linux 2.2.0 is almost out, and my OpenBSD patch finally made it to the

pre-2.2 series.

src/etc/etc.i386/INSTALL.linux

@@ -1,4 +1,4 @@
-$OpenBSD: INSTALL.linux,v 1.4 1998/09/25 01:58:38 espie Exp $
+$OpenBSD: INSTALL.linux,v 1.5 1999/01/09 17:18:20 espie Exp $
 
 Warning: this document is currently being reviewed. It's not yet complete,
 and probably contains loads of errors. As an example, I can't figure out
@@ -398,179 +398,11 @@ rerun lilo, and voila, OpenBSD was able to boot !
 
 Linux and OpenBSD partitions
 ----------------------------
-As of 2.0.35/2.1.122, Linux does not support OpenBSD partitions. The way
-the Linux kernel works is reasonably straightforward (code in
-drivers/block/genhd.c): when detecting a BSD partition (type A5), 
-it checks and parses the first block for a disklabel, and use that
-information to instantiate some new partitions, 
-that will show up in that drive's partition list, exactly like extended
-partitions do show up. Unfortunately, that check is hard coded for a type A5
-(NetBSD/FreeBSD) partition, and it recognizes 8 partitions disklabels only
-anyway.
-
-Just hacking the Linux code to recognize A6 is not quite enough.  You also
-need to trim down the resulting list of partitions, as your ext2fs
-partitions will now show up twice !
-I'm experimenting with the following patch, which should make it to linux-kernel
-soon:
---------------------------------------------------------------
-diff -ur linux.orig/drivers/block/genhd.c linux/drivers/block/genhd.c
---- linux.orig/drivers/block/genhd.c	Mon Aug  4 20:45:35 1997
-+++ linux/drivers/block/genhd.c	Thu Sep 24 18:55:31 1998
-@@ -205,11 +206,46 @@
- }
- 
- #ifdef CONFIG_BSD_DISKLABEL
-+static void check_and_add_bsd_partition(struct gendisk *hd, struct bsd_partition *bsd_p)
-+{
-+	struct hd_struct *lin_p;
-+		/* check relative position of partitions.  */
-+	for (lin_p = hd->part + 1; lin_p - hd->part < current_minor; lin_p++) {
-+			/* no relationship -> try again */
-+		if (lin_p->start_sect + lin_p->nr_sects <= bsd_p->p_offset 
-+			|| lin_p->start_sect >= bsd_p->p_offset + bsd_p->p_size)
-+			continue;	
-+			/* equal -> no need to add */
-+		if (lin_p->start_sect == bsd_p->p_offset && 
-+			lin_p->nr_sects == bsd_p->p_size) 
-+			return;
-+			/* bsd living within dos partition */
-+		if (lin_p->start_sect <= bsd_p->p_offset && lin_p->start_sect 
-+			+ lin_p->nr_sects >= bsd_p->p_offset + bsd_p->p_size) {
-+#ifdef DEBUG_BSD_DISKLABEL
-+			printk("w: %d %ld+%ld,%d+%d", 
-+				lin_p - hd->part, lin_p->start_sect, lin_p->nr_sects,
-+				bsd_p->p_offset, bsd_p->p_size);
-+#endif
-+			break;
-+		}
-+			/* ouch: bsd and linux overlap. Don't even try for that partition */
-+#ifdef DEBUG_BSD_DISKLABEL
-+		printk("???: %d %ld+%ld,%d+%d",
-+			lin_p - hd->part, lin_p->start_sect, lin_p->nr_sects,
-+			bsd_p->p_offset, bsd_p->p_size);
-+#endif
-+		printk("???");
-+		return;
-+	} /* if the bsd partition is not described by DOS, we end up there */
-+	add_partition(hd, current_minor, bsd_p->p_offset, bsd_p->p_size);
-+	current_minor++;
-+}
- /* 
-  * Create devices for BSD partitions listed in a disklabel, under a
-  * dos-like partition. See extended_partition() for more information.
-  */
--static void bsd_disklabel_partition(struct gendisk *hd, kdev_t dev)
-+static void bsd_disklabel_partition(struct gendisk *hd, kdev_t dev, int max_partitions)
- {
- 	struct buffer_head *bh;
- 	struct bsd_disklabel *l;
-@@ -225,19 +261,15 @@
- 		return;
- 	}
- 
--	p = &l->d_partitions[0];
