/*
 * Routines providing a simple monitor for use on the PowerMac.
 *
 * Copyright (C) 1996 Paul Mackerras.
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */
#include <linux/config.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/kallsyms.h>
#include <linux/cpumask.h>

#include <asm/ptrace.h>
#include <asm/string.h>
#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/naca.h>
#include <asm/paca.h>
#include <asm/ppcdebug.h>
#include <asm/cputable.h>

#include "nonstdio.h"
#include "privinst.h"

#define scanhex	xmon_scanhex
#define skipbl	xmon_skipbl

#ifdef CONFIG_SMP
volatile cpumask_t cpus_in_xmon = CPU_MASK_NONE;
static unsigned long got_xmon = 0;
static volatile int take_xmon = -1;
static volatile int leaving_xmon = 0;
#endif /* CONFIG_SMP */

static unsigned long adrs;
static int size = 1;
static unsigned long ndump = 64;
static unsigned long nidump = 16;
static unsigned long ncsum = 4096;
static int termch;
static char tmpstr[128];

static u_int bus_error_jmp[100];
#define setjmp xmon_setjmp
#define longjmp xmon_longjmp

/* Breakpoint stuff */
struct bpt {
	unsigned long address;
	unsigned instr;
	unsigned long count;
	unsigned char enabled;
};

#define NBPTS	16
static struct bpt bpts[NBPTS];
static struct bpt dabr;
static struct bpt iabr;
static unsigned bpinstr = 0x7fe00008;	/* trap */

/* Prototypes */
static int cmds(struct pt_regs *);
static int mread(unsigned long, void *, int);
static int mwrite(unsigned long, void *, int);
static int handle_fault(struct pt_regs *);
static void byterev(unsigned char *, int);
static void memex(void);
static int bsesc(void);
static void dump(void);
static void prdump(unsigned long, long);
static int ppc_inst_dump(unsigned long, long);
void print_address(unsigned long);
static void backtrace(struct pt_regs *);
static void excprint(struct pt_regs *);
static void prregs(struct pt_regs *);
static void memops(int);
static void memlocate(void);
static void memzcan(void);
static void memdiffs(unsigned char *, unsigned char *, unsigned, unsigned);
int skipbl(void);
int scanhex(unsigned long *valp);
static void scannl(void);
static int hexdigit(int);
void getstring(char *, int);
static void flush_input(void);
static int inchar(void);
static void take_input(char *);
/* static void openforth(void); */
static unsigned long read_spr(int);
static void write_spr(int, unsigned long);
static void super_regs(void);
static void remove_bpts(void);
static void insert_bpts(void);
static struct bpt *at_breakpoint(unsigned long pc);
static void bpt_cmds(void);
static void cacheflush(void);
#ifdef CONFIG_SMP
static void cpu_cmd(void);
#endif /* CONFIG_SMP */
static void csum(void);
static void bootcmds(void);
void dump_segments(void);
static void symbol_lookup(void);

static void debug_trace(void);

extern int print_insn_big_powerpc(FILE *, unsigned long, unsigned long);
extern void printf(const char *fmt, ...);
extern void xmon_vfprintf(void *f, const char *fmt, va_list ap);
extern int xmon_putc(int c, void *f);
extern int putchar(int ch);
extern int xmon_read_poll(void);
extern int setjmp(u_int *);
extern void longjmp(u_int *, int);
extern unsigned long _ASR;

pte_t *find_linux_pte(pgd_t *pgdir, unsigned long va);	/* from htab.c */

#define GETWORD(v)	(((v)[0] << 24) + ((v)[1] << 16) + ((v)[2] << 8) + (v)[3])

#define isxdigit(c)	(('0' <= (c) && (c) <= '9') \
			 || ('a' <= (c) && (c) <= 'f') \
			 || ('A' <= (c) && (c) <= 'F'))
#define isalnum(c)	(('0' <= (c) && (c) <= '9') \
			 || ('a' <= (c) && (c) <= 'z') \
			 || ('A' <= (c) && (c) <= 'Z'))
#define isspace(c)	(c == ' ' || c == '\t' || c == 10 || c == 13 || c == 0)

static char *help_string = "\
Commands:\n\
  b	show breakpoints\n\
  bd	set data breakpoint\n\
  bi	set instruction breakpoint\n\
  bc	clear breakpoint\n"
#ifdef CONFIG_SMP
  "\
  c	print cpus stopped in xmon\n\
  ci	send xmon interrupt to all other cpus\n\
  c#	try to switch to cpu number h (in hex)\n"
#endif
  "\
  C	checksum\n\
  d	dump bytes\n\
  di	dump instructions\n\
  df	dump float values\n\
  dd	dump double values\n\
  e	print exception information\n\
  f	flush cache\n\
  la	lookup symbol+offset of specified address\n\
  ls	lookup address of specified symbol\n\
  m	examine/change memory\n\
  mm	move a block of memory\n\
  ms	set a block of memory\n\
  md	compare two blocks of memory\n\
  ml	locate a block of memory\n\
  mz	zero a block of memory\n\
  mi	show information about memory allocation\n\
  p 	show the task list\n\
  r	print registers\n\
  s	single step\n\
  S	print special registers\n\
  t	print backtrace\n\
  T	Enable/Disable PPCDBG flags\n\
  x	exit monitor and recover\n\
  X	exit monitor and dont recover\n\
  u	dump segment table or SLB\n\
  ?	help\n"
  "\
  zr	reboot\n\
  zh	halt\n"
;

static int xmon_trace[NR_CPUS];
#define SSTEP	1		/* stepping because of 's' command */
#define BRSTEP	2		/* stepping over breakpoint */

static struct pt_regs *xmon_regs[NR_CPUS];

void __xmon_print_symbol(const char *fmt, unsigned long address);
#define xmon_print_symbol(fmt, addr)		\
do {						\
	__check_printsym_format(fmt, "");	\
	__xmon_print_symbol(fmt, addr);		\
} while(0)

/*
 * Stuff for reading and writing memory safely
 */
extern inline void sync(void)
{
	asm volatile("sync; isync");
}

/* (Ref: 64-bit PowerPC ELF ABI Spplement; Ian Lance Taylor, Zembu Labs).
 A PPC stack frame looks like this:

 High Address
    Back Chain
    FP reg save area
    GP reg save area
    Local var space
    Parameter save area		(SP+48)
    TOC save area		(SP+40)
    link editor doubleword	(SP+32)
    compiler doubleword		(SP+24)
    LR save			(SP+16)
    CR save			(SP+8)
    Back Chain			(SP+0)

 Note that the LR (ret addr) may not be saved in the current frame if
 no functions have been called from the current function.
 */

