gdb.cpp

// Copyright 2010 fail0verflow <master@fail0verflow.com>
// Licensed under the terms of the GNU GPL, version 2
// http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt


#include "types.h"
#include "gdb.h"

#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#ifdef _WIN32
#define _WINSOCKAPI_
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <iphlpapi.h>
#include <iphlpapi.h>
#else
#include <sys/select.h>
#include <sys/socket.h>
#include <netinet/in.h>
#endif
#include <stdarg.h>

#include <dbg.hpp>


#undef dbgprintf
#ifndef _DEBUG
#define dbgprintf(...)
#else
#define dbgprintf ::msg
#endif

#define		GDB_BFR_MAX	10000
#define		GDB_MAX_BP	10

#define		GDB_STUB_START	'$'
#define		GDB_STUB_END	'#'
#define		GDB_STUB_ACK	'+'
#define		GDB_STUB_NAK	'-'

static int sock = -1;
static struct sockaddr_in saddr_server, saddr_client;

static u8 cmd_bfr[GDB_BFR_MAX];
static u32 cmd_len;

static u32 sig = 0;
static u32 send_signal = 0;

typedef struct
{
	u32 active;
	u32 addr;
	u32 len;
} gdb_bp_t;

static gdb_bp_t bp_x[GDB_MAX_BP];
static gdb_bp_t bp_r[GDB_MAX_BP];
static gdb_bp_t bp_w[GDB_MAX_BP];
static gdb_bp_t bp_a[GDB_MAX_BP];

bool fail(const char *a, ...)
{
    char msg[1024];
    va_list va;

    va_start(va, a);
    vsnprintf(msg, sizeof msg, a, va);
    perror(msg);

    dbgprintf(msg);

#ifdef FAIL_DUMP_REGS
    dump_regs();
#endif

#ifdef FAIL_DUMP_LS
    dump_ls();
#endif

    //gdb_deinit();
    //exit(1);

    return false;
}

// private helpers
static u8 hex2char(u8 hex)
{
	if (hex >= '0' && hex <= '9')
		return hex - '0';
	else if (hex >= 'a' && hex <= 'f')
		return hex - 'a' + 0xa;
	else if (hex >= 'A' && hex <= 'F')
		return hex - 'A' + 0xa;

	printf("Invalid nibble: %c (%02x)\n", hex, hex);
	return 0;
}

static u8 nibble2hex(u8 n)
{
	n &= 0xf;
	if (n < 0xa)
		return '0' + n;
	else
		return 'A' + n - 0xa;
}

static void mem2hex(u8 *dst, u8 *src, u32 len)
{
	u8 tmp;

	while (len-- > 0)
    {
		tmp = *src++;
		*dst++ = nibble2hex(tmp>>4);
		*dst++ = nibble2hex(tmp);
	}
}

static void hex2mem(u8 *dst, u8 *src, u32 len)
{
	while (len-- > 0)
    {
		*dst = hex2char(*src++) << 4;
		*dst++ |= hex2char(*src++);
	}
}

static void wbe32hex(u8 *p, u32 v)
{
    u32 i;

    for (i = 0; i < 8; i++)
        p[i] =  nibble2hex(v >> (28 - 4*i));
}

static u32 re32hex(u8 *p)
{
    u32 i;
    u32 res = 0;

    for (i = 0; i < 8; i++)
        res = (res << 4) | hex2char(p[i]);

    return res;
}

static u8 gdb_read_byte(void)
{
	size_t res;
	u8 c;

	res = recv(sock, (char*)&c, 1, MSG_WAITALL);
	if (res != 1)
		return fail("recv failed");

	return c;
}

static u8 gdb_calc_chksum(void)
{
	u32 len = cmd_len;
	u8 *ptr = cmd_bfr;
	u8 c = 0;

	while(len-- > 0)
		c += *ptr++;

	return c;
}

static gdb_bp_t *gdb_bp_ptr(u32 type)
{
	switch (type)
    {
		case GDB_BP_TYPE_X:
			return bp_x;
		case GDB_BP_TYPE_R:
			return bp_r;
		case GDB_BP_TYPE_W:
			return bp_w;
		case GDB_BP_TYPE_A:
			return bp_a;
		default:
			return NULL;
	}
}

