View source for Default Bootloader "stm32mp15xx-dhcor-testbench"

Each DHCOR STM32MP1 module comes with preprogrammed default bootloader.
== Features/Suported interfaces==
* Bootloader console (UART4)
* PMIC (STPMIC1APQR)
* DDR3 Memory (size is coded by DDR3 coding pins)
* CPU type (STM32MP151, STM32MP153 and STM32MP157)
* On-Board I2C (I2C4)
* microSD (SDMMC1) 
* eMMC (SDMMC2)
* SPI boot Flash (QSPI_BK1)
* Gbit Ethernet KSZ9031 (ETH1)
* USB Host and Device

== Download/Build U-Boot SPL and U-Boot binaries ==

There are two ways to get the required U-Boot binaries.
These can either be downloaded or built from the sources by yourself.
Follow one of the two steps below.

=== Download prebuilt binaries ===

[https://www.dropbox.com/sh/os9so01tivajkxs/AACQ30W-7l-Zi_Zutu0Zv-Zua?dl=0 Dropbox: U-Boot_recovery_for_STM32MP1_DHSOM_via_DFU] ([https://source.denx.de/u-boot/u-boot/-/tree/v2022.04 source])

==== Build binaries from source ====
Checkout source code
<syntaxhighlight lang="shell">
git clone -b v2022.07_testbench https://github.com/dh-electronics/u-boot-stm32mp1.git
cd u-boot-stm32mp1
</syntaxhighlight>

Download and extract toolchain
Toolchain from: https://developer.arm.com/downloads/-/gnu-a
<syntaxhighlight lang="shell">
wget https://armkeil.blob.core.windows.net/developer/Files/downloads/gnu-a/10.3-2021.07/binrel/gcc-arm-10.3-2021.07-x86_64-arm-none-linux-gnueabihf.tar.xz
tar xf gcc-arm-10.3-2021.07-x86_64-arm-none-linux-gnueabihf.tar.xz -C /opt/toolchains
</syntaxhighlight>

Set env variables
<syntaxhighlight lang="shell">
export ARCH=arm
export CROSS_COMPILE=/opt/toolchains/gcc-arm-10.3-2021.07-x86_64-arm-none-linux-gnueabihf/bin/arm-none-linux-gnueabihf-
export SOURCE_DATE_EPOCH=1664184598 # Mon Sep 26 09:29:58 2022 UTC
</syntaxhighlight>

Create config, set testbench as default and build
<syntaxhighlight lang="shell">
make stm32mp15_dhcor_basic_defconfig
sed -i 's/stm32mp15xx-dhcor-avenger96/stm32mp15xx-dhcor-testbench/g' .config
make -j16
</syntaxhighlight>

Check sha256 sums and compare with sha256sum.txt
<syntaxhighlight lang="shell">
sha256sum u-boot.itb u-boot-spl.stm32
</syntaxhighlight>