#define SURVEILLANCE_TOKEN	9000

static inline void disable_surveillance(void)
{
#ifndef CONFIG_PPC_ISERIES
        rtas_call(rtas_token("set-indicator"), 3, 1, NULL, SURVEILLANCE_TOKEN,
		  0, 0);
#endif
}

int
xmon(struct pt_regs *excp)
{
	struct pt_regs regs;
	int cmd = 0;
	unsigned long msr;

	if (excp == NULL) {
		/* Ok, grab regs as they are now.
		 This won't do a particularily good job because the
		 prologue has already been executed.
		 ToDo: We could reach back into the callers save
		 area to do a better job of representing the
		 caller's state.
		 */
		asm volatile ("std	0,0(%0)\n\
			std	1,8(%0)\n\
			std	2,16(%0)\n\
			std	3,24(%0)\n\
			std	4,32(%0)\n\
			std	5,40(%0)\n\
			std	6,48(%0)\n\
			std	7,56(%0)\n\
			std	8,64(%0)\n\
			std	9,72(%0)\n\
			std	10,80(%0)\n\
			std	11,88(%0)\n\
			std	12,96(%0)\n\
			std	13,104(%0)\n\
			std	14,112(%0)\n\
			std	15,120(%0)\n\
			std	16,128(%0)\n\
			std	17,136(%0)\n\
			std	18,144(%0)\n\
			std	19,152(%0)\n\
			std	20,160(%0)\n\
			std	21,168(%0)\n\
			std	22,176(%0)\n\
			std	23,184(%0)\n\
			std	24,192(%0)\n\
			std	25,200(%0)\n\
			std	26,208(%0)\n\
			std	27,216(%0)\n\
			std	28,224(%0)\n\
			std	29,232(%0)\n\
			std	30,240(%0)\n\
			std	31,248(%0)" : : "b" (&regs));

		regs.nip = regs.link = ((unsigned long *)(regs.gpr[1]))[2];
		regs.msr = get_msr();
		regs.ctr = get_ctr();
		regs.xer = get_xer();
		regs.ccr = get_cr();
		regs.trap = 0;
		excp = &regs;
	}

	msr = get_msr();
	set_msrd(msr & ~MSR_EE);	/* disable interrupts */
	xmon_regs[smp_processor_id()] = excp;
	excprint(excp);
#ifdef CONFIG_SMP
	leaving_xmon = 0;
	/* possible race condition here if a CPU is held up and gets
	 * here while we are exiting */
	if (cpu_test_and_set(smp_processor_id(), cpus_in_xmon)) {
		/* xmon probably caused an exception itself */
		printf("We are already in xmon\n");
		for (;;)
			cpu_relax();
	}
	while (test_and_set_bit(0, &got_xmon)) {
		if (take_xmon == smp_processor_id()) {
			take_xmon = -1;
			break;
		}
		cpu_relax();
	}
	/*
	 * XXX: breakpoints are removed while any cpu is in xmon
	 */
#endif /* CONFIG_SMP */
	remove_bpts();
	disable_surveillance();
	printf("press ? for help ");
	cmd = cmds(excp);
	if (cmd == 's') {
		xmon_trace[smp_processor_id()] = SSTEP;
		excp->msr |= MSR_SE;
#ifdef CONFIG_SMP		
		take_xmon = smp_processor_id();
#endif		
	} else if (at_breakpoint(excp->nip)) {
		xmon_trace[smp_processor_id()] = BRSTEP;
		excp->msr |= MSR_SE;
	} else {
		xmon_trace[smp_processor_id()] = 0;
		insert_bpts();
	}
	xmon_regs[smp_processor_id()] = 0;
#ifdef CONFIG_SMP
	leaving_xmon = 1;
	if (cmd != 's')
		clear_bit(0, &got_xmon);
	cpu_clear(smp_processor_id(), cpus_in_xmon);
#endif /* CONFIG_SMP */
	set_msrd(msr);		/* restore interrupt enable */

	if (cmd == 'X')
		return 0;

	return 1;
}

int
xmon_bpt(struct pt_regs *regs)
{
	struct bpt *bp;

	bp = at_breakpoint(regs->nip);
	if (!bp)
		return 0;
	if (bp->count) {
		--bp->count;
		remove_bpts();
		excprint(regs);
		xmon_trace[smp_processor_id()] = BRSTEP;
		regs->msr |= MSR_SE;
	} else {
		printf("Stopped at breakpoint %x (%lx ", (bp - bpts) + 1,
			bp->address);
		xmon_print_symbol("%s)\n", bp->address);
		xmon(regs);
	}
	return 1;
}

int
xmon_sstep(struct pt_regs *regs)
{
	if (!xmon_trace[smp_processor_id()])
		return 0;
	if (xmon_trace[smp_processor_id()] == BRSTEP) {
		xmon_trace[smp_processor_id()] = 0;
		insert_bpts();
	} else {
		xmon(regs);
	}
	return 1;
}

int
xmon_dabr_match(struct pt_regs *regs)
{
	if (dabr.enabled && dabr.count) {
		--dabr.count;
		remove_bpts();
		excprint(regs);
		xmon_trace[smp_processor_id()] = BRSTEP;
		regs->msr |= MSR_SE;
	} else {
		dabr.instr = regs->nip;
		xmon(regs);
	}
	return 1;
}

int
xmon_iabr_match(struct pt_regs *regs)
{
	if (iabr.enabled && iabr.count) {
		--iabr.count;
		remove_bpts();
		excprint(regs);
		xmon_trace[smp_processor_id()] = BRSTEP;
		regs->msr |= MSR_SE;
	} else {
		xmon(regs);
	}
	return 1;
}

static struct bpt *
at_breakpoint(unsigned long pc)
{
	int i;
	struct bpt *bp;

	if (dabr.enabled && pc == dabr.instr)
		return &dabr;
	if (iabr.enabled && pc == iabr.address)
		return &iabr;
	bp = bpts;
	for (i = 0; i < NBPTS; ++i, ++bp)
		if (bp->enabled && pc == bp->address)
			return bp;
	return 0;
}

static void
insert_bpts()
{
	int i;
	struct bpt *bp;

	bp = bpts;
	for (i = 0; i < NBPTS; ++i, ++bp) {
		if (!bp->enabled)
			continue;
		if (mread(bp->address, &bp->instr, 4) != 4
		    || mwrite(bp->address, &bpinstr, 4) != 4) {
			printf("Couldn't insert breakpoint at %x, disabling\n",
			       bp->address);
			bp->enabled = 0;
		} else {
			store_inst((void *)bp->address);
		}
	}

	if (dabr.enabled)
		set_dabr(dabr.address);
	if ((cur_cpu_spec->cpu_features & CPU_FTR_IABR) && iabr.enabled)
		set_iabr(iabr.address);
}

static void
remove_bpts()
{
	int i;
	struct bpt *bp;
	unsigned instr;

	set_dabr(0);
	if ((cur_cpu_spec->cpu_features & CPU_FTR_IABR))
		set_iabr(0);

	bp = bpts;
	for (i = 0; i < NBPTS; ++i, ++bp) {
		if (!bp->enabled)
			continue;
		if (mread(bp->address, &instr, 4) == 4
		    && instr == bpinstr
		    && mwrite(bp->address, &bp->instr, 4) != 4)
			printf("Couldn't remove breakpoint at %x\n",
			       bp->address);
		else
			store_inst((void *)bp->address);
	}
}

static char *last_cmd;

