ppc4xx: Add variable "korat_usbcf" for Korat board
The new environment variable "korat_usbcf" selects the USB
port used by the Korat board's CompactFlash controller.
Signed-off-by: Larry Johnson <lrj@acm.org>
Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/doc/README.korat b/doc/README.korat
index 0a59f40..49cd102 100644
--- a/doc/README.korat
+++ b/doc/README.korat
@@ -49,3 +49,17 @@
leaving preprocessor symbol "CONFIG_KORAT_PERMANENT" undefined.
2008-02-22, Larry Johnson <lrj@acm.org>
+
+
+
+The CompactFlash(R) controller on the Korat board provides a hi-speed USB
+interface. This may be connected to either a dedicated port on the on-board
+USB controller, or to a USB port on the PowerPC 440EPx processor. The U-Boot
+environment variable "korat_usbcf" can be used to specify which of these two
+USB host ports is used for CompactFlash. The valid setting for the variable are
+the strings "pci" and "ppc". If the variable defined and set to "ppc", then the
+PowerPC USB port is used. In all other cases the on-board USB controller is
+used, but if "korat_usbcf" is defined but is set to a string other than the two
+valid options, a warning is also issued.
+
+2009-01-28, Larry Johnson <lrj@acm.org>