mn10300: add the MN10300/AM33 architecture to the kernel

Add architecture support for the MN10300/AM33 CPUs produced by MEI to the
kernel.

This patch also adds board support for the ASB2303 with the ASB2308 daughter
board, and the ASB2305.  The only processor supported is the MN103E010, which
is an AM33v2 core plus on-chip devices.

[akpm@linux-foundation.org: nuke cvs control strings]
Signed-off-by: Masakazu Urade <urade.masakazu@jp.panasonic.com>
Signed-off-by: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1947 insertions, 0 deletions

diff --git a/arch/mn10300/kernel/gdb-stub.c b/arch/mn10300/kernel/gdb-stub.c
new file mode 100644
index 000000000000..21891c71d549
--- /dev/null
+++ b/arch/mn10300/kernel/gdb-stub.c
@@ -0,0 +1,1947 @@
+/* MN10300 GDB stub
+ *
+ * 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
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Modified for Linux/mn10300 by David Howells <dhowells@redhat.com>
+ */
+
+/*
+ *  To enable debugger support, two things need to happen.  One, 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.
+ *  Two, a breakpoint needs to be generated to begin communication.  This
+ *  is most easily accomplished by a call to breakpoint().  Breakpoint()
+ *  simulates a breakpoint by executing a BREAK instruction.
+ *
+ *
+ *    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
+ *
+ *
+ *  ==============
+ *  MORE EXAMPLES:
+ *  ==============
+ *
+ *  For reference -- the following are the steps that one
+ *  company took (RidgeRun Inc) to get remote gdb debugging
+ *  going. In this scenario the host machine was a PC and the
+ *  target platform was a Galileo EVB64120A MIPS evaluation
+ *  board.
+ *
+ *  Step 1:
+ *  First download gdb-5.0.tar.gz from the internet.
+ *  and then build/install the package.
+ *
+ *  Example:
+ *    $ tar zxf gdb-5.0.tar.gz
+ *    $ cd gdb-5.0
+ *    $ ./configure --target=am33_2.0-linux-gnu
+ *    $ make
+ *    $ install
+ *    am33_2.0-linux-gnu-gdb
+ *
+ *  Step 2:
+ *  Configure linux for remote debugging and build it.
+ *
+ *  Example:
+ *    $ cd ~/linux
+ *    $ make menuconfig <go to "Kernel Hacking" and turn on remote debugging>
+ *    $ make dep; make vmlinux
+ *
+ *  Step 3:
+ *  Download the kernel to the remote target and start
+ *  the kernel running. It will promptly halt and wait
+ *  for the host gdb session to connect. It does this
+ *  since the "Kernel Hacking" option has defined
+ *  CONFIG_REMOTE_DEBUG which in turn enables your calls
+ *  to:
+ *     set_debug_traps();
+ *     breakpoint();
+ *
+ *  Step 4:
+ *  Start the gdb session on the host.
+ *
+ *  Example:
+ *    $ am33_2.0-linux-gnu-gdb vmlinux
+ *    (gdb) set remotebaud 115200
+ *    (gdb) target remote /dev/ttyS1
+ *    ...at this point you are connected to
+ *       the remote target and can use gdb
+ *       in the normal fasion. Setting
+ *       breakpoints, single stepping,
+ *       printing variables, etc.
+ *
+ */
+
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/bug.h>
+
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/gdb-stub.h>
+#include <asm/exceptions.h>
+#include <asm/cacheflush.h>
+#include <asm/serial-regs.h>
+#include <asm/busctl-regs.h>
+#include <asm/unit/leds.h>
+#include <asm/unit/serial.h>
+
+/* define to use F7F7 rather than FF which is subverted by JTAG debugger */
+#undef GDBSTUB_USE_F7F7_AS_BREAKPOINT
+
+/*
+ * BUFMAX defines the maximum number of characters in inbound/outbound buffers
+ * at least NUMREGBYTES*2 are needed for register packets
+ */
+#define BUFMAX 2048
+
+static const char gdbstub_banner[] =
+	"Linux/MN10300 GDB Stub (c) RedHat 2007\n";
+
+u8	gdbstub_rx_buffer[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
+u32	gdbstub_rx_inp;
+u32	gdbstub_rx_outp;
+u8	gdbstub_busy;
+u8	gdbstub_rx_overflow;
+u8	gdbstub_rx_unget;
+
+static u8	gdbstub_flush_caches;
+static char	input_buffer[BUFMAX];
+static char	output_buffer[BUFMAX];
+static char	trans_buffer[BUFMAX];
+
+static const char hexchars[] = "0123456789abcdef";
+
+struct gdbstub_bkpt {
+	u8	*addr;		/* address of breakpoint */
+	u8	len;		/* size of breakpoint */
+	u8	origbytes[7];	/* original bytes */
+};
+
+static struct gdbstub_bkpt gdbstub_bkpts[256];
+
+/*
+ * local prototypes
+ */
+static void getpacket(char *buffer);
+static int putpacket(char *buffer);
+static int computeSignal(enum exception_code excep);
+static int hex(unsigned char ch);
+static int hexToInt(char **ptr, int *intValue);
+static unsigned char *mem2hex(const void *mem, char *buf, int count,
+			      int may_fault);
+static const char *hex2mem(const char *buf, void *_mem, int count,
+			   int may_fault);
+
+/*
+ * Convert ch from a hex digit to an int
+ */
+static int hex(unsigned 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;
+}
+
+#ifdef CONFIG_GDBSTUB_DEBUGGING
+
+void debug_to_serial(const char *p, int n)
+{
+	__debug_to_serial(p, n);
+	/* gdbstub_console_write(NULL, p, n); */
+}
+
+void gdbstub_printk(const char *fmt, ...)
