Memtest86+

memtest86+ is memory test software based on the (commercially available) memtest86 program.

GRUB legacy
Replace the  (question marks) in the file below with correct numbers for the system's boot partition:

GRUB2
For grub2 just run, as long as the package has been emerged, a configuration file has already been installed to :

lilo
For lilo, add this to the lilo configuration file:

Then rebuild lilo's MBR entry:

External resources

 * http://www.pcworld.com/article/232640/memtest86.html - A PCWorld article describing the usefulness and features of memtest86+.