init.c

Android 一些工具

    char name[16];
    int number;
} mtd_part_map[MAX_MTD_PARTITIONS];

static int mtd_part_count = -1;

static void find_mtd_partitions(void)
{
    int fd;
    char buf[1024];
    char *pmtdbufp;
    ssize_t pmtdsize;
    int r;

    fd = open("/proc/mtd", O_RDONLY);
    if (fd < 0)
        return;

    buf[sizeof(buf) - 1] = '\0';
    pmtdsize = read(fd, buf, sizeof(buf) - 1);
    pmtdbufp = buf;
    while (pmtdsize > 0) {
        int mtdnum, mtdsize, mtderasesize;
        char mtdname[16];
        mtdname[0] = '\0';
        mtdnum = -1;
        r = sscanf(pmtdbufp, "mtd%d: %x %x %15s",
                   &mtdnum, &mtdsize, &mtderasesize, mtdname);
        if ((r == 4) && (mtdname[0] == '"')) {
            char *x = strchr(mtdname + 1, '"');
            if (x) {
                *x = 0;
            }
            INFO("mtd partition %d, %s\n", mtdnum, mtdname + 1);
            if (mtd_part_count < MAX_MTD_PARTITIONS) {
                strcpy(mtd_part_map[mtd_part_count].name, mtdname + 1);
                mtd_part_map[mtd_part_count].number = mtdnum;
                mtd_part_count++;
            } else {
                ERROR("too many mtd partitions\n");
            }
        }
        while (pmtdsize > 0 && *pmtdbufp != '\n') {
            pmtdbufp++;
            pmtdsize--;
        }
        if (pmtdsize > 0) {
            pmtdbufp++;
            pmtdsize--;
        }
    }
    close(fd);
}

int mtd_name_to_number(const char *name) 
{
    int n;
    if (mtd_part_count < 0) {
        mtd_part_count = 0;
        find_mtd_partitions();
    }
    for (n = 0; n < mtd_part_count; n++) {
        if (!strcmp(name, mtd_part_map[n].name)) {
            return mtd_part_map[n].number;
        }
    }
    return -1;
}

static void import_kernel_nv(char *name, int in_qemu)
{
    char *value = strchr(name, '=');

    if (value == 0) return;
    *value++ = 0;
    if (*name == 0) return;

    if (!in_qemu)
    {
        /* on a real device, white-list the kernel options */
        if (!strcmp(name,"qemu")) {
            strlcpy(qemu, value, sizeof(qemu));
        } else if (!strcmp(name,"androidboot.console")) {
            strlcpy(console, value, sizeof(console));
        } else if (!strcmp(name,"androidboot.mode")) {
            strlcpy(bootmode, value, sizeof(bootmode));
        } else if (!strcmp(name,"androidboot.serialno")) {
            strlcpy(serialno, value, sizeof(serialno));
        } else if (!strcmp(name,"androidboot.baseband")) {
            strlcpy(baseband, value, sizeof(baseband));
        } else if (!strcmp(name,"androidboot.carrier")) {
            strlcpy(carrier, value, sizeof(carrier));
        } else if (!strcmp(name,"androidboot.bootloader")) {
            strlcpy(bootloader, value, sizeof(bootloader));
        } else if (!strcmp(name,"androidboot.hardware")) {
            strlcpy(hardware, value, sizeof(hardware));
        } else {
            qemu_cmdline(name, value);
        }
    } else {
        /* in the emulator, export any kernel option with the
         * ro.kernel. prefix */
        char  buff[32];
        int   len = snprintf( buff, sizeof(buff), "ro.kernel.%s", name );
        if (len < (int)sizeof(buff)) {
            property_set( buff, value );
        }
    }
}

static void import_kernel_cmdline(int in_qemu)
{
    char cmdline[1024];
    char *ptr;
    int fd;

    fd = open("/proc/cmdline", O_RDONLY);
    if (fd >= 0) {
        int n = read(fd, cmdline, 1023);
        if (n < 0) n = 0;

        /* get rid of trailing newline, it happens */
        if (n > 0 && cmdline[n-1] == '\n') n--;

        cmdline[n] = 0;
        close(fd);
    } else {
        cmdline[0] = 0;
    }

    ptr = cmdline;
    while (ptr && *ptr) {
        char *x = strchr(ptr, ' ');
        if (x != 0) *x++ = 0;
        import_kernel_nv(ptr, in_qemu);
        ptr = x;
    }