/* Command interpreting routine */
static int
cmds(struct pt_regs *excp)
{
	int cmd = 0;

	last_cmd = NULL;
	for(;;) {
#ifdef CONFIG_SMP
		/* Need to check if we should take any commands on
		   this CPU. */
		if (leaving_xmon)
			return cmd;
		printf("%d:", smp_processor_id());
#endif /* CONFIG_SMP */
		printf("mon> ");
		fflush(stdout);
		flush_input();
		termch = 0;
		cmd = skipbl();
		if( cmd == '\n' ) {
			if (last_cmd == NULL)
				continue;
			take_input(last_cmd);
			last_cmd = NULL;
			cmd = inchar();
		}
		switch (cmd) {
		case 'm':
			cmd = inchar();
			switch (cmd) {
			case 'm':
			case 's':
			case 'd':
				memops(cmd);
				break;
			case 'l':
				memlocate();
				break;
			case 'z':
				memzcan();
				break;
			case 'i':
				show_mem();
				break;
			default:
				termch = cmd;
				memex();
			}
			break;
		case 'd':
			dump();
			break;
		case 'l':
			symbol_lookup();
			break;
		case 'r':
			prregs(excp);	/* print regs */
			break;
		case 'e':
			if (excp == NULL)
				printf("No exception information\n");
			else
				excprint(excp);
			break;
		case 'S':
			super_regs();
			break;
		case 't':
			backtrace(excp);
			break;
		case 'f':
			cacheflush();
			break;
		case 's':
		case 'x':
		case 'X':
		case EOF:
			return cmd;
		case '?':
			printf(help_string);
			break;
		case 'p':
			show_state();
			break;
		case 'b':
			bpt_cmds();
			break;
		case 'C':
			csum();
			break;
#ifdef CONFIG_SMP
		case 'c':
			cpu_cmd();
			break;
#endif /* CONFIG_SMP */
		case 'z':
			bootcmds();
		case 'T':
			debug_trace();
			break;
		case 'u':
			dump_segments();
			break;
		default:
			printf("Unrecognized command: ");
		        do {
				if( ' ' < cmd && cmd <= '~' )
					putchar(cmd);
				else
					printf("\\x%x", cmd);
				cmd = inchar();
		        } while (cmd != '\n'); 
			printf(" (type ? for help)\n");
			break;
		}
		cpu_relax();
	}
}

static void bootcmds(void)
{
	int cmd;

	cmd = inchar();
	if (cmd == 'r')
		ppc_md.restart(NULL);
	else if (cmd == 'h')
		ppc_md.halt();
	else if (cmd == 'p')
		ppc_md.power_off();
}

#ifdef CONFIG_SMP
static void cpu_cmd(void)
{
	unsigned long cpu;
	int timeout;
	int cmd;

	cmd = inchar();
	if (cmd == 'i') {
		printf("stopping all cpus\n");
		/* interrupt other cpu(s) */
		cpu = MSG_ALL_BUT_SELF;
		smp_send_debugger_break(cpu);
		return;
	}
	termch = cmd;
	if (!scanhex(&cpu)) {
		/* print cpus waiting or in xmon */
		printf("cpus stopped:");
		for (cpu = 0; cpu < NR_CPUS; ++cpu) {
			if (cpu_isset(cpu, cpus_in_xmon)) {
				printf(" %x", cpu);
				if (cpu == smp_processor_id())
					printf("*", cpu);
			}
		}
		printf("\n");
		return;
	}
	/* try to switch to cpu specified */
	take_xmon = cpu;
	timeout = 10000000;
	while (take_xmon >= 0) {
		if (--timeout == 0) {
			/* yes there's a race here */
			take_xmon = -1;
			printf("cpu %u didn't take control\n", cpu);
			return;
		}
	}
	/* now have to wait to be given control back */
	while (test_and_set_bit(0, &got_xmon)) {
		if (take_xmon == smp_processor_id()) {
			take_xmon = -1;
			break;
		}
		cpu_relax();
	}
}
#endif /* CONFIG_SMP */

static unsigned short fcstab[256] = {
	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
	0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
	0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
	0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
	0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
	0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
	0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
	0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
	0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
	0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
	0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
	0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
	0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
	0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
	0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
	0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
	0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
	0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
	0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
	0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
	0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
	0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
	0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
	0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
	0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
	0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
	0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
	0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
	0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
	0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
	0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
	0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
};

#define FCS(fcs, c)	(((fcs) >> 8) ^ fcstab[((fcs) ^ (c)) & 0xff])

static void
csum(void)
{
	unsigned int i;
	unsigned short fcs;
	unsigned char v;

	if (!scanhex(&adrs))
		return;
	if (!scanhex(&ncsum))
		return;
	fcs = 0xffff;
	for (i = 0; i < ncsum; ++i) {
		if (mread(adrs+i, &v, 1) == 0) {
			printf("csum stopped at %x\n", adrs+i);
			break;
		}
		fcs = FCS(fcs, v);
	}
	printf("%x\n", fcs);
}

static char *breakpoint_help_string = 
    "Breakpoint command usage:\n"
    "b                show breakpoints\n"
    "b <addr> [cnt]   set breakpoint at given instr addr\n"
    "bc               clear all breakpoints\n"
    "bc <n/addr>      clear breakpoint number n or at addr\n"
    "bi <addr> [cnt]  set hardware instr breakpoint (broken?)\n"
    "bd <addr> [cnt]  set hardware data breakpoint (broken?)\n"
    "";

static void
bpt_cmds(void)
{
	int cmd;
	unsigned long a;
	int mode, i;
	struct bpt *bp;

	cmd = inchar();
	switch (cmd) {
	case 'd':	/* bd - hardware data breakpoint */
		mode = 7;
		cmd = inchar();
		if (cmd == 'r')
			mode = 5;
		else if (cmd == 'w')
			mode = 6;
		else
			termch = cmd;
		dabr.address = 0;
		dabr.count = 0;
		dabr.enabled = scanhex(&dabr.address);
		scanhex(&dabr.count);
		if (dabr.enabled)
			dabr.address = (dabr.address & ~7) | mode;
		break;
	case 'i':	/* bi - hardware instr breakpoint */
		if (!(cur_cpu_spec->cpu_features & CPU_FTR_IABR)) {
			printf("Not implemented on POWER4\n");
			break;
		}
		iabr.address = 0;
		iabr.count = 0;
		iabr.enabled = scanhex(&iabr.address);
		if (iabr.enabled)
			iabr.address |= 3;
		scanhex(&iabr.count);
		break;
	case 'c':
		if (!scanhex(&a)) {
			/* clear all breakpoints */
			for (i = 0; i < NBPTS; ++i)
				bpts[i].enabled = 0;
			iabr.enabled = 0;
			dabr.enabled = 0;
			printf("All breakpoints cleared\n");
		} else {
			if (a <= NBPTS && a >= 1) {
				/* assume a breakpoint number */
				--a;	/* bp nums are 1 based */
				bp = &bpts[a];
			} else {
				/* assume a breakpoint address */
				bp = at_breakpoint(a);
			}
			if (bp == 0) {
				printf("No breakpoint at %x\n", a);
			} else {
				printf("Cleared breakpoint %x (%lx ", 
					(bp - bpts) + 1, bp->address);
				xmon_print_symbol("%s)\n", bp->address);
				bp->enabled = 0;
			}
		}
		break;
	case '?':
	        printf(breakpoint_help_string);
	        break;
	default:
		termch = cmd;
	        cmd = skipbl();
		if (cmd == '?') {
			printf(breakpoint_help_string);
			break;
		}
		termch = cmd;
		if (!scanhex(&a)) {
			/* print all breakpoints */
			int bpnum;

