My MBR formatted disk drive has Linux, OpenBSD and FreeBSD in separate partitions.
When Linux starts up and tries to recognize FreeBSD subpartitions, it always fails with this message:
sda3: <bsd:bad subpartition - ignored ...
Linux has no trouble with the OpenBSD subpartitions:
sda2: <openbsd: sda16 sda17 sda18 ...
FreeBSD subpartitions use relative block addresses whereas OpenBSD and NetBSD use absolute block addresses.
Here is a patch to Linux to adjust the FreeBSD partitions:
Code:
--- a/block/partitions/msdos.c 2015-12-27 18:17:37.000000000 -0800
+++ b/block/partitions/msdos.c 2015-12-29 10:44:25.813773357 -0800
@@ -300,6 +300,8 @@ static void parse_bsd(struct parsed_part
continue;
bsd_start = le32_to_cpu(p->p_offset);
bsd_size = le32_to_cpu(p->p_size);
+ if (memcmp(flavour, "bsd\0", 4) == 0)
+ bsd_start = bsd_start + offset;
if (offset == bsd_start && size == bsd_size)
/* full parent partition, we have it already */
continue;
Update 2017-05-29: This is now fixed in Linux-4.12-rc3 thanks to Christoph Hellwig and Jens Axboe and of course Linus.