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.

1 files changed, 69 insertions, 1 deletions

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);
+}