Uboot Upgrade Stategy

[naveedghori]

Hi,

I wanted to know if there was a document detailing a standard strategy to upgrading uboot in the field using the second boot partition. 

We are using eMMC and kernel uboot U-Boot 2014.04. Our kernel is based on version 3.14.28

Obviously we want to use the unused partition to upgrade and then only permanently switch to it once it is known to be good. This will stop bricking in the field. (Most devices have an network interface but not USB (or a way to force serial boot mode).

Best Regards,

Naveed

[Bio_TICFSL]

Hi Naveed,

As you may known, the details for it already in "4.5.7 Software Update and Wipe Partition using Recovery Mode" in User Guide.

For more details, you may search the information from web. For example :
http://www.londatiga.net/it/how-to-create-android-update-zip-package/

Note that :

setenv bootcmd_android_recovery 'run bootargs_base bootargs_android_recovery;mmc read 0 ${loadaddr} 0x800 0x1800;bootm'

0x1800 is the size may be too small . Please modify the value that match you needed.

Regards

[naveedghori]

I think you misunderstand me. I want a strategy to saftely update uboot so that any possibility of bricking the device is removed. THis is for while the device is already programmed and operational in the field.

The switch to the new uboot partition should only happen once we are sure that the new uboot image works.

Eg.

1. Current into linux via current uboot
2. Detect current uboot partition
3. Write new uboot into alternative uboot partition
4. Somehow check new partition: eg boot into new uboot once somehow and if it boot then switch on next reboot, if it fails then on next reset we will boot from the previous uboot partition.
5. Once we are happy that the new uboot is good we switch to it.

Hope this is clearer now.