static gdb_bp_t *gdb_bp_empty_slot(u32 type)
{
	gdb_bp_t *p;
	u32 i;

	p = gdb_bp_ptr(type);
	if (p == NULL)
		return NULL;

	for (i = 0; i < GDB_MAX_BP; i++)
    {
		if (p[i].active == 0)
			return &p[i];
	}

	return NULL;
}

static gdb_bp_t *gdb_bp_find(u32 type, u32 addr, u32 len)
{
	gdb_bp_t *p;
	u32 i;

	p = gdb_bp_ptr(type);
	if (p == NULL)
		return NULL;

	for (i = 0; i < GDB_MAX_BP; i++)
    {
		if (p[i].active == 1 &&
		    p[i].addr == addr &&
		    p[i].len == len)
			return &p[i];
	}

	return NULL;
}

static void gdb_bp_remove(u32 type, u32 addr, u32 len)
{
	gdb_bp_t *p;

	do
    {
		p = gdb_bp_find(type, addr, len);
		if (p != NULL)
        {
			dbgprintf("gdb: remvoed a breakpoint: %08x bytes at %08x\n", len, addr);
			p->active = 0;
			memset(p, 0, sizeof p);
		}
	} while (p != NULL);
}

static int gdb_bp_check(u32 addr, u32 type)
{
	gdb_bp_t *p;
	u32 i;

	p = gdb_bp_ptr(type);
	if (p == NULL)
		return 0;

	for (i = 0; i < GDB_MAX_BP; i++)
    {
		if (p[i].active == 1 &&
		    (addr >= p[i].addr && addr < p[i].addr + p[i].len))
			return 1;
	}

	return 0;
}

static void gdb_nak(void)
{
	const char nak = GDB_STUB_NAK;
	size_t res;

	res = send(sock, &nak, 1, 0);
	if (res != 1)
		fail("send failed");
}

static void gdb_ack(void)
{
	const char ack = GDB_STUB_ACK;
	size_t res;

	res = send(sock, &ack, 1, 0);
	if (res != 1)
		fail("send failed");
}

static bool gdb_read_command(void)
{
	u8 c;
	u8 chk_read, chk_calc;

	cmd_len = 0;
	memset(cmd_bfr, 0, sizeof cmd_bfr);

	c = gdb_read_byte();

    if (c == GDB_STUB_ACK ||
        c == GDB_STUB_NAK)
    {
        cmd_bfr[cmd_len++] = c;
        dbgprintf("gdb: read command %c with a length of %d: %s\n", cmd_bfr[0], cmd_len, cmd_bfr);
        return true;
    }

	if (c != GDB_STUB_START)
    {
		dbgprintf("gdb: read invalid byte %02x\n", c);
		return false;
	}

	while ((c = gdb_read_byte()) != GDB_STUB_END)
    {
		cmd_bfr[cmd_len++] = c;
		if (cmd_len == sizeof cmd_bfr)
			return fail("gdb: cmd_bfr overflow\n");
	}

	chk_read = hex2char(gdb_read_byte()) << 4;
	chk_read |= hex2char(gdb_read_byte());

	chk_calc = gdb_calc_chksum();

	if (chk_calc != chk_read)
    {
		dbgprintf("gdb: invalid checksum: calculated %02x and read %02x for $%s# (length: %d)\n", chk_calc, chk_read, cmd_bfr, cmd_len);
		cmd_len = 0;
	
		gdb_nak();

        return false;
	}

	dbgprintf("gdb: read command %c with a length of %d: %s\n", cmd_bfr[0], cmd_len, cmd_bfr);

    return true;
}

static int gdb_data_available(void)
{
	struct timeval t;
	fd_set _fds, *fds = &_fds;
	
