From: drew@caesar.cs.colorado.edu (Drew Eckhardt) Subject: Re: Booting Linux from Drive B: Date: Mon, 1 Jun 1992 22:20:49 GMT
In article <1992Jun1.205728.28981@athena.mit.edu> tytso@athena.mit.edu writes:
> From: u1amd@ohm.york.ac.uk (Alistair Macdonald)
> Date: 1 Jun 92 09:20:52 GMT
>
> Is it possible to modify the Linux boot disk, so that I can boot
> from Drive B: ?
By boot, you could mean
- to mount the root floppy
- to load the binary Image file.
Both are possible. To mount a different root filesystem, change
the bytes at offset 508 / 509 to minor / major number of the device
you want to boot. RTFM as to major / minor device numbers.
To load the image off of the second disk, you must patch
every int 13h call so that dl=1 instead of 0.
>That's not a Linux boto disk problem; that's a PC BIOS problem. There's
>no way to tell the ROM to boot off of something other than either A: or
>C: (and changing the boot order requires running a configuration
>program; there's no way to do it just before you boot).
Some BIOS's will boot off of any drive. The bootstrap loader
for MSDOS will detect which drive is being booted, the Linux
bootsector has it hardcoded to 0, or A:. Shoelace is different.
>In order to do something that sophisticated, you need something like a
>Heathkit H-89 which uses a 2MhZ Z-80 as a processor. :-) And yes, CP/M
>also had a more sophisticated hard disk partitioning scheme that what
>MS-LOSS uses. Go figure.
Or a modern BIOS on the latest whiz bang 486-50....
But that partitioning scheme is attrocious. UGH.