Build U-boot for the EMC2 board

[Antonio.Paolillo]

Dear all,

We are currently progressing on the usage of the EMC2 board in the context of the Tulipp Work Package 3.
We're trying to bring-up the board by running an updated version of U-boot (http://www.denx.de/wiki/U-Boot and http://www.wiki.xilinx.com/Build+U-Boot).
To run HIPPEROS on an embedded board, we need a patched version of U-boot.

Our goal is to combine FSBL and U-boot on a boot.bin file with the Xilinx bootgen utility, put this file on the sd-card and get as a result the uart port giving an U-boot console.

U-boot is currently working on other Zynq boards such as the ZedBoard and the ZC702.

On the trenz website (the daughter board fixed on the EMC2 board), we found a prebuilt package for the daughter board (TE0715) with a u-boot.elf file (containing an old U-boot version).
We can find this package here:
https://shop.trenz-electronic.de/en/TE0 ... Electronic
Click on "Downloads" tab -> "Reference Designs" -> "2015.4" -> "test_board".

We manage to run this U-boot version on the EMC2 by following these steps:
1) create the FSBL for TE0715 with the Vivado toolchain.
2) combine this FSBL with u-boot.elf image to create the boot.bin file
3) create an sd card with boot.bin file
4) the board booted and a console is available through UART-USB to drive it from a PC

We followed the same flow for the hello world example packed in the same archives and it worked.

Our question is: how do we manage, with the Xilinx U-boot, to create this u-boot.elf file.
We need the configuration specific to the TE0715-03 daughter board, but we don't find and _defconfig file to build U-boot for this board.
We cloned the U-boot repo and we put in u-boot-xlnx/zynq/zynq_te0715 the ps7_init.h/c files.
We need a zynq_te0715_defconfig file (or similar) in u-boot-xlnx/configs/ to be able to build uboot.. where can we find this file?
We tried with the zynq_zed_defconfig but it didn't work.

Do you already have experience with a custom build of U-boot?

Thank you in advance,
Antonio

[Emilie_Wheatley]

Hello Antonio,

We don't have a _defconfig file for the EMC2 and we didn't custom build a U-boot for it.
We've been using the file u-boot.elf from the Trenz website.
I will look into it and let you know when I have a way to custom build a u-boot file for the EMC2.

Regards,

Emilie

[Antonio.Paolillo]

We managed to make U-boot work on the EMC2 board.
We had to modify the following in the u-boot source code:
we changed the UART port in 'u-boot-xlnx/arch/arm/dts/zynq-zc702.dts' in section "aliases", we put 'serial0' to '&uart0' instead of '&uart1'.
This was enough to work with the FSBL, by using the u-boot defconfg for the zc102 board.

PS: we are still not sure the zc102 defcong is the best to use with this board.

[Ananya.Muddukrishna]

Hi,

Building U-boot by modifying files for the ZC702 is an error-prone approach.

A more certain way to build U-boot is by using Petalinux.
Petalinux takes the hardware handoff file as argument and generates proper boot files including the device tree blob and U-boot elf file.
See build instructions for the SDSoC platform emc2dp in tulipp-tool-chain GitHub repository.

Best regards,
Ananya