPCODE_JSR(op))
-		addr = trap_registers.regs[OPCODE_JSR_REG(op)];
-
-	/* RTS */
-	else if (OPCODE_RTS(op))
-		addr = trap_registers.pr;
-
-	/* RTE */
-	else if (OPCODE_RTE(op))
-		addr = trap_registers.regs[15];
-
-	/* Other */
-	else
-		addr = trap_registers.pc + 2;
-
-	flush_icache_range(addr, addr + 2);
-	return (short *) addr;
-}
-
-/* Set up a single-step.  Replace the instruction immediately after the
-   current instruction (i.e. next in the expected flow of control) with a
-   trap instruction, so that returning will cause only a single instruction
-   to be executed. Note that this model is slightly broken for instructions
-   with delay slots (e.g. B[TF]S, BSR, BRA etc), where both the branch
-   and the instruction in the delay slot will be executed. */
-static void do_single_step(void)
-{
-	unsigned short *addr = 0;
-
-	/* Determine where the target instruction will send us to */
-	addr = get_step_address();
-	stepped_address = (int)addr;
-
-	/* Replace it */
-	stepped_opcode = *(short *)addr;
-	*addr = STEP_OPCODE;
-
-	/* Flush and return */
-	flush_icache_range((long) addr, (long) addr + 2);
-}
-
-/* Undo a single step */
-static void undo_single_step(void)
-{
-	/* If we have stepped, put back the old instruction */
-	/* Use stepped_address in case we stopped elsewhere */
-	if (stepped_opcode != 0) {
-		*(short*)stepped_address = stepped_opcode;
-		flush_icache_range(stepped_address, stepped_address + 2);
-	}
-	stepped_opcode = 0;
-}
-
-/* Send a signal message */
-static void send_signal_msg(const int signum)
-{
-	out_buffer[0] = 'S';
-	out_buffer[1] = hex_asc_hi(signum);
-	out_buffer[2] = hex_asc_lo(signum);
-	out_buffer[3] = 0;
-	put_packet(out_buffer);
-}
-
-/* Reply that all was well */
-static void send_ok_msg(void)
-{
-	strcpy(out_buffer, "OK");
-	put_packet(out_buffer);
-}
-
-/* Reply that an error occurred */
-static void send_err_msg(void)
-{
-	strcpy(out_buffer, "E01");
-	put_packet(out_buffer);
-}
-
-/* Empty message indicates unrecognised command */
-static void send_empty_msg(void)
-{
-	put_packet("");
-}
-
-/* Read memory due to 'm' message */
-static void read_mem_msg(void)
-{
-	char *ptr;
-	int addr;
-	int length;
-
-	/* Jmp, disable bus error handler */
-	if (setjmp(rem_com_env) == 0) {
-
-		kgdb_nofault = 1;
-
-		/* Walk through, have m<addr>,<length> */
-		ptr = &in_buffer[1];
-		if (hex_to_int(&ptr, &addr) && (*ptr++ == ','))
-			if (hex_to_int(&ptr, &length)) {
-				ptr = 0;
-				if (length * 2 > OUTBUFMAX)
-					length = OUTBUFMAX / 2;
-				mem_to_hex((char *) addr, out_buffer, length);
-			}
-		if (ptr)
-			send_err_msg();
-		else
-			put_packet(out_buffer);
-	} else
-		send_err_msg();
-
-	/* Restore bus error handler */
-	kgdb_nofault = 0;
-}
-
-/* Write memory due to 'M' or 'X' message */
-static void write_mem_msg(int binary)
-{
-	char *ptr;
-	int addr;
-	int length;
-
-	if (setjmp(rem_com_env) == 0) {
-
-		kgdb_nofault = 1;
-
-		/* Walk through, have M<addr>,<length>:<data> */
-		ptr = &in_buffer[1];
-		if (hex_to_int(&ptr, &addr) && (*ptr++ == ','))
-			if (hex_to_int(&ptr, &length) && (*ptr++ == ':')) {
-				if (binary)
-					ebin_to_mem(ptr, (char*)addr, length);
-				else
-					hex_to_mem(ptr, (char*)addr, length);
-				flush_icache_range(addr, addr + length);
-				ptr = 0;
-				send_ok_msg();
-			}
-		if (ptr)
-			send_err_msg();
-	} else
-		send_err_msg();
-
-	/* Restore bus error handler */
-	kgdb_nofault = 0;
-}
-
-/* Continue message  */
-static void continue_msg(void)
-{
-	/* Try to read optional parameter, PC unchanged if none */
-	char *ptr = &in_buffer[1];
-	int addr;
-
-	if (hex_to_int(&ptr, &addr))
-		trap_registers.pc = addr;