			printf("   type            address    count\n");
			if (dabr.enabled) {
				printf("   data   %.16lx %8x [", dabr.address & ~7,
				       dabr.count);
				if (dabr.address & 1)
					printf("r");
				if (dabr.address & 2)
					printf("w");
				printf("]\n");
			}
			if (iabr.enabled)
				printf("   inst   %.16lx %8x\n", iabr.address & ~3,
				       iabr.count);
			for (bp = bpts, bpnum = 1; bp < &bpts[NBPTS]; ++bp, ++bpnum)
				if (bp->enabled) {
					printf("%2x trap   %.16lx %8x  ",
						bpnum, bp->address, bp->count);
					xmon_print_symbol("%s\n", bp->address);
				}
			break;
		}
		
		if (systemcfg->platform != PLATFORM_POWERMAC &&
		   !(systemcfg->platform & PLATFORM_PSERIES)) {
			printf("Not supported for this platform\n");
			break;
		}

		bp = at_breakpoint(a);
		if (bp == 0) {
			for (bp = bpts; bp < &bpts[NBPTS]; ++bp)
				if (!bp->enabled)
					break;
			if (bp >= &bpts[NBPTS]) {
				printf("Sorry, no free breakpoints.  Please clear one first.\n");
				break;
			}
		}
		bp->enabled = 1;
		bp->address = a;
		bp->count = 0;
		scanhex(&bp->count);
		printf("Set breakpoint %2x trap   %.16lx %8x  ", (bp-bpts) + 1, 
			bp->address, bp->count);
		xmon_print_symbol("%s\n", bp->address);
		break;
	}
}

/* Very cheap human name for vector lookup. */
static
const char *getvecname(unsigned long vec)
{
	char *ret;
	switch (vec) {
	case 0x100:	ret = "(System Reset)"; break; 
	case 0x200:	ret = "(Machine Check)"; break; 
	case 0x300:	ret = "(Data Access)"; break; 
	case 0x380:	ret = "(Data SLB Access)"; break;
	case 0x400:	ret = "(Instruction Access)"; break; 
	case 0x480:	ret = "(Instruction SLB Access)"; break;
	case 0x500:	ret = "(Hardware Interrupt)"; break; 
	case 0x600:	ret = "(Alignment)"; break; 
	case 0x700:	ret = "(Program Check)"; break; 
	case 0x800:	ret = "(FPU Unavailable)"; break; 
	case 0x900:	ret = "(Decrementer)"; break; 
	case 0xc00:	ret = "(System Call)"; break; 
	case 0xd00:	ret = "(Single Step)"; break; 
	case 0xf00:	ret = "(Performance Monitor)"; break; 
	default: ret = "";
	}
	return ret;
}

/*
 * Most of our exceptions are in the form:
 *    bl handler
 *    b .ret_from_exception
 * and this currently fails to catch them.
 */
static inline int exception_frame(unsigned long ip)
{
	extern void *ret_from_syscall_1, *ret_from_syscall_2, *ret_from_except;

	if ((ip == (unsigned long)ret_from_syscall_1) ||
	    (ip == (unsigned long)ret_from_syscall_2) ||
	    (ip == (unsigned long)ret_from_except))
		return 1;

	return 0;
}

static int xmon_depth_to_print = 64;

static void xmon_show_stack(unsigned long sp)
{
	unsigned long ip;
	unsigned long newsp;
	int count = 0;
	struct pt_regs regs;

	do {
		if (sp < PAGE_OFFSET) {
			printf("SP in userspace\n");
			break;
		}

		if (!mread((sp + 16), &ip, sizeof(unsigned long)))
			break;

		printf("[%016lx] [%016lx] ", sp, ip);
		xmon_print_symbol("%s\n", ip);

		if (exception_frame(ip)) {
			if (mread(sp+112, &regs, sizeof(regs)) != sizeof(regs))
				break;

                        printf("  exception: %lx %s regs %lx\n", regs.trap,
			       getvecname(regs.trap), sp+112);
		}

		if (!mread(sp, &newsp, sizeof(unsigned long)))
			break;
		if (newsp < sp)
			break;

		sp = newsp;
	} while (count++ < xmon_depth_to_print);
}

static void backtrace(struct pt_regs *excp)
{
	unsigned long sp;

	if (excp == NULL)
		sp = __get_SP();
	else
		sp = excp->gpr[1];

	scanhex(&sp);
	scannl();

	xmon_show_stack(sp);
}

spinlock_t exception_print_lock = SPIN_LOCK_UNLOCKED;

void excprint(struct pt_regs *fp)
{
	unsigned long flags;

	spin_lock_irqsave(&exception_print_lock, flags);

#ifdef CONFIG_SMP
	printf("cpu %d: ", smp_processor_id());
#endif /* CONFIG_SMP */

	printf("Vector: %lx %s at [%lx]\n", fp->trap, getvecname(fp->trap), fp);
	printf("    pc: %lx", fp->nip);
	xmon_print_symbol(" (%s)\n", fp->nip);

	printf("    lr: %lx", fp->link);
	xmon_print_symbol(" (%s)\n", fp->link);

	printf("    sp: %lx\n", fp->gpr[1]);
	printf("   msr: %lx\n", fp->msr);

	if (fp->trap == 0x300 || fp->trap == 0x380 || fp->trap == 0x600) {
		printf("   dar: %lx\n", fp->dar);
		printf(" dsisr: %lx\n", fp->dsisr);
	}

	printf("  current = 0x%lx\n", current);
	printf("  paca    = 0x%lx\n", get_paca());
	if (current) {
		printf("    pid   = %ld, comm = %s\n",
		       current->pid, current->comm);
	}

	spin_unlock_irqrestore(&exception_print_lock, flags);
}

void prregs(struct pt_regs *fp)
{
	int n;
	unsigned long base;

	if (scanhex((void *)&base))
		fp = (struct pt_regs *) base;

	if (setjmp(bus_error_jmp) == 0) {
		__debugger_fault_handler = handle_fault;
		sync();
		for (n = 0; n < 16; ++n)
			printf("R%.2ld = %.16lx   R%.2ld = %.16lx\n", n,
			       fp->gpr[n], n+16, fp->gpr[n+16]);
		printf("pc  = %.16lx   msr = %.16lx\nlr  = %.16lx   "
		       "cr  = %.16lx\n", fp->nip, fp->msr, fp->link, fp->ccr);
		printf("ctr = %.16lx   xer = %.16lx   trap = %8lx\n",
		       fp->ctr, fp->xer, fp->trap);

		sync();
		/* wait a little while to see if we get a machine check */
		__delay(200);
	} else {
		printf("*** Error reading regs\n");
	}
}

