debug-common-env.txt
============================
This file defines environment variables which are valid for powerpc boards
and for arm boards.

addramfs: add phram device for the rootfilesysten in ram
develop: for development, laod kernel via tftp and mount  rootfs via NFS
nfsargs: default arguments for nfs boot
ramfs: load rootfilesystem in RAM  kernel
rootfsfile: loacation of the rootfs file for ramfs
setramfspram: compute PRAM size for ramfs target
setrootfsaddr: compute rootfilesystem address for phram
tftpkernel: load a kernel with tftp into ram
tftpramfs: load rootfs with tftp into ram

debug-ppc-env.txt
============================
fdt_file: location of the dtb file on the tftp server
tftpfdt: load dtb file and set fdt address

debug-arm-env.txt
============================
tftpfdt: for arm only a dummy variable, because we have no fdt on arm
