i.MX25 SODIMM PC Boot device options

Voipac i.MX25 SODIMM PC - Development Kit is delivered with E-Fuses left intact by default, not programmed. Booting can be selected from various devices thus allowing all the possible options to be tested.

Modules support multiple booting options:

• NAND Flash
• microSD/MMC
• SPI Flash
• I2C EEPROM

All the configuration signals are tied to supply voltage using external pull-up resistors. These on-module resistors (R600 - R609) ensure that the default state is correctly initialized. More details can be found on page no. 6 of the schematic shipped with the development kit:

Boot configuration resistors can be located in the board assembly drawing.

The procedure described below requires extra care as the faulty E-Fuses will cause permanent module malfunction.

BE AWARE THAT E-FUSES PROGRAMMING IS NON REVERSAL PROCESS!
WARRANTY CLAIM CAUSED BY IMPROPER E-FUSES PROGRAMMING WILL NOT BE ACCEPTED!

Programming E-Fuses

Dumping factory E-Fuses configuration before programming:

barebox:/ md -b -s /dev/imx_iim_bank0
00000000: 10 10 00 00 01 00 00 02 2b 2b 80 00 02 d9 f4 b1 ........++......
00000010: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................

Writing E-Fuses (example set also MAC address 00:01:02:03:04:05):

barebox:/ imx_iim_bank0.permanent_write_enable=1
barebox:/ mw -b -d /dev/imx_iim_bank0 0x1a+6 0 1 2 3 4 5
barebox:/ md -b -s /dev/imx_iim_bank0
00000000: 10 10 00 00 01 00 00 02 2b 2b 80 00 02 d9 f4 b1 ........++......
00000010: 00 00 00 00 00 00 00 00 00 00 00 01 02 03 04 05 ................

More information about E-Fuse bank layout can be found in the official NXP documentation.