Current tasks to make boot sequence finished

Discussions about osFree boot sequence
admin
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Post by admin » Fri Dec 21, 2018 12:19 am

Viking

Joined: 29 Sep 2006
Posts: 42
Location: Sweden
Posted: Wed Oct 18, 2006 2:34 am
valerius wrote: 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 parameters. 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
Hi, thanks for answering so fast. I have tested some with the ext-os/2 but I tried it with grub (with chainloading)
and that did'nt work (seems like it hangs on the simple bootsector inside microfsd.fsd). I guess it works with lilo
but I wanted to use grub.

Anyway, I found an utilitie to handle ext2 (read/write) partitions/floppys. It's called LTools at:

http://www.it.hs-esslingen.de/~zimmerma ... ex_uk.html

It is similar as MTools but for ext2. It's for windows/dos and linux. The source is available. I tried to run the
binary for Linux and it can list the contents of a ext2 partition. Haven't tested the writeable support yet.

admin
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Post by admin » Fri Dec 21, 2018 12:21 am

valerius

Joined: 03 Apr 2005
Posts: 50
Location: Elizovo, Kamchatka, Russia
Posted: Wed Oct 18, 2006 5:33 am

2Viking:
Viking wrote: I have tested some with the ext-os/2 but I tried it with grub (with chainloading) and that did'nt work (seems
like it hangs on the simple bootsector inside microfsd.fsd)
А bootsector inside microfsd.fsd is only dummy bootsector. It has some data fields in itself, but has no loader.
(it contains only HLT instructionto hang the computer, LILO loads the next sector after dummy bootsector and
gives it control). If you want to use GRUB for loading microfsd, you must make microfsd.fsd with multiboot
standard support, but microfsd is not a multiboot kernel, so, IMHO, you can't use GRUB for loading it.

LTools? -- It is very interesting. I'll try it. It may be very useful for FreeLdr developing...
_________________
WBR,
Valery V. Sedletski

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