How do I use memmap to reserve memory on boot?

Question

I have a laptop with some corrupted ram addresses, so I'm trying to use memmap to reserve them before linux boots up.

I have been trying to use memmap=10M$1024M as a kernel boot option, but linux crashes (with no errors) and restarts. If I use a different syntax for memmap like memmap=1023M@0M it boots fine.

Do I have to specify a certain size block to reserve or could my kernel version not support reserving memory with memmap?

Maybe I'm better off using memmap=exactmap, and if so, could somebody point me to a good faq on how to use it?

Solution

i stumbled upon this:

http://www.gnu.org/software/grub/manual/html_node/badram.html#badram

This command notifies the memory manager that specified regions of RAM ought to be filtered out (usually, because they're damaged). This remains in effect after a payload kernel has been loaded by GRUB, as long as the loaded kernel obtains its memory map f> rom GRUB. Kernels that support this include Linux, GNU Mach, the kernel of FreeBSD and Multiboot kernels in general.

maybe that helps?

Comments

[alexl]

Im currently in a foreign country where its difficult to get any new parts, so Im looking for a fix for the next two months.

[ZaB]

Use memtest86 and set badram parameters....