Re: FYI: GRUB size reduced

[OKUJI Yoshinori]

From: Thierry Laronde <address@hidden>
Subject: FYI: GRUB size reduced
Date: Wed, 21 Feb 2001 16:27:53 +0100

> The result is a 66372 Ko stage2, and I find this size reasonable for an
> installation floppy, if combined with the use of an extended format (I have
> not tested at the moment the patches from Jochen).

In my experiment, I obtained the size 50kb. The key was to get rid of
fancy features (such as password) from stage2.c. At the moment, this
is the only way to reduce the size of stage2.

However, I think it will be the best way to compress the most part of
stage2, in the future. The size of pre_stage2 is about 86kb by default,
and the size of pre_stage2.gz is about 46kb. Because the bootstrap
code is 1kb and the code size of gunzip.c is about 5kb, if stage2
decompresses pre_stage2 on the fly, the size of stage2 would be
52kb. This size is comparable to that of stage2 obtained by omitting
many features in the tricky way, even though nothing is disabled here.

That is one of the things I want to do in GRUB 2. A plan related to
that is to move the user interface from the core image to an external
module (except for the minimal interface required for recovering). For
instance, as the menu interface need not to be supported, unless a
configuration file is found, the functions used for the menu interface
can completely be removed from the core. This will reduce the size of
the core image greatly, and, if we are lucky, the image will be able
to be embedded right after a MBR (so you won't have to use Stage 1.5
any longer). Because the empty space after a MBR is usually merely
31kb (the size we can use for real code is 31 - 1 - 5 = 25kb), this
will be a big challenge!

Okuji