--	while (p - &l->d_partitions[0] <= BSD_MAXPARTITIONS) {
-+	if (l->d_npartitions < max_partitions)
-+		max_partitions = l->d_npartitions;
-+	for (p = l->d_partitions; p - l->d_partitions <  max_partitions; p++) {
- 		if ((current_minor & mask) >= (4 + hd->max_p))
- 			break;
--
--		if (p->p_fstype != BSD_FS_UNUSED) {
--			add_partition(hd, current_minor, p->p_offset, p->p_size);
--			current_minor++;
--		}
--		p++;
-+		if (p->p_fstype != BSD_FS_UNUSED)
-+			check_and_add_bsd_partition(hd, p);
- 	}
- 	brelse(bh);
--
- }
- #endif
- 
-@@ -248,6 +280,11 @@
- 	struct partition *p;
- 	unsigned char *data;
- 	int mask = (1 << hd->minor_shift) - 1;
-+#ifdef CONFIG_BSD_DISKLABEL
-+	/* no bsd disklabel as a default */
-+	kdev_t bsd_kdev = 0;
-+	int bsd_maxpart;
-+#endif
- #ifdef CONFIG_BLK_DEV_IDE
- 	int tested_for_xlate = 0;
- 
-@@ -365,13 +402,29 @@
- 				hd->part[minor].nr_sects = 2;
- 		}
- #ifdef CONFIG_BSD_DISKLABEL
-+			/* tag first disklabel for late recognition */
- 		if (SYS_IND(p) == BSD_PARTITION) {
--			printk(" <");
--			bsd_disklabel_partition(hd, MKDEV(hd->major, minor));
--			printk(" >");
-+			printk("!");
-+			if (!bsd_kdev) {
-+				bsd_kdev = MKDEV(hd->major, minor);
-+				bsd_maxpart = BSD_MAXPARTITIONS;
-+			}
-+		} else if (SYS_IND(p) == OPENBSD_PARTITION) {
-+			printk("!");
-+			if (!bsd_kdev) {
-+				bsd_kdev = MKDEV(hd->major, minor);
-+				bsd_maxpart = OPENBSD_MAXPARTITIONS;
-+			}
- 		}
- #endif
- 	}
-+#ifdef CONFIG_BSD_DISKLABEL
-+	if (bsd_kdev) {
-+		printk(" <");
-+		bsd_disklabel_partition(hd, bsd_kdev, bsd_maxpart);
-+		printk(" >");
-+	}
-+#endif
- 	/*
- 	 *  Check for old-style Disk Manager partition table
- 	 */
-diff -ur linux.orig/include/linux/genhd.h linux/include/linux/genhd.h
---- linux.orig/include/linux/genhd.h	Wed Mar 18 20:25:30 1998
-+++ linux/include/linux/genhd.h	Thu Sep 24 18:55:43 1998
-@@ -69,12 +70,19 @@
- #ifdef CONFIG_BSD_DISKLABEL
- /*
-  * BSD disklabel support by Yossi Gottlieb <yogo@math.tau.ac.il>
-+ *
-+ * updated by Marc Espie <Marc.Espie@openbsd.org>
-  */
- 
-+/* check against BSD src/sys/sys/disklabel.h for consistency */
-+
- #define BSD_PARTITION		0xa5	/* Partition ID */
-+#define OPENBSD_PARTITION	0xa6
- 
- #define BSD_DISKMAGIC	(0x82564557UL)	/* The disk magic number */
- #define BSD_MAXPARTITIONS	8
-+#define OPENBSD_MAXPARTITIONS 16
-+
- #define BSD_FS_UNUSED		0	/* disklabel unused partition entry ID */
- struct bsd_disklabel {
- 	__u32	d_magic;		/* the magic number */
-----------------------------------------------------------------------
-It does:
-- trigger the recognition of OpenBSD disklabels,
-- force bsd partitions to appear at the end of the partition list,
-- check the bsd disklabel for redundancy and consistency with the dos
-partition table, so that the same partition does not show up twice.
-
-You also need a working ufs, such as
-<ftp://sunsite.unc.edu/pub/Linux/ALPHA/ufs/u2fs-0.4.3.tar.gz>
-This package yields a new module, plus a small patch to tie the module
-with the rest of the Linux kernel. I would recommend checking that patch
-manually, as Linux module information tends to vary widely, and it is
-pretty trivial to add by hand anyway.
+As of pre4-2.2.0, the up-coming 2.2 linux kernel does incorporate my 
+patch to handle OpenBSD partitions, and remove duplicate partitions that 
+are referenced in both the disklabel for OpenBSD, and the MBR.
+
+You also need a working ufs, which is also going to be in linux 2.2.
 
 Running Linux binaries under OpenBSD
 ------------------------------------