FreeCalypso > hg > freecalypso-hwlab
annotate eeproms/dumps/FT232R-notes @ 48:af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 22 Apr 2019 21:36:48 +0000 |
parents | |
children | 4e13c90c1405 |
rev | line source |
---|---|
48
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
1 Unlike FT2232x devices with external EEPROMs, an FT232R device is not expected |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
2 to ever have a blank EEPROM in normal usage: these chips have their EEPROM |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
3 built in, and FTDI ships them with this internal EEPROM already programmed. |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
4 It may be possible to create a "blank" EEPROM by explicitly programming 0xFFFF |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
5 into every word, but it would be an unnatural scenario, and I (Mother Mychaela) |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
6 do not currently have an FT232R device on which I can experiment: I don't have |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
7 an FT232R device which is not valuable and which is not already bricked. |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
8 |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
9 I have read out the EEPROM content from the two specimen I did have available: |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
10 FT232R-specimen1 came from a no-name ebay-sourced FT232RL breakout board; |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
11 FT232R-specimen2 came from George UberWaves' "FTDI Professional" USB-serial |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
12 cable with OsmocomBB branding. Specimen 2 is probably a genuine FT232RL chip |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
13 (I remember George telling me that he went out of his way to procure genuine |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
14 FTDI chips after having been burned by FTDI's Winblows drivers screwing around |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
15 with close-but-not-perfect clones), but specimen 1 is suspected to be one of |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
16 those less-than-perfect clones: the serial number string was programmed to |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
17 "00000000", whereas FTDI supposedly program true per-unit serial numbers. |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
18 |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
19 The only diffs between FT232R-specimen1 and FT232R-specimen2 are the just- |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
20 mentioned serial number string (specimen 2 has it set to "A9031HG6", which looks |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
21 like a real per-unit serial number), two non-understood "garbage" words after |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
22 the last string, and of course the checksum. |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
23 |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
24 The unit that was specimen 1 (the suspected fake) is now bricked: when I tried |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
25 to program my own EEPROM config generated with ftee-gen232r, the resulting |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
26 EEPROM content became a bitwise AND between the previous image and the new one, |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
27 as if the "EEPROM" is not really an erasable memory, but one of OTP kind where |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
28 ones can be turned into zeros, but not the other way around. I am not willing |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
29 to experiment on the specimen 2 chip because it is part of a valuable cable |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
30 assembly which I don't want to risk bricking, so I will need to order more |
af70c59654ed
EEPROM dumps moved into eeproms/dumps and properly annotated
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff
changeset
|
31 sacrificial hardware and wait for it to arrive before I can experiment further. |