This mega-commit brings the following:

. It makes cd9660 root f/s working again.
. It makes CD9660 a new-style option.
. It adds support to mount an ISO9660 multi-session CD-ROM as the root
  filesystem (the last session actually, but that's what is expected
  behaviour).

Sigh.  The CDIOREADTOCENTRYS did a copyout() of its own, and thus has
been unusable for me for this work.  Too bad it didn't simply stuff
the max 100 entries into the struct ioc_read_toc_entry, but relied on
a user supplied data buffer instead. :-(  I now had to reinvent the
wheel, and created a CDIOREADTOCENTRY ioctl command that can be used
in a kernel context.

While doing this, i noticed the following bogosities in existing CD-ROM
drivers:

wcd:	This driver is likely to be totally bogus when someone tries
	two succeeding CDIOREADTOCENTRYS (or now CDIOREADTOCENTRY)
	commands with requesting MSF format, since it apparently
	operates on an internal table.

scd:	This driver apparently returns just a single TOC entry only for
	the CDIOREADTOCENTRYS command.

I have only been able to test the CDIOREADTOCENTRY command with the
cd(4) driver.  I hereby request the respective maintainers of the
other CD-ROM drivers to verify my code for their driver.  When it
comes to merging this CD-ROM multisession stuff into RELENG_2_2 i will
only consider drivers where i've got a confirmation that it actually
works.

1 files changed, 47 insertions, 15 deletions

diff --git a/sys/amd64/amd64/autoconf.c b/sys/amd64/amd64/autoconf.c
index 7fad268..d18fb01 100644
--- a/sys/amd64/amd64/autoconf.c
+++ b/sys/amd64/amd64/autoconf.c
@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)autoconf.c	7.1 (Berkeley) 5/9/91
- *	$Id: autoconf.c,v 1.65 1997/04/26 11:45:02 peter Exp $
+ *	$Id: autoconf.c,v 1.66 1997/04/26 18:57:34 peter Exp $
  */
 
 /*
@@ -46,6 +46,7 @@
  * and the drivers are initialized.
  */
 #include "opt_smp.h"
+#include "opt_cd9660.h"
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -101,9 +102,17 @@ static void	setroot __P((void));
 
 #ifdef CD9660
 
+#include <sys/fcntl.h>
+#include <sys/proc.h>
+#include <sys/stat.h>
+#include <machine/clock.h>
 #include <isofs/cd9660/iso.h>
 
-/* We need to try out all our potential CDROM drives, so we need a table. */
+/*
+ * XXX All this CD-ROM root stuff is fairly messy.  Ick.
+ *
+ * We need to try out all our potential CDROM drives, so we need a table.
+ */
 static struct {
 	char *name;
 	int major;
@@ -112,25 +121,44 @@ static struct {
 	{ "mcd", 7 },
 	{ "scd", 16 },
 	{ "matcd", 17 },
+	{ "wcd", 19 },
 	{ 0, 0}
 };
 
-static int	find_cdrom_root __P((void *));
+static int	find_cdrom_root __P((void));
 
 static int
-find_cdrom_root(dummy)
-	void *dummy;
+find_cdrom_root()
 {
-	int i,j,k;
-
-	for (j = 0 ; j < 2; j++)
-		for (k = 0 ; try_cdrom[k].name ; k++) {
-			rootdev = makedev(try_cdrom[k].major,j*8);
-			printf("trying rootdev=0x%lx (%s%d)\n",
-				rootdev, try_cdrom[k].name,j);
-			i = (*cd9660_mountroot)();
-			if (!i) return i;
+	int i, j, error;
+	struct bdevsw *bd;
+	dev_t orootdev;
+
+#if CD9660_ROOTDELAY > 0
+	DELAY(CD9660_ROOTDELAY * 1000000);
+#endif
+	orootdev = rootdev;
+	for (i = 0 ; i < 2; i++)
+		for (j = 0 ; try_cdrom[j].name ; j++) {
+			if (try_cdrom[j].major >= nblkdev)
+				continue;
+			rootdev = makedev(try_cdrom[j].major, i * 8);
+			bd = bdevsw[major(rootdev)];
+			if (bd == NULL || bd->d_open == NULL)
+				continue;
+			if (bootverbose)
+				printf("trying %s%d as rootdev (0x%x)\n",
+				       try_cdrom[j].name, i, rootdev);
+			error = (bd->d_open)(rootdev, FREAD, S_IFBLK, curproc);
+			if (error == 0) {
+				if (bd->d_close != NULL)
+					(bd->d_close)(rootdev, FREAD, S_IFBLK,
+						      curproc);
+				return 0;
+			}
 		}
+
+	rootdev = orootdev;
 	return EINVAL;
 }
 #endif /* CD9660 */
@@ -233,7 +261,11 @@ configure(dummy)
 	if ((boothowto & RB_CDROM)) {
 		if (bootverbose)
 			printf("Considering CD-ROM root f/s.\n");
-		mountrootfsname = "cd9660";
+		/* NB: find_cdrom_root() sets rootdev if successful. */
+		if (find_cdrom_root() == 0)
+			mountrootfsname = "cd9660";
+		else if (bootverbose)
+			printf("No CD-ROM available as root f/s.\n");
 	}
 #endif