From Bill Paul:

- /sys/i386/i386/swapgeneric.c is just plain broke. But fear not, for I
  have unbroken it. One thing that swapgeneric.c does is walk through the
  list of configured devices searching for a boot device. The only easy
  way to accomplish this in 2.0 is to use Garret Wollman's kern_devconf
  stuff. *BUT*, the head of the kern_devconf linked list (dc_list) is declared
  static in /sys/kern/kern_devconf.c. This means that swapgeneric.c can't
  see it at link time. I had to remove the 'static' keyword to get around
  this little problem. I hope this doesn't break anything anywhere.

  *Furthermore,* there's a small matter of making the call to setconf()
  in swapgeneric.c disappear when 'config kernel swap generic' isn't used.
  You could change /sbin/config to create a dummy setconf() function in
  swapkernel.c, but that seems messy somehow. (It's also someting of an
  'it isn't broken, why are you fixing it' situation.) My solution was to
  do what the NetBSD people did and put an #ifdef GENERIC around the call
  to setconf(). If your kernel is called GENERIC or you define 'options
  GENERIC,' then you can use 'config kernel swap generic' and it'll work.

  That aside, the upshot is that: a) swapgeneric.c actually works, and
  and b) the -a boot flag now works as well. If you boot with -a, as in
  "Boot: wd(0,a)/kernel -a" you will be presented with a 'root device?'
  prompt after the autoconfig phase, at which point you can specify what
  device you want mounted as root. Regrettably, you can't specify an NFS
  filesystem. Yet. Three files are affected: /sys/i386/i386/swapgeneric.c,
  /sys/i386/i386/autoconf.c and /sys/kern/kern_devconf.c.

Submitted by:	wpaul

sys/amd64/amd64/autoconf.c

@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)autoconf.c	7.1 (Berkeley) 5/9/91
- *	$Id: autoconf.c,v 1.15 1994/10/22 17:51:45 phk Exp $
+ *	$Id: autoconf.c,v 1.16 1994/11/12 01:47:35 phk Exp $
  */
 
 /*
@@ -103,7 +103,13 @@ configure()
 #ifdef FFS
 	if (!mountroot) {
 		mountroot = ffs_mountroot;
+#ifdef GENERIC
+		if ((boothowto & RB_ASKNAME) == 0)
+			setroot();
+		setconf();
+#else
 		setroot();
+#endif
 	}
 #endif
 	if (!mountroot) {

sys/i386/i386/autoconf.c

@@ -34,7 +34,7 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)autoconf.c	7.1 (Berkeley) 5/9/91
- *	$Id: autoconf.c,v 1.15 1994/10/22 17:51:45 phk Exp $
+ *	$Id: autoconf.c,v 1.16 1994/11/12 01:47:35 phk Exp $
  */
 
 /*
@@ -103,7 +103,13 @@ configure()
 #ifdef FFS
 	if (!mountroot) {
 		mountroot = ffs_mountroot;
+#ifdef GENERIC
+		if ((boothowto & RB_ASKNAME) == 0)
+			setroot();
+		setconf();
+#else
 		setroot();
+#endif
 	}
 #endif
 	if (!mountroot) {

sys/i386/i386/swapgeneric.c

@@ -34,48 +34,75 @@
  * SUCH DAMAGE.
  *
  *	from: @(#)swapgeneric.c	5.5 (Berkeley) 5/9/91
- *	$Id: swapgeneric.c,v 1.3 1993/11/03 18:05:42 nate Exp $
+ *	$Id: swapgeneric.c,v 1.4 1994/08/13 03:49:45 wollman Exp $
  */
 
-#include <machine/pte.h>
-
 #include <sys/param.h>
 #include <sys/conf.h>
 #include <sys/buf.h>
-#include <sys/vm.h>
 #include <sys/systm.h>
 #include <sys/reboot.h>
+#include <sys/disklabel.h>
+#include <sys/devconf.h>
+
+#include "wd.h"
+#include "fd.h"
+#include "sd.h"
+#include "cd.h"
+#include "mcd.h"
+#include "scd.h"
+#include "pcd.h"
 
