km/common: simplify default environment

This is a first step to simplify the default environment. Move all
the environment variables which are only needed for debugging
purpose to textfiles in the scripts directory. In case of debugging
these files can be loaded via tftp into RAM and set via the env import
command. Other variables are identified as obsolete and were removed.

Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
Acked-by: Heiko Schocher <hs@denx.de>
cc: Wolfgang Denk <wd@denx.de>
cc: Detlev Zundel <dzu@denx.de>
diff --git a/board/keymile/scripts/README b/board/keymile/scripts/README
new file mode 100644
index 0000000..86c2b5a
--- /dev/null
+++ b/board/keymile/scripts/README
@@ -0,0 +1,23 @@
+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