added gdb support to vl

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@288 c046a42c-6fe2-441c-8c8c-71466251a162

3 files changed, 497 insertions, 65 deletions

diff --git a/Makefile b/Makefile
index a83bd74..e3b18f3 100644
--- a/Makefile
+++ b/Makefile
@@ -98,7 +98,7 @@ SRCS:= $(OBJS:.o=.c)
 OBJS+= libqemu.a
 
 # cpu emulator library
-LIBOBJS=thunk.o exec.o translate.o cpu-exec.o 
+LIBOBJS=thunk.o exec.o translate.o cpu-exec.o gdbstub.o
 
 ifeq ($(TARGET_ARCH), i386)
 LIBOBJS+=translate-i386.o op-i386.o helper-i386.o
diff --git a/gdbstub.c b/gdbstub.c
new file mode 100644
index 0000000..2d1f478
--- /dev/null
+++ b/gdbstub.c
@@ -0,0 +1,390 @@
+/*
+ * 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 <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <signal.h>
+
+#include "config.h"
+#ifdef TARGET_I386
+#include "cpu-i386.h"
+#endif
+#ifdef TARGET_ARM
+#include "cpu-arm.h"
+#endif
+#include "thunk.h"
+#include "exec.h"
+
+//#define DEBUG_GDB
+
+int gdbstub_fd = -1;
+
+/* return 0 if OK */
+static int gdbstub_open(int port)
+{
+    struct sockaddr_in sockaddr;
+    socklen_t len;
+    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;
+    }
+    
+    /* now wait for one connection */
+    for(;;) {
+        len = sizeof(sockaddr);
+        gdbstub_fd = accept(fd, (struct sockaddr *)&sockaddr, &len);
+        if (gdbstub_fd < 0 && errno != EINTR) {
+            perror("accept");
+            return -1;
+        } else if (gdbstub_fd >= 0) {
+            break;
+        }
+    }
+    
+    /* set short latency */
+    val = 1;
+    setsockopt(gdbstub_fd, SOL_TCP, TCP_NODELAY, &val, sizeof(val));
+    return 0;
+}
+
+static int get_char(void)
+{
+    uint8_t ch;
+    int ret;
+
+    for(;;) {
+        ret = read(gdbstub_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(const uint8_t *buf, int len)
+{
+    int ret;
+
+    while (len > 0) {
+        ret = write(gdbstub_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 or EOF */
+static int get_packet(char *buf, int buf_size)
+{
+    int ch, len, csum, csum1;
+    char reply[1];
+    
+    for(;;) {
+        for(;;) {
+            ch = get_char();
+            if (ch < 0)
+                return -1;
+            if (ch == '$')
+                break;
+        }
+        len = 0;
+        csum = 0;
+        for(;;) {
+            ch = get_char();
+            if (ch < 0)
+                return -1;
+            if (ch == '#')
+                break;
+            if (len > buf_size - 1)
+                return -1;
+            buf[len++] = ch;
+            csum += ch;
+        }
+        buf[len] = '\0';
+        ch = get_char();
+        if (ch < 0)
+            return -1;
+        csum1 = fromhex(ch) << 4;
+        ch = get_char();
+        if (ch < 0)
+            return -1;
+        csum1 |= fromhex(ch);
+        if ((csum & 0xff) != csum1) {
+            reply[0] = '-';
+            put_buffer(reply, 1);
+        } else {
+            reply[0] = '+';
+            put_buffer(reply, 1);
+            break;
+        }
+    }
+#ifdef DEBUG_GDB
+    printf("command='%s'\n", buf);
+#endif
+    return len;
+}
+
+/* return -1 if error, 0 if OK */
+static int put_packet(char *buf)
+{
+    char buf1[3];
+    int len, csum, ch, i;
+
+#ifdef DEBUG_GDB
+    printf("reply='%s'\n", buf);
+#endif
+
+    for(;;) {
+        buf1[0] = '$';
+        put_buffer(buf1, 1);
+        len = strlen(buf);
+        put_buffer(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(buf1, 3);
+
+        ch = get_char();
+        if (ch < 0)
+            return -1;
+        if (ch == '+')
+            break;
+    }
+    return 0;
+}
+
+static int memory_rw(uint8_t *buf, uint32_t addr, int len, int is_write)
+{
