Archipelago » qemu

/*

 * gdb server stub

 * 

 * Copyright (c) 2003 Fabrice Bellard

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#include "vl.h"

#include <sys/socket.h>

#include <netinet/in.h>

#include <netinet/tcp.h>

#include <signal.h>

//#define DEBUG_GDB

enum RSState {

    RS_IDLE,

    RS_GETLINE,

    RS_CHKSUM1,

    RS_CHKSUM2,

};

static int gdbserver_fd;

typedef struct GDBState {

    enum RSState state;

    int fd;

    char line_buf[4096];

    int line_buf_index;

    int line_csum;

} GDBState;

static int get_char(GDBState *s)

{

    uint8_t ch;

    int ret;

    for(;;) {

        ret = read(s->fd, &ch, 1);

        if (ret < 0) {

            if (errno != EINTR && errno != EAGAIN)

                return -1;

        } else if (ret == 0) {

            return -1;

        } else {

            break;

        }

    }

    return ch;

}

static void put_buffer(GDBState *s, const uint8_t *buf, int len)

{

    int ret;

    while (len > 0) {

        ret = write(s->fd, buf, len);

        if (ret < 0) {

            if (errno != EINTR && errno != EAGAIN)

                return;

        } else {

            buf += ret;

            len -= ret;

        }

    }

}

static inline int fromhex(int v)

{

    if (v >= '0' && v <= '9')

        return v - '0';

    else if (v >= 'A' && v <= 'F')

        return v - 'A' + 10;

    else if (v >= 'a' && v <= 'f')

        return v - 'a' + 10;

    else

        return 0;

}

static inline int tohex(int v)

{

    if (v < 10)

        return v + '0';

    else

        return v - 10 + 'a';

}

static void memtohex(char *buf, const uint8_t *mem, int len)

{

    int i, c;

    char *q;

    q = buf;

    for(i = 0; i < len; i++) {

        c = mem[i];

        *q++ = tohex(c >> 4);

        *q++ = tohex(c & 0xf);

    }

    *q = '\0';

}

static void hextomem(uint8_t *mem, const char *buf, int len)

{

    int i;

    for(i = 0; i < len; i++) {

        mem[i] = (fromhex(buf[0]) << 4) | fromhex(buf[1]);

        buf += 2;

    }

}

/* return -1 if error, 0 if OK */

static int put_packet(GDBState *s, char *buf)

{

    char buf1[3];

    int len, csum, ch, i;

#ifdef DEBUG_GDB

    printf("reply='%s'\n", buf);

#endif

    for(;;) {

        buf1[0] = '$';

        put_buffer(s, buf1, 1);

        len = strlen(buf);

        put_buffer(s, buf, len);

        csum = 0;

        for(i = 0; i < len; i++) {

            csum += buf[i];

        }

        buf1[0] = '#';

        buf1[1] = tohex((csum >> 4) & 0xf);

        buf1[2] = tohex((csum) & 0xf);

        put_buffer(s, buf1, 3);

        ch = get_char(s);

        if (ch < 0)

            return -1;

        if (ch == '+')

            break;

    }

    return 0;

}

#if defined(TARGET_I386)

static void to_le32(uint8_t *p, int v)

{

    p[0] = v;

    p[1] = v >> 8;

    p[2] = v >> 16;

    p[3] = v >> 24;

}

static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)

{

    int i, fpus;

    for(i = 0; i < 8; i++) {

        to_le32(mem_buf + i * 4, env->regs[i]);

    }

    to_le32(mem_buf + 8 * 4, env->eip);

    to_le32(mem_buf + 9 * 4, env->eflags);

    to_le32(mem_buf + 10 * 4, env->segs[R_CS].selector);

    to_le32(mem_buf + 11 * 4, env->segs[R_SS].selector);

    to_le32(mem_buf + 12 * 4, env->segs[R_DS].selector);

    to_le32(mem_buf + 13 * 4, env->segs[R_ES].selector);

    to_le32(mem_buf + 14 * 4, env->segs[R_FS].selector);

    to_le32(mem_buf + 15 * 4, env->segs[R_GS].selector);