+{
+	va_list args;
+	int len;
+
+	/* Emit the output into the temporary buffer */
+	va_start(args, fmt);
+	len = vsnprintf(trans_buffer, sizeof(trans_buffer), fmt, args);
+	va_end(args);
+	debug_to_serial(trans_buffer, len);
+}
+
+#endif
+
+static inline char *gdbstub_strcpy(char *dst, const char *src)
+{
+	int loop = 0;
+	while ((dst[loop] = src[loop]))
+	       loop++;
+	return dst;
+}
+
+/*
+ * scan for the sequence $<data>#<checksum>
+ */
+static void getpacket(char *buffer)
+{
+	unsigned char checksum;
+	unsigned char xmitcsum;
+	unsigned char ch;
+	int count, i, ret, error;
+
+	for (;;) {
+		/*
+		 * wait around for the start character,
+		 * ignore all other characters
+		 */
+		do {
+			gdbstub_io_rx_char(&ch, 0);
+		} while (ch != '$');
+
+		checksum = 0;
+		xmitcsum = -1;
+		count = 0;
+		error = 0;
+
+		/*
+		 * now, read until a # or end of buffer is found
+		 */
+		while (count < BUFMAX) {
+			ret = gdbstub_io_rx_char(&ch, 0);
+			if (ret < 0)
+				error = ret;
+
+			if (ch == '#')
+				break;
+			checksum += ch;
+			buffer[count] = ch;
+			count++;
+		}
+
+		if (error == -EIO) {
+			gdbstub_proto("### GDB Rx Error - Skipping packet"
+				      " ###\n");
+			gdbstub_proto("### GDB Tx NAK\n");
+			gdbstub_io_tx_char('-');
+			continue;
+		}
+
+		if (count >= BUFMAX || error)
+			continue;
+
+		buffer[count] = 0;
+
+		/* read the checksum */
+		ret = gdbstub_io_rx_char(&ch, 0);
+		if (ret < 0)
+			error = ret;
+		xmitcsum = hex(ch) << 4;
+
+		ret = gdbstub_io_rx_char(&ch, 0);
+		if (ret < 0)
+			error = ret;
+		xmitcsum |= hex(ch);
+
+		if (error) {
+			if (error == -EIO)
+				gdbstub_io("### GDB Rx Error -"
+					   " Skipping packet\n");
+			gdbstub_io("### GDB Tx NAK\n");
+			gdbstub_io_tx_char('-');
+			continue;
+		}
+
+		/* check the checksum */
+		if (checksum != xmitcsum) {
+			gdbstub_io("### GDB Tx NAK\n");
+			gdbstub_io_tx_char('-');	/* failed checksum */
+			continue;
+		}
+
+		gdbstub_proto("### GDB Rx '$%s#%02x' ###\n", buffer, checksum);
+		gdbstub_io("### GDB Tx ACK\n");
+		gdbstub_io_tx_char('+'); /* successful transfer */
+
+		/*
+		 * if a sequence char is present,
+		 * reply the sequence ID
+		 */
+		if (buffer[2] == ':') {
+			gdbstub_io_tx_char(buffer[0]);
+			gdbstub_io_tx_char(buffer[1]);
+
+			/*
+			 * remove sequence chars from buffer
+			 */
+			count = 0;
+			while (buffer[count])
+				count++;
+			for (i = 3; i <= count; i++)
+				buffer[i - 3] = buffer[i];
+		}
+
+		break;
+	}
+}
+
+/*
+ * send the packet in buffer.
+ * - return 0 if successfully ACK'd
+ * - return 1 if abandoned due to new incoming packet
+ */
+static int putpacket(char *buffer)
+{
+	unsigned char checksum;
+	unsigned char ch;
+	int count;
+
+	/*
+	 * $<packet info>#<checksum>.
+	 */
+	gdbstub_proto("### GDB Tx $'%s'#?? ###\n", buffer);
+
+	do {
+		gdbstub_io_tx_char('$');
+		checksum = 0;
+		count = 0;
+
+		while ((ch = buffer[count]) != 0) {
+			gdbstub_io_tx_char(ch);
+			checksum += ch;
+			count += 1;
+		}
+
+		gdbstub_io_tx_char('#');
+		gdbstub_io_tx_char(hexchars[checksum >> 4]);
+		gdbstub_io_tx_char(hexchars[checksum & 0xf]);
+
+	} while (gdbstub_io_rx_char(&ch, 0),
+		 ch == '-' && (gdbstub_io("### GDB Rx NAK\n"), 0),
+		 ch != '-' && ch != '+' &&
+		 (gdbstub_io("### GDB Rx ??? %02x\n", ch), 0),
+		 ch != '+' && ch != '$');
+
+	if (ch == '+') {
+		gdbstub_io("### GDB Rx ACK\n");
+		return 0;
+	}
+
+	gdbstub_io("### GDB Tx Abandoned\n");
+	gdbstub_rx_unget = ch;
+	return 1;
+}
+
+/*
+ * While we find nice hex chars, build an int.