+    int l, flags;
+    uint32_t page;
+
+    while (len > 0) {
+        page = addr & TARGET_PAGE_MASK;
+        l = (page + TARGET_PAGE_SIZE) - addr;
+        if (l > len)
+            l = len;
+        flags = page_get_flags(page);
+        if (!(flags & PAGE_VALID))
+            return -1;
+        if (is_write) {
+            if (!(flags & PAGE_WRITE))
+                return -1;
+            memcpy((uint8_t *)addr, buf, l);
+        } else {
+            if (!(flags & PAGE_READ))
+                return -1;
+            memcpy(buf, (uint8_t *)addr, l);
+        }
+        len -= l;
+        buf += l;
+        addr += l;
+    }
+    return 0;
+}
+
+/* port = 0 means default port */
+int cpu_gdbstub(void *opaque, void (*main_loop)(void *opaque), int port)
+{
+    CPUState *env;
+    const char *p;
+    int ret, ch, nb_regs, i;
+    char buf[4096];
+    uint8_t mem_buf[2000];
+    uint32_t *registers;
+    uint32_t addr, len;
+    
+    printf("Waiting gdb connection on port %d\n", port);
+    if (gdbstub_open(port) < 0)
+        return -1;
+    printf("Connected\n");
+    for(;;) {
+        ret = get_packet(buf, sizeof(buf));
+        if (ret < 0)
+            break;
+        p = buf;
+        ch = *p++;
+        switch(ch) {
+        case '?':
+            snprintf(buf, sizeof(buf), "S%02x", SIGTRAP);
+            put_packet(buf);
+            break;
+        case 'c':
+            main_loop(opaque);
+            snprintf(buf, sizeof(buf), "S%02x", 0);
+            put_packet(buf);
+            break;
+        case 'g':
+            env = cpu_gdbstub_get_env(opaque);
+            registers = (void *)mem_buf;
+#if defined(TARGET_I386)
+            for(i = 0; i < 8; i++) {
+                registers[i] = tswapl(env->regs[i]);
+            }
+            registers[8] = env->eip;
+            registers[9] = env->eflags;
+            registers[10] = env->segs[R_CS].selector;
+            registers[11] = env->segs[R_SS].selector;
+            registers[12] = env->segs[R_DS].selector;
+            registers[13] = env->segs[R_ES].selector;
+            registers[14] = env->segs[R_FS].selector;
+            registers[15] = env->segs[R_GS].selector;
+            nb_regs = 16;
+#endif
+            memtohex(buf, (const uint8_t *)registers, 
+                     sizeof(registers[0]) * nb_regs);
+            put_packet(buf);
+            break;
+        case 'G':
+            env = cpu_gdbstub_get_env(opaque);
+            registers = (void *)mem_buf;
+#if defined(TARGET_I386)
+            hextomem((uint8_t *)registers, p, 16 * 4);
+            for(i = 0; i < 8; i++) {
+                env->regs[i] = tswapl(registers[i]);
+            }
+            env->eip = registers[8];
+            env->eflags = registers[9];
+#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
+            put_packet("OK");
+            break;
+        case 'm':
+            addr = strtoul(p, (char **)&p, 16);
+            if (*p == ',')
+                p++;
+            len = strtoul(p, NULL, 16);
+            if (memory_rw(mem_buf, addr, len, 0) != 0)
+                memset(mem_buf, 0, len);
+            memtohex(buf, mem_buf, len);
+            put_packet(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 (memory_rw(mem_buf, addr, len, 1) != 0)
+                put_packet("ENN");
+            else
+                put_packet("OK");
+            break;
+        default:
+            /* put empty packet */
+            buf[0] = '\0';
+            put_packet(buf);
+            break;
+        }
+    }
+    return 0;
+}
diff --git a/vl.c b/vl.c
index 6cd238b..c9196e5 100644
--- a/vl.c
+++ b/vl.c
@@ -1783,27 +1783,116 @@ static void host_alarm_handler(int host_signum, siginfo_t *info,
     }
 }
 
