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diff --git a/doc/README.imx6 b/doc/README.imx6 index 513a06e..437af2f 100644 --- a/doc/README.imx6 +++ b/doc/README.imx6 @@ -8,3 +8,79 @@ SoC. 1.1 MAC Address: It is stored in fuse bank 4, with the 32 lsbs in word 2 and the 16 msbs in word 3. + +Example: + +For reading the MAC address fuses on a MX6Q: + +- The MAC address is stored in two fuse addresses (the fuse addresses are +described in the Fusemap Descriptions table from the mx6q Reference Manual): + +0x620[31:0] - MAC_ADDR[31:0] +0x630[15:0] - MAC_ADDR[47:32] + +In order to use the fuse API, we need to pass the bank and word values, which +are calculated as below: + +Fuse address for the lower MAC address: 0x620 +Base address for the fuses: 0x400 + +(0x620 - 0x400)/0x10 = 0x22 = 34 decimal + +As the fuses are arranged in banks of 8 words: + +34 / 8 = 4 and the remainder is 2, so in this case: + +bank = 4 +word = 2 + +And the U-boot command would be: + +=> fuse read 4 2 +Reading bank 4: + +Word 0x00000002: 9f027772 + +Doing the same for the upper MAC address: + +Fuse address for the upper MAC address: 0x630 +Base address for the fuses: 0x400 + +(0x630 - 0x400)/0x10 = 0x23 = 35 decimal + +As the fuses are arranged in banks of 8 words: + +35 / 8 = 4 and the remainder is 3, so in this case: + +bank = 4 +word = 3 + +And the U-boot command would be: + +=> fuse read 4 3 +Reading bank 4: + +Word 0x00000003: 00000004 + +,which matches the ethaddr value: +=> echo ${ethaddr} +00:04:9f:02:77:72 + +Some other useful hints: + +- The 'bank' and 'word' numbers can be easily obtained from the mx6 Reference +Manual. For the mx6quad case, please check the "46.5 OCOTP Memory Map/Register +Definition" from the "i.MX 6Dual/6Quad Applications Processor Reference Manual, +Rev. 1, 04/2013" document. For example, for the MAC fuses we have: + +Address: +21B_C620 Value of OTP Bank4 Word2 (MAC Address)(OCOTP_MAC0) + +21B_C630 Value of OTP Bank4 Word3 (MAC Address)(OCOTP_MAC1) + +- The command '=> fuse read 4 2 2' reads the whole MAC addresses at once: + +=> fuse read 4 2 2 +Reading bank 4: + +Word 0x00000002: 9f027772 00000004 |