Subject: Re: #1, make it boot! Engage.

From: [email-masked] (Bruce Perens)
Date: Tue, 20 Aug 96 21:34 PDT

From: "Charles A. Schuman" <[email-masked]>
> # fdisk  (then "p")
>  Device Boot Begin Start  End  Blocks   Id  System
> /dev/sda1  *    1      1    251   513891   6  DOS 16-bit >=32M
> /dev/sda2     252    252    976 1484437+  83  Linux native
> /dev/sda3     977    977   1003   55282+  82  Linux swap

Note the "*" is next to the DOS partition.
This will cause the DOS partition to boot, because it's marked as
the "Boot" partition. I'm not sure what MBR (master
boot record) you have. If you have the Debian one, holding the shift key
down while the system boots will cause a "123FA: " prompt (or something
similar). Press 2 and see if Linux comes up.

If you have the DOS MBR, you won't get that prompt. Use FDISK (on DOS or
Linux) or "activate" on Linux to set /dev/sda2 to be the "Boot" partition.
That will also set the _default_ partition booted by the Debian MBR.

> The drive is a SLED (Single Large Expensive Disk).

Are you sure it's not an IPTMCTWTSFN? That means "I Paid Too Much Compared
to What They Sell For Now". I have a whole room full of those. :-)

> Here's the messed up lilo.conf on what now is /target/etc/lilo.conf:
>
> boot=/dev/sda2
> root=/dev/sda2
> install=/target/boot/boot.b
> vga=normal
> delay=20
> image=/target/boot/vmlinuz
> label=Linux

That looks like an OK lilo.conf but it's living on the sda2 partition
(as it should), and you need to set that "Boot" designation or you'll
never run it.

> I can't even begin to speculate on what this is all doing.

At boot time, the boot ROM loads the first block of the disk. The first
446 bytes of that block contain the MBR. The next 66 bytes are the
partition table. If the MBR starts with the right byte pattern, the ROM
jumps into its code. The MBR looks for first partition in the table
with the "Boot" flag set. The first block (maybe more - I don't know)
of that partition is loaded, and the MBR jumps to that code. In your case
that should be what LILO wrote, but the flag is on the wrong partition so
you boot (or try to boot) the DOS partition instead.

	Bruce