+/* main execution loop */
+
+CPUState *cpu_gdbstub_get_env(void *opaque)
+{
+    return global_env;
+}
+
+void main_loop(void *opaque)
+{
+    struct pollfd ufds[2], *pf, *serial_ufd, *net_ufd, *gdb_ufd;
+    int ret, n, timeout;
+    uint8_t ch;
+    CPUState *env = global_env;
+
+    for(;;) {
+
+        ret = cpu_x86_exec(env);
+
+        /* if hlt instruction, we wait until the next IRQ */
+        if (ret == EXCP_HLT) 
+            timeout = 10;
+        else
+            timeout = 0;
+        /* poll any events */
+        serial_ufd = NULL;
+        pf = ufds;
+        if (!(serial_ports[0].lsr & UART_LSR_DR)) {
+            serial_ufd = pf;
+            pf->fd = 0;
+            pf->events = POLLIN;
+            pf++;
+        }
+        net_ufd = NULL;
+        if (net_fd > 0 && ne2000_can_receive(&ne2000_state)) {
+            net_ufd = pf;
+            pf->fd = net_fd;
+            pf->events = POLLIN;
+            pf++;
+        }
+        gdb_ufd = NULL;
+        if (gdbstub_fd > 0) {
+            gdb_ufd = pf;
+            pf->fd = gdbstub_fd;
+            pf->events = POLLIN;
+            pf++;
+        }
+
+        ret = poll(ufds, pf - ufds, timeout);
+        if (ret > 0) {
+            if (serial_ufd && (serial_ufd->revents & POLLIN)) {
+                n = read(0, &ch, 1);
+                if (n == 1) {
+                    serial_received_byte(&serial_ports[0], ch);
+                }
+            }
+            if (net_ufd && (net_ufd->revents & POLLIN)) {
+                uint8_t buf[MAX_ETH_FRAME_SIZE];
+
+                n = read(net_fd, buf, MAX_ETH_FRAME_SIZE);
+                if (n > 0) {
+                    if (n < 60) {
+                        memset(buf + n, 0, 60 - n);
+                        n = 60;
+                    }
+                    ne2000_receive(&ne2000_state, buf, n);
+                }
+            }
+            if (gdb_ufd && (gdb_ufd->revents & POLLIN)) {
+                uint8_t buf[1];
+                /* stop emulation if requested by gdb */
+                n = read(gdbstub_fd, buf, 1);
+                if (n == 1)
+                    break;
+            }
+        }
+
+        /* timer IRQ */
+        if (timer_irq_pending) {
+            pic_set_irq(0, 1);
+            pic_set_irq(0, 0);
+            timer_irq_pending = 0;
+        }
+
+        pic_handle_irq();
+    }
+}
+
 void help(void)
 {
     printf("Virtual Linux version " QEMU_VERSION ", Copyright (c) 2003 Fabrice Bellard\n"
-           "usage: vl [-h] bzImage initrd [kernel parameters...]\n"
+           "usage: vl [options] bzImage initrd [kernel parameters...]\n"
            "\n"
            "'bzImage' is a Linux kernel image (PAGE_OFFSET must be defined\n"
            "to 0x90000000 in asm/page.h and arch/i386/vmlinux.lds)\n"
            "'initrd' is an initrd image\n"
            "-m megs   set virtual RAM size to megs MB\n"
            "-n script set network init script [default=%s]\n"
+           "-s        wait gdb connection to port %d\n"
+           "-p port   change gdb connection port\n"
            "-d        output log in /tmp/vl.log\n"
            "\n"
            "During emulation, use C-a h to get terminal commands:\n",
-           DEFAULT_NETWORK_SCRIPT);
+           DEFAULT_NETWORK_SCRIPT, DEFAULT_GDBSTUB_PORT);
     term_print_help();
     exit(1);
 }
 
