Config

# default
/tftpboot/pxelinux.cfg/default

Kernel Boot Parameters

vga=791 - set screen resolution to 1024x768
noapic - disable APIC support (on broken motherboards)
textonly - boot to console

update pxelinux.0

cp /usr/lib/syslinux/pxelinux.0 /tftpboot/
cp /usr/lib/syslinux/menu.c32 /tftpboot/

Links
http://www.memtest86.com/ - Memtest86
http://www.memtest.org/ - Memtest86+
http://www.goldmemory.cz/ - GoldMemory
http://people.debian.org/%7Ejoeyh/d-i/images/daily/netboot/ - Debian PXE Instalation