	FD_ZERO(fds);
	FD_SET(sock, fds);

	t.tv_sec = 0;
	t.tv_usec = 2000;

	if (select(sock + 1, fds, NULL, NULL, &t) < 0)
		return fail("select failed");

	if (FD_ISSET(sock, fds))
		return 1;
	return 0;
}

static void gdb_reply(const char *reply)
{
    if (sock == -1)
        return;

	u8 chk;
	u32 left;
	u8 *ptr;
	int n;

	memset(cmd_bfr, 0, sizeof cmd_bfr);

	cmd_len = strlen(reply);
	if (cmd_len + 4 > sizeof cmd_bfr)
    {
        fail("cmd_bfr overflow in gdb_reply\n");
        return;
    }

	memcpy(cmd_bfr + 1, reply, cmd_len);

	cmd_len++;
	chk = gdb_calc_chksum();
	cmd_len--;
	cmd_bfr[0] = GDB_STUB_START;
	cmd_bfr[cmd_len + 1] = GDB_STUB_END;
	cmd_bfr[cmd_len + 2] = nibble2hex(chk >> 4);
	cmd_bfr[cmd_len + 3] = nibble2hex(chk);

	dbgprintf("gdb: reply (len: %d): %s\n", cmd_len, cmd_bfr);

	ptr = cmd_bfr;
	left = cmd_len + 4;
	while ((int)left > 0)
    {
		n = send(sock, (char*)ptr, left, 0);
        dbgprintf("gdb: reply (sent: %d of %d)\n", n, cmd_len);
		if (n < 0)
        {
            fail("gdb: send failed\n");
            return;
        }
		left -= n;
		ptr += n;
	}
}

static void gdb_handle_query(void)
{
	dbgprintf("gdb: query '%s'\n", cmd_bfr+1);
	gdb_ack();
	gdb_reply("");
}

static void gdb_handle_set_thread(void)
{
	gdb_ack();
	if (memcmp(cmd_bfr, "Hg0", 3) == 0 ||
	    memcmp(cmd_bfr, "Hc-1", 4) == 0)
		return gdb_reply("OK");
	gdb_reply("E01");
}

static void gdb_handle_signal(event_callback* callback)
{
    dbgprintf("gdb_handle_signal\n");

    u32 sig = 0;

    sig = hex2char(cmd_bfr[1]) << 4;
    sig |= hex2char(cmd_bfr[2]);

    u32 reg = 0;

    reg = hex2char(cmd_bfr[3]) << 4;
    reg |= hex2char(cmd_bfr[4]);

    u32 val = re32hex(cmd_bfr + 6);

    if (0 != callback)
    {
        callback(sig, val);
    }
/*
    char bfr[128];

	gdb_ack();
	memset(bfr, 0, sizeof bfr);
	sprintf(bfr, "T%02x81:%08x;", sig, ctx->pc);
	gdb_reply(bfr);
*/
}

void gdb_read_registers(u32 reg[130][4])
{
    u8 reply[4] = {0};

    //memset(reply, 0, sizeof reply);

    reply[0] = 'g';

    gdb_reply((char *)reply);

    // read ack/nak
    gdb_read_command();
    // read register values
    gdb_read_command();

    for (u32 i = 0; i < 128; i++)
    {
        reg[i][0] = re32hex(cmd_bfr + i * 32 + 0);
        reg[i][1] = re32hex(cmd_bfr + i * 32 + 8);
        reg[i][2] = re32hex(cmd_bfr + i * 32 + 16);
        reg[i][3] = re32hex(cmd_bfr + i * 32 + 24);
    }

    gdb_read_register(0x80, reg[0x80]);
    gdb_read_register(0x81, reg[0x81]);

