FreeCalypso > hg > freecalypso-tools

annotate doc/IMEI @ 558:a59a7f838fce

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
CHANGES: better explain that the newly added Am29DL640G flash support also covers S29PL064J and S71PL064J
author Mychaela Falconia <falcon@freecalypso.org>
date Wed, 29 Jan 2020 08:03:19 +0000
parents 4644799cb515
children 232e36a227dd
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
17
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 IMEI vs. IMEISV
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 ===============
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 There is a subtle distinction between an IMEI and an IMEISV. The first 14
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 digits are the same between the two: the supposedly-world-unique number of a
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 given piece of hardware. In a traditional IMEI 15-digit number the significant
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 14 digits are followed by a Luhn check digit, whereas an IMEISV has 16 digits:
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 the 14 significant digits of the IMEI, *no* Luhn check digit, and two digits of
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 "software version".
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11 It is up to device manufacturers and firmware designers to decide whether or
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 not to store the Luhn check digit in the GSM device's flash or EEPROM or
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13 whatever, but it is not sent over the air: instead the IMEISV is sent. It
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 appears that the GSM standard authors' intent was that the IMEI part is stored
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 immutably in each manufactured device whereas the SV digits are added by the
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16 running firmware to indicate its version, but the IMEI handling scheme
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 implemented in TI's reference firmware and retained by many of the TI-based GSM
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18 device manufacturers (at least FIC/Openmoko and Foxconn/Pirelli) dispenses away
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19 with the IMEI vs. IMEISV distinction.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
20
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 IMEI storage and retrieval in TI's reference firmware
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 =====================================================
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24 When running on the plain Calypso as opposed to Calypso+, TI's TCS211 reference
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 firmware supports two ways of storing and retrieving the IMEI: obfuscated and
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 unobfuscated. In both schemes the IMEI datum is stored as a file in the
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27 device's flash file system (FFS), and even though the FFS filename calls it the
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 IMEI, the content of this file is really treated as the IMEISV: 16 digits are
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
29 stored, the firmware function responsible for reading the IMEI datum out of FFS
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
30 and passing it on to the rest of the fw is called cl_get_imeisv(), the code in
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
31 this function does not transform the 16 digits in any way, and the downstream
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
32 recipients of these digits treat them as the IMEISV.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
33
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
34 The two specific schemes offered by TCS211 fw are as follows:
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
35
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
36 In the unobfuscated scheme (FF_PROTECTED_IMEI not defined), the so-called IMEI
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
37 but really IMEISV is stored in an FFS file named /pcm/IMEI. The file is 8 bytes
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
38 long, each byte stores two IMEISV digits, and the order of the digits within
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
39 each byte is reversed relative to the natural order: first the least significant
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
40 nibble is used, then the most significant nibble.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
41
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
42 In the obfuscated scheme (FF_PROTECTED_IMEI is defined), the so-called IMEI but
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
43 really IMEISV is stored in an FFS file named /gsm/imei.enc. The file is 16
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
44 bytes long: the first 8 bytes store the 16-digit IMEISV encrypted with DES,
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
45 using the Calypso die ID as the key, and the last 8 bytes store that Calypso die
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
46 ID DES-encrypted with itself. Underneath the obfuscation, the 16 IMEISV digits
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
47 are stored in the 8 bytes in the natural order: first the most significant
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
48 nibble is used, then the least significant nibble.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
49
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
50 IMEI storage and retrieval schemes implemented by device manufacturers
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
51 ======================================================================
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
52
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
53 Openmoko devices use the unobfuscated IMEI storage method unchanged from TI's
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
54 reference fw: the factory-assigned IMEI is stored in an FFS file named
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
55 /pcm/IMEI, and that is where the original mokoN firmwares look for it. Further
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
56 blurring the distinction between the IMEI and the IMEISV, the 16 digits stored
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
57 in /pcm/IMEI (which the fw treats as the IMEISV) were factory-programmed as the
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
58 15-digit IMEI (with the Luhn check digit) with an appended 0, i.e., the SV
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
59 digits get set to x0 where x is the Luhn check digit.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
60
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
61 Foxconn, the makers of the Pirelli DP-L10, have used the obfuscated version of
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
62 TI's IMEI handling mechanism instead, with an additional twist: instead of
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
63 storing the 16-byte encrypted datum in /gsm/imei.enc in FFS, they have moved it
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
64 into their own factory data record stored in a non-FFS sector of the flash.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
65 The content of the 16 digits treated as the IMEISV by the G23M component of the
