On Tue, Jan 01, 2008 at 06:26:49PM +0100, Christian Franke wrote:
> >>--- grub2.orig/kern/i386/pc/init.c 2007-10-22 22:22:51.359375000 +0200
> >>+++ grub2/kern/i386/pc/init.c 2007-12-31 16:05:59.953125000 +0100
> >>@@ -199,13 +199,8 @@ grub_machine_init (void)
> >>
> >> if (eisa_mmap)
> >> {
> >>- if ((eisa_mmap & 0xFFFF) == 0x3C00)
> >>- add_mem_region (0x100000, (eisa_mmap << 16) + 0x100000 * 15);
> >>- else
> >>- {
> >>- add_mem_region (0x100000, (eisa_mmap & 0xFFFF) << 10);
> >>- add_mem_region (0x1000000, eisa_mmap << 16);
> >>- }
> >>+ add_mem_region (0x100000, (eisa_mmap & 0xFFFF) << 10);
> >>+ add_mem_region (0x1000000, eisa_mmap & ~0xFFFF);
> >> }
> >> else
> >> add_mem_region (0x100000, grub_get_memsize (1) << 10);
> >>
> >
> >Ok, as it seems, this comes from:
> >
> > * grub_get_eisa_mmap() : return packed EISA memory map, lower 16 bits is
> > * memory between 1M and 16M in 1K parts, upper 16 bits is
> > * memory above 16M in 64K parts. If error, return zero.
> >
> >So the replacement of "eisa_mmap << 16" seems obviously correct, but the
> >"0x3C00" part you removed is completely misterious to me. Can you explain
> >what was it supposed to be doing or why you removed it?
> >
> >
>
> This part is intended to handle the (normal) case of one continuous
> region with not gap between 1M and 16M:
> (0x3C00 << 10) = 0x100000 * 15 = 15M
> But this part does not work due to the same bug.
>
> It is IMO not necessary to make this distinction. The function
> compact_mem_regions() called a few lines later joins the two regions anyway.
Ah, ok. Have you verified that this is so? (setting debug=mem variable
during init might help on that).
Sorry for being so inquisitive, but I need to understand things well before
touching this part of GRUB, which as I said I'm not very familiar with.
--
Robert Millan
<GPLv2> I know my rights; I want my phone call!
<DRM> What use is a phone call, if you are unable to speak?
(as seen on /.)
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