/*
	static u8 bfr[GDB_BFR_MAX - 4];
	u32 i;

	gdb_ack();
	memset(bfr, 0, sizeof bfr);

	for (i = 0; i < 128; i++)
    {
		wbe32hex(bfr + i*32 + 0, ctx->reg[i][0]);
		wbe32hex(bfr + i*32 + 8, ctx->reg[i][1]);
		wbe32hex(bfr + i*32 + 16, ctx->reg[i][2]);
		wbe32hex(bfr + i*32 + 24, ctx->reg[i][3]);
	}
	
	gdb_reply((char *)bfr);
*/
}

void gdb_write_registers(u32 reg[130][4])
{
    u8 reply[GDB_BFR_MAX - 4];

    memset(reply, 0, sizeof reply);

    reply[0] = 'G';

    for (u32 i = 0; i < 128; i++)
    {
        wbe32hex(reply + 1 + i*32 + 0, reg[i][0]);
        wbe32hex(reply + 1 + i*32 + 8, reg[i][1]);
        wbe32hex(reply + 1 + i*32 + 16, reg[i][2]);
        wbe32hex(reply + 1 + i*32 + 24, reg[i][3]);
    }

    gdb_reply((char *)reply);

    // read ack/nak
    gdb_read_command();
    // read OK/E##
    gdb_read_command();

/*
	gdb_ack();

	u32 i;

	for (i = 0; i < 128; i++)
    {
		ctx->reg[i][0] = re32hex(cmd_bfr + i*32 +  0);
		ctx->reg[i][1] = re32hex(cmd_bfr + i*32 +  8);
		ctx->reg[i][2] = re32hex(cmd_bfr + i*32 + 16);
		ctx->reg[i][3] = re32hex(cmd_bfr + i*32 + 24);
	}

	gdb_reply("OK");
*/
}

void gdb_read_register(u32 id, u32 reg[4])
{
	u8 reply[64];

	memset(reply, 0, sizeof reply);

    reply[0] = 'p';
    reply[1] = nibble2hex(id >> 4);
    reply[2] = nibble2hex(id);

    gdb_reply((char *)reply);

    // read ack/nak
    gdb_read_command();
    // read register value
    gdb_read_command();

    reg[0] = re32hex(cmd_bfr +  0);
    if (id < 128)
    {
        reg[1] = re32hex(cmd_bfr +  8);
        reg[2] = re32hex(cmd_bfr + 16);
        reg[3] = re32hex(cmd_bfr + 24);
    }

/*
    static u8 reply[32];
    u32 id;

    memset(reply, 0, sizeof reply);

	id = hex2char(cmd_bfr[1]) << 4;
	id |= hex2char(cmd_bfr[2]);

	gdb_ack();
	switch (id)
    {
		case 0 ... 127:
			wbe32hex(reply +  0, ctx->reg[id][0]);
			wbe32hex(reply +  8, ctx->reg[id][1]);
			wbe32hex(reply + 16, ctx->reg[id][2]);
			wbe32hex(reply + 24, ctx->reg[id][3]);
			break;
		case 128:
			// SPU ID
			wbe32hex(reply, SPU_ID);
			break;
		case 129:
			// PC
			wbe32hex(reply, ctx->pc);
			break;
		default:
			wbe32hex(reply, 0);
	}
	gdb_reply((char *)reply);
*/
}

void gdb_write_register(u32 id, u32 reg[4])
{
    u8 reply[64];

    if (id > 127 && id != 129)
        return;

    memset(reply, 0, sizeof reply);

    reply[0] = 'P';
    reply[1] = nibble2hex(id >> 4);
    reply[2] = nibble2hex(id);
    reply[3] = '=';
    wbe32hex(reply + 4 +  0, reg[0]);
    if (id < 128)
    {
        wbe32hex(reply + 4 +  8, reg[1]);
        wbe32hex(reply + 4 + 16, reg[2]);
        wbe32hex(reply + 4 + 24, reg[3]);
    }

    gdb_reply((char *)reply);

    // read ack/nak
    gdb_read_command();
    // read OK/E##
    gdb_read_command();

/*
	u32 id;
	u32 i;

	gdb_ack();

	id = hex2char(cmd_bfr[1]) << 4;
	id |= hex2char(cmd_bfr[2]);

	if (id == 129)
    {
		ctx->pc = 0;
		i = 4;
		while (i < cmd_len)
			ctx->pc = (ctx->pc << 4) | hex2char(cmd_bfr[i++]);
		ctx->pc -= 4;
		gdb_reply("OK");
		return;
	}

	if (id > 127)
		return gdb_reply("E01");

