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+SHA1 usage:
+-----------
+
+In the U-Boot Image for the pcs440ep board is a SHA1 checksum integrated.
+This SHA1 sum is used, to check, if the U-Boot Image in Flash is not
+corrupted.
+
+The following command is available:
+
+=> help sha1
+sha1 address len [addr]  calculate the SHA1 sum [save at addr]
+     -p calculate the SHA1 sum from the U-Boot image in flash and print
+     -c check the U-Boot image in flash
+
+"sha1 -p"
+	calculates and prints the SHA1 sum, from the Image stored in Flash
+
+"sha1 -c"
+	check, if the SHA1 sum from the Image stored in Flash is correct
+
+
+It is possible to calculate a SHA1 checksum from a memoryrange with:
+
+"sha1 address len"
+
+If you want to store a new Image in Flash for the pcs440ep board,
+which has no SHA1 sum, you can do the following:
+
+a) cp the new Image on a position in RAM (here 0x300000)
+   (for this example we use the Image from Flash, stored at 0xfffa0000 and
+    0x60000 Bytes long)
+
+"cp.b fffa0000 300000 60000"
+
+b) Initialize the SHA1 sum in the Image with 0x00
+   The SHA1 sum is stored in Flash at:
+			   CFG_MONITOR_BASE + CFG_MONITOR_LEN + SHA1_SUM_POS
+   for the pcs440ep Flash:	 0xfffa0000 +	      0x60000 +        -0x20
+			    = 0xffffffe0
+   for the example in RAM:	   0x300000 +	      0x60000 +        -0x20
+			    = 0x35ffe0
+
+   note: a SHA1 checksum is 20 bytes long.
+
+"mw.b 35ffe0 0 14"
+
+c) now calculate the SHA1 sum from the memoryrange and write
+   the calculated checksum at the right place:
+
+"sha1 300000 60000 35ffe0"
+
+Now you have a U-Boot-Image for the pcs440ep board with the correct SHA1 sum.
+
+If you do a "./MAKEALL pcs440ep" or a "make all" to get the U-Boot image,
+the correct SHA1 sum will be automagically included in the U-Boot image.
+
+Heiko Schocher, 11 Jul 2007