Re: Question about multiboot

[OKUJI Yoshinori]

From: Luca Abeni <address@hidden>
Subject: Question about multiboot
Date: Fri, 17 Nov 2000 17:13:17 -0500

> Now, how can the kernel understand which part of the upper memory is
> free (part of that memory contains the kernel itself and the modules)?
> Must the kernel computes the free memory by itself , or does the
> multiboot standard provide some way to obtain that information?

  The former is correct. It is up to you how to use memory.

> In the first case, is the maximum between the _end symbol and all the
> mod_end a safe assumption for the first free address in upper memory? 

  No. Multiboot Specification 0.6 specifies nothing about this. I'm
planning to add some restrictions about the positions of modules and
Multiboot info into 0.7, but you shouldn't assume that at the
moment. So you need to deal with fragmented memory zones. Anyway, this
is necessary, because many PC machines have memory holes.

Okuji