	// XXX: wrong?
	ctx->reg[id][0] = re32hex(cmd_bfr + 4 +  0);
	ctx->reg[id][1] = re32hex(cmd_bfr + 4 +  8);
	ctx->reg[id][2] = re32hex(cmd_bfr + 4 + 16);
	ctx->reg[id][3] = re32hex(cmd_bfr + 4 + 24);
	gdb_reply("OK");
*/
}

u32 gdb_read_mem(u32 addr, u8* buffer, u32 size)
{
    u8 reply[32];

    memset(reply, 0, sizeof reply);

    reply[0] = 'm';
    wbe32hex(reply + 1, addr);
    reply[9] = ',';
    wbe32hex(reply + 10, size);

    gdb_reply((char *)reply);

    // read ack/nak
    gdb_read_command();
    // read OK/E##/""
    gdb_read_command();

    u32 length = min(cmd_len, size);

    if (length > 0)
    {
        hex2mem(buffer, cmd_bfr, length);
    }

    return length;

/*
	static u8 reply[GDB_BFR_MAX - 4];
	u32 addr, len;
	u32 i;

	gdb_ack();

	i = 1;
	addr = 0;
	while (cmd_bfr[i] != ',')
		addr = (addr << 4) | hex2char(cmd_bfr[i++]);

	addr &= LSLR;
	i++;

	len = 0;
	while (i < cmd_len)
		len = (len << 4) | hex2char(cmd_bfr[i++]);
	dbgprintf("gdb: read memory: %08x bytes from %08x\n", len, addr);

	if (len*2 > sizeof reply)
		gdb_reply("E01");

	mem2hex(reply, ctx->ls + addr, len);
	gdb_reply((char *)reply);	
*/
}

u32 gdb_write_mem(u32 addr, u8* buffer, u32 size)
{
    u8 reply[GDB_BFR_MAX - 4];

    u32 length = min(GDB_BFR_MAX - 23, size);

    if (length > 0)
    {
        memset(reply, 0, sizeof reply);

        reply[0] = 'M';
        wbe32hex(reply + 1, addr);
        reply[9] = ',';
        wbe32hex(reply + 10, size);
        reply[18] = ':';

        mem2hex(reply + 19, buffer, length);

        gdb_reply((char *)reply);

        // read ack/nak
        gdb_read_command();
        // read OK/E##/""
        gdb_read_command();
    }

    return length;

/*
	u32 addr, len;
	u32 i;

	gdb_ack();

	i = 1;
	addr = 0;
	while (cmd_bfr[i] != ',')
		addr = (addr << 4) | hex2char(cmd_bfr[i++]);

	addr &= LSLR;
	i++;

	len = 0;
	while (cmd_bfr[i] != ':')
		len = (len << 4) | hex2char(cmd_bfr[i++]);
	dbgprintf("gdb: write memory: %08x bytes to %08x\n", len, addr);

	hex2mem(ctx->ls + addr, cmd_bfr + i, len);
	gdb_reply("OK");
*/
}

void gdb_continue(void)
{
    gdb_reply("c");
    // read ack/nak
    gdb_read_command();

/*
	gdb_ack();
	ctx->paused = 0;
	send_signal = 1;
*/
}

void gdb_step(void)
{
    gdb_reply("s");
    // read ack/nak
    gdb_read_command();
}

void gdb_pause(void)
{
    gdb_reply(" ");
    // read ack/nak
    gdb_read_command();
}

void gdb_add_bp(u32 addr, gdb_bp_type type, u32 size)
{
    u8 reply[32];

    u8 bpt = 0;
    switch (type)
    {
    case GDB_BP_TYPE_X:
        bpt = 0;
        //type = 1;
        break;
    case GDB_BP_TYPE_W:
        bpt = 2;
        break;
    case GDB_BP_TYPE_R:
        bpt = 3;
        break;
    case GDB_BP_TYPE_A:
        bpt = 4;
        break;
    default:
        dbgprintf("Unsupported breakpoint type.\n");
        return;
    }

    memset(reply, 0, sizeof reply);

    reply[0] = 'Z';
    reply[1] = nibble2hex(bpt);
    reply[2] = ',';
    wbe32hex(reply +  3, addr);
    reply[11] = ',';
    wbe32hex(reply + 12, size);

    gdb_reply((char *)reply);

