Initial import

1 files changed, 1612 insertions, 0 deletions

diff --git a/arch/cris/arch-v32/kernel/kgdb.c b/arch/cris/arch-v32/kernel/kgdb.c
new file mode 100644
index 000000000..b06813aeb
--- /dev/null
+++ b/arch/cris/arch-v32/kernel/kgdb.c
@@ -0,0 +1,1612 @@
+/*
+ *  arch/cris/arch-v32/kernel/kgdb.c
+ *
+ *  CRIS v32 version by Orjan Friberg, Axis Communications AB.
+ *
+ *  S390 version
+ *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
+ *
+ *  Originally written by Glenn Engel, Lake Stevens Instrument Division
+ *
+ *  Contributed by HP Systems
+ *
+ *  Modified for SPARC by Stu Grossman, Cygnus Support.
+ *
+ *  Modified for Linux/MIPS (and MIPS in general) by Andreas Busse
+ *  Send complaints, suggestions etc. to <andy@waldorf-gmbh.de>
+ *
+ *  Copyright (C) 1995 Andreas Busse
+ */
+
+/* FIXME: Check the documentation. */
+
+/*
+ *  kgdb usage notes:
+ *  -----------------
+ *
+ * If you select CONFIG_ETRAX_KGDB in the configuration, the kernel will be
+ * built with different gcc flags: "-g" is added to get debug infos, and
+ * "-fomit-frame-pointer" is omitted to make debugging easier. Since the
+ * resulting kernel will be quite big (approx. > 7 MB), it will be stripped
+ * before compresion. Such a kernel will behave just as usually, except if
+ * given a "debug=<device>" command line option. (Only serial devices are
+ * allowed for <device>, i.e. no printers or the like; possible values are
+ * machine depedend and are the same as for the usual debug device, the one
+ * for logging kernel messages.) If that option is given and the device can be
+ * initialized, the kernel will connect to the remote gdb in trap_init(). The
+ * serial parameters are fixed to 8N1 and 115200 bps, for easyness of
+ * implementation.
+ *
+ * To start a debugging session, start that gdb with the debugging kernel
+ * image (the one with the symbols, vmlinux.debug) named on the command line.
+ * This file will be used by gdb to get symbol and debugging infos about the
+ * kernel. Next, select remote debug mode by
+ *    target remote <device>
+ * where <device> is the name of the serial device over which the debugged
+ * machine is connected. Maybe you have to adjust the baud rate by
+ *    set remotebaud <rate>
+ * or also other parameters with stty:
+ *    shell stty ... </dev/...
+ * If the kernel to debug has already booted, it waited for gdb and now
+ * connects, and you'll see a breakpoint being reported. If the kernel isn't
+ * running yet, start it now. The order of gdb and the kernel doesn't matter.
+ * Another thing worth knowing about in the getting-started phase is how to
+ * debug the remote protocol itself. This is activated with
+ *    set remotedebug 1
+ * gdb will then print out each packet sent or received. You'll also get some
+ * messages about the gdb stub on the console of the debugged machine.
+ *
+ * If all that works, you can use lots of the usual debugging techniques on
+ * the kernel, e.g. inspecting and changing variables/memory, setting
+ * breakpoints, single stepping and so on. It's also possible to interrupt the
+ * debugged kernel by pressing C-c in gdb. Have fun! :-)
+ *
+ * The gdb stub is entered (and thus the remote gdb gets control) in the
+ * following situations:
+ *
+ *  - If breakpoint() is called. This is just after kgdb initialization, or if
+ *    a breakpoint() call has been put somewhere into the kernel source.
+ *    (Breakpoints can of course also be set the usual way in gdb.)
+ *    In eLinux, we call breakpoint() in init/main.c after IRQ initialization.
+ *
+ *  - If there is a kernel exception, i.e. bad_super_trap() or die_if_kernel()
+ *    are entered. All the CPU exceptions are mapped to (more or less..., see
+ *    the hard_trap_info array below) appropriate signal, which are reported
+ *    to gdb. die_if_kernel() is usually called after some kind of access
+ *    error and thus is reported as SIGSEGV.
+ *
+ *  - When panic() is called. This is reported as SIGABRT.
+ *
+ *  - If C-c is received over the serial line, which is treated as
+ *    SIGINT.
+ *
+ * Of course, all these signals are just faked for gdb, since there is no
+ * signal concept as such for the kernel. It also isn't possible --obviously--
+ * to set signal handlers from inside gdb, or restart the kernel with a
+ * signal.
+ *
+ * Current limitations:
+ *
+ *  - While the kernel is stopped, interrupts are disabled for safety reasons
+ *    (i.e., variables not changing magically or the like). But this also
+ *    means that the clock isn't running anymore, and that interrupts from the
+ *    hardware may get lost/not be served in time. This can cause some device
+ *    errors...
+ *
+ *  - When single-stepping, only one instruction of the current thread is
+ *    executed, but interrupts are allowed for that time and will be serviced
+ *    if pending. Be prepared for that.
+ *
+ *  - All debugging happens in kernel virtual address space. There's no way to
+ *    access physical memory not mapped in kernel space, or to access user
+ *    space. A way to work around this is using get_user_long & Co. in gdb
+ *    expressions, but only for the current process.
+ *
+ *  - Interrupting the kernel only works if interrupts are currently allowed,
+ *    and the interrupt of the serial line isn't blocked by some other means
+ *    (IPL too high, disabled, ...)
+ *
+ *  - The gdb stub is currently not reentrant, i.e. errors that happen therein
+ *    (e.g. accessing invalid memory) may not be caught correctly. This could
+ *    be removed in future by introducing a stack of struct registers.
+ *
+ */
+
+/*
+ *  To enable debugger support, two things need to happen.  One, a
+ *  call to kgdb_init() is necessary in order to allow any breakpoints
+ *  or error conditions to be properly intercepted and reported to gdb.
+ *  Two, a breakpoint needs to be generated to begin communication.  This
+ *  is most easily accomplished by a call to breakpoint().
+ *
+ *    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
+ *
+ *    c             Resume at current address              SNN   ( signal NN)
+ *    cAA..AA       Continue at address AA..AA             SNN
+ *
+ *    s             Step one instruction                   SNN
+ *    sAA..AA       Step one instruction from AA..AA       SNN
+ *
+ *    k             kill
+ *
+ *    ?             What was the last sigval ?             SNN   (signal NN)
+ *
+ *    bBB..BB	    Set baud rate to BB..BB		   OK or BNN, then sets
+ *							   baud rate
+ *
+ * All commands and responses are sent with a packet which includes a
+ * checksum.  A packet consists of
+ *
+ * $<packet info>#<checksum>.
+ *
+ * where
+ * <packet info> :: <characters representing the command or response>
+ * <checksum>    :: < two hex digits computed as modulo 256 sum of <packetinfo>>
+ *
+ * When a packet is received, it is first acknowledged with either '+' or '-'.
+ * '+' indicates a successful transfer.  '-' indicates a failed transfer.