void
cacheflush(void)
{
	int cmd;
	unsigned long nflush;

	cmd = inchar();
	if (cmd != 'i')
		termch = cmd;
	scanhex((void *)&adrs);
	if (termch != '\n')
		termch = 0;
	nflush = 1;
	scanhex(&nflush);
	nflush = (nflush + L1_CACHE_BYTES - 1) / L1_CACHE_BYTES;
	if (setjmp(bus_error_jmp) == 0) {
		__debugger_fault_handler = handle_fault;
		sync();

		if (cmd != 'i') {
			for (; nflush > 0; --nflush, adrs += L1_CACHE_BYTES)
				cflush((void *) adrs);
		} else {
			for (; nflush > 0; --nflush, adrs += L1_CACHE_BYTES)
				cinval((void *) adrs);
		}
		sync();
		/* wait a little while to see if we get a machine check */
		__delay(200);
	}
	__debugger_fault_handler = 0;
}

unsigned long
read_spr(int n)
{
	unsigned int instrs[2];
	unsigned long (*code)(void);
	unsigned long opd[3];
	unsigned long ret = -1UL;

	instrs[0] = 0x7c6002a6 + ((n & 0x1F) << 16) + ((n & 0x3e0) << 6);
	instrs[1] = 0x4e800020;
	opd[0] = (unsigned long)instrs;
	opd[1] = 0;
	opd[2] = 0;
	store_inst(instrs);
	store_inst(instrs+1);
	code = (unsigned long (*)(void)) opd;

	if (setjmp(bus_error_jmp) == 0) {
		__debugger_fault_handler = handle_fault;
		sync();

		ret = code();

		sync();
		/* wait a little while to see if we get a machine check */
		__delay(200);
	} else {
		printf("*** Error reading spr %x\n", n);
	}

	__debugger_fault_handler = 0;

	return ret;
}

void
write_spr(int n, unsigned long val)
{
	unsigned int instrs[2];
	unsigned long (*code)(unsigned long);
	unsigned long opd[3];

	instrs[0] = 0x7c6003a6 + ((n & 0x1F) << 16) + ((n & 0x3e0) << 6);
	instrs[1] = 0x4e800020;
	opd[0] = (unsigned long)instrs;
	opd[1] = 0;
	opd[2] = 0;
	store_inst(instrs);
	store_inst(instrs+1);
	code = (unsigned long (*)(unsigned long)) opd;

	if (setjmp(bus_error_jmp) == 0) {
		__debugger_fault_handler = handle_fault;
		sync();

		code(val);

		sync();
		/* wait a little while to see if we get a machine check */
		__delay(200);
	} else {
		printf("*** Error writing spr %x\n", n);
	}

	__debugger_fault_handler = 0;
}

static unsigned long regno;
extern char exc_prolog;
extern char dec_exc;

void
super_regs()
{
	int cmd;
	unsigned long val;
#ifdef CONFIG_PPC_ISERIES
	struct paca_struct *ptrPaca = NULL;
	struct ItLpPaca *ptrLpPaca = NULL;
	struct ItLpRegSave *ptrLpRegSave = NULL;
#endif

	cmd = skipbl();
	if (cmd == '\n') {
	        unsigned long sp, toc;
		asm("mr %0,1" : "=r" (sp) :);
		asm("mr %0,2" : "=r" (toc) :);

		printf("msr  = %.16lx  sprg0= %.16lx\n", get_msr(), get_sprg0());
		printf("pvr  = %.16lx  sprg1= %.16lx\n", get_pvr(), get_sprg1()); 
		printf("dec  = %.16lx  sprg2= %.16lx\n", get_dec(), get_sprg2());
		printf("sp   = %.16lx  sprg3= %.16lx\n", sp, get_sprg3());
		printf("toc  = %.16lx  dar  = %.16lx\n", toc, get_dar());
		printf("srr0 = %.16lx  srr1 = %.16lx\n", get_srr0(), get_srr1());
#ifdef CONFIG_PPC_ISERIES
		// Dump out relevant Paca data areas.
		printf("Paca: \n");
		ptrPaca = get_paca();
    
		printf("  Local Processor Control Area (LpPaca): \n");
		ptrLpPaca = ptrPaca->xLpPacaPtr;
		printf("    Saved Srr0=%.16lx  Saved Srr1=%.16lx \n", ptrLpPaca->xSavedSrr0, ptrLpPaca->xSavedSrr1);
		printf("    Saved Gpr3=%.16lx  Saved Gpr4=%.16lx \n", ptrLpPaca->xSavedGpr3, ptrLpPaca->xSavedGpr4);
		printf("    Saved Gpr5=%.16lx \n", ptrLpPaca->xSavedGpr5);
    
		printf("  Local Processor Register Save Area (LpRegSave): \n");
		ptrLpRegSave = ptrPaca->xLpRegSavePtr;
		printf("    Saved Sprg0=%.16lx  Saved Sprg1=%.16lx \n", ptrLpRegSave->xSPRG0, ptrLpRegSave->xSPRG0);
		printf("    Saved Sprg2=%.16lx  Saved Sprg3=%.16lx \n", ptrLpRegSave->xSPRG2, ptrLpRegSave->xSPRG3);
		printf("    Saved Msr  =%.16lx  Saved Nia  =%.16lx \n", ptrLpRegSave->xMSR, ptrLpRegSave->xNIA);
#endif

		return;
	}

	scanhex(&regno);
	switch (cmd) {
	case 'w':
		val = read_spr(regno);
		scanhex(&val);
		write_spr(regno, val);
		/* fall through */
	case 'r':
		printf("spr %lx = %lx\n", regno, read_spr(regno));
		break;
	case 'm':
		val = get_msr();
		scanhex(&val);
		set_msrd(val);
		break;
	}
	scannl();
}

int
mread(unsigned long adrs, void *buf, int size)
{
	volatile int n;
	char *p, *q;

	n = 0;
	if (setjmp(bus_error_jmp) == 0) {
		__debugger_fault_handler = handle_fault;
		sync();
		p = (char *)adrs;
		q = (char *)buf;
		switch (size) {
		case 2:
			*(short *)q = *(short *)p;
			break;
		case 4:
			*(int *)q = *(int *)p;
			break;
		case 8:
			*(long *)q = *(long *)p;
			break;
		default:
			for( ; n < size; ++n) {
				*q++ = *p++;
				sync();
			}
		}
		sync();
		/* wait a little while to see if we get a machine check */
		__delay(200);
		n = size;
	}
	__debugger_fault_handler = 0;
	return n;
}

int
mwrite(unsigned long adrs, void *buf, int size)
{
	volatile int n;
	char *p, *q;

	n = 0;
	if (setjmp(bus_error_jmp) == 0) {
		__debugger_fault_handler = handle_fault;
		sync();
		p = (char *) adrs;
		q = (char *) buf;
		switch (size) {
		case 2:
			*(short *)p = *(short *)q;
			break;
		case 4:
			*(int *)p = *(int *)q;
			break;
		case 8:
			*(long *)p = *(long *)q;
			break;
		default:
			for ( ; n < size; ++n) {
				*p++ = *q++;
				sync();
			}
		}
		sync();
		/* wait a little while to see if we get a machine check */
		__delay(200);
		n = size;
	} else {
		printf("*** Error writing address %x\n", adrs + n);
	}
	__debugger_fault_handler = 0;
	return n;
}

