On Thu, 16 Sep 1999, Sean wrote:

*plays the devil's advocate*

"David A. Gatwood" wrote:

quoted

On Wed, 15 Sep 1999, Tom Rini wrote:

quoted

quoted

quoted

So I'm not sure what you mean then by the "bootblock of the disk".

on intel machines disks are typically use the very first 512 bytes on
a disk as a bootblock and partition table, the bootblock portion of
this is something like 446 bytes long, the BIOS when booting the
machine has a boot device specified all it does it load that 446
bytes into memory and execute it that code could be the NT loader the
old DOS/win95 loader or it could be LILO, that code then can do
whatever it need to do.  in lilos case it loads its second stage
loader from the root filesystem and that takes care of loading the
kernel, if you replace ext2fs with xfs all that needs updating is
possibly the second stage LILO.  no specific partition or filesystem
is needed and the BIOS does not care what filesystem you use.

But a good loader knows how to deal w/ FSes.  The FreeBSD loader is
wonderful, and can boot any kernel on the disk, unlike lilo.

How many times do you compile your Linux kernel under say windows or the
macos so it would actually be on a different type of FS where this would
actually be an issue? *ponders*

Build... never.  Download... frequently.

quoted

Any booter that doesn't understand filesystems and has to have a list of
blocks is a serious kludge.  For instance, who is to say that you want to
boot off a block device at all?  And what if I wanted to replace a kernel
from within another OS?  Can you say pain in the...

if you dont have a block device, and your not going to boot from it than
why would you worry about whether you have a bootloader installed on a
block device? 

True enough.

weird i have installed on dozens of systems and lilo has worked
flawlessy, although I have had problems with WD E-Z drive writing over
the boot block stuff a few times(but only windows people are stupid
enough to use it), and I have had to wrestle with some scsi drives, though.

Try making it share a large disk with FreeDOS, and you'll find one
problem.  Try using a large ramdisk and you'll find a second.  Those are
the ones that come to mind immediately.

quoted

Depending on
a particular block to be always unused is more than a kludge, it's
downright dangerous.  What if two architectures share a drive?  What if
they happen to pick the same critical boot block?  Baaaad idea.  At least
if it's a filesystem at a particular location, you can read it and say
"hey, that's not a valid fs" or "hey, that partition table is bogus".
With a boot block, there are no second chances.  You just crash.

Lilo, can handle at least 3 OS's.

I was referring more to setting up  a system in which a driveis shared
between different machine types, like PPC and x86, for example.  Probably
not a good example, and difficult to do in practice, at least with current
hardware.

and it also gives errors as best it
can when it crashes.

LI

;-)


David


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