-}
-
-/* Continue message with signal */
-static void continue_with_sig_msg(void)
-{
-	int signal;
-	char *ptr = &in_buffer[1];
-	int addr;
-
-	/* Report limitation */
-	kgdb_to_gdb("Cannot force signal in kgdb, continuing anyway.\n");
-
-	/* Signal */
-	hex_to_int(&ptr, &signal);
-	if (*ptr == ';')
-		ptr++;
-
-	/* Optional address */
-	if (hex_to_int(&ptr, &addr))
-		trap_registers.pc = addr;
-}
-
-/* Step message */
-static void step_msg(void)
-{
-	continue_msg();
-	do_single_step();
-}
-
-/* Step message with signal */
-static void step_with_sig_msg(void)
-{
-	continue_with_sig_msg();
-	do_single_step();
-}
-
-/* Send register contents */
-static void send_regs_msg(void)
-{
-	kgdb_regs_to_gdb_regs(&trap_registers, registers);
-	mem_to_hex((char *) registers, out_buffer, NUMREGBYTES);
-	put_packet(out_buffer);
-}
-
-/* Set register contents - currently can't set other thread's registers */
-static void set_regs_msg(void)
-{
-	kgdb_regs_to_gdb_regs(&trap_registers, registers);
-	hex_to_mem(&in_buffer[1], (char *) registers, NUMREGBYTES);
-	gdb_regs_to_kgdb_regs(registers, &trap_registers);
-	send_ok_msg();
-}
-
-#ifdef CONFIG_SH_KGDB_CONSOLE
-/*
- * Bring up the ports..
- */
-static int __init kgdb_serial_setup(void)
-{
-	struct console dummy;
-	return kgdb_console_setup(&dummy, 0);
-}
-#else
-#define kgdb_serial_setup()	0
-#endif
-
-/* The command loop, read and act on requests */
-static void kgdb_command_loop(const int excep_code, const int trapa_value)
-{
-	int sigval;
-
-	/* Enter GDB mode (e.g. after detach) */
-	if (!kgdb_in_gdb_mode) {
-		/* Do serial setup, notify user, issue preemptive ack */
-		printk(KERN_NOTICE "KGDB: Waiting for GDB\n");
-		kgdb_in_gdb_mode = 1;
-		put_debug_char('+');
-	}
-
-	/* Reply to host that an exception has occurred */
-	sigval = compute_signal(excep_code);
-	send_signal_msg(sigval);
-
-	/* TRAP_VEC exception indicates a software trap inserted in place of
-	   code by GDB so back up PC by one instruction, as this instruction
-	   will later be replaced by its original one.  Do NOT do this for
-	   trap 0xff, since that indicates a compiled-in breakpoint which
-	   will not be replaced (and we would retake the trap forever) */
-	if ((excep_code == TRAP_VEC) && (trapa_value != (0x3c << 2)))
-		trap_registers.pc -= 2;
-
-	/* Undo any stepping we may have done */
-	undo_single_step();
-
-	while (1) {
-		out_buffer[0] = 0;
-		get_packet(in_buffer, BUFMAX);
-
-		/* Examine first char of buffer to see what we need to do */
-		switch (in_buffer[0]) {
-		case '?':	/* Send which signal we've received */
-			send_signal_msg(sigval);
-			break;
-
-		case 'g':	/* Return the values of the CPU registers */
-			send_regs_msg();
-			break;
-
-		case 'G':	/* Set the value of the CPU registers */
-			set_regs_msg();
-			break;
-
-		case 'm':	/* Read LLLL bytes address AA..AA */
-			read_mem_msg();
-			break;
-
-		case 'M':	/* Write LLLL bytes address AA..AA, ret OK */
-			write_mem_msg(0);	/* 0 = data in hex */
-			break;
-
-		case 'X':	/* Write LLLL bytes esc bin address AA..AA */
-			if (kgdb_bits == '8')
-				write_mem_msg(1); /* 1 = data in binary */
-			else
-				send_empty_msg();
-			break;
-
-		case 'C':	/* Continue, signum included, we ignore it */
-			continue_with_sig_msg();
-			return;
-
-		case 'c':	/* Continue at address AA..AA (optional) */
-			continue_msg();
-			return;
-
-		case 'S':	/* Step, signum included, we ignore it */
-			step_with_sig_msg();
-			return;
-
-		case 's':	/* Step one instruction from AA..AA */
-			step_msg();
-			return;
-
-		case 'k':	/* 'Kill the program' with a kernel ? */
-			break;
-
