This error indicates that you are trying to load an image that does not fit into your system memory map. For example, the image may request that it is loaded at an address that is already in use by iPXE or by the system BIOS.

If you see this error while trying to load memtest86+, then try using the ELF version of memtest86+ instead of the standard zImage version. You can download the ELF version from http://boot.ipxe.org/memtest.bin.1)

Update: Memtest86+ 5.01 seems to still suffer from this issue. The zImage can be loaded directly as a kernel on VirtualBox, but seems to fail on a physical machine.

This error is known to occur with some images produced by the old mknbi tool. If you are using an NBI image, try regenerating your image using the more up-to-date wraplinux tool.

1)
The ELF version of memtest86+ is built from the memtest86+ source code using 
  make memtest
WarningSome versions of GNU binutils seem to have a bug that requires the following workaround patch to memtest.lds:
-       .data : {
+       .data : AT ( 0xa000 ) {