static int fault_type;
static char *fault_chars[] = { "--", "**", "##" };

static int
handle_fault(struct pt_regs *regs)
{
	switch (regs->trap) {
	case 0x200:
		fault_type = 0;
		break;
	case 0x300:
	case 0x380:
		fault_type = 1;
		break;
	default:
		fault_type = 2;
	}

	longjmp(bus_error_jmp, 1);

	return 0;
}

#define SWAP(a, b, t)	((t) = (a), (a) = (b), (b) = (t))

void
byterev(unsigned char *val, int size)
{
	int t;
	
	switch (size) {
	case 2:
		SWAP(val[0], val[1], t);
		break;
	case 4:
		SWAP(val[0], val[3], t);
		SWAP(val[1], val[2], t);
		break;
	case 8: /* is there really any use for this? */
		SWAP(val[0], val[7], t);
		SWAP(val[1], val[6], t);
		SWAP(val[2], val[5], t);
		SWAP(val[3], val[4], t);
		break;
	}
}

static int brev;
static int mnoread;

static char *memex_help_string = 
    "Memory examine command usage:\n"
    "m [addr] [flags] examine/change memory\n"
    "  addr is optional.  will start where left off.\n"
    "  flags may include chars from this set:\n"
    "    b   modify by bytes (default)\n"
    "    w   modify by words (2 byte)\n"
    "    l   modify by longs (4 byte)\n"
    "    d   modify by doubleword (8 byte)\n"
    "    r   toggle reverse byte order mode\n"
    "    n   do not read memory (for i/o spaces)\n"
    "    .   ok to read (default)\n"
    "NOTE: flags are saved as defaults\n"
    "";

static char *memex_subcmd_help_string = 
    "Memory examine subcommands:\n"
    "  hexval   write this val to current location\n"
    "  'string' write chars from string to this location\n"
    "  '        increment address\n"
    "  ^        decrement address\n"
    "  /        increment addr by 0x10.  //=0x100, ///=0x1000, etc\n"
    "  \\        decrement addr by 0x10.  \\\\=0x100, \\\\\\=0x1000, etc\n"
    "  `        clear no-read flag\n"
    "  ;        stay at this addr\n"
    "  v        change to byte mode\n"
    "  w        change to word (2 byte) mode\n"
    "  l        change to long (4 byte) mode\n"
    "  u        change to doubleword (8 byte) mode\n"
    "  m addr   change current addr\n"
    "  n        toggle no-read flag\n"
    "  r        toggle byte reverse flag\n"
    "  < count  back up count bytes\n"
    "  > count  skip forward count bytes\n"
    "  x        exit this mode\n"
    "";

void
memex()
{
	int cmd, inc, i, nslash;
	unsigned long n;
	unsigned char val[16];

	scanhex((void *)&adrs);
	cmd = skipbl();
	if (cmd == '?') {
		printf(memex_help_string);
		return;
	} else {
		termch = cmd;
	}
	last_cmd = "m\n";
	while ((cmd = skipbl()) != '\n') {
		switch( cmd ){
		case 'b':	size = 1;	break;
		case 'w':	size = 2;	break;
		case 'l':	size = 4;	break;
		case 'd':	size = 8;	break;
		case 'r': 	brev = !brev;	break;
		case 'n':	mnoread = 1;	break;
		case '.':	mnoread = 0;	break;
		}
	}
	if( size <= 0 )
		size = 1;
	else if( size > 8 )
		size = 8;
	for(;;){
		if (!mnoread)
			n = mread(adrs, val, size);
		printf("%.16x%c", adrs, brev? 'r': ' ');
		if (!mnoread) {
			if (brev)
				byterev(val, size);
			putchar(' ');
			for (i = 0; i < n; ++i)
				printf("%.2x", val[i]);
			for (; i < size; ++i)
				printf("%s", fault_chars[fault_type]);
		}
		putchar(' ');
		inc = size;
		nslash = 0;
		for(;;){
			if( scanhex(&n) ){
				for (i = 0; i < size; ++i)
					val[i] = n >> (i * 8);
				if (!brev)
					byterev(val, size);
				mwrite(adrs, val, size);
				inc = size;
			}
			cmd = skipbl();
			if (cmd == '\n')
				break;
			inc = 0;
			switch (cmd) {
			case '\'':
				for(;;){
					n = inchar();
					if( n == '\\' )
						n = bsesc();
					else if( n == '\'' )
						break;
					for (i = 0; i < size; ++i)
						val[i] = n >> (i * 8);
					if (!brev)
						byterev(val, size);
					mwrite(adrs, val, size);
					adrs += size;
				}
				adrs -= size;
				inc = size;
				break;
			case ',':
				adrs += size;
				break;
			case '.':
				mnoread = 0;
				break;
			case ';':
				break;
			case 'x':
			case EOF:
				scannl();
				return;
			case 'b':
			case 'v':
				size = 1;
				break;
			case 'w':
				size = 2;
				break;
			case 'l':
				size = 4;
				break;
			case 'u':
				size = 8;
				break;
			case '^':
				adrs -= size;
				break;
				break;
			case '/':
				if (nslash > 0)
					adrs -= 1 << nslash;
				else
					nslash = 0;
				nslash += 4;
				adrs += 1 << nslash;
				break;
			case '\\':
				if (nslash < 0)
					adrs += 1 << -nslash;
				else
					nslash = 0;
				nslash -= 4;
				adrs -= 1 << -nslash;
				break;
			case 'm':
				scanhex((void *)&adrs);
				break;
			case 'n':
				mnoread = 1;
				break;
			case 'r':
				brev = !brev;
				break;
			case '<':
				n = size;
				scanhex(&n);
				adrs -= n;
				break;
			case '>':
				n = size;
				scanhex(&n);
				adrs += n;
				break;
			case '?':
				printf(memex_subcmd_help_string);
				break;
			}
		}
		adrs += inc;
	}
}

int
bsesc()
{
	int c;

	c = inchar();
	switch( c ){
	case 'n':	c = '\n';	break;
	case 'r':	c = '\r';	break;
	case 'b':	c = '\b';	break;
	case 't':	c = '\t';	break;
	}
	return c;
}

