[LEDE-DEV] WRT1900ACS - Kernel 4.4.12 boot failure

[Claudio Leite]

On 06/07/2016 11:00 AM, Claudio Leite wrote:
> On 06/07/2016 10:48 AM, Dheeran Senthilvel wrote:
> [snip]
>> =======> Step 3: Reboot <======
>>     After the above procedures, I don’t have the error anymore.
>
> Great -- so you're all set, as far as you can tell?
>
>> Wonder what really caused the problem in first place.
>
> Given the date when you initially had the issue I suspected that it was
> due to bugs in the NAND driver that potentially messed things up in your
> u_env. I would have expected 'resetenv' to make quick work of cleaning
> that up.
>
> It sort of looks like resetenv only half-cleared the problem. At least
> on the other model I tested it on it claims to erase the partition.
> Something goes wrong at some point here on your model and the old
> corrupted data was kept. 'saveenv' forces rewriting the good data back
> to flash.

Responding to myself -- it looks like the "corruption" from u-boot I 
thought was going on was just the defaults from uboot-envtools. 
fw_setenv, when trying to write the 'auto_recovery=yes' value during 
boot, was committing these to the then-empty flash partition.

root at wrt1900ac:/tmp# mtd erase u_env
Unlocking u_env ...
Erasing u_env ...
root at wrt1900ac:/tmp# fw_printenv
Warning: Bad CRC, using default environment
bootcmd=bootp; setenv bootargs root=/dev/nfs 
nfsroot=${serverip}:${rootpath} 
ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off; bootm
bootdelay=5
baudrate=115200
root at wrt1900ac:/tmp# fw_setenv test blah
Warning: Bad CRC, using default environment
root at wrt1900ac:/tmp# fw_printenv
bootcmd=bootp; setenv bootargs root=/dev/nfs 
nfsroot=${serverip}:${rootpath} 
ip=${ipaddr}:${serverip}:${gatewayip}:${netmask}:${hostname}::off; bootm
bootdelay=5
baudrate=115200
test=blah
root at wrt1900ac:/tmp#

So, no corruption at all. The bootloader resetenv just didn't commit the 
default values back to flash.

-Claudio