Common features of system components and BSP framework

This chapter provides lists of features which are provided by certain system components for the default BSP configuration.

System components

Trusted bootloader

For STM32MP1 platform these features are provided

  • Secure monitor based on 'arm-trusted-firmware'
  • Booting from SD card
  • Booting from QSPI flash
  • Locking OTP values on write

Supported by SOC and platform, but not in BSP:

  • Secure application
  • Secure boot

U-boot bootloader

For STM32MP1 platform an u-boot bootloader is provided

  • U-boot environment is located in NOR flash
  • Redundant u-boot environment
  • U-boot environment auto detection (sd card, nor) dependent on boot device
  • Auto flashing of u-boot environment with default boot command if environment is empty
  • Support for USB storage interfaces
  • Support for NOR and NAND Flashes of SOM via MTD framework
  • Support for eMMC flash and SD cards on baseboard
  • Support for UBI based flash storage
  • Support for file access on ext4 and fat32 filesystems
  • Support for SOC Ethernet interface
  • Support for booting from network
  • Basic network commands: tftp, ping, dhcp
  • Support for AB double copy boot scheme
  • Can boot extlinux non-double copy images and AB scheme double copy images

Supported by SOC platform, but not in BSP:

  • Display interface
  • Loading M4 program

Linux kernel

For STM32MP1 platform the following Kernel features are provided:

  • Linux kernel version 5.10 or higher
  • IPv4 stack
  • Filesystems ext4, fat, fat32
  • MTD flash framework
  • UBI flash framework
  • SD card and eMMC storage framework
  • Wireless Ethernet stack

Firmware Images

Firmware images provide adapted solutions for certain use cases.

Basic image (image-ktn)

Use case: Basic linux system without graphics support

For all platforms the basic image image-ktn provides:

  • SysV init system
  • Hardware watchdog
  • SwUpdate OTA update framework (not yet)
  • ifup/ifdown for Network configuration
  • wpa-supplicant for wireless connectivity
  • udevd for dynamic device generation
  • dbus daemon
  • udhcpc dhcp client
  • Openssh ssh server
  • zeroconf upnp ethernet configuration
  • can tools

Supported by SOC platform, but not in BSP:

  • Power save and deep sleep modes
  • Secure boot

SWUpdate AB double copy image (image-ktn-swu)

Use case: Demo image to show the integration of SWUpdate embedded software update framework

This images provides all features of image-ktn and additionally the SWUpdate framework for embedded devices on top of a double copy AB boot scheme. It provides support for updating the current boot device (SD card, eMMC, NAND) and provides a demo web interface to update the software of the device.

For more information about SWUpdate see https://sbabic.github.io/swupdate/

Yocto BSP build infrastructure

Features provided for all machines

  • Script to initialize build environment and to fetch sources from web
  • Creating a bootable SD card
  • Building bootloaders
  • Building images