#define isxdigit(c)	(('0' <= (c) && (c) <= '9') \
			 || ('a' <= (c) && (c) <= 'f') \
			 || ('A' <= (c) && (c) <= 'F'))
void
dump()
{
	int c;

	c = inchar();
	if ((isxdigit(c) && c != 'f' && c != 'd') || c == '\n')
		termch = c;
	scanhex((void *)&adrs);
	if( termch != '\n')
		termch = 0;
	if( c == 'i' ){
		scanhex(&nidump);
		if( nidump == 0 )
			nidump = 16;
		adrs += ppc_inst_dump(adrs, nidump);
		last_cmd = "di\n";
	} else {
		scanhex(&ndump);
		if( ndump == 0 )
			ndump = 64;
		prdump(adrs, ndump);
		adrs += ndump;
		last_cmd = "d\n";
	}
}

void
prdump(unsigned long adrs, long ndump)
{
	long n, m, c, r, nr;
	unsigned char temp[16];

	for( n = ndump; n > 0; ){
		printf("%.16lx", adrs);
		putchar(' ');
		r = n < 16? n: 16;
		nr = mread(adrs, temp, r);
		adrs += nr;
		for( m = 0; m < r; ++m ){
		        if ((m & 7) == 0 && m > 0)
			    putchar(' ');
			if( m < nr )
				printf("%.2x", temp[m]);
			else
				printf("%s", fault_chars[fault_type]);
		}
		for(; m < 16; ++m )
			printf("   ");
		printf("  |");
		for( m = 0; m < r; ++m ){
			if( m < nr ){
				c = temp[m];
				putchar(' ' <= c && c <= '~'? c: '.');
			} else
				putchar(' ');
		}
		n -= r;
		for(; m < 16; ++m )
			putchar(' ');
		printf("|\n");
		if( nr < r )
			break;
	}
}

int
ppc_inst_dump(unsigned long adr, long count)
{
	int nr, dotted;
	unsigned long first_adr;
	unsigned long inst, last_inst;
	unsigned char val[4];

	dotted = 0;
	for (first_adr = adr; count > 0; --count, adr += 4){
		nr = mread(adr, val, 4);
		if( nr == 0 ){
			const char *x = fault_chars[fault_type];
			printf("%.16lx  %s%s%s%s\n", adr, x, x, x, x);
			break;
		}
		inst = GETWORD(val);
		if (adr > first_adr && inst == last_inst) {
			if (!dotted) {
				printf(" ...\n");
				dotted = 1;
			}
			continue;
		}
		dotted = 0;
		last_inst = inst;
		printf("%.16lx  ", adr);
		printf("%.8x\t", inst);
		print_insn_big_powerpc(stdout, inst, adr);	/* always returns 4 */
		printf("\n");
	}
	return adr - first_adr;
}

void
print_address(unsigned long addr)
{
	const char *name;
	char *modname;
	long size, offset;

	name = kallsyms_lookup(addr, &size, &offset, &modname, tmpstr);

	if (name) {
		if (modname)
			printf("0x%lx\t# %s:%s+0x%lx", addr, modname, name, offset);
		else
			printf("0x%lx\t# %s+0x%lx", addr, name, offset);
	} else
		printf("0x%lx", addr);
}


/*
 * Memory operations - move, set, print differences
 */
static unsigned long mdest;		/* destination address */
static unsigned long msrc;		/* source address */
static unsigned long mval;		/* byte value to set memory to */
static unsigned long mcount;		/* # bytes to affect */
static unsigned long mdiffs;		/* max # differences to print */

void
memops(int cmd)
{
	scanhex((void *)&mdest);
	if( termch != '\n' )
		termch = 0;
	scanhex((void *)(cmd == 's'? &mval: &msrc));
	if( termch != '\n' )
		termch = 0;
	scanhex((void *)&mcount);
	switch( cmd ){
	case 'm':
		memmove((void *)mdest, (void *)msrc, mcount);
		break;
	case 's':
		memset((void *)mdest, mval, mcount);
		break;
	case 'd':
		if( termch != '\n' )
			termch = 0;
		scanhex((void *)&mdiffs);
		memdiffs((unsigned char *)mdest, (unsigned char *)msrc, mcount, mdiffs);
		break;
	}
}

void
memdiffs(unsigned char *p1, unsigned char *p2, unsigned nb, unsigned maxpr)
{
	unsigned n, prt;

	prt = 0;
	for( n = nb; n > 0; --n )
		if( *p1++ != *p2++ )
			if( ++prt <= maxpr )
				printf("%.16x %.2x # %.16x %.2x\n", p1 - 1,
					p1[-1], p2 - 1, p2[-1]);
	if( prt > maxpr )
		printf("Total of %d differences\n", prt);
}

static unsigned mend;
static unsigned mask;

void
memlocate()
{
	unsigned a, n;
	unsigned char val[4];

	last_cmd = "ml";
	scanhex((void *)&mdest);
	if (termch != '\n') {
		termch = 0;
		scanhex((void *)&mend);
		if (termch != '\n') {
			termch = 0;
			scanhex((void *)&mval);
			mask = ~0;
			if (termch != '\n') termch = 0;
			scanhex((void *)&mask);
		}
	}
	n = 0;
	for (a = mdest; a < mend; a += 4) {
		if (mread(a, val, 4) == 4
			&& ((GETWORD(val) ^ mval) & mask) == 0) {
			printf("%.16x:  %.16x\n", a, GETWORD(val));
			if (++n >= 10)
				break;
		}
	}
}

static unsigned long mskip = 0x1000;
static unsigned long mlim = 0xffffffff;

void
memzcan()
{
	unsigned char v;
	unsigned a;
	int ok, ook;

	scanhex(&mdest);
	if (termch != '\n') termch = 0;
	scanhex(&mskip);
	if (termch != '\n') termch = 0;
	scanhex(&mlim);
	ook = 0;
	for (a = mdest; a < mlim; a += mskip) {
		ok = mread(a, &v, 1);
		if (ok && !ook) {
			printf("%.8x .. ", a);
			fflush(stdout);
		} else if (!ok && ook)
			printf("%.8x\n", a - mskip);
		ook = ok;
		if (a + mskip < a)
			break;
	}
	if (ook)
		printf("%.8x\n", a - mskip);
}

/* Input scanning routines */
int
skipbl()
{
	int c;

	if( termch != 0 ){
		c = termch;
		termch = 0;
	} else
		c = inchar();
	while( c == ' ' || c == '\t' )
		c = inchar();
	return c;
}

#define N_PTREGS	44
static char *regnames[N_PTREGS] = {
	"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",
	"r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",
	"r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",
	"r24", "r25", "r26", "r27", "r28", "r29", "r30", "r31",
	"pc", "msr", "or3", "ctr", "lr", "xer", "ccr", "mq",
	"trap", "dar", "dsisr", "res"
};

int
scanhex(vp)
unsigned long *vp;
{
	int c, d;
	unsigned long v;

	c = skipbl();
	if (c == '%') {
		/* parse register name */
		char regname[8];
		int i;

		for (i = 0; i < sizeof(regname) - 1; ++i) {
			c = inchar();
			if (!isalnum(c)) {
				termch = c;
				break;
			}
			regname[i] = c;
		}
		regname[i] = 0;
		for (i = 0; i < N_PTREGS; ++i) {
			if (strcmp(regnames[i], regname) == 0) {
				unsigned long *rp = (unsigned long *)
					xmon_regs[smp_processor_id()];
				if (rp == NULL) {
					printf("regs not available\n");
					return 0;
				}
				*vp = rp[i];
				return 1;
			}
		}
		printf("invalid register name '%%%s'\n", regname);
		return 0;
	}