-		case 'D':	/* Detach from program, send reply OK */
-			kgdb_in_gdb_mode = 0;
-			send_ok_msg();
-			get_debug_char();
-			return;
-
-		default:
-			send_empty_msg();
-			break;
-		}
-	}
-}
-
-/* There has been an exception, most likely a breakpoint. */
-static void handle_exception(struct pt_regs *regs)
-{
-	int excep_code, vbr_val;
-	int count;
-	int trapa_value = ctrl_inl(TRA);
-
-	/* Copy kernel regs (from stack) */
-	for (count = 0; count < 16; count++)
-		trap_registers.regs[count] = regs->regs[count];
-	trap_registers.pc = regs->pc;
-	trap_registers.pr = regs->pr;
-	trap_registers.sr = regs->sr;
-	trap_registers.gbr = regs->gbr;
-	trap_registers.mach = regs->mach;
-	trap_registers.macl = regs->macl;
-
-	asm("stc vbr, %0":"=r"(vbr_val));
-	trap_registers.vbr = vbr_val;
-
-	/* Get excode for command loop call, user access */
-	asm("stc r2_bank, %0":"=r"(excep_code));
-
-	/* Act on the exception */
-	kgdb_command_loop(excep_code, trapa_value);
-
-	/* Copy back the (maybe modified) registers */
-	for (count = 0; count < 16; count++)
-		regs->regs[count] = trap_registers.regs[count];
-	regs->pc = trap_registers.pc;
-	regs->pr = trap_registers.pr;
-	regs->sr = trap_registers.sr;
-	regs->gbr = trap_registers.gbr;
-	regs->mach = trap_registers.mach;
-	regs->macl = trap_registers.macl;
-
-	vbr_val = trap_registers.vbr;
-	asm("ldc %0, vbr": :"r"(vbr_val));
-}
-
-asmlinkage void kgdb_handle_exception(unsigned long r4, unsigned long r5,
-				      unsigned long r6, unsigned long r7,
-				      struct pt_regs __regs)
-{
-	struct pt_regs *regs = RELOC_HIDE(&__regs, 0);
-	handle_exception(regs);
-}
-
-/* Initialise the KGDB data structures and serial configuration */
-int __init kgdb_init(void)
-{
-	in_nmi = 0;
-	kgdb_nofault = 0;
-	stepped_opcode = 0;
-	kgdb_in_gdb_mode = 0;
-
-	if (kgdb_serial_setup() != 0) {
-		printk(KERN_NOTICE "KGDB: serial setup error\n");
-		return -1;
-	}
-
-	/* Init ptr to exception handler */
-	kgdb_debug_hook = handle_exception;
-	kgdb_bus_err_hook = kgdb_handle_bus_error;
-
-	/* Enter kgdb now if requested, or just report init done */
-	printk(KERN_NOTICE "KGDB: stub is initialized.\n");
-
-	return 0;
-}
-
-/* Make function available for "user messages"; console will use it too. */
-
-char gdbmsgbuf[BUFMAX];
-#define MAXOUT ((BUFMAX-2)/2)
-
-static void kgdb_msg_write(const char *s, unsigned count)
-{
-	int i;
-	int wcount;
-	char *bufptr;
-
-	/* 'O'utput */
-	gdbmsgbuf[0] = 'O';
-
-	/* Fill and send buffers... */
-	while (count > 0) {
-		bufptr = gdbmsgbuf + 1;
-
-		/* Calculate how many this time */
-		wcount = (count > MAXOUT) ? MAXOUT : count;
-
-		/* Pack in hex chars */
-		for (i = 0; i < wcount; i++)
-			bufptr = pack_hex_byte(bufptr, s[i]);
-		*bufptr = '\0';
-
-		/* Move up */
-		s += wcount;
-		count -= wcount;
-
-		/* Write packet */
-		put_packet(gdbmsgbuf);
-	}
-}
-
-static void kgdb_to_gdb(const char *s)
-{
-	kgdb_msg_write(s, strlen(s));
-}
-
-#ifdef CONFIG_SH_KGDB_CONSOLE
-void kgdb_console_write(struct console *co, const char *s, unsigned count)
-{
-	/* Bail if we're not talking to GDB */
-	if (!kgdb_in_gdb_mode)
-		return;
-
-	kgdb_msg_write(s, count);
-}
-#endif
-
-#ifdef CONFIG_KGDB_SYSRQ
-static void sysrq_handle_gdb(int key, struct tty_struct *tty)
-{
-	printk("Entering GDB stub\n");
-	breakpoint();
-}
-
-static struct sysrq_key_op sysrq_gdb_op = {
-        .handler        = sysrq_handle_gdb,
-        .help_msg       = "Gdb",
-        .action_msg     = "GDB",
-};
-
-static int gdb_register_sysrq(void)
-{
-	printk("Registering GDB sysrq handler\n");
-	register_sysrq_key('g', &sysrq_gdb_op);
-	return 0;
-}
-module_init(gdb_register_sysrq);
-#endif

