On Thu, 2 Apr 2009, Marcel Moolenaar wrote: [...] > It looks like you have a boot menu entry at 0x1b6. Can you > try the following patch: > > Index: g_part_ebr.c > =================================================================== > --- g_part_ebr.c (revision 190655) > +++ g_part_ebr.c (working copy) > _at__at_ -403,9 +403,13 _at__at_ > if (magic != DOSMAGIC) > goto out; > > - /* The sector is all zeroes, except for the partition entries. */ > + /* > + * The sector is all zeroes, except for the partition entries > + * and a possible IBM Boot Manager menu entry. The menu entry > + * is 9 bytes in length and preceeds the partition entries. > + */ > sum = 0; > - for (index = 0; index < DOSPARTOFF; index++) > + for (index = 0; index < DOSPARTOFF - 9; index++) > sum += buf[index]; > if (sum != 0) > goto out; > > > The real fix will be a bit more involved, because we should > avoid wiping out the boot menu entry on a write. But at least > with the patch you should be able to read the EBR. Much better. I can see extended partition nodes after booting with the patched kernel: # ls -la /dev/ad* crw-r----- 1 root operator 0, 73 4 3 21:12 /dev/ad0 crw-r----- 1 root operator 0, 79 4 3 21:12 /dev/ad0s1 crw-r----- 1 root operator 0, 80 4 3 21:12 /dev/ad0s2 crw-r----- 1 root operator 0, 82 4 3 21:12 /dev/ad0s2a crw-r----- 1 root operator 0, 83 4 3 21:12 /dev/ad0s2b crw-r----- 1 root operator 0, 84 4 3 21:12 /dev/ad0s2d crw-r----- 1 root operator 0, 85 4 3 21:12 /dev/ad0s2e crw-r----- 1 root operator 0, 81 4 3 21:12 /dev/ad0s3 crw-r----- 1 root operator 0, 86 4 3 21:12 /dev/ad0s3+00000001 crw-r----- 1 root operator 0, 88 4 3 21:12 /dev/ad0s3+000410a1 crw-r----- 1 root operator 0, 90 4 3 21:12 /dev/ad0s3+00103bf1 crw-r----- 1 root operator 0, 92 4 3 21:12 /dev/ad0s3+0017cda1 lrwxr-xr-x 1 root wheel 14 4 3 21:12 /dev/ad0s5 -> ad0s3+00000001 lrwxr-xr-x 1 root wheel 14 4 3 21:12 /dev/ad0s6 -> ad0s3+000410a1 lrwxr-xr-x 1 root wheel 14 4 3 21:12 /dev/ad0s7 -> ad0s3+00103bf1 lrwxr-xr-x 1 root wheel 14 4 3 21:12 /dev/ad0s8 -> ad0s3+0017cda1 # gpart show => 63 228338775 ad0 MBR (109G) 63 18688257 1 !12 (8.9G) 18688320 16783200 2 freebsd [active] (8.0G) 35471520 192855600 3 !15 (92G) 228327120 11718 - free - (5.7M) => 0 16783200 ad0s2 BSD (8.0G) 0 786432 1 freebsd-ufs (384M) 786432 4194304 2 freebsd-swap (2.0G) 4980736 393216 4 freebsd-ufs (192M) 5373952 11409248 5 freebsd-ufs (5.4G) => 0 192855600 ad0s3 EBR (92G) 0 16783200 1 !131 (8.0G) 16783200 50243760 266401 !11 (24G) 67026960 31251024 1063921 freebsd (15G) 98277984 94577616 1559969 freebsd (45G) The only downside is that I'll have to update /etc/fstab to boot correctly as /dev/ad0s7a is still missing. -- Thanks, Tai-hwa LiangReceived on Fri Apr 03 2009 - 03:29:56 UTC
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