+ * Return number of chars processed.
+ */
+static int hexToInt(char **ptr, int *intValue)
+{
+	int numChars = 0;
+	int hexValue;
+
+	*intValue = 0;
+
+	while (**ptr) {
+		hexValue = hex(**ptr);
+		if (hexValue < 0)
+			break;
+
+		*intValue = (*intValue << 4) | hexValue;
+		numChars++;
+
+		(*ptr)++;
+	}
+
+	return (numChars);
+}
+
+/*
+ * We single-step by setting breakpoints. When an exception
+ * is handled, we need to restore the instructions hoisted
+ * when the breakpoints were set.
+ *
+ * This is where we save the original instructions.
+ */
+static struct gdb_bp_save {
+	u8	*addr;
+	u8	opcode[2];
+} step_bp[2];
+
+static const unsigned char gdbstub_insn_sizes[256] =
+{
+	/* 1  2  3  4  5  6  7  8  9  a  b  c  d  e  f */
+	1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3, 1, 3, 3, 3,	/* 0 */
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 1 */
+	2, 2, 2, 2, 3, 3, 3, 3, 2, 2, 2, 2, 3, 3, 3, 3, /* 2 */
+	3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 1, 1, 1, 1, /* 3 */
+	1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, 1, 1, 2, 2, /* 4 */
+	1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, /* 5 */
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 6 */
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* 7 */
+	2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 8 */
+	2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* 9 */
+	2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* a */
+	2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, /* b */
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 2, 2, /* c */
+	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, /* d */
+	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, /* e */
+	0, 2, 2, 2, 2, 2, 2, 4, 0, 3, 0, 4, 0, 6, 7, 1  /* f */
+};
+
+static int __gdbstub_mark_bp(u8 *addr, int ix)
+{
+	if (addr < (u8 *) 0x70000000UL)
+		return 0;
+	/* 70000000-7fffffff: vmalloc area */
+	if (addr < (u8 *) 0x80000000UL)
+		goto okay;
+	if (addr < (u8 *) 0x8c000000UL)
+		return 0;
+	/* 8c000000-93ffffff: SRAM, SDRAM */
+	if (addr < (u8 *) 0x94000000UL)
+		goto okay;
+	return 0;
+
+okay:
+	if (gdbstub_read_byte(addr + 0, &step_bp[ix].opcode[0]) < 0 ||
+	    gdbstub_read_byte(addr + 1, &step_bp[ix].opcode[1]) < 0)
+		return 0;
+
+	step_bp[ix].addr = addr;
+	return 1;
+}
+
+static inline void __gdbstub_restore_bp(void)
+{
+#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
+	if (step_bp[0].addr) {
+		gdbstub_write_byte(step_bp[0].opcode[0], step_bp[0].addr + 0);
+		gdbstub_write_byte(step_bp[0].opcode[1], step_bp[0].addr + 1);
+	}
+	if (step_bp[1].addr) {
+		gdbstub_write_byte(step_bp[1].opcode[0], step_bp[1].addr + 0);
+		gdbstub_write_byte(step_bp[1].opcode[1], step_bp[1].addr + 1);
+	}
+#else
+	if (step_bp[0].addr)
+		gdbstub_write_byte(step_bp[0].opcode[0], step_bp[0].addr + 0);
+	if (step_bp[1].addr)
+		gdbstub_write_byte(step_bp[1].opcode[0], step_bp[1].addr + 0);
+#endif
+
+	gdbstub_flush_caches = 1;
+
+	step_bp[0].addr		= NULL;
+	step_bp[0].opcode[0]	= 0;
+	step_bp[0].opcode[1]	= 0;
+	step_bp[1].addr		= NULL;
+	step_bp[1].opcode[0]	= 0;
+	step_bp[1].opcode[1]	= 0;
+}
+
+/*
+ * emulate single stepping by means of breakpoint instructions
+ */
+static int gdbstub_single_step(struct pt_regs *regs)
+{
+	unsigned size;
+	uint32_t x;
+	uint8_t cur, *pc, *sp;
+
+	step_bp[0].addr		= NULL;
+	step_bp[0].opcode[0]	= 0;
+	step_bp[0].opcode[1]	= 0;
+	step_bp[1].addr		= NULL;
+	step_bp[1].opcode[0]	= 0;
+	step_bp[1].opcode[1]	= 0;
+	x = 0;
+
+	pc = (u8 *) regs->pc;
+	sp = (u8 *) (regs + 1);
+	if (gdbstub_read_byte(pc, &cur) < 0)