    /* XXX: convert floats */

    for(i = 0; i < 8; i++) {

        memcpy(mem_buf + 16 * 4 + i * 10, &env->fpregs[i], 10);

    }

    to_le32(mem_buf + 36 * 4, env->fpuc);

    fpus = (env->fpus & ~0x3800) | (env->fpstt & 0x7) << 11;

    to_le32(mem_buf + 37 * 4, fpus);

    to_le32(mem_buf + 38 * 4, 0); /* XXX: convert tags */

    to_le32(mem_buf + 39 * 4, 0); /* fiseg */

    to_le32(mem_buf + 40 * 4, 0); /* fioff */

    to_le32(mem_buf + 41 * 4, 0); /* foseg */

    to_le32(mem_buf + 42 * 4, 0); /* fooff */

    to_le32(mem_buf + 43 * 4, 0); /* fop */

    return 44 * 4;

}

static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)

{

    uint32_t *registers = (uint32_t *)mem_buf;

    int i;

    for(i = 0; i < 8; i++) {

        env->regs[i] = tswapl(registers[i]);

    }

    env->eip = registers[8];

    env->eflags = registers[9];

#if defined(CONFIG_USER_ONLY)

#define LOAD_SEG(index, sreg)\

            if (tswapl(registers[index]) != env->segs[sreg].selector)\

                cpu_x86_load_seg(env, sreg, tswapl(registers[index]));

            LOAD_SEG(10, R_CS);

            LOAD_SEG(11, R_SS);

            LOAD_SEG(12, R_DS);

            LOAD_SEG(13, R_ES);

            LOAD_SEG(14, R_FS);

            LOAD_SEG(15, R_GS);

#endif

}

#elif defined (TARGET_PPC)

static void to_le32(uint32_t *buf, uint32_t v)

{

    uint8_t *p = (uint8_t *)buf;

    p[3] = v;

    p[2] = v >> 8;

    p[1] = v >> 16;

    p[0] = v >> 24;

}

static uint32_t from_le32 (uint32_t *buf)

{

    uint8_t *p = (uint8_t *)buf;

    return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);

}

static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)

{

    uint32_t *registers = (uint32_t *)mem_buf, tmp;

    int i;

    /* fill in gprs */

    for(i = 0; i < 32; i++) {

        to_le32(&registers[i], env->gpr[i]);

    }

    /* fill in fprs */

    for (i = 0; i < 32; i++) {

        to_le32(&registers[(i * 2) + 32], *((uint32_t *)&env->fpr[i]));

        to_le32(&registers[(i * 2) + 33], *((uint32_t *)&env->fpr[i] + 1));

    }

    /* nip, msr, ccr, lnk, ctr, xer, mq */

    to_le32(&registers[96], (uint32_t)env->nip/* - 4*/);

    to_le32(&registers[97], _load_msr(env));

    tmp = 0;

    for (i = 0; i < 8; i++)

        tmp |= env->crf[i] << (32 - ((i + 1) * 4));

    to_le32(&registers[98], tmp);

    to_le32(&registers[99], env->lr);

    to_le32(&registers[100], env->ctr);

    to_le32(&registers[101], _load_xer(env));

    to_le32(&registers[102], 0);

    return 103 * 4;

}

static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)

{

    uint32_t *registers = (uint32_t *)mem_buf;

    int i;

    /* fill in gprs */

    for (i = 0; i < 32; i++) {

        env->gpr[i] = from_le32(&registers[i]);

    }

    /* fill in fprs */

    for (i = 0; i < 32; i++) {

        *((uint32_t *)&env->fpr[i]) = from_le32(&registers[(i * 2) + 32]);

        *((uint32_t *)&env->fpr[i] + 1) = from_le32(&registers[(i * 2) + 33]);

    }

    /* nip, msr, ccr, lnk, ctr, xer, mq */

    env->nip = from_le32(&registers[96]);

    _store_msr(env, from_le32(&registers[97]));

    registers[98] = from_le32(&registers[98]);

    for (i = 0; i < 8; i++)

        env->crf[i] = (registers[98] >> (32 - ((i + 1) * 4))) & 0xF;

    env->lr = from_le32(&registers[99]);

    env->ctr = from_le32(&registers[100]);

