VAR-SOM-AM43 Yocto NAND Recovery

From Variscite Wiki

1 NAND Recovery introduction

As an easy and fast way to recover the VAR-SOM-AM43 NAND flash, Variscite provides a recovery SD card image that can be used to install the pre-built Linux and Android systems.
This SD card image includes a script (nand-recovery.sh) that installs all the boot images and root file-system.

Preparing rescue SD-Card

  • Plug your SD card to your Linux machine, run dmesg and see what device is added (i.e. /dev/sdX)
  • gunzip am43-som-nand-recovery-sd.vX.img.gz (get latest)
  • dd if=am43-som-nand-recovery-sd.vX.img of=/dev/sdX bs=128k

2 Creating Variscite's prebuilt rescue SD-Card

$ sudo umount /dev/sdX*
$ zcat am43-som-nand-recovery-sd.vX.img.gz | sudo dd of=/dev/sdX bs=1M

Replace /dev/sdX with your actual device.

3 Connect target debug serial to linux host

Follow : http://www.variscite.com/images/stories/DataSheets/VAR_DVK_AM43_Quick_Start_Guide.pdf
to connect target serial debug port to host PC

4 Boot NAND recovery SD-Card

  • Power-off the board.
  • Insert the SD card into the SD/MMC slot of the carrier board (DVK)
  • Push SW1 to SD-Card mode (On), and SW2 to non-eMMC (off)
  • The board will automatically boot into Linux from SD-Card
  • login as 'root', no password is required


5 NAND recovery script usage


NAND recovery script usage:

/sbin/nand-recovery.sh 

This script installs the Linux binaries on the VAR-SOM-AM43 NAND-Flash.