+		return -EFAULT;
+
+	gdbstub_bkpt("Single Step from %p { %02x }\n", pc, cur);
+
+	gdbstub_flush_caches = 1;
+
+	size = gdbstub_insn_sizes[cur];
+	if (size > 0) {
+		if (!__gdbstub_mark_bp(pc + size, 0))
+			goto fault;
+	} else {
+		switch (cur) {
+			/* Bxx (d8,PC) */
+		case 0xc0:
+		case 0xc1:
+		case 0xc2:
+		case 0xc3:
+		case 0xc4:
+		case 0xc5:
+		case 0xc6:
+		case 0xc7:
+		case 0xc8:
+		case 0xc9:
+		case 0xca:
+			if (gdbstub_read_byte(pc + 1, (u8 *) &x) < 0)
+				goto fault;
+			if (!__gdbstub_mark_bp(pc + 2, 0))
+				goto fault;
+			if ((x < 0 || x > 2) &&
+			    !__gdbstub_mark_bp(pc + (s8) x, 1))
+				goto fault;
+			break;
+
+			/* LXX (d8,PC) */
+		case 0xd0:
+		case 0xd1:
+		case 0xd2:
+		case 0xd3:
+		case 0xd4:
+		case 0xd5:
+		case 0xd6:
+		case 0xd7:
+		case 0xd8:
+		case 0xd9:
+		case 0xda:
+			if (!__gdbstub_mark_bp(pc + 1, 0))
+				goto fault;
+			if (regs->pc != regs->lar &&
+			    !__gdbstub_mark_bp((u8 *) regs->lar, 1))
+				goto fault;
+			break;
+
+			/* SETLB - loads the next for bytes into the LIR
+			 * register */
+		case 0xdb:
+			if (!__gdbstub_mark_bp(pc + 1, 0))
+				goto fault;
+			break;
+
+			/* JMP (d16,PC) or CALL (d16,PC) */
+		case 0xcc:
+		case 0xcd:
+			if (gdbstub_read_byte(pc + 1, ((u8 *) &x) + 0) < 0 ||
+			    gdbstub_read_byte(pc + 2, ((u8 *) &x) + 1) < 0)
+				goto fault;
+			if (!__gdbstub_mark_bp(pc + (s16) x, 0))
+				goto fault;
+			break;
+
+			/* JMP (d32,PC) or CALL (d32,PC) */
+		case 0xdc:
+		case 0xdd:
+			if (gdbstub_read_byte(pc + 1, ((u8 *) &x) + 0) < 0 ||
+			    gdbstub_read_byte(pc + 2, ((u8 *) &x) + 1) < 0 ||
+			    gdbstub_read_byte(pc + 3, ((u8 *) &x) + 2) < 0 ||
+			    gdbstub_read_byte(pc + 4, ((u8 *) &x) + 3) < 0)
+				goto fault;
+			if (!__gdbstub_mark_bp(pc + (s32) x, 0))
+				goto fault;
+			break;
+
+			/* RETF */
+		case 0xde:
+			if (!__gdbstub_mark_bp((u8 *) regs->mdr, 0))
+				goto fault;
+			break;
+
+			/* RET */
+		case 0xdf:
+			if (gdbstub_read_byte(pc + 2, (u8 *) &x) < 0)
+				goto fault;
+			sp += (s8)x;
+			if (gdbstub_read_byte(sp + 0, ((u8 *) &x) + 0) < 0 ||
+			    gdbstub_read_byte(sp + 1, ((u8 *) &x) + 1) < 0 ||
+			    gdbstub_read_byte(sp + 2, ((u8 *) &x) + 2) < 0 ||
+			    gdbstub_read_byte(sp + 3, ((u8 *) &x) + 3) < 0)
+				goto fault;
+			if (!__gdbstub_mark_bp((u8 *) x, 0))
+				goto fault;
+			break;
+
+		case 0xf0:
+			if (gdbstub_read_byte(pc + 1, &cur) < 0)
+				goto fault;
+
+			if (cur >= 0xf0 && cur <= 0xf7) {
+				/* JMP (An) / CALLS (An) */
+				switch (cur & 3) {
+				case 0: x = regs->a0; break;
+				case 1: x = regs->a1; break;
+				case 2: x = regs->a2; break;
+				case 3: x = regs->a3; break;
+				}
+				if (!__gdbstub_mark_bp((u8 *) x, 0))
+					goto fault;
+			} else if (cur == 0xfc) {
+				/* RETS */
+				if (gdbstub_read_byte(
+					    sp + 0, ((u8 *) &x) + 0) < 0 ||
+				    gdbstub_read_byte(
+					    sp + 1, ((u8 *) &x) + 1) < 0 ||
+				    gdbstub_read_byte(
+					    sp + 2, ((u8 *) &x) + 2) < 0 ||
+				    gdbstub_read_byte(
+					    sp + 3, ((u8 *) &x) + 3) < 0)
+					goto fault;
+				if (!__gdbstub_mark_bp((u8 *) x, 0))
+					goto fault;
+			} else if (cur == 0xfd) {
+				/* RTI */
+				if (gdbstub_read_byte(
+					    sp + 4, ((u8 *) &x) + 0) < 0 ||
+				    gdbstub_read_byte(
+					    sp + 5, ((u8 *) &x) + 1) < 0 ||
+				    gdbstub_read_byte(
+					    sp + 6, ((u8 *) &x) + 2) < 0 ||
+				    gdbstub_read_byte(
+					    sp + 7, ((u8 *) &x) + 3) < 0)
+					goto fault;
+				if (!__gdbstub_mark_bp((u8 *) x, 0))
+					goto fault;
+			} else {