    _store_xer(env, from_le32(&registers[101]));

}

#else

static int cpu_gdb_read_registers(CPUState *env, uint8_t *mem_buf)

{

    return 0;

}

static void cpu_gdb_write_registers(CPUState *env, uint8_t *mem_buf, int size)

{

}

#endif

/* port = 0 means default port */

static int gdb_handle_packet(GDBState *s, const char *line_buf)

{

    CPUState *env = cpu_single_env;

    const char *p;

    int ch, reg_size, type;

    char buf[4096];

    uint8_t mem_buf[2000];

    uint32_t *registers;

    uint32_t addr, len;

#ifdef DEBUG_GDB

    printf("command='%s'\n", line_buf);

#endif

    p = line_buf;

    ch = *p++;

    switch(ch) {

    case '?':

        snprintf(buf, sizeof(buf), "S%02x", SIGTRAP);

        put_packet(s, buf);

        break;

    case 'c':

        if (*p != '\0') {

            addr = strtoul(p, (char **)&p, 16);

#if defined(TARGET_I386)

            env->eip = addr;

#elif defined (TARGET_PPC)

            env->nip = addr;

#endif

        }

        vm_start();

        break;

    case 's':

        if (*p != '\0') {

            addr = strtoul(p, (char **)&p, 16);

#if defined(TARGET_I386)

            env->eip = addr;

#elif defined (TARGET_PPC)

            env->nip = addr;

#endif

        }

        cpu_single_step(env, 1);

        vm_start();

        break;

    case 'g':

        reg_size = cpu_gdb_read_registers(env, mem_buf);

        memtohex(buf, mem_buf, reg_size);

        put_packet(s, buf);

        break;

    case 'G':

        registers = (void *)mem_buf;

        len = strlen(p) / 2;

        hextomem((uint8_t *)registers, p, len);

        cpu_gdb_write_registers(env, mem_buf, len);

        put_packet(s, "OK");

        break;

    case 'm':

        addr = strtoul(p, (char **)&p, 16);

        if (*p == ',')

            p++;

        len = strtoul(p, NULL, 16);

        if (cpu_memory_rw_debug(env, addr, mem_buf, len, 0) != 0)

            memset(mem_buf, 0, len);

        memtohex(buf, mem_buf, len);

        put_packet(s, buf);

        break;

    case 'M':

        addr = strtoul(p, (char **)&p, 16);

        if (*p == ',')

            p++;

        len = strtoul(p, (char **)&p, 16);

        if (*p == ',')

            p++;

        hextomem(mem_buf, p, len);

        if (cpu_memory_rw_debug(env, addr, mem_buf, len, 1) != 0)

            put_packet(s, "ENN");

        else

            put_packet(s, "OK");

        break;

    case 'Z':

        type = strtoul(p, (char **)&p, 16);

        if (*p == ',')

            p++;

        addr = strtoul(p, (char **)&p, 16);

        if (*p == ',')

            p++;

        len = strtoul(p, (char **)&p, 16);

        if (type == 0 || type == 1) {

            if (cpu_breakpoint_insert(env, addr) < 0)

                goto breakpoint_error;

            put_packet(s, "OK");

        } else {

        breakpoint_error:

            put_packet(s, "ENN");

        }

        break;

    case 'z':

        type = strtoul(p, (char **)&p, 16);

        if (*p == ',')

            p++;

        addr = strtoul(p, (char **)&p, 16);

        if (*p == ',')

            p++;

        len = strtoul(p, (char **)&p, 16);

        if (type == 0 || type == 1) {

            cpu_breakpoint_remove(env, addr);

            put_packet(s, "OK");

        } else {

            goto breakpoint_error;

        }

        break;

    default:

        //        unknown_command:

        /* put empty packet */

        buf[0] = '\0';

        put_packet(s, buf);

        break;

    }

    return RS_IDLE;

}

static void gdb_vm_stopped(void *opaque, int reason)

{

    GDBState *s = opaque;

    char buf[256];

    int ret;

    /* disable single step if it was enable */

    cpu_single_step(cpu_single_env, 0);

    if (reason == EXCP_DEBUG)

        ret = SIGTRAP;

    else

        ret = 0;

    snprintf(buf, sizeof(buf), "S%02x", ret);

    put_packet(s, buf);

