2_ The second difference is more relevant to this particular case. In Syslinux 4.06 (and older), linux.c32 is capable of booting newer (bigger) Linux kernels (like the one used in PMagic). The "traditional" directives ("KERNEL" or "LINUX") might fail in these cases. Note that the linux.c32 module included in Syslinux 4.06 (used by UBCD 5.2 pre-releases), although capable of booting newer Linux kernels, is still under development, so there are cases where it might fail. Having said that, I strongly suggest using it for pmagic's kernels, since the original PMagic distro already uses it (and has been using it for a long time).
I did some searching and found this:http://forums.partedmagic.com/viewtopic ... 6530#p6530
It was Icecube that suggests using linux.c32 in PMagic in the first place.
The thread also mentions about Ubuntu, which doesn't use the linux.c32 in its isolinux boot entry. (Note 1)
I will change the syntax to something like below in the help files, but just for this case only. Because I'm still confused about what linux.c32 can do and whether it is still useful in the new Syslinux 5.01.
APPEND /pmagic/bzImage initrd=/ubcd/boot/cpustress/initrd.gz root=/dev/ram0
ramdisk_size=12000 noapic <other-parameters...>
(Information about DISPLAY files)
I don't think I'll write a DISPLAY file for this (and I don't know what to write). I'll let someone else to do that.
(Note 1) <Ubuntu-CD>/isolinux/txt.cfg:
menu label ^Try Ubuntu without installing
append file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash --