Forward-port the old mdstart tool from the Gentoo Busybox-1.1.3.
Only fires the RAID_AUTORUN ioctl on existing /dev/md nodes.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>

diff -Nuar --exclude '*.orig' busybox-1.7.4/include/applets.h busybox-1.7.4+gentoo/include/applets.h
--- busybox-1.7.4/include/applets.h	2007-09-03 04:48:46.000000000 -0700
+++ busybox-1.7.4+gentoo/include/applets.h	2008-03-11 10:25:43.000000000 -0700
@@ -222,6 +222,7 @@
 USE_MATCHPATHCON(APPLET(matchpathcon, _BB_DIR_USR_SBIN, _BB_SUID_NEVER))
 USE_MD5SUM(APPLET_ODDNAME(md5sum, md5_sha1_sum, _BB_DIR_USR_BIN, _BB_SUID_NEVER, md5sum))
 USE_MDEV(APPLET(mdev, _BB_DIR_SBIN, _BB_SUID_NEVER))
+USE_MDSTART(APPLET(mdstart, _BB_DIR_SBIN, _BB_SUID_NEVER))
 USE_MESG(APPLET(mesg, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
 USE_MKDIR(APPLET_NOFORK(mkdir, mkdir, _BB_DIR_BIN, _BB_SUID_NEVER, mkdir))
 //USE_MKE2FS(APPLET(mke2fs, _BB_DIR_SBIN, _BB_SUID_NEVER))
diff -Nuar --exclude '*.orig' busybox-1.7.4/include/usage.h busybox-1.7.4+gentoo/include/usage.h
--- busybox-1.7.4/include/usage.h	2007-09-03 04:48:46.000000000 -0700
+++ busybox-1.7.4+gentoo/include/usage.h	2008-03-11 10:19:04.000000000 -0700
@@ -2072,6 +2072,11 @@
        "the last line match .* to override this.)\n\n" \
 	)
 
+#define mdstart_trivial_usage \
+	"{[PARTITION] MD-NODE}..."
+#define mdstart_full_usage \
+	"Run the RAID_AUTORUN ioctl on the given MD number"
+	
 #define mesg_trivial_usage \
        "[y|n]"
 #define mesg_full_usage \
diff -Nuar --exclude '*.orig' busybox-1.7.4/util-linux/Config.in busybox-1.7.4+gentoo/util-linux/Config.in
--- busybox-1.7.4/util-linux/Config.in	2007-09-03 04:48:56.000000000 -0700
+++ busybox-1.7.4+gentoo/util-linux/Config.in	2008-03-11 10:26:20.000000000 -0700
@@ -305,6 +305,13 @@
 	  /lib/firmware/ and if it exists, send it to the kernel for
 	  loading into the hardware.
 
+config MDSTART
+	bool "mdstart"
+	default n
+	help
+	  Allows you to autostart /dev/md devices if using an initramfs to
+	  boot.
+
 config MKSWAP
 	bool "mkswap"
 	default n
diff -Nuar --exclude '*.orig' busybox-1.7.4/util-linux/Kbuild busybox-1.7.4+gentoo/util-linux/Kbuild
--- busybox-1.7.4/util-linux/Kbuild	2007-09-03 04:48:56.000000000 -0700
+++ busybox-1.7.4+gentoo/util-linux/Kbuild	2008-03-11 10:28:47.000000000 -0700
@@ -18,6 +18,7 @@
 lib-$(CONFIG_IPCRM)		+=ipcrm.o
 lib-$(CONFIG_IPCS)		+=ipcs.o
 lib-$(CONFIG_LOSETUP)		+=losetup.o
+lib-$(CONFIG_MDSTART)       +=mdStart.o
 lib-$(CONFIG_MDEV)		+=mdev.o
 lib-$(CONFIG_MKFS_MINIX)	+=mkfs_minix.o
 lib-$(CONFIG_MKSWAP)		+=mkswap.o
diff -Nuar --exclude '*.orig' busybox-1.7.4/util-linux/mdStart.c busybox-1.7.4+gentoo/util-linux/mdStart.c
--- busybox-1.7.4/util-linux/mdStart.c	1969-12-31 16:00:00.000000000 -0800
+++ busybox-1.7.4+gentoo/util-linux/mdStart.c	2008-03-11 10:19:04.000000000 -0700
@@ -0,0 +1,59 @@
+/*
+ * Linux 2.6(+) RAID Autostarter
+ *
+ * Copyright (C) 2005 by Tim Yamin <plasmaroo@gentoo.org> <plasm@roo.me.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <linux/major.h>
+#include <linux/raid/md_u.h>
+
+extern int
+mdstart_main(int argc, char *argv[])
+{
+	int i, fd, part = 0, retval = 0;
+
+	if(argc < 2)
+	{
+		bb_show_usage();
+	}
+
+	for(i = 1; i < argc; i++)
+	{
+		if(sscanf(argv[i], "%d", &part) == 1)
+			continue;
+
+		fd = open(argv[i], 0, 0);
+		if (fd >= 0)
+		{
+			ioctl(fd, RAID_AUTORUN, part);
+			close(fd);
+		} else
+		{
+			printf("Error: Failed to open %s!\n", argv[i]);
+			retval=1;
+		}
+
+		part = 0;
+	}
+
+	return retval;
+}