diff --git a/sys/boot/alpha/libalpha/bootinfo.c b/sys/boot/alpha/libalpha/bootinfo.c
index f4318c952daf..fa0842b59169 100644
--- a/sys/boot/alpha/libalpha/bootinfo.c
+++ b/sys/boot/alpha/libalpha/bootinfo.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: bootinfo.c,v 1.4 1999/03/08 11:05:42 dcs Exp $
+ *	$Id: bootinfo.c,v 1.6 1999/03/20 14:13:09 dcs Exp $
  */
 
 #include <stand.h>
@@ -153,12 +153,30 @@ int
 bi_load(struct bootinfo_v1 *bi, vm_offset_t *ffp_save,
 	struct loaded_module *mp)
 {
+    char			*rootdevname;
+    struct alpha_devdesc	*rootdev;
     struct loaded_module	*xp;
     vm_offset_t			addr, bootinfo_addr;
     u_int			pad;
     vm_offset_t			ssym, esym;
     struct module_metadata	*md;
 
+    /* 
+     * Allow the environment variable 'rootdev' to override the supplied device 
+     * This should perhaps go to MI code and/or have $rootdev tested/set by
+     * MI code before launching the kernel.
+     */
+    rootdevname = getenv("rootdev");
+    alpha_getdev((void **)(&rootdev), rootdevname, NULL);
+    if (rootdev == NULL) {		/* bad $rootdev/$currdev */
+	printf("can't determine root device\n");
+	return(EINVAL);
+    }
+
+    /* Try reading the /etc/fstab file to select the root device */
+    getrootmount(alpha_fmtdev((void *)rootdev));
+    free(rootdev);
+
     ssym = esym = 0;
     if ((md = mod_findmetadata(mp, MODINFOMD_SSYM)) != NULL)
 	ssym = *((vm_offset_t *)&(md->md_data));
diff --git a/sys/boot/common/boot.c b/sys/boot/common/boot.c
index 28accc38ce63..70b467144636 100644
--- a/sys/boot/common/boot.c
+++ b/sys/boot/common/boot.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: boot.c,v 1.12 1999/05/30 10:45:03 dfr Exp $
+ *	$Id: boot.c,v 1.13 1999/07/15 20:40:52 n_hibma Exp $
  */
 
 /*
@@ -262,3 +262,71 @@ getbootfile(int try)
     return(name);
 }
 
+/*
+ * Try to find the /etc/fstab file on the filesystem (rootdev),
+ * which should be be the root filesystem, and parse it to find 
+ * out what the kernel ought to think the root filesystem is.
+ *
+ * If we're successful, set vfs.root.mountfrom to <vfstype>:<path>
+ * so that the kernel can tell both which VFS and which node to use
+ * to mount the device.  If this variable's already set, don't
+ * overwrite it.
+ */
+int
+getrootmount(char *rootdev)
+{
+    char	lbuf[128], *cp, *ep, *dev, *fstyp;
+    int		fd, error;
+
+    if (getenv("vfs.root.mountfrom") != NULL)
+	return(0);
+
+    sprintf(lbuf, "%s/etc/fstab", rootdev);
+    if ((fd = open(lbuf, O_RDONLY)) < 0)
+	return(1);
+
+    /* loop reading lines from /etc/fstab    What was that about sscanf again? */
+    error = 1;
+    while (fgetstr(lbuf, sizeof(lbuf), fd) >= 0) {
+	if ((lbuf[0] == 0) || (lbuf[0] == '#'))
+	    continue;
+	
+	/* skip device name */
+	for (cp = lbuf; (*cp != 0) && !isspace(*cp); cp++)
+	    ;
+	if (*cp == 0)		/* misformatted */
+	    continue;
+	/* delimit and save */
+	*cp++ = 0;
+	dev = strdup(lbuf);
+    
+	/* skip whitespace up to mountpoint */
+	while ((*cp != 0) && isspace(*cp))
+	    cp++;
+	/* must have /<space> to be root */
+	if ((*cp == 0) || (*cp != '/') || !isspace(*(cp + 1)))
+	    continue;
+	/* skip whitespace up to fstype */
+	cp += 2;
+	while ((*cp != 0) && isspace(*cp))
+	    cp++;
+	if (*cp == 0)		/* misformatted */
+	    continue;
+	/* skip text to end of fstype and delimit */
+	ep = cp;
+	while ((*cp != 0) && !isspace(*cp))
+	    cp++;
+	*cp = 0;
+	fstyp = strdup(ep);
+
+	/* build the final result and save it */
+	sprintf(lbuf, "%s:%s", fstyp, dev);
+	free(dev);
+	free(fstyp);
+	setenv("vfs.root.mountfrom", lbuf, 0);
+	error = 0;
+	break;
+    }
+    close(fd);
+    return(error);
+}
diff --git a/sys/boot/common/bootstrap.h b/sys/boot/common/bootstrap.h
index 848e74b37ab7..1cabf7033457 100644
--- a/sys/boot/common/bootstrap.h
+++ b/sys/boot/common/bootstrap.h
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: bootstrap.h,v 1.21 1999/04/16 21:21:47 peter Exp $
+ *	$Id: bootstrap.h,v 1.22 1999/06/26 12:26:54 peter Exp $
  */
 
