valerius
Joined: 03 Apr 2005
Posts: 50
Location: Elizovo, Kamchatka, Russia
Posted: Sun Oct 15, 2006 6:10 am
2Viking: ext2 blackbox (aka microfsd) is taken from OS/2 ext2 IFS (you can find it in
http://hobbes.nmsu.edu/ searching by ext2 keyword). As written in .INF ebook, to use
ext2 microfsd, you must install lilo in 1st sector of ext2 partition and to start microfsd
from it as a kernel. Lilo starts microfsd, microfsd loads os2ldr and so on. With Lilo there
is no BPB, of course. But parameters which are common for BPB can be given to microfsd
by lilo as kernel paramet ers. To get rid from lilo, you can use a simple bootsector, which
can replace lilo.
I have written such a bootsector, my bootsector has BPB in it and can load any file as a
sequence of sectors; The starting sector and length in sectors and load address and entry
point address are written in bootsector fields, so you can write in bootsector the arbitrary
values. My bootsector is filesystem independent, so, in principle, you can use it instead of
lilo, but I did not tested it for now with ext2 filesystem, but I am experimenting now with
FAT filesystem, and trying to write a FAT microfsd, as FAT is more convenient for me than
ext2, as for FAT there is mtools, they are very convenient for manipulating disk images,
and there is no such utilities for ext2. I want to contribute to osFree boot sequence project,
and when my tools will be ready, i'll show the sources.
My bootsector is, of course, written in assembler, but microfsd it loads can be written in C
as well as in assembler. the only limitation is no more than 64 Kb in size. My bootsector can
load microfsd from any file in any directory, as well as from bootblock or from empty area
before bootsector (there is 62 empty sectors before any logical disk bootsector, we can place
microfsd here).
WBR,
valery
_________________
WBR,
Valery V. Sedletski
Last edited by valerius on Sun Oct 15, 2006 6:33 am; edited 1 time in total