U-boot env offset

• OJ

  O. JUD

  8/14/23, 3:54 PM

  Hi, 

  Could you confirm that your version U-boot save environment variable at default adresses from NXP documentation as below when yocto image is burned on emmc ? 

  CONFIG_ENV_SIZE=0x4000
  CONFIG_ENV_OFFSET=0x400000

  I tried to read with hexdump on /dev/mmcblk2 and nothing is showed . 

  Can you provide the good values. 

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• KK

  Kothandaraman Kannadasan Staff member

  8/24/23, 1:31 AM

  Dear @O. JUD,

  iMX8MP UBoot is configured to use the default ENV_SIZE and ENV_OFFSET specified by NXP.

  CONFIG_ENV_SIZE=0x4000
  CONFIG_ENV_OFFSET=0x400000

   

  We were able to read out the uboot environment saved at offset 0x400000 of eMMC using hexdump.

  Below is the command used for dumping the uboot environment:

  $ hexdump -s 0x400000 -n 0x4000 -C /dev/mmcblk2

   

  

   

  You should make sure 'saveenv' uboot command is executed at least once prior to dumping the uboot environment so that environment is stored in the specific offset of eMMC.
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