FreeCalypso > hg > freecalypso-reveng

annotate pirelli/flash2-chksum @ 275:cbd944ebeff0

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Pirelli PCB RE: traced out Calypso FDP and flash reset input
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 24 Mar 2018 20:38:24 +0000
parents d69f7512e3c1
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
215
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
13 fw update state record
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
24 ====================
d69f7512e3c1 Pirelli: documented and verified the checksum scheme used for the factory block
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
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:
diff changeset
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.