arch/sh/kernel/time_32.c

@@ -277,11 +277,4 @@ void __init time_init(void)
 		       ((sh_hpt_frequency + 500) / 1000) / 1000,
 		       ((sh_hpt_frequency + 500) / 1000) % 1000);
 
-#if defined(CONFIG_SH_KGDB)
-	/*
-	 * Set up kgdb as requested. We do it here because the serial
-	 * init uses the timer vars we just set up for figuring baud.
-	 */
-	kgdb_init();
-#endif
 }

arch/sh/kernel/traps_32.c

@@ -28,17 +28,6 @@
 #include <asm/fpu.h>
 #include <asm/kprobes.h>
 
-#ifdef CONFIG_SH_KGDB
-#include <asm/kgdb.h>
-#define CHK_REMOTE_DEBUG(regs)			\
-{						\
-	if (kgdb_debug_hook && !user_mode(regs))\
-		(*kgdb_debug_hook)(regs);       \
-}
-#else
-#define CHK_REMOTE_DEBUG(regs)
-#endif
-
 #ifdef CONFIG_CPU_SH2
 # define TRAP_RESERVED_INST	4
 # define TRAP_ILLEGAL_SLOT_INST	6
@@ -94,7 +83,6 @@ void die(const char * str, struct pt_regs * regs, long err)
 
 	printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
 
-	CHK_REMOTE_DEBUG(regs);
 	print_modules();
 	show_regs(regs);
 
@@ -683,7 +671,6 @@ asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
 	error_code = lookup_exception_vector();
 
 	local_irq_enable();
-	CHK_REMOTE_DEBUG(regs);
 	force_sig(SIGILL, tsk);
 	die_if_no_fixup("reserved instruction", regs, error_code);
 }
@@ -761,7 +748,6 @@ asmlinkage void do_illegal_slot_inst(unsigned long r4, unsigned long r5,
 	inst = lookup_exception_vector();
 
 	local_irq_enable();
-	CHK_REMOTE_DEBUG(regs);
 	force_sig(SIGILL, tsk);
 	die_if_no_fixup("illegal slot instruction", regs, inst);
 }

arch/sh/mm/fault_32.c

@@ -20,7 +20,6 @@
 #include <asm/system.h>
 #include <asm/mmu_context.h>
 #include <asm/tlbflush.h>
-#include <asm/kgdb.h>
 
 /*
  * This routine handles page faults.  It determines the address,
@@ -282,11 +281,6 @@ asmlinkage int __kprobes __do_page_fault(struct pt_regs *regs,
 	if (notify_page_fault(regs, lookup_exception_vector()))
 		goto out;
 
-#ifdef CONFIG_SH_KGDB
-	if (kgdb_nofault && kgdb_bus_err_hook)
-		kgdb_bus_err_hook();
-#endif
-
 	ret = 1;
 
 	/*