+ *
+ * Example:
+ *
+ * Host:                  Reply:
+ * $m0,10#2a               +$00010203040506070809101112131415#42
+ *
+ */
+
+
+#include <linux/string.h>
+#include <linux/signal.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/linkage.h>
+#include <linux/reboot.h>
+
+#include <asm/setup.h>
+#include <asm/ptrace.h>
+
+#include <asm/irq.h>
+#include <hwregs/reg_map.h>
+#include <hwregs/reg_rdwr.h>
+#include <hwregs/intr_vect_defs.h>
+#include <hwregs/ser_defs.h>
+
+/* From entry.S. */
+extern void gdb_handle_exception(void);
+/* From kgdb_asm.S. */
+extern void kgdb_handle_exception(void);
+
+static int kgdb_started = 0;
+
+/********************************* Register image ****************************/
+
+typedef
+struct register_image
+{
+	                      /* Offset */
+	unsigned int   r0;    /* 0x00 */
+	unsigned int   r1;    /* 0x04 */
+	unsigned int   r2;    /* 0x08 */
+	unsigned int   r3;    /* 0x0C */
+	unsigned int   r4;    /* 0x10 */
+	unsigned int   r5;    /* 0x14 */
+	unsigned int   r6;    /* 0x18 */
+	unsigned int   r7;    /* 0x1C */
+	unsigned int   r8;    /* 0x20; Frame pointer (if any) */
+	unsigned int   r9;    /* 0x24 */
+	unsigned int   r10;   /* 0x28 */
+	unsigned int   r11;   /* 0x2C */
+	unsigned int   r12;   /* 0x30 */
+	unsigned int   r13;   /* 0x34 */
+	unsigned int   sp;    /* 0x38; R14, Stack pointer */
+	unsigned int   acr;   /* 0x3C; R15, Address calculation register. */
+
+	unsigned char  bz;    /* 0x40; P0, 8-bit zero register */
+	unsigned char  vr;    /* 0x41; P1, Version register (8-bit) */
+	unsigned int   pid;   /* 0x42; P2, Process ID */
+	unsigned char  srs;   /* 0x46; P3, Support register select (8-bit) */
+        unsigned short wz;    /* 0x47; P4, 16-bit zero register */
+	unsigned int   exs;   /* 0x49; P5, Exception status */
+	unsigned int   eda;   /* 0x4D; P6, Exception data address */
+	unsigned int   mof;   /* 0x51; P7, Multiply overflow register */
+	unsigned int   dz;    /* 0x55; P8, 32-bit zero register */
+	unsigned int   ebp;   /* 0x59; P9, Exception base pointer */
+	unsigned int   erp;   /* 0x5D; P10, Exception return pointer. Contains the PC we are interested in. */
+	unsigned int   srp;   /* 0x61; P11, Subroutine return pointer */
+	unsigned int   nrp;   /* 0x65; P12, NMI return pointer */
+	unsigned int   ccs;   /* 0x69; P13, Condition code stack */
+	unsigned int   usp;   /* 0x6D; P14, User mode stack pointer */
+	unsigned int   spc;   /* 0x71; P15, Single step PC */
+	unsigned int   pc;    /* 0x75; Pseudo register (for the most part set to ERP). */
+
+} registers;
+
+typedef
+struct bp_register_image
+{
+	/* Support register bank 0. */
+	unsigned int   s0_0;
+	unsigned int   s1_0;
+	unsigned int   s2_0;
+	unsigned int   s3_0;
+	unsigned int   s4_0;
+	unsigned int   s5_0;
+	unsigned int   s6_0;
+	unsigned int   s7_0;
+	unsigned int   s8_0;
+	unsigned int   s9_0;
+	unsigned int   s10_0;
+	unsigned int   s11_0;
+	unsigned int   s12_0;
+	unsigned int   s13_0;
+	unsigned int   s14_0;
+	unsigned int   s15_0;
+
+	/* Support register bank 1. */
+	unsigned int   s0_1;
+	unsigned int   s1_1;
+	unsigned int   s2_1;
+	unsigned int   s3_1;
+	unsigned int   s4_1;
+	unsigned int   s5_1;
+	unsigned int   s6_1;
+	unsigned int   s7_1;
+	unsigned int   s8_1;
+	unsigned int   s9_1;
+	unsigned int   s10_1;
+	unsigned int   s11_1;
+	unsigned int   s12_1;
+	unsigned int   s13_1;
+	unsigned int   s14_1;
+	unsigned int   s15_1;
+
+	/* Support register bank 2. */
+	unsigned int   s0_2;
+	unsigned int   s1_2;
+	unsigned int   s2_2;
+	unsigned int   s3_2;
+	unsigned int   s4_2;
+	unsigned int   s5_2;
+	unsigned int   s6_2;
+	unsigned int   s7_2;
+	unsigned int   s8_2;
+	unsigned int   s9_2;
+	unsigned int   s10_2;
+	unsigned int   s11_2;
+	unsigned int   s12_2;
+	unsigned int   s13_2;
+	unsigned int   s14_2;
+	unsigned int   s15_2;
+
+	/* Support register bank 3. */
+	unsigned int   s0_3; /* BP_CTRL */
+	unsigned int   s1_3; /* BP_I0_START */
+	unsigned int   s2_3; /* BP_I0_END */
+	unsigned int   s3_3; /* BP_D0_START */
+	unsigned int   s4_3; /* BP_D0_END */
+	unsigned int   s5_3; /* BP_D1_START */
+	unsigned int   s6_3; /* BP_D1_END */
+	unsigned int   s7_3; /* BP_D2_START */
+	unsigned int   s8_3; /* BP_D2_END */
+	unsigned int   s9_3; /* BP_D3_START */
+	unsigned int   s10_3; /* BP_D3_END */
+	unsigned int   s11_3; /* BP_D4_START */
+	unsigned int   s12_3; /* BP_D4_END */
+	unsigned int   s13_3; /* BP_D5_START */
+	unsigned int   s14_3; /* BP_D5_END */
+	unsigned int   s15_3; /* BP_RESERVED */
+
+} support_registers;
+
+enum register_name
+{
+	R0,  R1,  R2,  R3,
+	R4,  R5,  R6,  R7,
+	R8,  R9,  R10, R11,
+	R12, R13, SP,  ACR,
+
+	BZ,  VR,  PID, SRS,
+	WZ,  EXS, EDA, MOF,
+	DZ,  EBP, ERP, SRP,
+	NRP, CCS, USP, SPC,
+	PC,
+
+	S0,  S1,  S2,  S3,
+	S4,  S5,  S6,  S7,
+	S8,  S9,  S10, S11,
+	S12, S13, S14, S15
+
+};
+
+/* The register sizes of the registers in register_name. An unimplemented register
+   is designated by size 0 in this array. */
+static int register_size[] =
+{
+	4, 4, 4, 4,
+	4, 4, 4, 4,
+	4, 4, 4, 4,
+	4, 4, 4, 4,
+
+	1, 1, 4, 1,
+	2, 4, 4, 4,
+	4, 4, 4, 4,
+	4, 4, 4, 4,
+
+	4,
+
+	4, 4, 4, 4,
+	4, 4, 4, 4,
+	4, 4, 4, 4,
+	4, 4, 4
+
+};
+
+/* Contains the register image of the kernel.