}

static void gdb_read_byte(GDBState *s, int ch)

{

    int i, csum;

    char reply[1];

    if (vm_running) {

        /* when the CPU is running, we cannot do anything except stop

           it when receiving a char */

        vm_stop(EXCP_INTERRUPT);

    } else {

        switch(s->state) {

        case RS_IDLE:

            if (ch == '$') {

                s->line_buf_index = 0;

                s->state = RS_GETLINE;

            }

            break;

        case RS_GETLINE:

            if (ch == '#') {

            s->state = RS_CHKSUM1;

            } else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {

                s->state = RS_IDLE;

            } else {

            s->line_buf[s->line_buf_index++] = ch;

            }

            break;

        case RS_CHKSUM1:

            s->line_buf[s->line_buf_index] = '\0';

            s->line_csum = fromhex(ch) << 4;

            s->state = RS_CHKSUM2;

            break;

        case RS_CHKSUM2:

            s->line_csum |= fromhex(ch);

            csum = 0;

            for(i = 0; i < s->line_buf_index; i++) {

                csum += s->line_buf[i];

            }

            if (s->line_csum != (csum & 0xff)) {

                reply[0] = '-';

                put_buffer(s, reply, 1);

                s->state = RS_IDLE;

            } else {

                reply[0] = '+';

                put_buffer(s, reply, 1);

                s->state = gdb_handle_packet(s, s->line_buf);

            }

            break;

        }

    }

}

static int gdb_can_read(void *opaque)

{

    return 256;

}

static void gdb_read(void *opaque, const uint8_t *buf, int size)

{

    GDBState *s = opaque;

    int i;

    if (size == 0) {

        /* end of connection */

        qemu_del_vm_stop_handler(gdb_vm_stopped, s);

        qemu_del_fd_read_handler(s->fd);

        qemu_free(s);

        vm_start();

    } else {

        for(i = 0; i < size; i++)

            gdb_read_byte(s, buf[i]);

    }

}

static void gdb_accept(void *opaque, const uint8_t *buf, int size)

{

    GDBState *s;

    struct sockaddr_in sockaddr;

    socklen_t len;

    int val, fd;

    for(;;) {

        len = sizeof(sockaddr);

        fd = accept(gdbserver_fd, (struct sockaddr *)&sockaddr, &len);

        if (fd < 0 && errno != EINTR) {

            perror("accept");

            return;

        } else if (fd >= 0) {

            break;

        }

    }

    /* set short latency */

    val = 1;

    setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof(val));

    s = qemu_mallocz(sizeof(GDBState));

    if (!s) {

        close(fd);

        return;

    }

    s->fd = fd;

    fcntl(fd, F_SETFL, O_NONBLOCK);

    /* stop the VM */

    vm_stop(EXCP_INTERRUPT);

    /* start handling I/O */

    qemu_add_fd_read_handler(s->fd, gdb_can_read, gdb_read, s);

    /* when the VM is stopped, the following callback is called */

    qemu_add_vm_stop_handler(gdb_vm_stopped, s);

}

static int gdbserver_open(int port)

{

    struct sockaddr_in sockaddr;

    int fd, val, ret;

    fd = socket(PF_INET, SOCK_STREAM, 0);

    if (fd < 0) {

        perror("socket");

        return -1;

    }

    /* allow fast reuse */

    val = 1;

    setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));

    sockaddr.sin_family = AF_INET;

    sockaddr.sin_port = htons(port);

    sockaddr.sin_addr.s_addr = 0;

    ret = bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr));

    if (ret < 0) {

        perror("bind");

        return -1;

    }

    ret = listen(fd, 0);

    if (ret < 0) {

        perror("listen");

        return -1;

    }

    fcntl(fd, F_SETFL, O_NONBLOCK);

    return fd;

}

int gdbserver_start(int port)

{

    gdbserver_fd = gdbserver_open(port);

    if (gdbserver_fd < 0)

        return -1;

    /* accept connections */

    qemu_add_fd_read_handler(gdbserver_fd, NULL, gdb_accept, NULL);

    return 0;

}