booting memtest86 from USB stick

I want to boot memtest86 from my USB stick with syslinux.

I have installed the packages memtest86 and memtest86+ and copied the .bin files to my USB stick.

I have added the entry to syslinux.cfg:

LABEL memtest
    MENU LABEL Memtest86
    KERNEL memtest86.bin

LABEL memtest+
    MENU LABEL Memtest86+
    KERNEL memtest86+.bin

but this does not work. When I boot, I get endless printout on my screen:

How can I boot memtest86 from USB stick ?

Solution

TL;DR:

please replace the KERNEL command with LINUX, or
rename your memtest86.bin to memtest86 or anything else.

From the syslinux wiki:

KERNEL file

Select the file SYSLINUX will boot. The "kernel" doesn't have to be a Linux kernel, it can be a boot sector or a COMBOOT file.

Because neither Linux kernel boot sector images, nor COMBOOT files have reliable magic numbers, Syslinux will look at the file extension. The following extensions are recognized (case insensitive):

none or other - Linux kernel image

.bin - CD boot sector

...

Using one of these keywords instead of KERNEL forces the filetype, regardless of the filename:

LINUX image

You can use this, instead of using KERNEL file to boot a linux kernel image.

...

Hence your memtest86 kernel was wrongly recognized as a boot sector image.

There are also similar reports from this blog post:

When trying to boot Memtest86 I see "0104" repeating forever. What's wrong?

You probably called the kernel "memtest86.bin". If the file extension is ".bin", PXELinux will try to load the file as a MBR instead of a kernel file. Rename the file and change the configuration, everything will work fine then.