Custom uboot configuration - migration from 2015.04 to 2017.03

[nexy_sm]

Hi all,

we recently decided to update our uboot for a custom board based on i.MX6 from 2015.04 to 2017.03. I am now a bit confused, mostly because I am not able to find the documentation. For example, the way of configuring uboot has changed, I see that what used to be before in include config file (from include/configs) is now moved to defconfig file (in configs folder). Having this in mind I have the following questions:

1. Since my board is based on Sabre Auto, if I take configuration of Sabre Auto as a starting point in 2017.03, how should I chage it and adopt it for my board? Should I use menuconfig or not? Or should I change .h files directly?

2. I read that uboot now suports device tree, has a driver model, and is able to configure hardware based on the device tree configuration. Do you recommend using this and how can I simply disable this feature. When I set CONFIG_OF_CONTROL=n I cant compile any more due to the errors.

3. Is it recommended to have a reduced device tree in order to configure only devices which are needed in uboot?

Thank you very much

[gusarambula · Accepted solution]

Hello Nemanja Savic,

There are some guidelines on the BSP Porting Guide which is included as part of the BSP Release’s documentation. This document does cover the generalities of u-boot porting.

(1) If your board is based on the SABRE Auto I would recommend taking the latest BSP as a starting point, as you suggest. The bootloader is independent from the Kernel to some extent so you do not need to use menuconfig and you can change the uboot device tree, definitions and hardware configuration directly to the source files.

(2) If you are using our BSP latest release you will see that the device tree option is used. If you wish to disable it you would need to provide the hardware configuration that is on the device tree on the regular format used by uboot.

(3) You may configure only the devices required for the bootloader and load the rest of the hardware configuration in kernel. Since the kernel and u-boot’s device trees are so similar now some people include most hardware on the bootloader, but it is not necessary.

I hope this information helps!

Regards,