RE: Details on blocklist in stage2/stage1_5

[Jason Ivey]

Bill, Okuji,

I didn't want to start any debates over this.  PowerQuest was just under
the impression that as found in the documentation there are a number of
well defined variables that we could manipulate.  We have no grand
illusions that these locations and even the implementation of the logic
will remain constant throughout the lifetime of GRUB.  Keeping up to
speed with Microsoft and NTFS without documentation and without source
is something we are accustomed to and have come to expect that with
every new release something will break our functionality.

Back to my original question, I think I understand what I needed to know
about the block lists from looking at the install source.  Okuji, aren't
the values in the run lists calculated at install time and not compile
time?  Since these block lists are describing the physical sector
locations of stage2 then the only time they can be calculated is during
the install process.  Therefore, if PowerQuest changes or moves a
partition which contains the stage2 file we would have to update the
block list.  Also, if in the case where our product either fragments or
defragments the file making a different number of sector runs then we
have to change both the block list and the last two byte field which I
believe is some offset for the starting address of stage2.  

Thanks for your time,

Jason

-----Original Message-----
From: Bill Rees [mailto:address@hidden 
Sent: Thursday, June 20, 2002 1:08 AM
To: Yoshinori K. Okuji
Cc: Jason Ivey; address@hidden
Subject: Re: Details on blocklist in stage2/stage1_5

Well I have written boot loader code for a couple of different
architectures
(ppc, mips and x86) so I'm kind of  familiar with some of the problems.
I'll take a look more closely at the grub code and see if I can propose
something.

bill


----- Original Message -----
From: "Yoshinori K. Okuji" <address@hidden>
To: "Bill Rees" <address@hidden>
Cc: "Jason Ivey" <address@hidden>; <address@hidden>
Sent: Wednesday, June 19, 2002 9:38 PM
Subject: Re: Details on blocklist in stage2/stage1_5


> At Wed, 19 Jun 2002 16:08:38 -0700,
> Bill Rees wrote:
> > Why keep changing these locations?  I like the idea that another
platform is
> > trying to use grub and nailing down at least a tiny protocol to
handle
> > version info or the relocation of version info might be a good move
for
the
> > future.
>
> Have you even written any boot loader yourself? MBR is too small, so
> the implementation is always tricky. That means that it isn't feasible
> to keep things unchanged.
>
> Okuji
>