Re: grub-install

[P@draigBrady.com]

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Yoshinori K. Okuji wrote:
> On Monday 25 July 2005 04:04, Hollis Blanchard wrote:
> 
>>Is there a reason not to add all modules all the time?
> 
> 
> I should have written more info in English. This is documented well, but only 
> in Japanese.
> 
> There are several reasons. In the context of i386-pc:
> 
> - The size problem. We must keep the core image at least 31KB, so that we can 
> embed it into the space right after the MBR. This is the most important 
> reason. Very specific to i386-pc. I have no idea if other architectures have 
> similar restrictions, but probably they do.

In case others don't know the reason for "31KB":

As can be seen in the attached common linux disk layout diagram,
the optional DOS compatability region used by stage 1.5 is added by
default by most partition managers, and is there so that partitions
start on a cylinder boundry. Therefore its size is determined by the
number of sectors (512 bytes) per cylinder. The maximum sectors per
cylinder is 64, and so the largest size available for grub's stage 1.5
is 63 * 512, or 32256 bytes.

Pádraig.

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