IMS TT video issues
I have just spent most of the last couple of days installing Debian Woody on
a PowerMac 9600/300 and getting kernel 2.4.18 built and (mostly) working. I
have a couple of remaining issues that are plaguing me.
1) If I use a pre-built 2.4.18 kernel, or a normal home-built one, the
monitor goes blank on boot-up. I have tried just about all of the
combinations of video=ofonly, video=fbdev and video=imsttfb without
success. The 2.2 installation kernel that I was using to install does
work, and looking at /var/log/dmesg, the difference is that 2.2 thinks the
video board uses the TVP RAMDAC, whereas 2.4 thinks it uses the IBM
If I comment out the line that sets "pdev->ramdac = IBM" in
drivers/video/imsttfb.c, and let it fall through to the TVP case, I get
monitor output using video=imsttfb, except that the cursor is invisible or
The /proc/devices-tree entry indicates that I have an imstt128mb8A (IBM
RAMDAC), and setting the output-device in OpenFirmware to
/bandit@F4000000/IMS,tt128mb8A gives me boot-time output. lspci -v
indicates the card is an IMS 9129 Twin Turbo 128 Rev 01 (PCI device ID is
0x9128), and claims it has 16MB memory (rather than the 4 or 8Mb suggested
by the driver). I haven't pulled the video card out yet to check out what
chips are on board.
What on earth is happening? I'm not going to be running X on this machine,
so I only care about console output, but I don't want to accidentally blow
the video card up. I would like a cursor too, it makes it much easier to
see where you're typing.
2) Having got video on bootup, how can I get rid of the d**m penguin on the
bootup screen? It really makes scrolling r-e-a-l-l-y slow.
3) Can I force an extra SCSI controller to be lower in the search order than
the on-board controllers? If so, how? The next step will be to move data
from my old machine over, however I need to put a PCI SCSI card in the
PowerMac with the drives from the old machine attached, the data is on U2W
drives and the internal controller doesn't do U2W. When I tried putting
the card in the PowerMac the kernel scanned it first, changing the root
filesystem drive from /dev/sda to /dev/sdb. It wasn't a success, needless
A final comment about the install process: it would have been much easier if
the Debian on PowerPC installation Manual had mentioned "nvsetenv" somewhere.
I wasted a lot of time rebooting and trying to type blind at prompts because
OpenFirmware input and output was connected to the serial port. This
installation was a complete replacement for MacOS, by the time I found out I
needed to change the OpenFirmware settings it was too late to run bootvars.
The 2.2 installation kernel was booting however, I could have used nvsetenv
much earlier to reset the output and input device.