Bug 19266

I'm having a strange problem booting after installing 4.0-RELEASE onto a
Maxtor 7200rpm ATA66 drive attached to a Promise Ultra66 controller.

Installation (booted from CD-ROM) went by without problems, but booting off the drive fails at
varying points during boot0 or the BTX boot loader. Sometimes I see a
message about "elf_loadexec: archsw.readin failed", sometimes not even that.

If I move the drive on the onboard (standard) IDE controller, I can boot
fine (until the time comes to mount things, because the fstab is wrong, but
that is to be expected.)

The system also has an onboard SCSI controller with drives attached and
3.4-RELEASE installed, could that be part of the problem? (Disabling it
didn't make a difference.)

I checked the archive, and the recommended fix for the "archsw.readin"
problem seems to be to reinstall boot blocks. I can't do this, however,
since I can't boot from the drive. I've redone the installation, would that
have the same effect? But wouldn't the boot blocks be okay anyway, since I
can boot if the drive is connected to a standard IDE controller?

Fix: 

Workaround: Move drive onto onboard standard IDE controller. (Uses slower BIOSPIO though.)