+   (Global so that they can be reached from assembler code.) */
+registers reg;
+support_registers sreg;
+
+/************** Prototypes for local library functions ***********************/
+
+/* Copy of strcpy from libc. */
+static char *gdb_cris_strcpy(char *s1, const char *s2);
+
+/* Copy of strlen from libc. */
+static int gdb_cris_strlen(const char *s);
+
+/* Copy of memchr from libc. */
+static void *gdb_cris_memchr(const void *s, int c, int n);
+
+/* Copy of strtol from libc. Does only support base 16. */
+static int gdb_cris_strtol(const char *s, char **endptr, int base);
+
+/********************** Prototypes for local functions. **********************/
+
+/* Write a value to a specified register regno in the register image
+   of the current thread. */
+static int write_register(int regno, char *val);
+
+/* Read a value from a specified register in the register image. Returns the
+   status of the read operation. The register value is returned in valptr. */
+static int read_register(char regno, unsigned int *valptr);
+
+/* Serial port, reads one character. ETRAX 100 specific. from debugport.c */
+int getDebugChar(void);
+
+/* Serial port, writes one character. ETRAX 100 specific. from debugport.c */
+void putDebugChar(int val);
+
+/* Returns the integer equivalent of a hexadecimal character. */
+static int hex(char ch);
+
+/* Convert the memory, pointed to by mem into hexadecimal representation.
+   Put the result in buf, and return a pointer to the last character
+   in buf (null). */
+static char *mem2hex(char *buf, unsigned char *mem, int count);
+
+/* Convert the array, in hexadecimal representation, pointed to by buf into
+   binary representation. Put the result in mem, and return a pointer to
+   the character after the last byte written. */
+static unsigned char *hex2mem(unsigned char *mem, char *buf, int count);
+
+/* Put the content of the array, in binary representation, pointed to by buf
+   into memory pointed to by mem, and return a pointer to
+   the character after the last byte written. */
+static unsigned char *bin2mem(unsigned char *mem, unsigned char *buf, int count);
+
+/* Await the sequence $<data>#<checksum> and store <data> in the array buffer
+   returned. */
+static void getpacket(char *buffer);
+
+/* Send $<data>#<checksum> from the <data> in the array buffer. */
+static void putpacket(char *buffer);
+
+/* Build and send a response packet in order to inform the host the
+   stub is stopped. */
+static void stub_is_stopped(int sigval);
+
+/* All expected commands are sent from remote.c. Send a response according
+   to the description in remote.c. Not static since it needs to be reached
+   from assembler code. */
+void handle_exception(int sigval);
+
+/* Performs a complete re-start from scratch. ETRAX specific. */
+static void kill_restart(void);
+
+/******************** Prototypes for global functions. ***********************/
+
+/* The string str is prepended with the GDB printout token and sent. */
+void putDebugString(const unsigned char *str, int len);
+
+/* A static breakpoint to be used at startup. */
+void breakpoint(void);
+
+/* Avoid warning as the internal_stack is not used in the C-code. */
+#define USEDVAR(name)    { if (name) { ; } }
+#define USEDFUN(name) { void (*pf)(void) = (void *)name; USEDVAR(pf) }
+
+/********************************** Packet I/O ******************************/
+/* BUFMAX defines the maximum number of characters in
+   inbound/outbound buffers */
+/* FIXME: How do we know it's enough? */
+#define BUFMAX 512
+
+/* Run-length encoding maximum length. Send 64 at most. */
+#define RUNLENMAX 64
+
+/* The inbound/outbound buffers used in packet I/O */
+static char input_buffer[BUFMAX];
+static char output_buffer[BUFMAX];
+
+/* Error and warning messages. */
+enum error_type
+{
+	SUCCESS, E01, E02, E03, E04, E05, E06,
+};
+
+static char *error_message[] =
+{
+	"",
+	"E01 Set current or general thread - H[c,g] - internal error.",
+	"E02 Change register content - P - cannot change read-only register.",
+	"E03 Thread is not alive.", /* T, not used. */
+	"E04 The command is not supported - [s,C,S,!,R,d,r] - internal error.",
+	"E05 Change register content - P - the register is not implemented..",
+	"E06 Change memory content - M - internal error.",
+};
+
+/********************************** Breakpoint *******************************/
+/* Use an internal stack in the breakpoint and interrupt response routines.
+   FIXME: How do we know the size of this stack is enough?
+   Global so it can be reached from assembler code. */
+#define INTERNAL_STACK_SIZE 1024
+char internal_stack[INTERNAL_STACK_SIZE];
+
+/* Due to the breakpoint return pointer, a state variable is needed to keep
+   track of whether it is a static (compiled) or dynamic (gdb-invoked)
+   breakpoint to be handled. A static breakpoint uses the content of register
+   ERP as it is whereas a dynamic breakpoint requires subtraction with 2
+   in order to execute the instruction. The first breakpoint is static; all
+   following are assumed to be dynamic. */
+static int dynamic_bp = 0;
+
+/********************************* String library ****************************/
+/* Single-step over library functions creates trap loops. */
+
+/* Copy char s2[] to s1[]. */
+static char*
+gdb_cris_strcpy(char *s1, const char *s2)
+{
+	char *s = s1;
+
+	for (s = s1; (*s++ = *s2++) != '\0'; )
+		;
+	return s1;
+}
+
+/* Find length of s[]. */
+static int
+gdb_cris_strlen(const char *s)
+{
+	const char *sc;
+
+	for (sc = s; *sc != '\0'; sc++)
+		;
+	return (sc - s);
+}
+
+/* Find first occurrence of c in s[n]. */
+static void*
+gdb_cris_memchr(const void *s, int c, int n)
+{
+	const unsigned char uc = c;
+	const unsigned char *su;
+
+	for (su = s; 0 < n; ++su, --n)
+		if (*su == uc)
+			return (void *)su;
+	return NULL;
+}
+/******************************* Standard library ****************************/
+/* Single-step over library functions creates trap loops. */
+/* Convert string to long. */
+static int
+gdb_cris_strtol(const char *s, char **endptr, int base)
+{
+	char *s1;
+	char *sd;
+	int x = 0;
+
+	for (s1 = (char*)s; (sd = gdb_cris_memchr(hex_asc, *s1, base)) != NULL; ++s1)
+		x = x * base + (sd - hex_asc);
+
+        if (endptr) {
+                /* Unconverted suffix is stored in endptr unless endptr is NULL. */
+                *endptr = s1;
+        }
+
+	return x;
+}
+
+/********************************* Register image ****************************/
+
+/* Write a value to a specified register in the register image of the current
+   thread. Returns status code SUCCESS, E02 or E05. */
+static int
+write_register(int regno, char *val)
+{
+	int status = SUCCESS;
+
+        if (regno >= R0 && regno <= ACR) {
+		/* Consecutive 32-bit registers. */
+		hex2mem((unsigned char *)&reg.r0 + (regno - R0) * sizeof(unsigned int),
+			val, sizeof(unsigned int));
+
+	} else if (regno == BZ || regno == VR || regno == WZ || regno == DZ) {
+		/* Read-only registers. */
+		status = E02;
+
+	} else if (regno == PID) {
+		/* 32-bit register. (Even though we already checked SRS and WZ, we cannot
+		   combine this with the EXS - SPC write since SRS and WZ have different size.) */
+		hex2mem((unsigned char *)&reg.pid, val, sizeof(unsigned int));
+
+	} else if (regno == SRS) {
+		/* 8-bit register. */
+		hex2mem((unsigned char *)&reg.srs, val, sizeof(unsigned char));
+
+	} else if (regno >= EXS && regno <= SPC) {
+		/* Consecutive 32-bit registers. */
