Add support for Linux 2.4

[Lili1228]

Linux 2.4.37.11 was the last version of a kernel to (reliably) support UMSDOS, which adds Linux permissions to FAT partitions. There's also a site to add UVFAT (UMSDOS combined with VFAT == LFN) support to the 2.4.19, which patches successfully on 2.4.24 and requires some renaming on 2.4.25-2.4.37.11.

Considering DOS == FAT, this can make implementing rootfs much easier.

[haileys]

It looks like Linux 2.4's boot protocol is incompatible with what's currently in use. It would be possible to check the version field of the real mode kernel header and handle older boot protocols accordingly, but I don't intend to work on this myself. There may be other incompatibilities too. I would accept pull requests around this though if it's a project you would like to take on.

[tpimh]

@mariuszkurek It makes much more sense to make UMSDOS work on more recent kernels, doesn't it?

[Lili1228]

Sense, but also work.