gptmbr.bin vs RAIDframe

[Stephen Borrill <netbsd%precedence.co.uk@localhost>]

I've been testing out wedges combined with RAIDframe on HDDs > 2TB. I 
have:
# gpt show wd1
       start        size  index  contents
           0           1         PMBR
           1           1         Pri GPT header
           2          32         Pri GPT table
          34    20972448      1  GPT part - NetBSD RAIDFrame component
    20972482    20972448      2  GPT part - NetBSD RAIDFrame component
    41944930  5818588205      3  GPT part - NetBSD RAIDFrame component
  5860533135          32         Sec GPT table
  5860533167           1         Sec GPT header

(wd2 is same)
I've then set up 3x RAIDframe RAID1 on the 3 wedges from each disk.
raid0 and raid1 (from the wedges with indices 1 and 2) are used directly 
(i.e. /dev/raid0a is root). There's another GPT on raid2:
# gpt show raid2
       start        size  index  contents
           0           1         PMBR
           1           1         Pri GPT header
           2          32         Pri GPT table
          34  5818587965      1  GPT part - NetBSD FFSv1/FFSv2
  5818587999          32         Sec GPT table
  5818588031           1         Sec GPT header

and I've named this "usr". My fstab contains the following and all is 
well:
/dev/raid0a     /       ffs     rw               1 1
/dev/raid1a     none    swap    sw,dp
NAME=usr        /usr    ffs     rw               1 2

This copes with missing components and wedges being renumbered.

The only missing part is trying to make the system directly bootable. I 
tried "gpt biosboot -i 1 wd0" which didn't give any errors, but equally 
didn't work. At boot time gptmgr prints "Missing OS" which appears to be 
because it cannot locate the 0xaa55 signature.

--
Stephen