Press the Tab key to change the default OS and then press the "Save To Prefs" button.
Which kernel should I use ?
With this version of BootX, you should use at least kernel 2.1.125. Precompiled are available via ftp on samba.anu.edu.au
Do I still need a vmlinux on my root partition
BootX currently loads only the kernel present on the MacOS side. You can keep a kernel on / or /boot if you want to be able to use OF-booting again but it's not used when booting from BootX
What kernel args should I use
You should fill the "root device" field with the name of your boot device without the "/dev/" (it will be added automatically by BootX). If you use the RamDisk, just leave the field empty.
You may want to add video=some_video_config in order to force you video settings. The "no video driver" option is equivalent to "video=ofonly".
Do I absolutely need a ramdisk ?
No ! You can boot linux with only a vmlinux file. The ramdisk is an option. Usually it contains the installer. If your linux configuration is already installed, you only need the kernel.
Why do I get -622 errors ?
This error means that MacOS Virtual Memory refused to lock down and make contiguous the memory required for the kernel and ram disk. I don't have a workaround for this problem yet. Disabling VM will work, but if you want to keep it enabled, then try changing your MacOS VM size and disk cache size until you get something that works.
UPDATE: Those should be gone with 1.0.2b3, the bootstrap will now reorder the kernel pages in memory.
Why is my PowerBook G3 Series display not working unless I check "no video driver" ?
First check your kernel version. I strongly suggest using at least a precompiled 2.2.1 from ftp://samba.anu.edu.au. Then, add to your kernel command line:
video=atyfb:vmode:14,cmode:32,mclk:63
This will setup your screen to 1024x768 using 32 bits color. The "mclk" value is the speed of the video controller. It appears that some PowerBooks will use a different speed, 63 is the speed used by mine under MacOS.
You may also need to add ",pll:135" to avoid snow effets. The exact setting seems to depend on the revision of your PowerBook motherboard.
