STMicroelectronics STM32MP1
===========================
STM32MP1 is a microprocessor designed by STMicroelectronics
based on a dual Arm Cortex-A7.
It is an Armv7-A platform, using dedicated code from TF-A.
The STM32MP1 chip also embeds a Cortex-M4.
More information can be found on `STM32MP1 Series`_ page.
Design
------
The STM32MP1 resets in the ROM code of the Cortex-A7.
The primary boot core (core 0) executes the boot sequence while
secondary boot core (core 1) is kept in a holding pen loop.
The ROM code boot sequence loads the TF-A binary image from boot device
to embedded SRAM.
The TF-A image must be properly formatted with a STM32 header structure
for ROM code is able to load this image.
Tool stm32image can be used to prepend this header to the generated TF-A binary.
At compilation step, BL2, BL32 and DTB file are linked together in a single
binary. The stm32image tool is also generated and the header is added to TF-A
binary. This binary file with header is named tf-a-stm32mp157c-ev1.stm32.
It can then be copied in the first partition of the boot device.
Memory mapping
~~~~~~~~~~~~~~
::
0x00000000 +-----------------+
| | ROM
0x00020000 +-----------------+
| |
| ... |
| |
0x2FFC0000 +-----------------+ \
| | |
| ... | |
| | |
0x2FFD8000 +-----------------+ |
| TF-A DTB | | Embedded SRAM
0x2FFDC000 +-----------------+ |
| BL2 | |
0x2FFEF000 +-----------------+ |
| BL32 | |
0x30000000 +-----------------+ /
| |
| ... |
| |
0x40000000 +-----------------+
| |
| | Devices
| |
0xC0000000 +-----------------+ \
| | |
0xC0100000 +-----------------+ |
| BL33 | | Non-secure RAM (DDR)
| ... | |
| | |
0xFFFFFFFF +-----------------+ /
Boot sequence
~~~~~~~~~~~~~
ROM code -> BL2 (compiled with BL2_AT_EL3) -> BL32 (SP_min) -> BL33 (U-Boot)
or if Op-TEE is used:
ROM code -> BL2 (compiled with BL2_AT_EL3) -> OP-TEE -> BL33 (U-Boot)
Build Instructions
------------------
Boot media(s) supported by BL2 must be specified in the build command.
Available storage medias are:
- ``STM32MP_SDMMC``
- ``STM32MP_EMMC``
- ``STM32MP_RAW_NAND``
- ``STM32MP_SPI_NAND``
- ``STM32MP_SPI_NOR``
To build with SP_min and support for all bootable devices:
.. code:: bash
make CROSS_COMPILE=arm-linux-gnueabihf- PLAT=stm32mp1 ARCH=aarch32 ARM_ARCH_MAJOR=7 AARCH32_SP=sp_min STM32MP_SDMMC=1 STM32MP_EMMC=1 STM32MP_RAW_NAND=1 STM32MP_SPI_NAND=1
STM32MP_SPI_NOR=1 DTB_FILE_NAME=stm32mp157c-ev1.dtb
cd <u-boot_directory>
make stm32mp15_trusted_defconfig
make DEVICE_TREE=stm32mp157c-ev1 all
To build TF-A with OP-TEE support for all bootable devices:
.. code:: bash
make CROSS_COMPILE=arm-linux-gnueabihf- PLAT=stm32mp1 ARCH=aarch32 ARM_ARCH_MAJOR=7 AARCH32_SP=optee STM32MP_SDMMC=1 STM32MP_EMMC=1 STM32MP_RAW_NAND=1 STM32MP_SPI_NAND=1 STM32MP_SPI_NOR=1 DTB_FILE_NAME=stm32mp157c-ev1.dtb
cd <optee_directory>
make CROSS_COMPILE=arm-linux-gnueabihf- ARCH=arm PLATFORM=stm32mp1 CFG_EMBED_DTB_SOURCE_FILE=stm32mp157c-ev1.dts
cd <u-boot_directory>
make stm32mp15_optee_defconfig
make DEVICE_TREE=stm32mp157c-ev1 all
The following build options are supported:
- ``ENABLE_STACK_PROTECTOR``: To enable the stack protection.
Populate SD-card
----------------
The SD-card has to be formated with GPT.
It should contain at least those partitions:
- fsbl: to copy the tf-a-stm32mp157c-ev1.stm32 binary
- ssbl: to copy the u-boot.stm32 binary
Usually, two copies of fsbl are used (fsbl1 and fsbl2) instead of one partition fsbl.
.. _STM32MP1 Series: https://www.st.com/en/microcontrollers-microprocessors/stm32mp1-series.html