+		hex2mem((unsigned char *)&reg.exs + (regno - EXS) * sizeof(unsigned int),
+			 val, sizeof(unsigned int));
+
+       } else if (regno == PC) {
+               /* Pseudo-register. Treat as read-only. */
+               status = E02;
+
+       } else if (regno >= S0 && regno <= S15) {
+               /* 32-bit registers. */
+               hex2mem((unsigned char *)&sreg.s0_0 + (reg.srs * 16 * sizeof(unsigned int)) + (regno - S0) * sizeof(unsigned int), val, sizeof(unsigned int));
+	} else {
+		/* Non-existing register. */
+		status = E05;
+	}
+	return status;
+}
+
+/* Read a value from a specified register in the register image. Returns the
+   value in the register or -1 for non-implemented registers. */
+static int
+read_register(char regno, unsigned int *valptr)
+{
+	int status = SUCCESS;
+
+	/* We read the zero registers from the register struct (instead of just returning 0)
+	   to catch errors. */
+
+	if (regno >= R0 && regno <= ACR) {
+		/* Consecutive 32-bit registers. */
+		*valptr = *(unsigned int *)((char *)&reg.r0 + (regno - R0) * sizeof(unsigned int));
+
+	} else if (regno == BZ || regno == VR) {
+		/* Consecutive 8-bit registers. */
+		*valptr = (unsigned int)(*(unsigned char *)
+                                         ((char *)&reg.bz + (regno - BZ) * sizeof(char)));
+
+	} else if (regno == PID) {
+		/* 32-bit register. */
+		*valptr =  *(unsigned int *)((char *)&reg.pid);
+
+	} else if (regno == SRS) {
+		/* 8-bit register. */
+		*valptr = (unsigned int)(*(unsigned char *)((char *)&reg.srs));
+
+	} else if (regno == WZ) {
+		/* 16-bit register. */
+		*valptr = (unsigned int)(*(unsigned short *)(char *)&reg.wz);
+
+	} else if (regno >= EXS && regno <= PC) {
+		/* Consecutive 32-bit registers. */
+		*valptr = *(unsigned int *)((char *)&reg.exs + (regno - EXS) * sizeof(unsigned int));
+
+	} else if (regno >= S0 && regno <= S15) {
+		/* Consecutive 32-bit registers, located elsewhere. */
+		*valptr = *(unsigned int *)((char *)&sreg.s0_0 + (reg.srs * 16 * sizeof(unsigned int)) + (regno - S0) * sizeof(unsigned int));
+
+	} else {
+		/* Non-existing register. */
+		status = E05;
+	}
+	return status;
+
+}
+
+/********************************** Packet I/O ******************************/
+/* Returns the integer equivalent of a hexadecimal character. */
+static int
+hex(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 hexadecimal representation.
+   Put the result in buf, and return a pointer to the last character
+   in buf (null). */
+
+static char *
+mem2hex(char *buf, unsigned char *mem, int count)
+{
+	int i;
+	int ch;
+
+        if (mem == NULL) {
+		/* Invalid address, caught by 'm' packet handler. */
+                for (i = 0; i < count; i++) {
+                        *buf++ = '0';
+                        *buf++ = '0';
+                }
+        } else {
+                /* Valid mem address. */
+		for (i = 0; i < count; i++) {
+			ch = *mem++;
+			buf = hex_byte_pack(buf, ch);
+		}
+        }
+        /* Terminate properly. */
+	*buf = '\0';
+	return buf;
+}
+
+/* Same as mem2hex, but puts it in network byte order. */
+static char *
+mem2hex_nbo(char *buf, unsigned char *mem, int count)
+{
+	int i;
+	int ch;
+
+	mem += count - 1;
+	for (i = 0; i < count; i++) {
+		ch = *mem--;
+		buf = hex_byte_pack(buf, ch);
+        }
+
+        /* Terminate properly. */
+	*buf = '\0';
+	return buf;
+}
+
+/* Convert the array, in hexadecimal representation, pointed to by buf into
+   binary representation. Put the result in mem, and return a pointer to
+   the character after the last byte written. */
+static unsigned char*
+hex2mem(unsigned char *mem, char *buf, 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;
+}
+
+/* Put the content of the array, in binary representation, pointed to by buf
+   into memory pointed to by mem, and return a pointer to the character after
+   the last byte written.
+   Gdb will escape $, #, and the escape char (0x7d). */
+static unsigned char*
+bin2mem(unsigned char *mem, unsigned char *buf, int count)
+{
+	int i;
+	unsigned char *next;
+	for (i = 0; i < count; i++) {
+		/* Check for any escaped characters. Be paranoid and
+		   only unescape chars that should be escaped. */
+		if (*buf == 0x7d) {
+			next = buf + 1;
+			if (*next == 0x3 || *next == 0x4 || *next == 0x5D) {
+				 /* #, $, ESC */
+				buf++;
+				*buf += 0x20;
+			}
+		}
+		*mem++ = *buf++;
+	}
+	return mem;
+}
+
+/* Await the sequence $<data>#<checksum> and store <data> in the array buffer
+   returned. */
+static void
+getpacket(char *buffer)
+{
+	unsigned char checksum;
+	unsigned char xmitcsum;
+	int i;
+	int count;
+	char ch;
+
+	do {
+		while((ch = getDebugChar ()) != '$')
+			/* Wait for the start character $ and ignore all other characters */;
+		checksum = 0;
+		xmitcsum = -1;
+		count = 0;
+		/* Read until a # or the end of the buffer is reached */
+		while (count < BUFMAX) {
+			ch = getDebugChar();
+			if (ch == '#')
+				break;
+			checksum = checksum + ch;
+			buffer[count] = ch;
+			count = count + 1;
+		}
+
+		if (count >= BUFMAX)
+			continue;
+
+		buffer[count] = 0;
+
+		if (ch == '#') {
+			xmitcsum = hex(getDebugChar()) << 4;
+			xmitcsum += hex(getDebugChar());
+			if (checksum != xmitcsum) {
+				/* Wrong checksum */
+				putDebugChar('-');
+			} else {
+				/* Correct checksum */
+				putDebugChar('+');
+				/* If sequence characters are received, reply with them */
+				if (buffer[2] == ':') {
+					putDebugChar(buffer[0]);
+					putDebugChar(buffer[1]);
+					/* Remove the sequence characters from the buffer */
+					count = gdb_cris_strlen(buffer);
+					for (i = 3; i <= count; i++)
+						buffer[i - 3] = buffer[i];
+				}
+			}
+		}
+	} while (checksum != xmitcsum);
+}
+
+/* Send $<data>#<checksum> from the <data> in the array buffer. */
+
+static void
+putpacket(char *buffer)
+{
+	int checksum;
+	int runlen;
+	int encode;
+
+	do {
+		char *src = buffer;
+		putDebugChar('$');
+		checksum = 0;
+		while (*src) {
+			/* Do run length encoding */
+			putDebugChar(*src);
+			checksum += *src;
+			runlen = 0;
+			while (runlen < RUNLENMAX && *src == src[runlen]) {
+				runlen++;
+			}
+			if (runlen > 3) {
+				/* Got a useful amount */
+				putDebugChar ('*');
+				checksum += '*';
+				encode = runlen + ' ' - 4;
+				putDebugChar(encode);
+				checksum += encode;
+				src += runlen;
+			} else {
+				src++;
+			}
+		}
+		putDebugChar('#');
+		putDebugChar(hex_asc_hi(checksum));
+		putDebugChar(hex_asc_lo(checksum));
+	} while(kgdb_started && (getDebugChar() != '+'));
+}
+
+/* The string str is prepended with the GDB printout token and sent. Required
+   in traditional implementations. */
+void
+putDebugString(const unsigned char *str, int len)
+{
+	/* Move SPC forward if we are single-stepping. */
+	asm("spchere:");
+	asm("move $spc, $r10");
+	asm("cmp.d spchere, $r10");
+	asm("bne nosstep");
+	asm("nop");
+	asm("move.d spccont, $r10");
+	asm("move $r10, $spc");
+	asm("nosstep:");
+
+        output_buffer[0] = 'O';
+        mem2hex(&output_buffer[1], (unsigned char *)str, len);
+        putpacket(output_buffer);
+
+	asm("spccont:");
+}
+
+/********************************** Handle exceptions ************************/
+/* Build and send a response packet in order to inform the host the
+   stub is stopped. TAAn...:r...;n...:r...;n...:r...;
+                    AA = signal number
+                    n... = register number (hex)
+                    r... = register contents
+                    n... = `thread'
+                    r... = thread process ID.  This is a hex integer.
