Bootloader does not start the kernel

[Christoph Pleger]

After the installation has been finished, grub does not start the kernel but
prints an error message "Selected item cannot fit into memory". Since the
machine has 6GB of memory, this seems to be a bug in grub.

[Colin Watson (cjwatson)]

Perhaps this change?

grub (0.95+cvs20040624-8) unstable; urgency=low

  * patches/2gb_limit.diff: New. Fix problem with systems with more than
    2 GB memory (notably, x86_64-based systems). Thanks Goswin Brederlow.

 -- Robert Millan <email address hidden> Sat, 14 Aug 2004 19:29:55 +0200

I don't own a machine with that much memory, though ...

[Colin Watson (cjwatson)]

I've looked at the patch, and I'm not convinced by it; it updates the prototype
of memcheck() and its internal workings, but it doesn't update any of the
callers of memcheck(), so I don't see how it can be 64-bit clean as it stands.

I've mailed the Debian maintainer and the patch submitter asking for clarification.

[Goswin von Brederlow (brederlo)]

The patch doesn't need (and can't) handle 64-bit clean addresses. Grub reads out
the 64bit available memory ranges from the bios and limits itself to the first
4GB of ram before memchecking or loading images. The reason for that is simply
that grub is running in 32bit mode and has no way to access more ram and, even
if it had, 32bit kernel would not be able to start from there.

The patch fixes that values above 2GB become negative with signed ints and then
all comparisons are reversed and fail.

MfG
   Goswin

[Tollef Fog Heen (tfheen)]

ubuntu16 with the 2gb limit patch from Debian unstable grub is just uploaded, which should fix this problem.

[Matt Zimmerman (mdz)]

*** Bug 8608 has been marked as a duplicate of this bug. ***

[Sebastien Bacher (seb128)]

*** Bug 9096 has been marked as a duplicate of this bug. ***