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Benoît Thébaudeaueec3f022013-04-23 10:17:47 +00001U-Boot for Freescale i.MX6
2
3This file contains information for the port of U-Boot to the Freescale i.MX6
4SoC.
5
61. CONVENTIONS FOR FUSE ASSIGNMENTS
7-----------------------------------
8
91.1 MAC Address: It is stored in fuse bank 4, with the 32 lsbs in word 2 and the
10 16 msbs in word 3.
Fabio Estevam6f3bef92013-12-23 13:07:17 -020011
12Example:
13
14For reading the MAC address fuses on a MX6Q:
15
16- The MAC address is stored in two fuse addresses (the fuse addresses are
17described in the Fusemap Descriptions table from the mx6q Reference Manual):
18
190x620[31:0] - MAC_ADDR[31:0]
200x630[15:0] - MAC_ADDR[47:32]
21
22In order to use the fuse API, we need to pass the bank and word values, which
23are calculated as below:
24
25Fuse address for the lower MAC address: 0x620
26Base address for the fuses: 0x400
27
28(0x620 - 0x400)/0x10 = 0x22 = 34 decimal
29
30As the fuses are arranged in banks of 8 words:
31
3234 / 8 = 4 and the remainder is 2, so in this case:
33
34bank = 4
35word = 2
36
37And the U-boot command would be:
38
39=> fuse read 4 2
40Reading bank 4:
41
42Word 0x00000002: 9f027772
43
44Doing the same for the upper MAC address:
45
46Fuse address for the upper MAC address: 0x630
47Base address for the fuses: 0x400
48
49(0x630 - 0x400)/0x10 = 0x23 = 35 decimal
50
51As the fuses are arranged in banks of 8 words:
52
5335 / 8 = 4 and the remainder is 3, so in this case:
54
55bank = 4
56word = 3
57
58And the U-boot command would be:
59
60=> fuse read 4 3
61Reading bank 4:
62
63Word 0x00000003: 00000004
64
65,which matches the ethaddr value:
66=> echo ${ethaddr}
6700:04:9f:02:77:72
68
69Some other useful hints:
70
71- The 'bank' and 'word' numbers can be easily obtained from the mx6 Reference
72Manual. For the mx6quad case, please check the "46.5 OCOTP Memory Map/Register
73Definition" from the "i.MX 6Dual/6Quad Applications Processor Reference Manual,
74Rev. 1, 04/2013" document. For example, for the MAC fuses we have:
75
76Address:
7721B_C620 Value of OTP Bank4 Word2 (MAC Address)(OCOTP_MAC0)
78
7921B_C630 Value of OTP Bank4 Word3 (MAC Address)(OCOTP_MAC1)
80
81- The command '=> fuse read 4 2 2' reads the whole MAC addresses at once:
82
83=> fuse read 4 2 2
84Reading bank 4:
85
86Word 0x00000002: 9f027772 00000004