+				if (!__gdbstub_mark_bp(pc + 2, 0))
+					goto fault;
+			}
+
+			break;
+
+			/* potential 3-byte conditional branches */
+		case 0xf8:
+			if (gdbstub_read_byte(pc + 1, &cur) < 0)
+				goto fault;
+			if (!__gdbstub_mark_bp(pc + 3, 0))
+				goto fault;
+
+			if (cur >= 0xe8 && cur <= 0xeb) {
+				if (gdbstub_read_byte(
+					    pc + 2, ((u8 *) &x) + 0) < 0)
+					goto fault;
+				if ((x < 0 || x > 3) &&
+				    !__gdbstub_mark_bp(pc + (s8) x, 1))
+					goto fault;
+			}
+			break;
+
+		case 0xfa:
+			if (gdbstub_read_byte(pc + 1, &cur) < 0)
+				goto fault;
+
+			if (cur == 0xff) {
+				/* CALLS (d16,PC) */
+				if (gdbstub_read_byte(
+					    pc + 2, ((u8 *) &x) + 0) < 0 ||
+				    gdbstub_read_byte(
+					    pc + 3, ((u8 *) &x) + 1) < 0)
+					goto fault;
+				if (!__gdbstub_mark_bp(pc + (s16) x, 0))
+					goto fault;
+			} else {
+				if (!__gdbstub_mark_bp(pc + 4, 0))
+					goto fault;
+			}
+			break;
+
+		case 0xfc:
+			if (gdbstub_read_byte(pc + 1, &cur) < 0)
+				goto fault;
+			if (cur == 0xff) {
+				/* CALLS (d32,PC) */
+				if (gdbstub_read_byte(
+					    pc + 2, ((u8 *) &x) + 0) < 0 ||
+				    gdbstub_read_byte(
+					    pc + 3, ((u8 *) &x) + 1) < 0 ||
+				    gdbstub_read_byte(
+					    pc + 4, ((u8 *) &x) + 2) < 0 ||
+				    gdbstub_read_byte(
+					    pc + 5, ((u8 *) &x) + 3) < 0)
+					goto fault;
+				if (!__gdbstub_mark_bp(
+					    pc + (s32) x, 0))
+					goto fault;
+			} else {
+				if (!__gdbstub_mark_bp(
+					    pc + 6, 0))
+					goto fault;
+			}
+			break;
+
+		}
+	}
+
+	gdbstub_bkpt("Step: %02x at %p; %02x at %p\n",
+		     step_bp[0].opcode[0], step_bp[0].addr,
+		     step_bp[1].opcode[0], step_bp[1].addr);
+
+	if (step_bp[0].addr) {
+#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
+		if (gdbstub_write_byte(0xF7, step_bp[0].addr + 0) < 0 ||
+		    gdbstub_write_byte(0xF7, step_bp[0].addr + 1) < 0)
+			goto fault;
+#else
+		if (gdbstub_write_byte(0xFF, step_bp[0].addr + 0) < 0)
+			goto fault;
+#endif
+	}
+
+	if (step_bp[1].addr) {
+#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
+		if (gdbstub_write_byte(0xF7, step_bp[1].addr + 0) < 0 ||
+		    gdbstub_write_byte(0xF7, step_bp[1].addr + 1) < 0)
+			goto fault;
+#else
+		if (gdbstub_write_byte(0xFF, step_bp[1].addr + 0) < 0)
+			goto fault;
+#endif
+	}
+
+	return 0;
+
+ fault:
+	/* uh-oh - silly address alert, try and restore things */
+	__gdbstub_restore_bp();
+	return -EFAULT;
+}
+
+#ifdef CONFIG_GDBSTUB_CONSOLE
+
+void gdbstub_console_write(struct console *con, const char *p, unsigned n)
+{
+	static const char gdbstub_cr[] = { 0x0d };
+	char outbuf[26];
+	int qty;
+	u8 busy;
+
+	busy = gdbstub_busy;
+	gdbstub_busy = 1;
+
+	outbuf[0] = 'O';
+
+	while (n > 0) {
+		qty = 1;
+
+		while (n > 0 && qty < 20) {
+			mem2hex(p, outbuf + qty, 2, 0);
+			qty += 2;
+			if (*p == 0x0a) {
+				mem2hex(gdbstub_cr, outbuf + qty, 2, 0);
+				qty += 2;
+			}
+			p++;
+			n--;
+		}
+
+		outbuf[qty] = 0;
+		putpacket(outbuf);
+	}
+
+	gdbstub_busy = busy;
+}
+
+static kdev_t gdbstub_console_dev(struct console *con)
+{
+	return MKDEV(1, 3); /* /dev/null */
+}
+
+static struct console gdbstub_console = {
+	.name	= "gdb",
+	.write	= gdbstub_console_write,
+	.device	= gdbstub_console_dev,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1,
+};
+
+#endif
+
+/*
+ * Convert the memory pointed to by mem into hex, placing result in buf.
+ * - if successful, return a pointer to the last char put in buf (NUL)
+ * - in case of mem fault, return NULL
+ * may_fault is non-zero if we are reading from arbitrary memory, but is
+ * currently not used.
