- dropped, use mdadm instead

[packages/busybox.git] / busybox-switchroot.patch

diff -urN busybox-1.00-rc3.org/include/applets.h busybox-1.00-rc3/include/applets.h
--- busybox-1.00-rc3.org/include/applets.h	2004-09-25 18:10:24.215527160 +0200
+++ busybox-1.00-rc3/include/applets.h	2004-09-25 19:07:03.622283988 +0200
@@ -547,6 +547,9 @@
 #ifdef CONFIG_SWAPONOFF
 	APPLET(swapon, swap_on_off_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
 #endif
+#ifdef CONFIG_SWITCHROOT
+	APPLET(switchroot, switchroot_main, _BB_DIR_SBIN, _BB_SUID_NEVER)
+#endif
 #ifdef CONFIG_SYNC
 	APPLET(sync, sync_main, _BB_DIR_BIN, _BB_SUID_NEVER)
 #endif
diff -urN busybox-1.00-rc3.org/include/usage.h busybox-1.00-rc3/include/usage.h
--- busybox-1.00-rc3.org/include/usage.h	2004-09-25 18:10:24.213527588 +0200
+++ busybox-1.00-rc3/include/usage.h	2004-09-25 19:09:49.403769193 +0200
@@ -2261,6 +2261,11 @@
 	"Options:\n" \
 	"\t-a\tStart swapping on all swap devices"
 
+#define switchroot_trivial_usage \
+	"NEW_ROOT"
+#define switchroot_full_usage \
+	"Make NEW_ROOT the new root file system."
+ 
 #define sync_trivial_usage \
 	""
 #define sync_full_usage \
diff -urN busybox-1.00-rc3.org/util-linux/Config.in busybox-1.00-rc3/util-linux/Config.in
--- busybox-1.00-rc3.org/util-linux/Config.in	2004-09-25 18:10:25.736201391 +0200
+++ busybox-1.00-rc3/util-linux/Config.in	2004-09-25 18:30:59.861818921 +0200
@@ -261,6 +261,12 @@
 	  of wild and crazy things with your Linux system and is far more
 	  powerful than 'chroot'.
 
