From 22f56109bab1f14a1a0843f99d13408802e847b0 Mon Sep 17 00:00:00 2001
From: msmith <msmith@FreeBSD.org>
Date: Wed, 21 Jul 1999 00:08:54 +0000
Subject: Walk around the end of all the silly guessing of device types and
 unit numbers that we have been doing in the past, and read /etc/fstab off the
 proposed root filesystem to determine the actual device name and vfs type for
 the root filesystem.  These are then exported to the kernel via the
 environment variable vfs.root.mountfrom.

---
 sys/boot/common/boot.c | 70 +++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 69 insertions(+), 1 deletion(-)

(limited to 'sys/boot/common/boot.c')

diff --git a/sys/boot/common/boot.c b/sys/boot/common/boot.c
index 28accc3..70b4671 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);
+}
-- 
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