Re: [PATCH] [RFC] be more verbose when probing EDD

H. Peter Anvin
2007-12-22T02:22:58Z

Andi Kleen wrote:
>> Those don't live in an area of memory which is hard-limited to 32K.
>
> Why not 64k?
>

Because the bootloader needs some memory in the same segment that it
controls. Furthermore, since there were some residual uses of the
0x9000 segment (now removed, but not all bootloaders could be easily
fixed), we were limited to about 40K for everything.

Unfortunately we already have the problem that some bootloaders (notably
LOADLIN and mknbi) hardcoded an arbitrary limit which was even smaller
than that (about 16K, which we're already pushing up against.)

> Ok, that's a different argument than before. Ok. Although it's
> only a few bytes.
>
> I would lobby for any message at least contain the suggestion to try
> edd=off. That could save users a lot of time.

The important thing is that there is a message before and after. The
rest can be dealt with by Google on in documentation. That's what the
patch currently in x86setup.git does.

-hpa