A few 6400 users running linux-pmac have run into problems not
encountered on other machines.  Reports range from users with no 
problems to people ending up with a non-bootable machine and needing
to take it to an Apple repair center to get it going again.  With that
in mind, here are a few precautions to follow when installing and
running Powermac/Linux on the 6400 (and perhaps 6500 and 5400).  

You should hopefully end up with a fully functional linux-pmac system 
on your 6400 by supplementing the linux-pmac INSTALL directions with these notes.

- Be SURE to set your Open Firmware boot variables so that you can 
  monitor what OF is doing when you boot.  From MacOS, use Boot Variables
  v1.3 or later.  Check the All Variables option when you open it up.
  Then fill the following options, leaving everything else at whatever
  setting they're already at (or as instructed in the INSTALL directions).

  load-base       100000
  input-device    kbd
  output-device   screen
  
  You can make auto-boot? false if you like, so that you can interact
  directly with OF.  To boot whatever is set in boot-device, simply type
  'boot'.  Type 'bye' to boot to MacOS.  There's more info on using OF
  elsewhere in the faq-o-matic.

- You shouldn't have to zap PRAM unless things go terribly wrong - 
  leaving auto-boot? off and setting the variables above should 
  consistently get you into Open Firmware, where you can figure out 
  what's going wrong.  But if you do run into problems and can't get
  back into MacOS, take note that zapping PRAM doesn't always 
  successfully reset everything so that MacOS loads.  First try rebooting
  and holding down command-option-p-r until the machine resets and chimes
  a few times.  This should zap the PRAM and let you back into MacOS.
  If that fails, and you can't boot anything from your machine, try 
  unplugging *everything* that you reasonably can from the motherboard and 
  removing the battery from the CPU for a few hours (or days even).  Then 
  try zapping the PRAM again.  

  You won't be able to use the method of hooking up a second computer to
  the serial port to talk to OF as described in the INSTALL directions -
  the 6400 has an internal modem so the modem port is covered.  The printer
  port doesn't appear to work for this.

- booting off an external scsi drive has given some people problems.  Once
  you know the device ID and root partition # on your external scsi, try 
  setting boot-device to scsi/sd@X:Y, where X is the scsi ID and Y is 
  the partition.  In some cases you may need to leave Y at 0 regardless 
  of the actual root partition #.
  If this doesn't work, you'll probably have to boot off the IDE or a 
  floppy.

- for an IDE install, use boot-device ata/ATA-Disk@0:0 to boot off the IDE.

- You may have to specify in the boot-file option the name of the kernel
  and root location - for example,

  boot-file     /vmlinux root=/dev/hda5

  This is for a root partition on the internal IDE on partition # 5.


If you have any corrections or more info, please add them!!!

posted by wj@acpub.duke.edu, 7/22/97

I have gathered from my own experiments and from reading the newsgroup archives:

set the base to 1000000

In order to boot from hard disk, 
need to set OF output to something other than screen.

I can boot from floppy without problems, with output set to screen, and base
set to 100000.  I get CLAIM FAILED when booting from the SCSI HD.  I will try
the newer settings.

I have an 6400 and Linux-PPC (installed on internal IDE) just don't want to boot! I tried everything! Has anybody an idea? Thanks Thorsten

I have had no problems booting mklinux (DR3) on my performa 6400 (internal IDE), i just followed the installer
But there are still some problems i can't solve..
1: i can't print anything, i have no response to my epson stylus
2: i do have no access to my internal geoport modem,so there is no way to enter
the web.
3: there is no access to my floppy
4: there is no access to my hfs+ volume


be sure, i tried everything!!!
Who may help ? Otherwise i should use disk-space in another way. With this problems
i described above i can not work with.

I too am in the process of configuring Linux on a 6400 and have a couple of almost
answers to the previous entry.  

1.  HFS+ disk are not suported yet.
2.  The GeoPort modem is only of any use under MacOS because it is a 
hardware/software solution.  To get onto the net you'll need to remove the 
Geoport and attach an external modem.

I've got problems with a Performa 6400 Creative Studio (the one with TV-in/-out and FMRadio ports).
Basically I've installed LinuxPPC/5.0 and everything went straight, until I rebooted.
Now the console is right and working, but in X it has got serious problems with the colormap (white becomes blue, black is brown, blue is green, etc...).
just can't find any kind of fix for this one...
Xconfigurator probes a 'Valkyrie' video card with 756k NVRAM, then it can't start Xwindows and when I quit it, the symlink for /etc/X11/X points wrongly to XF68_FBDev, instead of Xpmac!
Tried almost everything... I even reformatted and reinstalled the whole thing, but now also the installer gives me wrong colormaps!!!

Anybody's got any clue?!?
Thanks