    // read ack/nak
    gdb_read_command();
    // read OK/E##/""
    gdb_read_command();

/*
	gdb_bp_t *bp;
	u32 type;
	u32 i;

	gdb_ack();

	type = hex2char(cmd_bfr[1]);
	switch (type)
    {
		case 0:
		case 1:
			type = GDB_BP_TYPE_X;
			break;
		case 2:
			type = GDB_BP_TYPE_W;
			break;
		case 3:
			type = GDB_BP_TYPE_R;
			break;
		case 4:
			type = GDB_BP_TYPE_A;
			break;
		default:
			return gdb_reply("E01");
	}

	bp = gdb_bp_empty_slot(type);
	if (bp == NULL)
		return gdb_reply("E02");

	bp->active = 1;
	bp->addr = 0;
	bp->len = 0;

	i = 3;
	while (cmd_bfr[i] != ',')
		bp->addr = (bp->addr << 4) | hex2char(cmd_bfr[i++]);
	i++;

	while (i < cmd_len)
		bp->len = (bp->len << 4) | hex2char(cmd_bfr[i++]);

	dbgprintf("gdb: added %d breakpoint: %08x bytes at %08x\n", type, bp->len, bp->addr);
	gdb_reply("OK");
*/
}

void gdb_remove_bp(u32 addr, gdb_bp_type type, u32 size)
{
    u8 reply[32];

    u8 bpt = 0;
    switch (type)
    {
    case GDB_BP_TYPE_X:
        bpt = 0;
        //type = 1;
        break;
    case GDB_BP_TYPE_W:
        bpt = 2;
        break;
    case GDB_BP_TYPE_R:
        bpt = 3;
        break;
    case GDB_BP_TYPE_A:
        bpt = 4;
        break;
    default:
        dbgprintf("Unsupported breakpoint type.\n");
        return;
    }

    memset(reply, 0, sizeof reply);

    reply[0] = 'z';
    reply[1] = nibble2hex(bpt);
    reply[2] = ',';
    wbe32hex(reply +  3, addr);
    reply[11] = ',';
    wbe32hex(reply + 12, size);

    gdb_reply((char *)reply);

    // read ack/nak
    gdb_read_command();
    // read OK/E##/""
    gdb_read_command();

/*
	u32 type, addr, len, i;

	gdb_ack();

	type = hex2char(cmd_bfr[1]);
	switch (type)
    {
		case 0:
		case 1:
			type = GDB_BP_TYPE_X;
			break;
		case 2:
			type = GDB_BP_TYPE_W;
			break;
		case 3:
			type = GDB_BP_TYPE_R;
			break;
		case 4:
			type = GDB_BP_TYPE_A;
			break;
		default:
			return gdb_reply("E01");
	}

	addr = 0;
	len = 0;

	i = 3;
	while (cmd_bfr[i] != ',')
		addr = (addr << 4) | hex2char(cmd_bfr[i++]);
	i++;

	while (i < cmd_len)
		len = (len << 4) | hex2char(cmd_bfr[i++]);

	gdb_bp_remove(type, addr, len);
	gdb_reply("OK");
*/
}

static void gdb_parse_command(event_callback* callback)
{
	if (cmd_len == 0)
		return;

