IOT-GATE-iMX7 and SBC-IOT-iMX7: U-Boot: Building Images
Contents
Overview
The CompuLab device IOT-GATE-iMX7/SBC-IOT-iMX7 firmware consists of two components: Secondary Program Loader (SPL) and U-Boot.
Both components are based on U-Boot source code.
SPL is the bootstrap utility invoked by the CPU internal boot ROM code of the i.MX7 SoC.
U-Boot initializes hardware modules necessary for system boot and loads the operating system.
The latest U-Boot package is available at the CL-SOM-iMX7 Resources web page.
Building Firmware images for IOT-GATE-iMX7/SBC-IOT-iMX7
Getting U-Boot sources
There are two ways to get U-Boot sources that can be used as a baseline for the IOT-GATE-iMX7/SBC-IOT-iMX7 U-Boot.
You can create a copy of "Das U-Boot" source tree or download a snapshot and extract it.
We assume that you have created /home/development/cl-som-imx7/u-boot directory for the IOT-GATE-iMX7/SBC-IOT-iMX7 B-Boot development.
Git clone
- Install git version control system.
- Create a clone of U-Boot tree
cd /home/development/cl-som-imx7/u-boot git clone https://github.com/compulab/u-boot.git -b v2017.07-cl-som-imx7-1.9 u-boot-cl-som-imx7 cd u-boot-cl-som-imx7
- Create a branch for CL-SOM-iMX7 development
git checkout -b cl-som-imx7-1.9-devel
Building the firmware images
- First, compile U-Boot. The following commands create the u-boot.imx binary (along with other image types):
export ARCH=arm export CROSS_COMPILE=arm-none-linux-eabi- make mrproper make cl-som-imx7_defconfig && make
- Merge the SPL and U-Boot images into one firmware image:
dd if=/dev/zero count=640 bs=1K | tr '\000' '\377' > cl-som-imx7-firmware dd if=SPL of=cl-som-imx7-firmware bs=1K seek=1 conv=notrunc dd if=u-boot.img of=cl-som-imx7-firmware bs=1K seek=64 conv=notrunc
- You can now install the cl-som-imx7-firmware file into an SD card or IOT-GATE-iMX7/SBC-IOT-iMX7 SPI flash.
