On Sun, 1 Mar 1998, Benjamin Scott wrote:
<snip>
With efficient code and data compression, 128K goes a long way. Remember, UNIX used to run on systems with 128K total main memory. I would hope we would be able to implement a glorified bootloader in that space. :-)
Less than 128, BTW.
AV = Alexander Viro viro@math.psu.edu AV> Why? What kind of filesystem should it understand? FAT??? Damn, AV> I'ld prefer not to have the stinker around at all.
FAT has two key advantages: It is very simple, and it is nearly universal. The first helps us keep our code size down and minimizes the possability of bugs. The second is useful in emergency situations. I don't think I've met a microcomputer OS yet that didn't have some way to support FAT (either built-in or with add-on software). That can be very handy if you need a kernel in a hurry and the only other networked machine around is a Mac or some such thing. :-)
FAT actually bears a strong resemblence to the "stand" filesystems some UNIXes use to boot. Such filesystems are typcially limited in filename length, have no security, and are flat (no directories). FAT isn't ideal for this, but suits the purpose, and like I said, is nearly universal.
Let me summarize my objections against FAT. a) 8+3 limit. Single dot limit. (I.e. no names like kernel-2.0.33) b) Extremely fragile (lists are much more fragile than trees) c) EXTREMELY FRAGILE just because DOS (shrug) or Sucks95 (BARF!) can access it. d) Nontrivial loaders (other than get the first sector of some partition and let it run) are needed only for Linux and *BSD. On these systems we can add a new filesystem. e) If you managed to hose read-only mounted filesystem in Linux/*BSD it means that you hosed all your disk. It is not an easy job, believe me. Then you'll have to boot from floppy anyway. I keep Linux boot floppies around, but DOS? What for? And if you don't have Linux/*BSD you don't need filesystem with kernels at all, so for UNIX-free machines it's non-issue.
Conclusion: hell with FAT. If we need a filesystem let's implement a good one. It's not that hard. Al