        /* don't expose the raw commandline to nonpriv processes */
    chmod("/proc/cmdline", 0440);
}

static void get_hardware_name(void)
{
    char data[1024];
    int fd, n;
    char *x, *hw, *rev;

    /* Hardware string was provided on kernel command line */
    if (hardware[0])
        return;

    fd = open("/proc/cpuinfo", O_RDONLY);
    if (fd < 0) return;

    n = read(fd, data, 1023);
    close(fd);
    if (n < 0) return;

    data[n] = 0;
    hw = strstr(data, "\nHardware");
    rev = strstr(data, "\nRevision");

    if (hw) {
        x = strstr(hw, ": ");
        if (x) {
            x += 2;
            n = 0;
            while (*x && !isspace(*x)) {
                hardware[n++] = tolower(*x);
                x++;
                if (n == 31) break;
            }
            hardware[n] = 0;
        }
    }

    if (rev) {
        x = strstr(rev, ": ");
        if (x) {
            revision = strtoul(x + 2, 0, 16);
        }
    }
}

static void drain_action_queue(void)
{
    struct listnode *node;
    struct command *cmd;
    struct action *act;
    int ret;

    while ((act = action_remove_queue_head())) {
        INFO("processing action %p (%s)\n", act, act->name);
        list_for_each(node, &act->commands) {
            cmd = node_to_item(node, struct command, clist);
            ret = cmd->func(cmd->nargs, cmd->args);
            INFO("command '%s' r=%d\n", cmd->args[0], ret);
        }
    }
}

void open_devnull_stdio(void)
{
    int fd;
    static const char *name = "/dev/__null__";
    if (mknod(name, S_IFCHR | 0600, (1 << 8) | 3) == 0) {
        fd = open(name, O_RDWR);
        unlink(name);
        if (fd >= 0) {
            dup2(fd, 0);
            dup2(fd, 1);
            dup2(fd, 2);
            if (fd > 2) {
                close(fd);
            }
            return;
        }
    }

    exit(1);
}

int main(int argc, char **argv)
{
    int device_fd = -1;
    int property_set_fd = -1;
    int signal_recv_fd = -1;
    int s[2];
    int fd;
    struct sigaction act;
    char tmp[PROP_VALUE_MAX];
    struct pollfd ufds[4];
    char *tmpdev;

    act.sa_handler = sigchld_handler;
    act.sa_flags = SA_NOCLDSTOP;
    act.sa_mask = 0;
    act.sa_restorer = NULL;
    sigaction(SIGCHLD, &act, 0);

    /* clear the umask */
    umask(0);

        /* Get the basic filesystem setup we need put
         * together in the initramdisk on / and then we'll
         * let the rc file figure out the rest.
         */
    mkdir("/dev", 0755);
    mkdir("/proc", 0755);
    mkdir("/sys", 0755);

    mount("tmpfs", "/dev", "tmpfs", 0, "mode=0755");
    mkdir("/dev/pts", 0755);
    mkdir("/dev/socket", 0755);
    mount("devpts", "/dev/pts", "devpts", 0, NULL);
    mount("proc", "/proc", "proc", 0, NULL);
    mount("sysfs", "/sys", "sysfs", 0, NULL);

        /* We must have some place other than / to create the
         * device nodes for kmsg and null, otherwise we won't
         * be able to remount / read-only later on.
         * Now that tmpfs is mounted on /dev, we can actually
         * talk to the outside world.
         */
    open_devnull_stdio();
    log_init();
    
    INFO("reading config file\n");
    parse_config_file("/init.rc");

    /* pull the kernel commandline and ramdisk properties file in */
    qemu_init();
    import_kernel_cmdline(0);

    get_hardware_name();
    snprintf(tmp, sizeof(tmp), "/init.%s.rc", hardware);
    parse_config_file(tmp);

    action_for_each_trigger("early-init", action_add_queue_tail);
    drain_action_queue();

