FreeCalypso > hg > freecalypso-reveng

annotate pirelli/flash2-chksum @ 403:50c0fac9a4a8

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compal/boot/c118-dfboot.disasm: new analysis
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 15 Jan 2023 00:54:33 +0000
parents d69f7512e3c1
children
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d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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1 Pirelli's flash usage scheme allocates 3 "magic" areas in the flash2 bank:
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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2
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 offset 0x480000 thru 0x7DFFFF: staging area for high-level fw updates
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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4 offset 0x7E0000 thru 0x7EFFFF: fw update control/state structure
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 offset 0x7F0000 thru 0x7FFFFF: factory record with IMEI and RF calibration
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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6
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 The image or record stored in each of these "magic" areas ends with the
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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8 following 12-byte signature and checksum structure:
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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9
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 Offset[1] Type[2] Contains
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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11 xxFFF4 32-bit word 0x12345678
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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12 xxFFF8 32-bit word Length of the fw update image or factory or
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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13 fw update state record
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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14 xxFFFC 16-bit word Checksum 1
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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15 xxFFFE 16-bit word Checksum 2
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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16
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 [1] The offset is from the beginning of the flash partition in question, the
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 xx digits will be 35 in the case of the 0x360000 byte fw update staging
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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19 area partition or 00 in the case of the two 64 KiB sectors.
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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20
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 [2] All 16-bit and 32-bit values are in little-endian byte order.
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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22
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 Checksum computation
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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24 ====================
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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25
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 The checksum is computed in two stages. First all 16-bit words in the main
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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27 body of the image (using the image length from the xxFFF8 word) are added
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 together as a ripple-carry sum, and this 16-bit sum is written into the 0xFFFC
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 word. Then the 5 16-bit words from xxFFF4 through xxFFFC (inclusive) are added
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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30 together (again as a ripple-carry sum), and this sum is written into the xxFFFE
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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31 word. Remember the little-endian byte order throughout!
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
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32
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33 The ../miscprog/pircksum2.c program verifies this checksum computation scheme.