boot2 broken ? (booting from pst fails)

[Toerless Eckert]

Has someone ever managed to boot FreeBSD off a Promise SuperTRAK SX6000
RAID controller ? I tried all options i can think of, but it always
failed: boot0 and boot1 work nicely, but boot2 simply hangs as soon
as it tries to do the first bios read from the array. I am somewhat
suspecting that this is related to the BIOS of that controller being
offended by the environment of the btx client it's being called from
(boot2 is the first btx client in the boot phases).

- Tried FreeBSD 5.0(release) and 4.8(release) boot1/boot2 - same effect.
- Problem is unrelated to disk being a raid. Same effect happens when
  simply moving a perfectly booting ide disk from a "normal" ide controller
  to the sx6000 (hangs in boot2).
- Windows XP boots fine off the sx6000 (also via FreeBSD boot0). Have not
  tried other OSs like Linux though.
- Tried all "OS" settings in the sx6000 BIOS config. No change.

- Q: Any ideas what i could do ?

- Q: Is btx actually switching to real mode for int 13 ? Could it be
     that there's a bug in that code ?

- Q: Are there any alternatives how i could boot a 4.8 or 5.0 freebsd
     solely from the disk ? (I guess i could try to install a linux and
     then use liloboot, but that also uses the btx code from loader...)

Thanks
	Toerless