Fix the error return in disk_readslicetab() when an MBR/GPT partition

wasn't found, and use that in userdisk_open() to allow raw disks
and ISO images to be read.

This is a temporary fix - disk.c has changed a lot in CURRENT so this
code may be reworked or made redundant on the next IFC. It is useful
to be able to boot from CD in the meantime.

2 files changed, 11 insertions, 1 deletions

diff --git a/sys/boot/common/disk.c b/sys/boot/common/disk.c
index 81902c0..6dad222 100644
--- a/sys/boot/common/disk.c
+++ b/sys/boot/common/disk.c
@@ -192,6 +192,7 @@ disk_readslicetab(struct disk_devdesc *dev,
 	 */
 	if (buf[0x1fe] != 0x55 || buf[0x1ff] != 0xaa) {
 		DEBUG("no slice table/MBR (no magic)");
+		rc = EEXIST;
 		return (rc);
 	}
 
diff --git a/sys/boot/userboot/userboot/userboot_disk.c b/sys/boot/userboot/userboot/userboot_disk.c
index 074d3e1..ee2baef 100644
--- a/sys/boot/userboot/userboot/userboot_disk.c
+++ b/sys/boot/userboot/userboot/userboot_disk.c
@@ -103,6 +103,7 @@ userdisk_open(struct open_file *f, ...)
 {
 	va_list			ap;
 	struct disk_devdesc	*dev;
+	int			rc;
 
 	va_start(ap, f);
 	dev = va_arg(ap, struct disk_devdesc *);
@@ -111,7 +112,15 @@ userdisk_open(struct open_file *f, ...)
 	if (dev->d_unit < 0 || dev->d_unit >= userboot_disk_maxunit)
 		return (EIO);
 
-	return (disk_open(dev));
+	rc = disk_open(dev);
+
+	/*
+	 * No MBR/GPT - assume a raw disk image
+	 */
+	if (rc)
+		dev->d_offset = 0;
+
+	return (0);
 }
 
 static int