STM32MP15 U-Boot

Applicable for

STM32MP15x lines

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This article briefly describes the STM32MP15x lines  support in U-Boot.

1. STM32MP15x lines  support

For detailed information, read the file in the delivered U-Boot code = doc/board/st/stm32mp1.rst or the documentation generated by make htlmdocs: board/st/stm32mp1.html.

Code :

• arch/arm/mach-stm32mp : arch specific code for STM32 Arm^® Cortex^® MPUs 
  • arch/arm/mach-stm32mp/Kconfig : generic configuration for STM32 Arm^® Cortex^® MPUs 
  • arch/arm/mach-stm32mp/Kconfig.15x : specific configuration for STM32MP15x lines 
• board/st/common : STMicroelectronics common code
• board/st/stm32mp1 : STMicroelectronics boards support for STM32MP1 series
• drivers/*/*stm32* : drivers

Configuration files:

• defconfig file
  • configs/stm32mp15_defconfig when FIP is used in OpenSTLinux
• config files
  • include/configs/stm32mp15_common.h : generic for STM32MP15x lines 
  • include/configs/stm32mp15_st_common.h : STMicroelectronics board for STM32MP15x lines 
• STM32_MPU_device_tree in arch/arm/dts  : stm32mp15*.dts*
  • <Device tree>.dts : same as kernel
  • <Device tree>-u-boot.dtsi : addition for u-boot automatically included in build process
  • stm32mp15-scmi-u-boot.dtsi : SoC add-on file included in <Device tree>-u-boot.dtsi
  • stm32mp15-u-boot.dtsi : SoC add-on file for board support without SCMI, only for downstream support not used with OpenSTLinux

The two next defconfig are kept only for compatibility with upstream, don't use them:

• configs/stm32mp15_trusted_defconfig with stm32 image header support (CONFIG_STM32MP15x_STM32IMAGE)
• configs/stm32mp15_basic_defconfig when SPL is used

2. Selecting targets : choose defconfig and device tree

The STM32 MPU boot chain is supported by one U-Boot configuration with defconfig = stm32mp15_defconfig

Several boards are supported with the associated device-tree (same name as kernel):

Board part number	Device tree	Description
STM32MP157A-EV1 Evaluation board	stm32mp157a-ev1	MB1262+MB1263
STM32MP157C-EV1 Evaluation board	stm32mp157c-ev1
STM32MP157D-EV1 Evaluation board	stm32mp157d-ev1
STM32MP157F-EV1 Evaluation board	stm32mp157f-ev1
STM32MP157A-DK1 Discovery kit	stm32mp157a-dk1	MB1272
STM32MP157D-DK1 Discovery kit	stm32mp157d-dk1
STM32MP157C-DK2 Discovery kit	stm32mp157c-dk2	MB1272+MB1407
STM32MP157F-DK2 Discovery kit	stm32mp157f-dk2

For information the 'Evaluation' daughter-board only (MB1263 without MB1262) is also supported by stm32mp15*-ed1.dts device tree files.

Warning

In OpenSTLinux, the content the board device tree <board>.dts have the same content then upstreamed smci device tree <board>-scmi.dts, thanks to #include "<board>-scmi.dtsi" in official U-Boot version, the smci device tree <board>-scmi.dts are used with stm32mp15_defconfig when the system resources are secured in OP-TEE (RCC_TZCR.TZEN:1), the configuration recommended by STMicroelectronics for product. see board/st/stm32mp1.html (vlatest) for details.

3. Compilation

See U-Boot_overview#U-Boot_build with the defconfig file: stm32mp15_defconfig

 make stm32mp15_defconfig
 make DEVICE_TREE=<Device tree> all

The supported variables are:

• DEVICE_TREE: select in arch/arm/dts the device tree that is used
• KBUILD_OUTPUT: change the destination directory for the build
• EXT_DTB: select external device tree
• EXT_DTS: select PATH of external device tree source, by default the sub-directory "arch/arm/dts/external-dt" is used to allow sub-module.

The output files u-boot.dtb and u-boot-nodtb.bin are integrated in TF-A FIP.

Note: All the compiled device trees are available in $KBUILD_OUTPUT/arch/arm/dts/*.dtb.
You can select them instead of u-boot.dtb without U-Boot recompilation.

4. Examples

4.1. STM32MP157F-EV1 Evaluation board

 make stm32mp15_defconfig
 make DEVICE_TREE=stm32mp157f-ev1 all

An existing FIP file is updated with:

 fiptool --verbose update --nt-fw u-boot-nodtb.bin --hw-config u-boot.dtb \
              fip-stm32mp157f-ev1.bin

4.2. STM32MP157C-EV1 Evaluation board

 make stm32mp15_defconfig
 make DEVICE_TREE=stm32mp157c-ev1 all

An existing FIP file is updated with:

 fiptool --verbose update --nt-fw u-boot-nodtb.bin --hw-config u-boot.dtb \
              fip-stm32mp157c-ev1.bin

4.3. STM32MP157D-DK1 Discovery kit

 make stm32mp15_defconfig
 make DEVICE_TREE=stm32mp157d-dk1 all

An existing FIP file is updated with:

 fiptool --verbose update --nt-fw u-boot-nodtb.bin --hw-config u-boot.dtb \
              fip-stm32mp157d-dk1.bin

4.4. STM32MP157C-DK2 Discovery kit

Using export to select the device tree

 export KBUILD_OUTPUT=../build/stm32mp15
 export DEVICE_TREE=stm32mp157c-dk2
 make stm32mp15_defconfig
 make all

An existing FIP file is updated with:

 fiptool --verbose update --nt-fw $KBUILD_OUTPUT/u-boot-nodtb.bin \
              --hw-config  $KBUILD_OUTPUT/u-boot.dtb \
              fip-stm32mp157c-dk2.bin

4.5. Custom board with external device tree

 make stm32mp15_defconfig
 make EXT_DTB=stm32mp151a-myboard.dtb all

Then you can create or update the FIP

Das U-Boot -- the universal boot loader (see U-Boot)

Arm^® is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.

Cortex^®

Firmware image package is a packaging format used by TF-A

System control and management interface

Secondary program loader, Also known as U-Boot SPL

Open portable trusted execution environment

Reset and clock control

Device tree binary (or Blob)

Device tree source (in software context) or digital temperature sensor (in peripheral context)

Das U-Boot -- the universal boot loader (see U-Boot)

Arm^® is a registered trademark of Arm Limited (or its subsidiaries) in the US and/or elsewhere.

Cortex^®

Firmware image package is a packaging format used by TF-A

System control and management interface

Secondary program loader, Also known as U-Boot SPL

Open portable trusted execution environment

Reset and clock control

Device tree binary (or Blob)

Device tree source (in software context) or digital temperature sensor (in peripheral context)

Trusted firmware for Arm^® Cortex^®-A