Change boot option from OS

Ten64 Forum
1

Hi,
Is it possible to change next boot to other OS?
I have OpenWRT on NAND and UBUNTU on NVM.
I don’t have serial connection to the unit. I want booot next time to different OS, that first in u-boot variables. From OpenWRT i can reach u-boot environment (fw_printenv/fw_setenv) and change it. From ubuntu i cannot do it. Is any way to reach u-boot variables from linux? Is other way to change boot option from remote?

Thanks,
Dmitry

2

This is now possible on the new firmware versions (v0.9.x and later).

Access to the flash (NOR and NAND) from NVMe/USB/sdcard was disabled in the previous versions for multiple reasons:

  • Older versions of some distributions contained a flash driver which was not able to access the NAND chip, and could corrupt it if used incorrectly

  • At the time, it was anticipated that a solution for EFI variables via U-Boot would come out. The community has since decided on another method which does not touch the flash from the OS.

If you want, you can re-enable this in the earlier U-Boot by deleting the following portion of the setup_distroboot_efi variable:

fdt set "/soc/spi@20c0000" "status" "disabled"

(be careful attempting this remotely, the boot process will get stuck if not edited correctly)

I’m not aware of any method to re-enable it from a running operating system.

3

Thanks, @mcbridematt !
After update to 0.9.1 and configure /etc/fw_env.config i can reach u-boot env partition.
Could you point me what variable used to boot without menu entering?
It changes from 0.8 firmware.

Thanks!

4

Do you mean, which commands you should set to boot each source (disk vs NAND) directly?

Adjusting the bootcmd variable should work now:

# For OpenWrt
fw_setenv bootcmd 'run bootcmd_openwrt_nand'

# For bootflow boot (NVMe/SD/USB)
fw_setenv bootcmd 'bootflow scan -lb'

If you need to boot from a drive that is not the first detected, you will need to use some combination of bootflow scan -l and bootflow select .

The bootflow documentation shows what options you can use: bootflow command — Das U-Boot unknown version documentation