+                    n... = other string not starting with valid hex digit.
+                    gdb should ignore this n,r pair and go on to the next.
+                    This way we can extend the protocol. */
+static void
+stub_is_stopped(int sigval)
+{
+	char *ptr = output_buffer;
+	unsigned int reg_cont;
+
+	/* Send trap type (converted to signal) */
+
+	*ptr++ = 'T';
+	ptr = hex_byte_pack(ptr, sigval);
+
+	if (((reg.exs & 0xff00) >> 8) == 0xc) {
+
+		/* Some kind of hardware watchpoint triggered. Find which one
+		   and determine its type (read/write/access).  */
+		int S, bp, trig_bits = 0, rw_bits = 0;
+		int trig_mask = 0;
+		unsigned int *bp_d_regs = &sreg.s3_3;
+		/* In a lot of cases, the stopped data address will simply be EDA.
+		   In some cases, we adjust it to match the watched data range.
+		   (We don't want to change the actual EDA though). */
+		unsigned int stopped_data_address;
+		/* The S field of EXS. */
+		S = (reg.exs & 0xffff0000) >> 16;
+
+		if (S & 1) {
+			/* Instruction watchpoint. */
+			/* FIXME: Check against, and possibly adjust reported EDA. */
+		} else {
+			/* Data watchpoint.  Find the one that triggered. */
+			for (bp = 0; bp < 6; bp++) {
+
+				/* Dx_RD, Dx_WR in the S field of EXS for this BP. */
+				int bitpos_trig = 1 + bp * 2;
+				/* Dx_BPRD, Dx_BPWR in BP_CTRL for this BP. */
+				int bitpos_config = 2 + bp * 4;
+
+				/* Get read/write trig bits for this BP. */
+				trig_bits = (S & (3 << bitpos_trig)) >> bitpos_trig;
+
+				/* Read/write config bits for this BP. */
+				rw_bits = (sreg.s0_3 & (3 << bitpos_config)) >> bitpos_config;
+				if (trig_bits) {
+					/* Sanity check: the BP shouldn't trigger for accesses
+					   that it isn't configured for. */
+					if ((rw_bits == 0x1 && trig_bits != 0x1) ||
+					    (rw_bits == 0x2 && trig_bits != 0x2))
+						panic("Invalid r/w trigging for this BP");
+
+					/* Mark this BP as trigged for future reference. */
+					trig_mask |= (1 << bp);
+
+					if (reg.eda >= bp_d_regs[bp * 2] &&
+					    reg.eda <= bp_d_regs[bp * 2 + 1]) {
+						/* EDA within range for this BP; it must be the one
+						   we're looking for. */
+						stopped_data_address = reg.eda;
+						break;
+					}
+				}
+			}
+			if (bp < 6) {
+				/* Found a trigged BP with EDA within its configured data range. */
+			} else if (trig_mask) {
+				/* Something triggered, but EDA doesn't match any BP's range. */
+				for (bp = 0; bp < 6; bp++) {
+					/* Dx_BPRD, Dx_BPWR in BP_CTRL for this BP. */
+					int bitpos_config = 2 + bp * 4;
+
+					/* Read/write config bits for this BP (needed later). */
+					rw_bits = (sreg.s0_3 & (3 << bitpos_config)) >> bitpos_config;
+
+					if (trig_mask & (1 << bp)) {
+						/* EDA within 31 bytes of the configured start address? */
+						if (reg.eda + 31 >= bp_d_regs[bp * 2]) {
+							/* Changing the reported address to match
+							   the start address of the first applicable BP. */
+							stopped_data_address = bp_d_regs[bp * 2];
+							break;
+						} else {
+							/* We continue since we might find another useful BP. */
+							printk("EDA doesn't match trigged BP's range");
+						}
+					}
+				}
+			}
+
+			/* No match yet? */
+			BUG_ON(bp >= 6);
+			/* Note that we report the type according to what the BP is configured
+			   for (otherwise we'd never report an 'awatch'), not according to how
+			   it trigged. We did check that the trigged bits match what the BP is
+			   configured for though. */
+			if (rw_bits == 0x1) {
+				/* read */
+				strncpy(ptr, "rwatch", 6);
+				ptr += 6;
+			} else if (rw_bits == 0x2) {
+				/* write */
+				strncpy(ptr, "watch", 5);
+				ptr += 5;
+			} else if (rw_bits == 0x3) {
+				/* access */
+				strncpy(ptr, "awatch", 6);
+				ptr += 6;
+			} else {
+				panic("Invalid r/w bits for this BP.");
+			}
+
+			*ptr++ = ':';
+			/* Note that we don't read_register(EDA, ...) */
+			ptr = mem2hex_nbo(ptr, (unsigned char *)&stopped_data_address, register_size[EDA]);
+			*ptr++ = ';';
+		}
+	}
+	/* Only send PC, frame and stack pointer. */
+	read_register(PC, &reg_cont);
+	ptr = hex_byte_pack(ptr, PC);
+	*ptr++ = ':';
+	ptr = mem2hex(ptr, (unsigned char *)&reg_cont, register_size[PC]);
+	*ptr++ = ';';
+
+	read_register(R8, &reg_cont);
+	ptr = hex_byte_pack(ptr, R8);
+	*ptr++ = ':';
+	ptr = mem2hex(ptr, (unsigned char *)&reg_cont, register_size[R8]);
+	*ptr++ = ';';
+
+	read_register(SP, &reg_cont);
+	ptr = hex_byte_pack(ptr, SP);
+	*ptr++ = ':';
+	ptr = mem2hex(ptr, (unsigned char *)&reg_cont, register_size[SP]);
+	*ptr++ = ';';
+
+	/* Send ERP as well; this will save us an entire register fetch in some cases. */
+        read_register(ERP, &reg_cont);
+	ptr = hex_byte_pack(ptr, ERP);
+        *ptr++ = ':';
+        ptr = mem2hex(ptr, (unsigned char *)&reg_cont, register_size[ERP]);
+        *ptr++ = ';';
+
+	/* null-terminate and send it off */
+	*ptr = 0;
+	putpacket(output_buffer);
+}
+
+/* Returns the size of an instruction that has a delay slot. */
+
+int insn_size(unsigned long pc)
+{
+	unsigned short opcode = *(unsigned short *)pc;
+	int size = 0;
+
+	switch ((opcode & 0x0f00) >> 8) {
+	case 0x0:
+	case 0x9:
+	case 0xb:
+		size = 2;
+		break;
+	case 0xe:
+	case 0xf:
+		size = 6;
+		break;
+	case 0xd:
+		/* Could be 4 or 6; check more bits. */
+		if ((opcode & 0xff) == 0xff)
+			size = 4;
+		else
+			size = 6;
+		break;
+	default:
+		panic("Couldn't find size of opcode 0x%x at 0x%lx\n", opcode, pc);
+	}
+
+	return size;
+}
+
+void register_fixup(int sigval)
+{
+	/* Compensate for ACR push at the beginning of exception handler. */
+	reg.sp += 4;
+
+	/* Standard case. */
+	reg.pc = reg.erp;
+	if (reg.erp & 0x1) {
+		/* Delay slot bit set.  Report as stopped on proper instruction.  */
+		if (reg.spc) {
+			/* Rely on SPC if set. */
+			reg.pc = reg.spc;
+		} else {
+			/* Calculate the PC from the size of the instruction
+			   that the delay slot we're in belongs to. */
+			reg.pc += insn_size(reg.erp & ~1) - 1 ;
+		}
+	}
+
+	if ((reg.exs & 0x3) == 0x0) {
+		/* Bits 1 - 0 indicate the type of memory operation performed
+		   by the interrupted instruction. 0 means no memory operation,
+		   and EDA is undefined in that case. We zero it to avoid confusion. */
+		reg.eda = 0;
+	}
+
+	if (sigval == SIGTRAP) {
+		/* Break 8, single step or hardware breakpoint exception. */
+
+		/* Check IDX field of EXS. */