 /*
  * Generic configuration;  all in one
  */
-dev_t	rootdev = makedev(0,0);
+dev_t	rootdev = NODEV;
-dev_t	dumpdev = makedev(0,1);
+dev_t	dumpdev = NODEV;
+
 int	nswap;
 struct	swdevt swdevt[] = {
-	{ 1,	0,	0 },
+	{ 1,		0,	0 },
-	{ 0,	1,	0 },
+	{ NODEV,	0,	0 }, /* For NFS diskless */
+	{ NODEV,	0,	0 },
 };
 long	dumplo;
 int	dmmin, dmmax, dmtext;
 
-extern	struct driver wddriver;
+extern struct kern_devconf *dc_list;
-extern	struct driver wxdriver;
+void gets(char *);
 
 struct	genericconf {
-	caddr_t	gc_driver;
 	char	*gc_name;
 	dev_t	gc_root;
 } genericconf[] = {
-	{ (caddr_t)&wddriver,	"wd",	makedev(0, 0),	},
+#if NWD > 0
-	{ (caddr_t)&wxdriver,	"wx",	makedev(0, 0),	},
+	{ "wd",		makedev(0, 0),	},
+#endif
+#if NFD > 0
+	{ "fd",		makedev(2, 0),	},
+#endif
+#if NSD > 0
+	{ "sd",		makedev(4, 0),	},
+#endif
+#if NCD > 0
+	{ "cd",		makedev(6, 0),	},
+#endif
+#if NMCD > 0
+	{ "mcd",	makedev(7, 0),	},
+#endif
+#if NSCD > 0
+	{ "scd",	makedev(16,0),	},
+#endif
+#if NPCD > 0
+	{ "pcd",	makedev(17,0),	},
+#endif
 	{ 0 },
 };
 
-setconf()
+void setconf(void)
 {
-#ifdef notdef
 	register struct genericconf *gc;
+	register struct kern_devconf *kdc;
 	int unit, swaponroot = 0;
 
 	if (rootdev != NODEV)
@@ -85,7 +112,7 @@ setconf()
 retry:
 		printf("root device? ");
 		gets(name);
-		for (gc = genericconf; gc->gc_driver; gc++)
+		for (gc = genericconf; gc->gc_name; gc++)
 			if (gc->gc_name[0] == name[0] &&
 			    gc->gc_name[1] == name[1])
 				goto gotit;
@@ -105,33 +132,33 @@ setconf()
 		goto retry;
 	}
 	unit = 0;
-	for (gc = genericconf; gc->gc_driver; gc++) {
+	for (gc = genericconf; gc->gc_name; gc++) {
-		for (ui = vbdinit; ui->ui_driver; ui++) {
+		kdc = dc_list;
-			if (ui->ui_alive == 0)
+		while (kdc->kdc_next) {
-				continue;
+			if (!strcmp(kdc->kdc_name, gc->gc_name) &&
-			if (ui->ui_unit == 0 && ui->ui_driver ==
+				kdc->kdc_unit == 0) {
-			    (struct vba_driver *)gc->gc_driver) {
+				printf("root on %s0\n", kdc->kdc_name);
-				printf("root on %s0\n",
-				    ui->ui_driver->ud_dname);
 				goto found;
 			}
+			kdc = kdc->kdc_next;
 		}
 	}
-	printf("no suitable root\n");
+	printf("no suitable root -- press any key to reboot\n\n");
-	asm("halt");
+	cngetc();
+	cpu_reset();
+	for(;;) ;
 found:
-	gc->gc_root = makedev(major(gc->gc_root), unit*8);
+	gc->gc_root = makedev(major(gc->gc_root), unit * MAXPARTITIONS);
 	rootdev = gc->gc_root;
 doswap:
-	swdevt[0].sw_dev = argdev = dumpdev =
+	swdevt[0].sw_dev = dumpdev =
 	    makedev(major(rootdev), minor(rootdev)+1);
 	/* swap size and dumplo set during autoconfigure */
 	if (swaponroot)
 		rootdev = dumpdev;
-#endif
 }
 
-gets(cp)
+void gets(cp)
 	char *cp;
 {
 	register char *lp;