CM-T43: U-Boot: Creating a bootable SD card

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CM-T43 system-on-module uses SPI flash as its main boot storage. In addition to the on-board SPI flash, the CM-T43 can also boot from an SD card. This article describes the preparation and boot process using an SD card.

SD card requirements

The CM-T43 firmware can be written as raw data, or as a set of files in a FAT formatted partition.

  • If using the raw data option, make sure that:
    • The SD card partitions do not start in the first 1MB of the SD card. Otherwise, the partitions may be overwritten by this procedure.
  • If using the filesystem option:
    • Format the SD-card with FAT16/32
    • Use MBR to store partition data

Installing firmware on an SD card

Installing firmware as raw data

  • Insert the SD card into the workstation card reader
  • The SD card will be identified as /dev/sdX, where X is the SD card drive letter.
  • Run the following command:
dd if=cm-t43-firmware of=/dev/sdX bs=1K seek=320 oflag=dsync

Installing firmware as files in a FAT formatted partition

  • Copy the file MLO located in the images folder into the SD-card partition.
  • Copy the file u-boot.img located in the images folder into the SD-card partition.

Booting from an SD card

  • Plug the SD card into the P9 SD card socket of the SB-SOM-T43
  • Hold the ALT.BOOT (SW3) button while resetting/powering on the CM-T43 evaluation system
  • The CM-T43 will boot from the SD card

See also