U-Boot Custom .config

For Developers
1

I'm attempting to add some configuration updates to my OpenWRT build - namely with the U-Boot package.

My board is based off the am335x-evm, and it uses that UBoot build.

How do I add to the default UBoot Config that OpenWRT's make system adds to UBoot? Where does it pull that config from?

Thanks!

2

U-Boot isn't a package provided by OpenWrt. It would have been installed by the OEM as the device's bootloader. In most circumstances and devices, the bootloader isn't altered to install OpenWrt.

Are you asking how to access U-Boot?

  • generally via serial connector
  • fw-printenv may show you once booted in OpenWrt
3

UBoot is absolutely a package that is included in the OpenWRT buildroot for building OMAP sd card images

2 Likes
4

Except a circumstance such as that.

It's important to mention the device (and why). My bad.

5

Take a look in include/u-boot.mk at UBOOT_CONFIG:=$(1) which later becomes $(UBOOT_CONFIG)_config, it takes name of the device as specified in the package recipe. The config is part of U-Boot source, so You can add patch for the config, like it's done in any other packages, or inject an additional step like it's done here: https://github.com/openwrt/openwrt/blob/main/package/boot/uboot-d1/Makefile#L69.