+ */
+static
+unsigned char *mem2hex(const void *_mem, char *buf, int count, int may_fault)
+{
+	const u8 *mem = _mem;
+	u8 ch[4];
+
+	if ((u32) mem & 1 && count >= 1) {
+		if (gdbstub_read_byte(mem, ch) != 0)
+			return 0;
+		*buf++ = hexchars[ch[0] >> 4];
+		*buf++ = hexchars[ch[0] & 0xf];
+		mem++;
+		count--;
+	}
+
+	if ((u32) mem & 3 && count >= 2) {
+		if (gdbstub_read_word(mem, ch) != 0)
+			return 0;
+		*buf++ = hexchars[ch[0] >> 4];
+		*buf++ = hexchars[ch[0] & 0xf];
+		*buf++ = hexchars[ch[1] >> 4];
+		*buf++ = hexchars[ch[1] & 0xf];
+		mem += 2;
+		count -= 2;
+	}
+
+	while (count >= 4) {
+		if (gdbstub_read_dword(mem, ch) != 0)
+			return 0;
+		*buf++ = hexchars[ch[0] >> 4];
+		*buf++ = hexchars[ch[0] & 0xf];
+		*buf++ = hexchars[ch[1] >> 4];
+		*buf++ = hexchars[ch[1] & 0xf];
+		*buf++ = hexchars[ch[2] >> 4];
+		*buf++ = hexchars[ch[2] & 0xf];
+		*buf++ = hexchars[ch[3] >> 4];
+		*buf++ = hexchars[ch[3] & 0xf];
+		mem += 4;
+		count -= 4;
+	}
+
+	if (count >= 2) {
+		if (gdbstub_read_word(mem, ch) != 0)
+			return 0;
+		*buf++ = hexchars[ch[0] >> 4];
+		*buf++ = hexchars[ch[0] & 0xf];
+		*buf++ = hexchars[ch[1] >> 4];
+		*buf++ = hexchars[ch[1] & 0xf];
+		mem += 2;
+		count -= 2;
+	}
+
+	if (count >= 1) {
+		if (gdbstub_read_byte(mem, ch) != 0)
+			return 0;
+		*buf++ = hexchars[ch[0] >> 4];
+		*buf++ = hexchars[ch[0] & 0xf];
+	}
+
+	*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
+ * may_fault is non-zero if we are reading from arbitrary memory, but is
+ * currently not used.
+ */
+static
+const char *hex2mem(const char *buf, void *_mem, int count, int may_fault)
+{
+	u8 *mem = _mem;
+	union {
+		u32 val;
+		u8 b[4];
+	} ch;
+
+	if ((u32) mem & 1 && count >= 1) {
+		ch.b[0]  = hex(*buf++) << 4;
+		ch.b[0] |= hex(*buf++);
+		if (gdbstub_write_byte(ch.val, mem) != 0)
+			return 0;
+		mem++;
+		count--;
+	}
+
+	if ((u32) mem & 3 && count >= 2) {
+		ch.b[0]  = hex(*buf++) << 4;
+		ch.b[0] |= hex(*buf++);
+		ch.b[1]  = hex(*buf++) << 4;
+		ch.b[1] |= hex(*buf++);
+		if (gdbstub_write_word(ch.val, mem) != 0)
+			return 0;
+		mem += 2;
+		count -= 2;
+	}
+
+	while (count >= 4) {
+		ch.b[0]  = hex(*buf++) << 4;
+		ch.b[0] |= hex(*buf++);
+		ch.b[1]  = hex(*buf++) << 4;
+		ch.b[1] |= hex(*buf++);
+		ch.b[2]  = hex(*buf++) << 4;
+		ch.b[2] |= hex(*buf++);
+		ch.b[3]  = hex(*buf++) << 4;
+		ch.b[3] |= hex(*buf++);
+		if (gdbstub_write_dword(ch.val, mem) != 0)
+			return 0;
+		mem += 4;
+		count -= 4;
+	}
+
+	if (count >= 2) {
+		ch.b[0]  = hex(*buf++) << 4;
+		ch.b[0] |= hex(*buf++);
+		ch.b[1]  = hex(*buf++) << 4;
+		ch.b[1] |= hex(*buf++);
+		if (gdbstub_write_word(ch.val, mem) != 0)
+			return 0;
+		mem += 2;
+		count -= 2;
+	}
+
+	if (count >= 1) {
+		ch.b[0]  = hex(*buf++) << 4;
+		ch.b[0] |= hex(*buf++);
+		if (gdbstub_write_byte(ch.val, mem) != 0)
+			return 0;
+	}
+
+	return buf;
+}
+
+/*
+ * This table contains the mapping between MN10300 exception codes, and
+ * signals, which are primarily what GDB understands.  It also indicates
+ * which hardware traps we need to commandeer when initializing the stub.