+config CONFIG_SWITCHROOT
+	bool "switchroot"
+	default n
+	help
+	  Utility for changing root (like 'chroot' but) for initramfs.
+
 config CONFIG_RDATE
 	bool "rdate"
 	default n
diff -urN busybox-1.00-rc3.org/util-linux/Makefile.in busybox-1.00-rc3/util-linux/Makefile.in
--- busybox-1.00-rc3.org/util-linux/Makefile.in	2004-09-25 18:10:25.771193895 +0200
+++ busybox-1.00-rc3/util-linux/Makefile.in	2004-09-25 18:31:52.266592428 +0200
@@ -41,6 +41,7 @@
 UTILLINUX-$(CONFIG_RAID_START)		+=raid_start.o
 UTILLINUX-$(CONFIG_NFSMOUNT)		+=nfsmount.o
 UTILLINUX-$(CONFIG_PIVOT_ROOT)		+=pivot_root.o
+UTILLINUX-$(CONFIG_SWITCHROOT)		+=switchroot.o
 UTILLINUX-$(CONFIG_RDATE)		+=rdate.o
 UTILLINUX-$(CONFIG_SWAPONOFF)		+=swaponoff.o
 UTILLINUX-$(CONFIG_UMOUNT)		+=umount.o
diff -urN busybox-1.00-rc3.org/util-linux/switchroot.c busybox-1.00-rc3/util-linux/switchroot.c
--- busybox-1.00-rc3.org/util-linux/switchroot.c	1970-01-01 01:00:00.000000000 +0100
+++ busybox-1.00-rc3/util-linux/switchroot.c	2004-09-25 19:03:58.933849154 +0200
@@ -0,0 +1,208 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * switchroot.c - Change root file system (initramfs).
+ * based on GPL v2 nash from RH.
+ * 
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/mount.h>
+#include "busybox.h"
+
+#ifndef	MS_MOVE
+#define	MS_MOVE	8192
+#endif
+
+#define	MAX_INIT_ARGS	32
+
+char * getArg(char * cmd, char * end, char ** arg) {
+    char quote = '\0';
+
+    if (cmd >= end) return NULL;
+
+    while (isspace(*cmd) && cmd < end) cmd++;
+    if (cmd >= end) return NULL;
+
+    if (*cmd == '"')
+        cmd++, quote = '"';
+    else if (*cmd == '\'')
+        cmd++, quote = '\'';
+
+    if (quote) {
+        *arg = cmd;
+
+        /* This doesn't support \ escapes */
+        while (cmd < end && *cmd != quote) cmd++;
+
+        if (cmd == end) {
+            bb_error_msg("error: quote mismatch for %s\n", *arg);
+            return NULL;
+        }
+
+        *cmd = '\0';
+        cmd++;
+    } else {
+        *arg = cmd;
+        while (!isspace(*cmd) && cmd < end) cmd++;
+        *cmd = '\0';
+    }
+
+    cmd++;
+
+    while (isspace(*cmd)) cmd++;
+
+    return cmd;
+}
+
+#ifdef __powerpc__
+#define CMDLINESIZE 256
+#else
+#define CMDLINESIZE 1024
+#endif
+
+/* get the contents of the kernel command line from /proc/cmdline */
+static char * getKernelCmdLine(void) {
+    int fd, i;
+    char * buf;
+
+    fd = open("/proc/cmdline", O_RDONLY, 0);
+    if (fd < 0) {
+        bb_error_msg("getKernelCmdLine: failed to open /proc/cmdline: %d\n", errno);
+        return NULL;
+    }
+
+    buf = malloc(CMDLINESIZE);
+    if (!buf)
+        return buf;
+
+    i = read(fd, buf, CMDLINESIZE);
+    if (i < 0) {
+        bb_error_msg("getKernelCmdLine: failed to read /proc/cmdline: %d\n", errno);
+        close(fd);
+        return NULL;
+    }
+
+    close(fd);
+    if (i == 0)
+        buf[0] = '\0';
+    else
+        buf[i - 1] = '\0';
+    return buf;
+}
+
+/* get the start of a kernel arg "arg".  returns everything after it
+ * (useful for things like getting the args to init=).  so if you only
+ * want one arg, you need to terminate it at the n */
+static char * getKernelArg(char * arg) {
+    char * start, * cmdline;
+
+    cmdline = start = getKernelCmdLine();
+    if (start == NULL) return NULL;
+    while (*start) {
+        if (isspace(*start)) {
+            start++;
+            continue;
+        }
+        if (strncmp(start, arg, strlen(arg)) == 0) {
+            return start + strlen(arg);
+        }
+        while (*++start && !isspace(*start))
+            ;
+    }
+
+    return NULL;
+}
+
+int switchroot_main(int argc, char **argv) {
+    char * new;
+    const char * initprogs[] = { "/sbin/init", "/etc/init",
+                                 "/bin/init", "/bin/sh", NULL };
+    char * init, * cmdline = NULL;
+    char ** initargs;
+    int fd, i = 0;
+
+    if (argc != 1)
+		bb_show_usage();
+
+	new = argv[1];
+
+    if (chdir(new)) {
+	    bb_perror_msg_and_die("chdir(%s) failed: %d\n", new, errno);
+    }
+
+    if ((fd = open("/dev/console", O_RDWR)) < 0) {
+		bb_error_msg("ERROR opening /dev/console!!!!: %d\n", errno);
+    }
+
+    if (dup2(fd, 0) != 0) bb_error_msg("error dup2'ing fd of %d to 0\n", fd);
+    if (dup2(fd, 1) != 1) bb_error_msg("error dup2'ing fd of %d to 1\n", fd);
+    if (dup2(fd, 2) != 2) bb_error_msg("error dup2'ing fd of %d to 2\n", fd);
+    if (fd > 2)
+        close(fd);
+
+    init = getKernelArg("init=");
+    if (init == NULL)
+        cmdline = getKernelCmdLine();
+
+    if (mount(".", "/", NULL, MS_MOVE, NULL)) {
+	    bb_perror_msg_and_die("switchroot: mount failed: %d\n", errno);
+    }
+
+    if (chroot(".") || chdir("/")) {
+        bb_perror_msg_and_die("switchroot: chroot() failed: %d\n", errno);
+    }
+
+    if (init == NULL) {
+        int j;
+        for (j = 0; initprogs[j] != NULL; j++) {
+            if (!access(initprogs[j], X_OK)) {
+                init = strdup(initprogs[j]);
+                break;
+            }
+        }
+    }
+
+    initargs = (char **)malloc(sizeof(char *)*(MAX_INIT_ARGS+1));
+    if (cmdline && init) {
+        initargs[i++] = strdup(init);
+    } else {
+        cmdline = init;
+        initargs[0] = NULL;
+    }
+
+    if (cmdline != NULL) {
+        char * chptr, * start;
+
+        start = chptr = cmdline;
+        for (; (i < MAX_INIT_ARGS) && (*start != '\0'); i++) {
+            while (*chptr && !isspace(*chptr)) chptr++;
+            if (*chptr != '\0') *(chptr++) = '\0';
+            initargs[i] = strdup(start);
+            start = chptr;
+        }
+    }
+
+    initargs[i] = NULL;
+
+    if (access(initargs[0], X_OK)) {
+		bb_error_msg("WARNING: can't access %s\n", initargs[0]);
+    }
+    execv(initargs[0], initargs);
+	bb_error_msg_and_die("exec of init (%s) failed!!!: %d\n", initargs[0], errno);
+    return 1;
+}
+
+/*
+Local Variables:
+c-file-style: "linux"
+c-basic-offset: 4
+tab-width: 4
+End:
+*/