 #include <sys/types.h>
@@ -68,6 +68,7 @@ extern int	bf_run(char *line);
 /* boot.c */
 extern int	autoboot(int delay, char *prompt);
 extern void	autoboot_maybe(void);
+extern int	getrootmount(char *rootdev);
 
 /* misc.c */
 extern char	*unargv(int argc, char *argv[]);
diff --git a/sys/boot/i386/libi386/bootinfo.c b/sys/boot/i386/libi386/bootinfo.c
index 20517c2a312e..a07012e061b9 100644
--- a/sys/boot/i386/libi386/bootinfo.c
+++ b/sys/boot/i386/libi386/bootinfo.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: bootinfo.c,v 1.19 1999/06/04 03:18:28 ghelmer Exp $
+ *	$Id: bootinfo.c,v 1.20 1999/06/21 18:27:01 rnordier Exp $
  */
 
 #include <stand.h>
@@ -258,6 +258,10 @@ bi_load(char *args, int *howtop, int *bootdevp, vm_offset_t *bip)
 	return(EINVAL);
     }
 
+    /* Try reading the /etc/fstab file to select the root device */
+    getrootmount(i386_fmtdev((void *)rootdev));
+
+    /* Do legacy rootdev guessing */
     switch(rootdev->d_type) {
     case DEVT_DISK:
 	/* pass in the BIOS device number of the current disk */
@@ -269,7 +273,7 @@ bi_load(char *args, int *howtop, int *bootdevp, vm_offset_t *bip)
 	return(EINVAL);
 
     default:
-	printf("aout_exec: WARNING - don't know how to boot from device type %d\n", rootdev->d_type);
+	printf("WARNING - don't know how to boot from device type %d\n", rootdev->d_type);
     }
     free(rootdev);
     *bootdevp = bootdevnr;
diff --git a/sys/boot/i386/libi386/bootinfo32.c b/sys/boot/i386/libi386/bootinfo32.c
index 20517c2a312e..a07012e061b9 100644
--- a/sys/boot/i386/libi386/bootinfo32.c
+++ b/sys/boot/i386/libi386/bootinfo32.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: bootinfo.c,v 1.19 1999/06/04 03:18:28 ghelmer Exp $
+ *	$Id: bootinfo.c,v 1.20 1999/06/21 18:27:01 rnordier Exp $
  */
 
 #include <stand.h>
@@ -258,6 +258,10 @@ bi_load(char *args, int *howtop, int *bootdevp, vm_offset_t *bip)
 	return(EINVAL);
     }
 
+    /* Try reading the /etc/fstab file to select the root device */
+    getrootmount(i386_fmtdev((void *)rootdev));
+
+    /* Do legacy rootdev guessing */
     switch(rootdev->d_type) {
     case DEVT_DISK:
 	/* pass in the BIOS device number of the current disk */
@@ -269,7 +273,7 @@ bi_load(char *args, int *howtop, int *bootdevp, vm_offset_t *bip)
 	return(EINVAL);
 
     default:
-	printf("aout_exec: WARNING - don't know how to boot from device type %d\n", rootdev->d_type);
+	printf("WARNING - don't know how to boot from device type %d\n", rootdev->d_type);
     }
     free(rootdev);
     *bootdevp = bootdevnr;
diff --git a/sys/boot/i386/libi386/bootinfo64.c b/sys/boot/i386/libi386/bootinfo64.c
index 20517c2a312e..a07012e061b9 100644
--- a/sys/boot/i386/libi386/bootinfo64.c
+++ b/sys/boot/i386/libi386/bootinfo64.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: bootinfo.c,v 1.19 1999/06/04 03:18:28 ghelmer Exp $
+ *	$Id: bootinfo.c,v 1.20 1999/06/21 18:27:01 rnordier Exp $
  */
 
 #include <stand.h>
@@ -258,6 +258,10 @@ bi_load(char *args, int *howtop, int *bootdevp, vm_offset_t *bip)
 	return(EINVAL);
     }
 
+    /* Try reading the /etc/fstab file to select the root device */
+    getrootmount(i386_fmtdev((void *)rootdev));
+
+    /* Do legacy rootdev guessing */
     switch(rootdev->d_type) {
     case DEVT_DISK:
 	/* pass in the BIOS device number of the current disk */
@@ -269,7 +273,7 @@ bi_load(char *args, int *howtop, int *bootdevp, vm_offset_t *bip)
 	return(EINVAL);
 
     default:
-	printf("aout_exec: WARNING - don't know how to boot from device type %d\n", rootdev->d_type);
+	printf("WARNING - don't know how to boot from device type %d\n", rootdev->d_type);
     }
     free(rootdev);
     *bootdevp = bootdevnr;