+ */
+static const struct excep_to_sig_map {
+	enum exception_code	excep;	/* MN10300 exception code */
+	unsigned char		signo;	/* Signal that we map this into */
+} excep_to_sig_map[] = {
+	{ EXCEP_ITLBMISS,	SIGSEGV		},
+	{ EXCEP_DTLBMISS,	SIGSEGV		},
+	{ EXCEP_TRAP,		SIGTRAP		},
+	{ EXCEP_ISTEP,		SIGTRAP		},
+	{ EXCEP_IBREAK,		SIGTRAP		},
+	{ EXCEP_OBREAK,		SIGTRAP		},
+	{ EXCEP_UNIMPINS,	SIGILL		},
+	{ EXCEP_UNIMPEXINS,	SIGILL		},
+	{ EXCEP_MEMERR,		SIGSEGV		},
+	{ EXCEP_MISALIGN,	SIGSEGV		},
+	{ EXCEP_BUSERROR,	SIGBUS		},
+	{ EXCEP_ILLINSACC,	SIGSEGV		},
+	{ EXCEP_ILLDATACC,	SIGSEGV		},
+	{ EXCEP_IOINSACC,	SIGSEGV		},
+	{ EXCEP_PRIVINSACC,	SIGSEGV		},
+	{ EXCEP_PRIVDATACC,	SIGSEGV		},
+	{ EXCEP_FPU_DISABLED,	SIGFPE		},
+	{ EXCEP_FPU_UNIMPINS,	SIGFPE		},
+	{ EXCEP_FPU_OPERATION,	SIGFPE		},
+	{ EXCEP_WDT,		SIGALRM		},
+	{ EXCEP_NMI,		SIGQUIT		},
+	{ EXCEP_IRQ_LEVEL0,	SIGINT		},
+	{ EXCEP_IRQ_LEVEL1,	SIGINT		},
+	{ EXCEP_IRQ_LEVEL2,	SIGINT		},
+	{ EXCEP_IRQ_LEVEL3,	SIGINT		},
+	{ EXCEP_IRQ_LEVEL4,	SIGINT		},
+	{ EXCEP_IRQ_LEVEL5,	SIGINT		},
+	{ EXCEP_IRQ_LEVEL6,	SIGINT		},
+	{ 0, 0}
+};
+
+/*
+ * convert the MN10300 exception code into a UNIX signal number
+ */
+static int computeSignal(enum exception_code excep)
+{
+	const struct excep_to_sig_map *map;
+
+	for (map = excep_to_sig_map; map->signo; map++)
+		if (map->excep == excep)
+			return map->signo;
+
+	return SIGHUP; /* default for things we don't know about */
+}
+
+static u32 gdbstub_fpcr, gdbstub_fpufs_array[32];
+
+/*
+ *
+ */
+static void gdbstub_store_fpu(void)
+{
+#ifdef CONFIG_FPU
+
+	asm volatile(
+		"or %2,epsw\n"
+#ifdef CONFIG_MN10300_PROC_MN103E010
+		"nop\n"
+		"nop\n"
+#endif
+		"mov %1, a1\n"
+		"fmov fs0,  (a1+)\n"
+		"fmov fs1,  (a1+)\n"
+		"fmov fs2,  (a1+)\n"
+		"fmov fs3,  (a1+)\n"
+		"fmov fs4,  (a1+)\n"
+		"fmov fs5,  (a1+)\n"
+		"fmov fs6,  (a1+)\n"
+		"fmov fs7,  (a1+)\n"
+		"fmov fs8,  (a1+)\n"
+		"fmov fs9,  (a1+)\n"
+		"fmov fs10, (a1+)\n"
+		"fmov fs11, (a1+)\n"
+		"fmov fs12, (a1+)\n"
+		"fmov fs13, (a1+)\n"
+		"fmov fs14, (a1+)\n"
+		"fmov fs15, (a1+)\n"
+		"fmov fs16, (a1+)\n"
+		"fmov fs17, (a1+)\n"
+		"fmov fs18, (a1+)\n"
+		"fmov fs19, (a1+)\n"
+		"fmov fs20, (a1+)\n"
+		"fmov fs21, (a1+)\n"
+		"fmov fs22, (a1+)\n"
+		"fmov fs23, (a1+)\n"
+		"fmov fs24, (a1+)\n"
+		"fmov fs25, (a1+)\n"
+		"fmov fs26, (a1+)\n"
+		"fmov fs27, (a1+)\n"
+		"fmov fs28, (a1+)\n"
+		"fmov fs29, (a1+)\n"
+		"fmov fs30, (a1+)\n"
+		"fmov fs31, (a1+)\n"
+		"fmov fpcr, %0\n"
+		: "=d"(gdbstub_fpcr)
+		: "g" (&gdbstub_fpufs_array), "i"(EPSW_FE)
+		: "a1"
+		);
+#endif
+}
+
+/*
+ *
+ */
+static void gdbstub_load_fpu(void)
+{
+#ifdef CONFIG_FPU
+
+	asm volatile(
+		"or %1,epsw\n"
+#ifdef CONFIG_MN10300_PROC_MN103E010
+		"nop\n"
+		"nop\n"
+#endif
+		"mov %0, a1\n"
+		"fmov (a1+), fs0\n"
+		"fmov (a1+), fs1\n"
+		"fmov (a1+), fs2\n"
+		"fmov (a1+), fs3\n"
+		"fmov (a1+), fs4\n"
+		"fmov (a1+), fs5\n"
+		"fmov (a1+), fs6\n"
+		"fmov (a1+), fs7\n"
+		"fmov (a1+), fs8\n"
+		"fmov (a1+), fs9\n"
+		"fmov (a1+), fs10\n"
+		"fmov (a1+), fs11\n"
+		"fmov (a1+), fs12\n"
+		"fmov (a1+), fs13\n"
