Using memtest86 with UEFI

[Robert Heller]

At Thu, 14 Apr 2022 18:22:00 +0100 "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> 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.

And it is probably not something the UEFI boot code knows what to do with.  
That is, it is not a UEFI boot loader.

> 

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