+		if (((reg.exs & 0xff00) >> 8) == 0x18) {
+
+			/* Break 8. */
+
+                        /* Static (compiled) breakpoints must return to the next instruction
+			   in order to avoid infinite loops (default value of ERP). Dynamic
+			   (gdb-invoked) must subtract the size of the break instruction from
+			   the ERP so that the instruction that was originally in the break
+			   instruction's place will be run when we return from the exception. */
+			if (!dynamic_bp) {
+				/* Assuming that all breakpoints are dynamic from now on. */
+				dynamic_bp = 1;
+			} else {
+
+				/* Only if not in a delay slot. */
+				if (!(reg.erp & 0x1)) {
+					reg.erp -= 2;
+					reg.pc -= 2;
+				}
+			}
+
+		} else if (((reg.exs & 0xff00) >> 8) == 0x3) {
+			/* Single step. */
+			/* Don't fiddle with S1. */
+
+		} else if (((reg.exs & 0xff00) >> 8) == 0xc) {
+
+			/* Hardware watchpoint exception. */
+
+			/* SPC has been updated so that we will get a single step exception
+			   when we return, but we don't want that. */
+			reg.spc = 0;
+
+			/* Don't fiddle with S1. */
+		}
+
+	} else if (sigval == SIGINT) {
+		/* Nothing special. */
+	}
+}
+
+static void insert_watchpoint(char type, int addr, int len)
+{
+	/* Breakpoint/watchpoint types (GDB terminology):
+	   0 = memory breakpoint for instructions
+	   (not supported; done via memory write instead)
+	   1 = hardware breakpoint for instructions (supported)
+	   2 = write watchpoint (supported)
+	   3 = read watchpoint (supported)
+	   4 = access watchpoint (supported) */
+
+	if (type < '1' || type > '4') {
+		output_buffer[0] = 0;
+		return;
+	}
+
+	/* Read watchpoints are set as access watchpoints, because of GDB's
+	   inability to deal with pure read watchpoints. */
+	if (type == '3')
+		type = '4';
+
+	if (type == '1') {
+		/* Hardware (instruction) breakpoint. */
+		/* Bit 0 in BP_CTRL holds the configuration for I0. */
+		if (sreg.s0_3 & 0x1) {
+			/* Already in use. */
+			gdb_cris_strcpy(output_buffer, error_message[E04]);
+			return;
+		}
+		/* Configure. */
+		sreg.s1_3 = addr;
+		sreg.s2_3 = (addr + len - 1);
+		sreg.s0_3 |= 1;
+	} else {
+		int bp;
+		unsigned int *bp_d_regs = &sreg.s3_3;
+
+		/* The watchpoint allocation scheme is the simplest possible.
+		   For example, if a region is watched for read and
+		   a write watch is requested, a new watchpoint will
+		   be used. Also, if a watch for a region that is already
+		   covered by one or more existing watchpoints, a new
+		   watchpoint will be used. */
+
+		/* First, find a free data watchpoint. */
+		for (bp = 0; bp < 6; bp++) {
+			/* Each data watchpoint's control registers occupy 2 bits
+			   (hence the 3), starting at bit 2 for D0 (hence the 2)
+			   with 4 bits between for each watchpoint (yes, the 4). */
+			if (!(sreg.s0_3 & (0x3 << (2 + (bp * 4))))) {
+				break;
+			}
+		}
+
+		if (bp > 5) {
+			/* We're out of watchpoints. */
+			gdb_cris_strcpy(output_buffer, error_message[E04]);
+			return;
+		}
+
+		/* Configure the control register first. */
+		if (type == '3' || type == '4') {
+			/* Trigger on read. */
+			sreg.s0_3 |= (1 << (2 + bp * 4));
+		}
+		if (type == '2' || type == '4') {
+			/* Trigger on write. */
+			sreg.s0_3 |= (2 << (2 + bp * 4));
+		}
+
+		/* Ugly pointer arithmetics to configure the watched range. */
+		bp_d_regs[bp * 2] = addr;
+		bp_d_regs[bp * 2 + 1] = (addr + len - 1);
+	}
+
+	/* Set the S1 flag to enable watchpoints. */
+	reg.ccs |= (1 << (S_CCS_BITNR + CCS_SHIFT));
+	gdb_cris_strcpy(output_buffer, "OK");
+}
+
+static void remove_watchpoint(char type, int addr, int len)
+{
+	/* Breakpoint/watchpoint types:
+	   0 = memory breakpoint for instructions
+	   (not supported; done via memory write instead)
+	   1 = hardware breakpoint for instructions (supported)
+	   2 = write watchpoint (supported)
+	   3 = read watchpoint (supported)
+	   4 = access watchpoint (supported) */
+	if (type < '1' || type > '4') {
+		output_buffer[0] = 0;
+		return;
+	}
+
+	/* Read watchpoints are set as access watchpoints, because of GDB's
+	   inability to deal with pure read watchpoints. */
+	if (type == '3')
+		type = '4';
+
+	if (type == '1') {
+		/* Hardware breakpoint. */
+		/* Bit 0 in BP_CTRL holds the configuration for I0. */
+		if (!(sreg.s0_3 & 0x1)) {
+			/* Not in use. */
+			gdb_cris_strcpy(output_buffer, error_message[E04]);
+			return;
+		}
+		/* Deconfigure. */
+		sreg.s1_3 = 0;
+		sreg.s2_3 = 0;
+		sreg.s0_3 &= ~1;
+	} else {
+		int bp;
+		unsigned int *bp_d_regs = &sreg.s3_3;
+		/* Try to find a watchpoint that is configured for the
+		   specified range, then check that read/write also matches. */
+
+		/* Ugly pointer arithmetic, since I cannot rely on a
+		   single switch (addr) as there may be several watchpoints with
+		   the same start address for example. */
+
+		for (bp = 0; bp < 6; bp++) {
+			if (bp_d_regs[bp * 2] == addr &&
+			    bp_d_regs[bp * 2 + 1] == (addr + len - 1)) {
+				/* Matching range. */
+				int bitpos = 2 + bp * 4;
+				int rw_bits;
+
+				/* Read/write bits for this BP. */
+				rw_bits = (sreg.s0_3 & (0x3 << bitpos)) >> bitpos;
+
+				if ((type == '3' && rw_bits == 0x1) ||
+				    (type == '2' && rw_bits == 0x2) ||
+				    (type == '4' && rw_bits == 0x3)) {
+					/* Read/write matched. */
+					break;
+				}
+			}
+		}
+
+		if (bp > 5) {
+			/* No watchpoint matched. */
+			gdb_cris_strcpy(output_buffer, error_message[E04]);
+			return;
+		}
+
+		/* Found a matching watchpoint. Now, deconfigure it by
+		   both disabling read/write in bp_ctrl and zeroing its
+		   start/end addresses. */
+		sreg.s0_3 &= ~(3 << (2 + (bp * 4)));
+		bp_d_regs[bp * 2] = 0;
+		bp_d_regs[bp * 2 + 1] = 0;
+	}
+
+	/* Note that we don't clear the S1 flag here. It's done when continuing.  */
+	gdb_cris_strcpy(output_buffer, "OK");
+}
+
+
+
+/* All expected commands are sent from remote.c. Send a response according
+   to the description in remote.c. */
+void
+handle_exception(int sigval)
+{
+	/* Avoid warning of not used. */
+
+	USEDFUN(handle_exception);
+	USEDVAR(internal_stack[0]);
+
+	register_fixup(sigval);
+
+	/* Send response. */
+	stub_is_stopped(sigval);
+
+	for (;;) {
+		output_buffer[0] = '\0';
+		getpacket(input_buffer);
+		switch (input_buffer[0]) {
+			case 'g':
+				/* Read registers: g
+				   Success: Each byte of register data is described by two hex digits.