    INFO("device init\n");
    device_fd = device_init();

    property_init();

    if (console[0]) {
        snprintf(tmp, sizeof(tmp), "/dev/%s", console);
        console_name = strdup(tmp);
    }

    fd = open(console_name, O_RDWR);
    if (fd >= 0)
        have_console = 1;
    close(fd);

    if( load_565rle_image(INIT_IMAGE_FILE) ) {
	fd = open("/dev/tty0", O_WRONLY);
	if (fd >= 0) {
	    const char *msg;
            msg = "\n"
		"\n"
		"\n"
		"\n"
		"\n"
		"\n"
		"\n"  // console is 40 cols x 30 lines
		"\n"
		"\n"
		"\n"
		"\n"
		"\n"
		"\n"
		"\n"
		"             A N D R O I D ";
	    write(fd, msg, strlen(msg));
	    close(fd);
	}
    }

    if (qemu[0])
        import_kernel_cmdline(1); 

    if (!strcmp(bootmode,"factory"))
        property_set("ro.factorytest", "1");
    else if (!strcmp(bootmode,"factory2"))
        property_set("ro.factorytest", "2");
    else
        property_set("ro.factorytest", "0");

    property_set("ro.serialno", serialno[0] ? serialno : "");
    property_set("ro.bootmode", bootmode[0] ? bootmode : "unknown");
    property_set("ro.baseband", baseband[0] ? baseband : "unknown");
    property_set("ro.carrier", carrier[0] ? carrier : "unknown");
    property_set("ro.bootloader", bootloader[0] ? bootloader : "unknown");

    property_set("ro.hardware", hardware);
    snprintf(tmp, PROP_VALUE_MAX, "%d", revision);
    property_set("ro.revision", tmp);

        /* execute all the boot actions to get us started */
    action_for_each_trigger("init", action_add_queue_tail);
    drain_action_queue();

        /* read any property files on system or data and
         * fire up the property service.  This must happen
         * after the ro.foo properties are set above so
         * that /data/local.prop cannot interfere with them.
         */
    property_set_fd = start_property_service();

    /* create a signalling mechanism for the sigchld handler */
    if (socketpair(AF_UNIX, SOCK_STREAM, 0, s) == 0) {
        signal_fd = s[0];
        signal_recv_fd = s[1];
        fcntl(s[0], F_SETFD, FD_CLOEXEC);
        fcntl(s[0], F_SETFL, O_NONBLOCK);
        fcntl(s[1], F_SETFD, FD_CLOEXEC);
        fcntl(s[1], F_SETFL, O_NONBLOCK);
    }

    /* make sure we actually have all the pieces we need */
    if ((device_fd < 0) ||
        (property_set_fd < 0) ||
        (signal_recv_fd < 0)) {
        ERROR("init startup failure\n");
        return 1;
    }

    /* execute all the boot actions to get us started */
    action_for_each_trigger("early-boot", action_add_queue_tail);
    action_for_each_trigger("boot", action_add_queue_tail);
    drain_action_queue();

        /* run all property triggers based on current state of the properties */
    queue_all_property_triggers();
    drain_action_queue();

        /* enable property triggers */   
    property_triggers_enabled = 1;     

    ufds[0].fd = device_fd;
    ufds[0].events = POLLIN;
    ufds[1].fd = property_set_fd;
    ufds[1].events = POLLIN;
    ufds[2].fd = signal_recv_fd;
    ufds[2].events = POLLIN;

#if BOOTCHART
    if (bootchart_init() < 0)
        ERROR("bootcharting init failure\n");
    else {
        NOTICE("bootcharting started\n");
        bootchart_count = BOOTCHART_MAX_COUNT;
    }
#endif

    for(;;) {
        int nr, timeout = -1;

        ufds[0].revents = 0;
        ufds[1].revents = 0;
        ufds[2].revents = 0;

        drain_action_queue();
        restart_processes();

        if (process_needs_restart) {
            timeout = (process_needs_restart - gettime()) * 1000;
            if (timeout < 0)
                timeout = 0;
        }

#if BOOTCHART
        if (bootchart_count > 0) {
            if (timeout < 0 || timeout > BOOTCHART_POLLING_MS)
                timeout = BOOTCHART_POLLING_MS;
            if (bootchart_step() < 0 || --bootchart_count == 0) {
                bootchart_finish();
                bootchart_count = 0;
            }
        }
#endif
        nr = poll(ufds, 3, timeout);
        if (nr <= 0)
            continue;

        if (ufds[2].revents == POLLIN) {
            /* we got a SIGCHLD - reap and restart as needed */
            read(signal_recv_fd, tmp, sizeof(tmp));
            while (!wait_for_one_process(0))
                ;
            continue;
        }

        if (ufds[0].revents == POLLIN)
            handle_device_fd(device_fd);

        if (ufds[1].revents == POLLIN)
            handle_property_set_fd(property_set_fd);
    }

    return 0;
}