	/* skip leading "0x" if any */

	if (c == '0') {
		c = inchar();
		if (c == 'x')
			c = inchar();
	} else if (c == '$') {
		int i;
		for (i=0; i<63; i++) {
			c = inchar();
			if (isspace(c)) {
				termch = c;
				break;
			}
			tmpstr[i] = c;
		}
		tmpstr[i++] = 0;
		*vp = kallsyms_lookup_name(tmpstr);
		if (!(*vp)) {
			printf("unknown symbol '%s'\n", tmpstr);
			return 0;
		}
		return 1;
	}

	d = hexdigit(c);
	if (d == EOF) {
		termch = c;
		return 0;
	}
	v = 0;
	do {
		v = (v << 4) + d;
		c = inchar();
		d = hexdigit(c);
	} while (d != EOF);
	termch = c;
	*vp = v;
	return 1;
}

void
scannl()
{
	int c;

	c = termch;
	termch = 0;
	while( c != '\n' )
		c = inchar();
}

int
hexdigit(int c)
{
	if( '0' <= c && c <= '9' )
		return c - '0';
	if( 'A' <= c && c <= 'F' )
		return c - ('A' - 10);
	if( 'a' <= c && c <= 'f' )
		return c - ('a' - 10);
	return EOF;
}

void
getstring(char *s, int size)
{
	int c;

	c = skipbl();
	do {
		if( size > 1 ){
			*s++ = c;
			--size;
		}
		c = inchar();
	} while( c != ' ' && c != '\t' && c != '\n' );
	termch = c;
	*s = 0;
}

static char line[256];
static char *lineptr;

void
flush_input()
{
	lineptr = NULL;
}

int
inchar()
{
	if (lineptr == NULL || *lineptr == 0) {
		if (fgets(line, sizeof(line), stdin) == NULL) {
			lineptr = NULL;
			return EOF;
		}
		lineptr = line;
	}
	return *lineptr++;
}

void
take_input(str)
char *str;
{
	lineptr = str;
}


static void
symbol_lookup(void)
{
	int type = inchar();
	unsigned long addr;
	static char tmp[64];

	switch (type) {
	case 'a':
		if (scanhex(&addr)) {
			printf("%lx: ", addr);
			xmon_print_symbol("%s\n", addr);
		}
		termch = 0;
		break;
	case 's':
		getstring(tmp, 64);
		if (setjmp(bus_error_jmp) == 0) {
			__debugger_fault_handler = handle_fault;
			sync();
			addr = kallsyms_lookup_name(tmp);
			if (addr)
				printf("%s: %lx\n", tmp, addr);
			else
				printf("Symbol '%s' not found.\n", tmp);
			sync();
		}
		__debugger_fault_handler = 0;
		termch = 0;
		break;
	}
}


/* xmon version of __print_symbol */
void __xmon_print_symbol(const char *fmt, unsigned long address)
{
	char *modname;
	const char *name;
	unsigned long offset, size;

	if (setjmp(bus_error_jmp) == 0) {
		__debugger_fault_handler = handle_fault;
		sync();
		name = kallsyms_lookup(address, &size, &offset, &modname,
				       tmpstr);
		sync();
		/* wait a little while to see if we get a machine check */
		__delay(200);
	} else {
		name = "symbol lookup failed";
	}

	__debugger_fault_handler = 0;

	if (!name) {
		char addrstr[sizeof("0x%lx") + (BITS_PER_LONG*3/10)];

		sprintf(addrstr, "0x%lx", address);
		printf(fmt, addrstr);
		return;
	}

	if (modname) {
		/* This is pretty small. */
		char buffer[sizeof("%s+%#lx/%#lx [%s]")
			   + strlen(name) + 2*(BITS_PER_LONG*3/10)
			   + strlen(modname)];

		sprintf(buffer, "%s+%#lx/%#lx [%s]",
			name, offset, size, modname);
		printf(fmt, buffer);
	} else {
		char buffer[sizeof("%s+%#lx/%#lx")
			   + strlen(name) + 2*(BITS_PER_LONG*3/10)];

		sprintf(buffer, "%s+%#lx/%#lx", name, offset, size);
		printf(fmt, buffer);
	}
}

static void debug_trace(void)
{
        unsigned long val, cmd, on;

	cmd = skipbl();
	if (cmd == '\n') {
		/* show current state */
		unsigned long i;
		printf("naca->debug_switch = 0x%lx\n", naca->debug_switch);
		for (i = 0; i < PPCDBG_NUM_FLAGS ;i++) {
			on = PPCDBG_BITVAL(i) & naca->debug_switch;
			printf("%02x %s %12s   ", i, on ? "on " : "off",  trace_names[i] ? trace_names[i] : "");
			if (((i+1) % 3) == 0)
				printf("\n");
		}
		printf("\n");
		return;
	}
	while (cmd != '\n') {
		on = 1;	/* default if no sign given */
		while (cmd == '+' || cmd == '-') {
			on = (cmd == '+');
			cmd = inchar();
			if (cmd == ' ' || cmd == '\n') {  /* Turn on or off based on + or - */
				naca->debug_switch = on ? PPCDBG_ALL:PPCDBG_NONE;
				printf("Setting all values to %s...\n", on ? "on" : "off");
				if (cmd == '\n') return;
				else cmd = skipbl(); 
			}
			else
				termch = cmd;
		}
		termch = cmd;	/* not +/- ... let scanhex see it */
		scanhex((void *)&val);
		if (val >= 64) {
			printf("Value %x out of range:\n", val);
			return;
		}
		if (on) {
			naca->debug_switch |= PPCDBG_BITVAL(val);
			printf("enable debug %x %s\n", val, trace_names[val] ? trace_names[val] : "");
		} else {
			naca->debug_switch &= ~PPCDBG_BITVAL(val);
			printf("disable debug %x %s\n", val, trace_names[val] ? trace_names[val] : "");
		}
		cmd = skipbl();
	}
}

static void dump_slb(void)
{
	int i;
	unsigned long tmp;

	printf("SLB contents of cpu %d\n", smp_processor_id());

	for (i = 0; i < naca->slb_size; i++) {
		asm volatile("slbmfee  %0,%1" : "=r" (tmp) : "r" (i));
		printf("%02d %016lx ", i, tmp);

		asm volatile("slbmfev  %0,%1" : "=r" (tmp) : "r" (i));
		printf("%016lx\n", tmp);
	}
}

static void dump_stab(void)
{
	int i;
	unsigned long *tmp = (unsigned long *)get_paca()->xStab_data.virt;

	printf("Segment table contents of cpu %d\n", smp_processor_id());

	for (i = 0; i < PAGE_SIZE/16; i++) {
		unsigned long a, b;

		a = *tmp++;
		b = *tmp++;

		if (a || b) {
			printf("%03d %016lx ", i, a);
			printf("%016lx\n", b);
		}
	}
}

void xmon_init(void)
{
	__debugger = xmon;
	__debugger_bpt = xmon_bpt;
	__debugger_sstep = xmon_sstep;
	__debugger_iabr_match = xmon_iabr_match;
	__debugger_dabr_match = xmon_dabr_match;
}

void dump_segments(void)
{
	if (cur_cpu_spec->cpu_features & CPU_FTR_SLB)
		dump_slb();
	else
		dump_stab();
}