Using memtest86 with UEFI

[Colin Watson]

On Thu, Apr 14, 2022 at 12:17:16PM -0400, Robert Heller wrote:
> memtest86 appears to a somewhat strange beast:
> 
> sauron% file /boot/memtest86/memtest.bin 
> /boot/memtest86/memtest.bin: DOS/MBR boot sector
> sauron% file /boot/memtest86/memtest.img 
> /boot/memtest86/memtest.img: DOS/MBR boot sector
> sauron% file /boot/memtest
> /boot/memtest: DOS/MBR boot sector
> sauron% fdisk -l /boot/memtest
> Disk /boot/memtest: 161 KiB, 164864 bytes, 322 sectors
> Units: sectors of 1 * 512 = 512 bytes
> Sector size (logical/physical): 512 bytes / 512 bytes
> I/O size (minimum/optimal): 512 bytes / 512 bytes
> Disklabel type: dos
> Disk identifier: 0x52c3ebe2
> 
> Device         Boot    Start        End    Sectors  Size Id Type
> /boot/memtest1      12124343 3284782550 3272658208  1.5T 5a unknown
> /boot/memtest2       6778473    6778473          0    0B 4c unknown
> /boot/memtest4             0          0          0    0B  0 Empty
> 
> Partition table entries are not in disk order.

It's formatted as a boot sector (i.e. something the BIOS can boot from
directly) but that doesn't mean it actually has a partition table.
fdisk is just showing you whatever garbage results from trying to
interpret machine code as a partition table.  The result is meaningless.

-- 
Colin Watson (he/him)                              [cjwatson at ubuntu.com]