Memory test coverage

[sherp]

Hi,

My understanding is that Memtest86 is self relocating, hence able to test the memory region it is executing from in a following step.

Does Memtest relocate BIOS memory regions as well? I doubt it as BIOS is unlikely to be built as position independent code?
Any other memory regions that are not/unlikely to be covered?

Thanks!

[David (PassMark)]

Yes Memtest86 V4 relocates itself. Many devices occupy part of a PC's address space (this is called Memory mapped I/O). Video cards, timers, sound cards, SATA controller, etc.. all hide some of the RAM's address space.

In a correctly configured BIOS there is a memory map of memory locations that are save to test.

If you want to see what this looks like you can go into Windows device manager and select View / Resources by type from the menu.

In future UEFI versions of the software, this might not be the case as we can't relocate all the UEFI code that gets loaded automatically.

[sherp]

In a correctly configured BIOS there is a memory map of memory locations that are save to test.

OK, makes sense to me now.

Thanks.