+				   Registers are in the internal order for GDB, and the bytes
+				   in a register  are in the same order the machine uses.
+				   Failure: void. */
+			{
+				char *buf;
+				/* General and special registers. */
+				buf = mem2hex(output_buffer, (char *)&reg, sizeof(registers));
+				/* Support registers. */
+				/* -1 because of the null termination that mem2hex adds. */
+				mem2hex(buf,
+					(char *)&sreg + (reg.srs * 16 * sizeof(unsigned int)),
+					16 * sizeof(unsigned int));
+				break;
+			}
+			case 'G':
+				/* Write registers. GXX..XX
+				   Each byte of register data  is described by two hex digits.
+				   Success: OK
+				   Failure: void. */
+				/* General and special registers. */
+				hex2mem((char *)&reg, &input_buffer[1], sizeof(registers));
+				/* Support registers. */
+				hex2mem((char *)&sreg + (reg.srs * 16 * sizeof(unsigned int)),
+					&input_buffer[1] + sizeof(registers),
+					16 * sizeof(unsigned int));
+				gdb_cris_strcpy(output_buffer, "OK");
+				break;
+
+			case 'P':
+				/* Write register. Pn...=r...
+				   Write register n..., hex value without 0x, with value r...,
+				   which contains a hex value without 0x and two hex digits
+				   for each byte in the register (target byte order). P1f=11223344 means
+				   set register 31 to 44332211.
+				   Success: OK
+				   Failure: E02, E05 */
+				{
+					char *suffix;
+					int regno = gdb_cris_strtol(&input_buffer[1], &suffix, 16);
+					int status;
+
+					status = write_register(regno, suffix+1);
+
+					switch (status) {
+						case E02:
+							/* Do not support read-only registers. */
+							gdb_cris_strcpy(output_buffer, error_message[E02]);
+							break;
+						case E05:
+							/* Do not support non-existing registers. */
+							gdb_cris_strcpy(output_buffer, error_message[E05]);
+							break;
+						default:
+							/* Valid register number. */
+							gdb_cris_strcpy(output_buffer, "OK");
+							break;
+					}
+				}
+				break;
+
+			case 'm':
+				/* Read from memory. mAA..AA,LLLL
+				   AA..AA is the address and LLLL is the length.
+				   Success: XX..XX is the memory content.  Can be fewer bytes than
+				   requested if only part of the data may be read. m6000120a,6c means
+				   retrieve 108 byte from base address 6000120a.
+				   Failure: void. */
+				{
+                                        char *suffix;
+					unsigned char *addr = (unsigned char *)gdb_cris_strtol(&input_buffer[1],
+                                                                                               &suffix, 16);
+					int len = gdb_cris_strtol(suffix+1, 0, 16);
+
+					/* Bogus read (i.e. outside the kernel's
+					   segment)? . */
+					if (!((unsigned int)addr >= 0xc0000000 &&
+					      (unsigned int)addr < 0xd0000000))
+						addr = NULL;
+
+                                        mem2hex(output_buffer, addr, len);
+                                }
+				break;
+
+			case 'X':
+				/* Write to memory. XAA..AA,LLLL:XX..XX
+				   AA..AA is the start address,  LLLL is the number of bytes, and
+				   XX..XX is the binary data.
+				   Success: OK
+				   Failure: void. */
+			case 'M':
+				/* Write to memory. MAA..AA,LLLL:XX..XX
+				   AA..AA is the start address,  LLLL is the number of bytes, and
+				   XX..XX is the hexadecimal data.
+				   Success: OK
+				   Failure: void. */
+				{
+					char *lenptr;
+					char *dataptr;
+					unsigned char *addr = (unsigned char *)gdb_cris_strtol(&input_buffer[1],
+										      &lenptr, 16);
+					int len = gdb_cris_strtol(lenptr+1, &dataptr, 16);
+					if (*lenptr == ',' && *dataptr == ':') {
+						if (input_buffer[0] == 'M') {
+							hex2mem(addr, dataptr + 1, len);
+						} else /* X */ {
+							bin2mem(addr, dataptr + 1, len);
+						}
+						gdb_cris_strcpy(output_buffer, "OK");
+					}
+					else {
+						gdb_cris_strcpy(output_buffer, error_message[E06]);
+					}
+				}
+				break;
+
+			case 'c':
+				/* Continue execution. cAA..AA
+				   AA..AA is the address where execution is resumed. If AA..AA is
+				   omitted, resume at the present address.
+				   Success: return to the executing thread.