 int main(int argc, char **argv)
 {
-    int c, ret, initrd_size, i;
+    int c, ret, initrd_size, i, use_gdbstub, gdbstub_port;
     struct linux_params *params;
     struct sigaction act;
     struct itimerval itv;
@@ -1815,8 +1904,10 @@ int main(int argc, char **argv)
     
     phys_ram_size = 32 * 1024 * 1024;
     pstrcpy(network_script, sizeof(network_script), DEFAULT_NETWORK_SCRIPT);
+    use_gdbstub = 0;
+    gdbstub_port = DEFAULT_GDBSTUB_PORT;
     for(;;) {
-        c = getopt(argc, argv, "hm:dn:");
+        c = getopt(argc, argv, "hm:dn:sp:");
         if (c == -1)
             break;
         switch(c) {
@@ -1834,6 +1925,12 @@ int main(int argc, char **argv)
         case 'n':
             pstrcpy(network_script, sizeof(network_script), optarg);
             break;
+        case 's':
+            use_gdbstub = 1;
+            break;
+        case 'p':
+            gdbstub_port = atoi(optarg);
+            break;
         }
     }
     if (optind + 1 >= argc)
@@ -1974,66 +2071,11 @@ int main(int argc, char **argv)
     getitimer(ITIMER_REAL, &itv);
     pit_min_timer_count = ((uint64_t)itv.it_interval.tv_usec * PIT_FREQ) / 
         1000000;
-
-    for(;;) {
-        struct pollfd ufds[2], *pf, *serial_ufd, *net_ufd;
-        int ret, n, timeout;
-        uint8_t ch;
-
-        ret = cpu_x86_exec(env);
-
-        /* if hlt instruction, we wait until the next IRQ */
-        if (ret == EXCP_HLT) 
-            timeout = 10;
-        else
-            timeout = 0;
-        /* poll any events */
-        serial_ufd = NULL;
-        net_ufd = NULL;
-        pf = ufds;
-        if (!(serial_ports[0].lsr & UART_LSR_DR)) {
-            serial_ufd = pf;
-            pf->fd = 0;
-            pf->events = POLLIN;
-            pf++;
-        }
-        if (net_fd > 0 && ne2000_can_receive(&ne2000_state)) {
-            net_ufd = pf;
-            pf->fd = net_fd;
-            pf->events = POLLIN;
-            pf++;
-        }
-        ret = poll(ufds, pf - ufds, timeout);
-        if (ret > 0) {
-            if (serial_ufd && (serial_ufd->revents & POLLIN)) {
-                n = read(0, &ch, 1);
-                if (n == 1) {
-                    serial_received_byte(&serial_ports[0], ch);
-                }
-            }
-            if (net_ufd && (net_ufd->revents & POLLIN)) {
-                uint8_t buf[MAX_ETH_FRAME_SIZE];
-
-                n = read(net_fd, buf, MAX_ETH_FRAME_SIZE);
-                if (n > 0) {
-                    if (n < 60) {
-                        memset(buf + n, 0, 60 - n);
-                        n = 60;
-                    }
-                    ne2000_receive(&ne2000_state, buf, n);
-                }
-            }
-        }
-
-        /* timer IRQ */
-        if (timer_irq_pending) {
-            pic_set_irq(0, 1);
-            pic_set_irq(0, 0);
-            timer_irq_pending = 0;
-        }
-
-        pic_handle_irq();
+    
+    if (use_gdbstub) {
+        cpu_gdbstub(NULL, main_loop, gdbstub_port);
+    } else {
+        main_loop(NULL);
     }
-
     return 0;
 }