+		"fmov (a1+), fs14\n"
+		"fmov (a1+), fs15\n"
+		"fmov (a1+), fs16\n"
+		"fmov (a1+), fs17\n"
+		"fmov (a1+), fs18\n"
+		"fmov (a1+), fs19\n"
+		"fmov (a1+), fs20\n"
+		"fmov (a1+), fs21\n"
+		"fmov (a1+), fs22\n"
+		"fmov (a1+), fs23\n"
+		"fmov (a1+), fs24\n"
+		"fmov (a1+), fs25\n"
+		"fmov (a1+), fs26\n"
+		"fmov (a1+), fs27\n"
+		"fmov (a1+), fs28\n"
+		"fmov (a1+), fs29\n"
+		"fmov (a1+), fs30\n"
+		"fmov (a1+), fs31\n"
+		"fmov %2, fpcr\n"
+		:
+		: "g" (&gdbstub_fpufs_array), "i"(EPSW_FE), "d"(gdbstub_fpcr)
+		: "a1"
+	);
+#endif
+}
+
+/*
+ * set a software breakpoint
+ */
+int gdbstub_set_breakpoint(u8 *addr, int len)
+{
+	int bkpt, loop, xloop;
+
+#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
+	len = (len + 1) & ~1;
+#endif
+
+	gdbstub_bkpt("setbkpt(%p,%d)\n", addr, len);
+
+	for (bkpt = 255; bkpt >= 0; bkpt--)
+		if (!gdbstub_bkpts[bkpt].addr)
+			break;
+	if (bkpt < 0)
+		return -ENOSPC;
+
+	for (loop = 0; loop < len; loop++)
+		if (gdbstub_read_byte(&addr[loop],
+				      &gdbstub_bkpts[bkpt].origbytes[loop]
+				      ) < 0)
+			return -EFAULT;
+
+	gdbstub_flush_caches = 1;
+
+#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
+	for (loop = 0; loop < len; loop++)
+		if (gdbstub_write_byte(0xF7, &addr[loop]) < 0)
+			goto restore;
+#else
+	for (loop = 0; loop < len; loop++)
+		if (gdbstub_write_byte(0xFF, &addr[loop]) < 0)
+			goto restore;
+#endif
+
+	gdbstub_bkpts[bkpt].addr = addr;
+	gdbstub_bkpts[bkpt].len = len;
+
+	gdbstub_bkpt("Set BKPT[%02x]: %p-%p {%02x%02x%02x%02x%02x%02x%02x}\n",
+		     bkpt,
+		     gdbstub_bkpts[bkpt].addr,
+		     gdbstub_bkpts[bkpt].addr + gdbstub_bkpts[bkpt].len - 1,
+		     gdbstub_bkpts[bkpt].origbytes[0],
+		     gdbstub_bkpts[bkpt].origbytes[1],
+		     gdbstub_bkpts[bkpt].origbytes[2],
+		     gdbstub_bkpts[bkpt].origbytes[3],
+		     gdbstub_bkpts[bkpt].origbytes[4],
+		     gdbstub_bkpts[bkpt].origbytes[5],
+		     gdbstub_bkpts[bkpt].origbytes[6]
+		     );
+
+	return 0;
+
+restore:
+	for (xloop = 0; xloop < loop; xloop++)
+		gdbstub_write_byte(gdbstub_bkpts[bkpt].origbytes[xloop],
+				   addr + xloop);
+	return -EFAULT;
+}
+
+/*
+ * clear a software breakpoint
+ */
+int gdbstub_clear_breakpoint(u8 *addr, int len)
+{
+	int bkpt, loop;
+
+#ifdef GDBSTUB_USE_F7F7_AS_BREAKPOINT
+	len = (len + 1) & ~1;
+#endif
+
+	gdbstub_bkpt("clearbkpt(%p,%d)\n", addr, len);
+
+	for (bkpt = 255; bkpt >= 0; bkpt--)
+		if (gdbstub_bkpts[bkpt].addr == addr &&
+		    gdbstub_bkpts[bkpt].len == len)
+			break;
+	if (bkpt < 0)
+		return -ENOENT;
+
+	gdbstub_bkpts[bkpt].addr = NULL;
+
+	gdbstub_flush_caches = 1;
+
+	for (loop = 0; loop < len; loop++)
+		if (gdbstub_write_byte(gdbstub_bkpts[bkpt].origbytes[loop],
+				       addr + loop) < 0)
+			return -EFAULT;
+
+	return 0;
+}
+
+/*
+ * This function does all command processing for interfacing to gdb
+ * - returns 1 if the exception should be skipped, 0 otherwise.
+ */
+static int gdbstub(struct pt_regs *regs, enum exception_code excep)
+{
+	unsigned long *stack;
+	unsigned long epsw, mdr;
+	uint32_t zero, ssp;
+	uint8_t broke;
+	char *ptr;
+	int sigval;
+	int addr;