+				   Failure: will never know. */
+
+				if (input_buffer[1] != '\0') {
+					/* FIXME: Doesn't handle address argument. */
+					gdb_cris_strcpy(output_buffer, error_message[E04]);
+					break;
+				}
+
+				/* Before continuing, make sure everything is set up correctly. */
+
+				/* Set the SPC to some unlikely value.  */
+				reg.spc = 0;
+				/* Set the S1 flag to 0 unless some watchpoint is enabled (since setting
+				   S1 to 0 would also disable watchpoints). (Note that bits 26-31 in BP_CTRL
+				   are reserved, so don't check against those). */
+				if ((sreg.s0_3 & 0x3fff) == 0) {
+					reg.ccs &= ~(1 << (S_CCS_BITNR + CCS_SHIFT));
+				}
+
+				return;
+
+			case 's':
+				/* Step. sAA..AA
+				   AA..AA is the address where execution is resumed. If AA..AA is
+				   omitted, resume at the present address. Success: return to the
+				   executing thread. Failure: will never know. */
+
+				if (input_buffer[1] != '\0') {
+					/* FIXME: Doesn't handle address argument. */
+					gdb_cris_strcpy(output_buffer, error_message[E04]);
+					break;
+				}
+
+				/* Set the SPC to PC, which is where we'll return
+				   (deduced previously). */
+				reg.spc = reg.pc;
+
+				/* Set the S1 (first stacked, not current) flag, which will
+				   kick into action when we rfe. */
+				reg.ccs |= (1 << (S_CCS_BITNR + CCS_SHIFT));
+				return;
+
+                       case 'Z':
+
+                               /* Insert breakpoint or watchpoint, Ztype,addr,length.
+                                  Remote protocol says: A remote target shall return an empty string
+                                  for an unrecognized breakpoint or watchpoint packet type. */
+                               {
+                                       char *lenptr;
+                                       char *dataptr;
+                                       int addr = gdb_cris_strtol(&input_buffer[3], &lenptr, 16);
+                                       int len = gdb_cris_strtol(lenptr + 1, &dataptr, 16);
+                                       char type = input_buffer[1];
+
+				       insert_watchpoint(type, addr, len);
+                                       break;
+                               }
+
+                       case 'z':
+                               /* Remove breakpoint or watchpoint, Ztype,addr,length.
+                                  Remote protocol says: A remote target shall return an empty string
+                                  for an unrecognized breakpoint or watchpoint packet type. */
+                               {
+                                       char *lenptr;
+                                       char *dataptr;
+                                       int addr = gdb_cris_strtol(&input_buffer[3], &lenptr, 16);
+                                       int len = gdb_cris_strtol(lenptr + 1, &dataptr, 16);
+                                       char type = input_buffer[1];
+
+                                       remove_watchpoint(type, addr, len);
+                                       break;
+                               }
+
+
+			case '?':
+				/* The last signal which caused a stop. ?
+				   Success: SAA, where AA is the signal number.
+				   Failure: void. */
+				output_buffer[0] = 'S';
+				output_buffer[1] = hex_asc_hi(sigval);
+				output_buffer[2] = hex_asc_lo(sigval);
+				output_buffer[3] = 0;
+				break;
+
+			case 'D':
+				/* Detach from host. D
+				   Success: OK, and return to the executing thread.
+				   Failure: will never know */
+				putpacket("OK");
+				return;
+
+			case 'k':
+			case 'r':
+				/* kill request or reset request.
+				   Success: restart of target.
+				   Failure: will never know. */
+				kill_restart();
+				break;
+
+			case 'C':
+			case 'S':
+			case '!':
+			case 'R':
+			case 'd':
+				/* Continue with signal sig. Csig;AA..AA
+				   Step with signal sig. Ssig;AA..AA
+				   Use the extended remote protocol. !
+				   Restart the target system. R0
+				   Toggle debug flag. d
+				   Search backwards. tAA:PP,MM
+				   Not supported: E04 */
+
+				/* FIXME: What's the difference between not supported
+				   and ignored (below)? */
+				gdb_cris_strcpy(output_buffer, error_message[E04]);
+				break;
+
+			default:
+				/* The stub should ignore other request and send an empty
+				   response ($#<checksum>). This way we can extend the protocol and GDB
+				   can tell whether the stub it is talking to uses the old or the new. */
+				output_buffer[0] = 0;
+				break;
+		}
+		putpacket(output_buffer);
+	}
+}
+
+void
+kgdb_init(void)
+{
+	reg_intr_vect_rw_mask intr_mask;
+	reg_ser_rw_intr_mask ser_intr_mask;
+
+	/* Configure the kgdb serial port. */
+#if defined(CONFIG_ETRAX_KGDB_PORT0)
+	/* Note: no shortcut registered (not handled by multiple_interrupt).
+	   See entry.S.  */
+	set_exception_vector(SER0_INTR_VECT, kgdb_handle_exception);
+	/* Enable the ser irq in the global config. */
+	intr_mask = REG_RD(intr_vect, regi_irq, rw_mask);
+	intr_mask.ser0 = 1;
+	REG_WR(intr_vect, regi_irq, rw_mask, intr_mask);
+
+	ser_intr_mask = REG_RD(ser, regi_ser0, rw_intr_mask);
+	ser_intr_mask.dav = regk_ser_yes;
+	REG_WR(ser, regi_ser0, rw_intr_mask, ser_intr_mask);
+#elif defined(CONFIG_ETRAX_KGDB_PORT1)
+	/* Note: no shortcut registered (not handled by multiple_interrupt).
+	   See entry.S.  */
+	set_exception_vector(SER1_INTR_VECT, kgdb_handle_exception);
+	/* Enable the ser irq in the global config. */
+	intr_mask = REG_RD(intr_vect, regi_irq, rw_mask);
+	intr_mask.ser1 = 1;
+	REG_WR(intr_vect, regi_irq, rw_mask, intr_mask);
+
+	ser_intr_mask = REG_RD(ser, regi_ser1, rw_intr_mask);
+	ser_intr_mask.dav = regk_ser_yes;
+	REG_WR(ser, regi_ser1, rw_intr_mask, ser_intr_mask);
+#elif defined(CONFIG_ETRAX_KGDB_PORT2)
+	/* Note: no shortcut registered (not handled by multiple_interrupt).
+	   See entry.S.  */
+	set_exception_vector(SER2_INTR_VECT, kgdb_handle_exception);
+	/* Enable the ser irq in the global config. */
+	intr_mask = REG_RD(intr_vect, regi_irq, rw_mask);
+	intr_mask.ser2 = 1;
+	REG_WR(intr_vect, regi_irq, rw_mask, intr_mask);
+
+	ser_intr_mask = REG_RD(ser, regi_ser2, rw_intr_mask);
+	ser_intr_mask.dav = regk_ser_yes;
+	REG_WR(ser, regi_ser2, rw_intr_mask, ser_intr_mask);
+#elif defined(CONFIG_ETRAX_KGDB_PORT3)
+	/* Note: no shortcut registered (not handled by multiple_interrupt).
+	   See entry.S.  */
+	set_exception_vector(SER3_INTR_VECT, kgdb_handle_exception);
+	/* Enable the ser irq in the global config. */
+	intr_mask = REG_RD(intr_vect, regi_irq, rw_mask);
+	intr_mask.ser3 = 1;
+	REG_WR(intr_vect, regi_irq, rw_mask, intr_mask);
+
+	ser_intr_mask = REG_RD(ser, regi_ser3, rw_intr_mask);
+	ser_intr_mask.dav = regk_ser_yes;
+	REG_WR(ser, regi_ser3, rw_intr_mask, ser_intr_mask);
+#endif
+
+}
+/* Performs a complete re-start from scratch. */
+static void
+kill_restart(void)
+{
+	machine_restart("");
+}
+
+/* Use this static breakpoint in the start-up only. */
+
+void
+breakpoint(void)
+{
+	kgdb_started = 1;
+	dynamic_bp = 0;     /* This is a static, not a dynamic breakpoint. */
+	__asm__ volatile ("break 8"); /* Jump to kgdb_handle_breakpoint. */
+}
+
+/****************************** End of file **********************************/