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
66 fw is the same as Openmoko's: 15-digit IMEI with the Luhn check digit followed
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
67 by a 0 digit.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
68
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
69 Compal, the makers of Motorola C1xx phones, have similarly moved their IMEI out
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
70 of FFS into their own proprietary flash data structures, and we have never
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
71 decoded the latter, hence we don't know exactly where and how their IMEI is
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
72 stored. If you wish to run FreeCalypso firmware on these phones, you have to
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
73 set your own IMEISV for our fw even if you are not seeking to make it different
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
74 from the factory-assigned one, as we don't know how to retrieve the latter.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
75
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
76 Changing the IMEI
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
77 =================
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
78
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
79 When someone says that they wish to change the IMEI on their phone, they need
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
80 to be a little clearer as to what they really mean, as there are two possible
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
81 interpretations of the just-stated wish:
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
82
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
83 1. Transmitting a different IMEISV toward the network by running your own
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
84 firmware on the device,
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
85
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
86 or
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
87
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
88 2. Changing the IMEI seen by the device's original proprietary firmware.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
89
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
90 Interpretation 1 is much easier than interpretation 2: when you are writing your
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
91 own firmware for an "alien" GSM device (hardware designed and made by someone
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
92 other than you), it is much easier to just set your own IMEISV and be done with
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
93 it than to figure out how to retrieve the factory-assigned one. Thus those
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
94 device manufacturers who try to make it more difficult to change their IMEIs
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
95 are actually creating the opposite effect: people will just set their own IMEISV
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
96 when running their own fw on their hw.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
97
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
98 Openmoko devices are a rare exception in that if you write your own IMEISV into
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
99 /pcm/IMEI in FFS, your new IMEISV will take effect not only with FreeCalypso
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
100 firmware, but also with the legacy mokoN fw versions, because they all look in
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
101 /pcm/IMEI. The same does NOT hold with Compal/Motorola or Foxconn/Pirelli
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
102 phones, however: if you wish to change their IMEI to be seen by their original
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
103 proprietary firmwares, you are on your own, as we do not currently have any
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
104 tools for accomplishing such a feat.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
105
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
106 IMEI handling in FreeCalypso
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
107 ============================
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
108
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
109 The FreeCalypso family of projects has adopted the following IMEI storage and
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
110 retrieval scheme both for our own FreeCalypso-made hardware and for FreeCalypso
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
111 firmwares running on alien hardware: all of our firmware versions regardless of
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
112 target will look first in /etc/IMEISV, then in /pcm/IMEI when needing to obtain
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
113 the IMEISV for GSM operation. This is the new unified convention; previously
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
114 we used varying IMEISV retrieval schemes depending on the target and in
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
115 different FC firmware projects. The new unified convention is backward-
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
116 compatible with our previous schemes on every target.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
117
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
118 The /etc/IMEISV file is a FreeCalypso invention. The file is 8 bytes long, and
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
119 stores the 16 digits of the IMEISV in the natural order: first the most
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
120 significant nibble is used, then the least significant nibble. This nibble
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
121 order makes the IMEISV number directly readable in a hex dump of the file, and
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
122 the filename /etc/IMEISV makes it clear that the last two digits are the SV and
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
123 are not required to be equal to the Luhn check digit and 0.
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
124
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
125 Both /etc/IMEISV and /pcm/IMEI can be written with the fc-fsio utility's
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
126 set-imeisv command:
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
127
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
128 set-imeisv fc XXXXXXXX-YYYYYY-ZZ # write /etc/IMEISV
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
129 set-imeisv pcm XXXXXXXX-YYYYYY-ZZ # write /pcm/IMEI
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
130
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
131 When working on Openmoko devices, we recommend writing your IMEISV into
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
132 /pcm/IMEI (set-imeisv pcm command) and not creating an /etc/IMEISV file: newer
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
133 FC firmware versions will look in both locations, but older FC fw versions and
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
134 the legacy mokoN ones look only in /pcm/IMEI. On all other targets we recommend
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
135 using the new /etc/IMEISV storage format, i.e., you should use the set-imeisv fc
4644799cb515 doc/IMEI written
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
136 variant.