Toshiba 8100 Fix (was Re: 5.4-STABLE changes breaks IDE boot (was Re: 5.3 -> 5.4 breaks ATA (Intel ICH2))

[Michael L. Squires]

I have a Toshiba 8100 notebook which runs 5.4-STABLE.  Kernels compiled 
after some time in September 2005 fail to boot; the machine locks up right 
after the ata controller is called in the boot messages.

I have traced the problem to a change to /usr/src/sys/dev/pci.c, (see 
below from my cvsup log).  I found the problem by cvsup'ing /usr/src for 
dates starting with my last working kernel and once I had the date of 
problem code tied down to a couple of days adding in each update to see if 
it caused the failure to boot.  I then added the fix to the latest 5.4 
sources to make sure that the fix still worked.

The problem (really the Toshiba 8100 BIOS problem) was 
triggered by:

  Edit src/sys/dev/pci/pci.c
   Add delta 1.264.2.12 2005.09.05.18.09.20 imp

which changes line 835 of pci.c from

         if (base == 0)
to
  	if (base == 0 || map == testval)

The sysctl parameter "hw.pci.enable_io_modes" is supposed to allow PCs 
with "lazy" BIOSes to boot, but in the case of the 8100 setting

hw.pci.enable_io_modes: 0

doesn't allow the system to boot.

This is obviously a problem with the Toshiba BIOS, which I know from other 
times has other problems; I am putting this here in case someone else has 
the same problem and wants to boot FreeBSD 5.4-STABLE with a kernel 
revision after 9/5/2005.

Mike Squires