	switch(cmd_bfr[0])
    {
    case GDB_STUB_ACK:
        dbgprintf("ACK received.\n");
        break;
    case GDB_STUB_NAK:
        dbgprintf("NAK received.\n");
        break;
    case 'T':
        gdb_handle_signal(callback);
        break;
    default:
        dbgprintf("Unhandled command: %02X ('%c')\n", cmd_bfr[0], cmd_bfr[0]);
        break;
/*
    case 'q':
        gdb_handle_query();
        break;
    case 'H':
        gdb_handle_set_thread();
        break;
    case '?':
        gdb_handle_signal();
        break;
    case 'k':
        gdb_ack();
        fail("killed by gdb");
        break;
    case 'g':
        gdb_read_registers();
        break;
    case 'G':
        gdb_write_registers();
        break;
    case 'p':
        gdb_read_register();
        break;
    case 'P':
        gdb_write_register();
        break;
    case 'm':
        gdb_read_mem();
        break;
    case 'M':
        gdb_write_mem();
        break;
    case 'c':
        gdb_continue();
        break;
    case 'z':
        gdb_remove_bp();
        break;
    case 'Z':
        gdb_add_bp();
        break;
    default:
        gdb_ack();
        gdb_reply("");
        break;
*/
	}
}

#ifdef _WIN32
	WSADATA InitData;
#endif

// exported functions

bool gdb_init(u32 port)
{
	int tmpsock;
	socklen_t len;
	int on;
#ifdef _WIN32
	WSAStartup(MAKEWORD(2,2), &InitData);
#endif
	memset(bp_x, 0, sizeof bp_x);
	memset(bp_r, 0, sizeof bp_r);
	memset(bp_w, 0, sizeof bp_w);
	memset(bp_a, 0, sizeof bp_a);

	tmpsock = socket(AF_INET, SOCK_STREAM, 0);
	if (tmpsock == -1)
		return fail("Failed to create gdb socket");

    sock = tmpsock;

	on = 1;
	if (setsockopt(tmpsock, SOL_SOCKET, SO_REUSEADDR, (char*)&on, sizeof on) < 0)
		return fail("Failed to setsockopt");

	memset(&saddr_server, 0, sizeof saddr_server);
	saddr_server.sin_family = AF_INET;
	saddr_server.sin_port = htons(port);
	saddr_server.sin_addr.s_addr = inet_addr("127.0.0.1");

	dbgprintf("Connecting to gdb server...\n");
	int result = connect(tmpsock, (struct sockaddr *)&saddr_server, sizeof saddr_server);

	if (result < 0)
		return fail("Failed to connect to gdb server");

	dbgprintf("Server connected.\n");
    
	saddr_client.sin_addr.s_addr = ntohl(saddr_client.sin_addr.s_addr);
	/*if (((saddr_client.sin_addr.s_addr >> 24) & 0xff) != 127 ||
	    ((saddr_client.sin_addr.s_addr >> 16) & 0xff) !=   0 ||
	    ((saddr_client.sin_addr.s_addr >>  8) & 0xff) !=   0 ||
	    ((saddr_client.sin_addr.s_addr >>  0) & 0xff) !=   1)
		fail("gdb: incoming connection not from localhost");
	*/
	//close(tmpsock);

    return true;
}


void gdb_deinit(void)
{
	if (sock == -1)
		return;

	closesocket(sock);
	sock = -1;

#ifdef _WIN32
	WSACleanup();
#endif
}

void gdb_kill()
{
    gdb_reply("k");
    // read ack/nak
    gdb_read_command();

    gdb_deinit();
}


void gdb_handle_events(event_callback* callback)
{
	if (sock == -1)
		return;

	while (gdb_data_available())
    {
		gdb_read_command();
		gdb_parse_command(callback);
	}
}

/*
int gdb_signal(u32 s)
{
	if (sock == -1)
		return 1;

	sig = s;

	if (send_signal)
    {
		gdb_handle_signal();
		send_signal = 0;
	}

	return 0;
}
*/

int gdb_bp_x(u32 addr)
{
	if (sock == -1)
		return 0;

	return gdb_bp_check(addr, GDB_BP_TYPE_X);
}

int gdb_bp_r(u32 addr)
{
	if (sock == -1)
		return 0;

	return gdb_bp_check(addr, GDB_BP_TYPE_R);
}

int gdb_bp_w(u32 addr)
{
	if (sock == -1)
		return 0;

	return gdb_bp_check(addr, GDB_BP_TYPE_W);
}

int gdb_bp_a(u32 addr)
{
	if (sock == -1)
		return 0;

	return gdb_bp_check(addr, GDB_BP_TYPE_A);
}