Accessing UBoot env from user space

Technical Support for Routers
1

My AR-300m (“Shadow”) can read its U-Boot environment from Linux with the fw_printenv command after I set the /etc/fw_env.config to:
/dev/mtd1 0 0x10000

However, I cannot find any information on the proper fw_conf.config for the AR750S (“Slate”)

#fw_printenv
Warning: Bad CRC, using default environment
…

Has any managed to get this working?

Strangely:

hexdump /dev/mtd1

shows the dev paritition is erased to All 0xff’s

whereas on the Shadow, it contains the env variables.

Both units /proc/mtd indicate that the u-boot-env should be

/dev/mtd: 00010000 00010000 “u-boot-env”

I’m stumped…

Both routers are running 19.07.7 from NAND flash

Is the /dev/mtd1 partition usually erased?!

2

The partition is usually erased. If no data in this partition, uboot will just use default values.

Are you able to write using fw_setenv?