1SHA1 usage: 2----------- 3 4In the U-Boot Image for the pcs440ep board is a SHA1 checksum integrated. 5This SHA1 sum is used, to check, if the U-Boot Image in Flash is not 6corrupted. 7 8The following command is available: 9 10=> help sha1 11sha1 address len [addr] calculate the SHA1 sum [save at addr] 12 -p calculate the SHA1 sum from the U-Boot image in flash and print 13 -c check the U-Boot image in flash 14 15"sha1 -p" 16 calculates and prints the SHA1 sum, from the Image stored in Flash 17 18"sha1 -c" 19 check, if the SHA1 sum from the Image stored in Flash is correct 20 21 22It is possible to calculate a SHA1 checksum from a memoryrange with: 23 24"sha1 address len" 25 26If you want to store a new Image in Flash for the pcs440ep board, 27which has no SHA1 sum, you can do the following: 28 29a) cp the new Image on a position in RAM (here 0x300000) 30 (for this example we use the Image from Flash, stored at 0xfffa0000 and 31 0x60000 Bytes long) 32 33"cp.b fffa0000 300000 60000" 34 35b) Initialize the SHA1 sum in the Image with 0x00 36 The SHA1 sum is stored in Flash at: 37 CONFIG_SYS_MONITOR_BASE + CONFIG_SYS_MONITOR_LEN + SHA1_SUM_POS 38 for the pcs440ep Flash: 0xfffa0000 + 0x60000 + -0x20 39 = 0xffffffe0 40 for the example in RAM: 0x300000 + 0x60000 + -0x20 41 = 0x35ffe0 42 43 note: a SHA1 checksum is 20 bytes long. 44 45"mw.b 35ffe0 0 14" 46 47c) now calculate the SHA1 sum from the memoryrange and write 48 the calculated checksum at the right place: 49 50"sha1 300000 60000 35ffe0" 51 52Now you have a U-Boot-Image for the pcs440ep board with the correct SHA1 sum. 53 54If you do a "buildman -k pcs440ep" or a "make all" to get the U-Boot image, 55which will be found in ../current/ipam390/ - the correct SHA1 sum will be 56automagically included in the U-Boot image. 57 58Heiko Schocher, 11 Jul 2007 59