New experimental multiboot version of memtest86+ only sees 640K of memory

[Burt P.]

Binary package hint: memtest86+

The two new memtest86+ options added in the maverick beta load memtest but only see 640K of memory.
This is on a system that has this problem too: https://bugs.launchpad.net/debian/+source/memtest86+/+bug/19885

Now four unusable memtest options in default grub menu.

[Burt P. (pburt0)]

If I choose (C) configure -> (3) Memory Sizing -> (2) Probe, it will see the full 2GB of memory.
I tried using the official memtest booted directly from a disk, and it worked with (1) BIOS - Std, so this is only happening with this multiboot version.

[Ken (kenmailis)]

I modified memtest.lds to multiboot memtest ELF bootable at different memory locations:
0x5000
0x10000
0x100000

the recompiled memtest ELF bootable booted, but had same problem, it see only 640K memory.
if I select probe, the system hang, I had to cycle power to bring system up again.

[Mantas Kriaučiūnas (mantas)]

Vladimir 'φ-coder' Serbinenko <email address hidden> wrote a patch for fixing memtest86+ multiboot memory detection - I'm attaching that patch from Debian bugreport 568176, but I don't know if this patch will work with new memtest86+ 5.0.1, released at year 2013.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "Patch for fixing memtest86+ 4.20 multiboot memory detection" seems to be a patch. If it isn't, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are a member of the ~ubuntu-reviewers, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issues please contact him.]

[Fantu (fantonifabio)]

I'm working on a new build for debian experimental with version 5.31b but I don't have knowledge about assembly and the boot part except a little something done years ago that I hardly remember anything about, I don't have enough time recently to read up and study the parts. Is there anyone with enough knowledge about it to help me get the correct multiboot part please?

work done for now about memtest86+ package is here: https://salsa.debian.org/debian/memtest86plus/-/commits/debian/experimental

[Fantu (fantonifabio)]

today I did a fast test applying the "newer" multiboot patch I found from coreboot repo (https://review.coreboot.org/plugins/gitiles/memtest86plus/+/8cc1aeb540a02d9600491ca5fa799b7c8f25c363 based on Vladimir Serbinenko taken here), refreshed for 5.31b (https://salsa.debian.org/debian/memtest86plus/-/commit/deed716beaefcd25dd676b291801df7421f1fbf0), did also a small change to fix build fails https://salsa.debian.org/debian/memtest86plus/-/commit/326577b966a18c7c743be36c82985f52c5155804

but testing it on one computer on multiboot entry memtest freeze always at start, so seems another changes/fix are needed

if someone want test it: https://salsa.debian.org/debian/memtest86plus/-/tree/multiboot-test