Emcraft Systems has open sourced its ports of U-Boot and uClinux for Cortex-M3 and Cortex-M4 which are available on github at https://github.com/EmcraftSystems.
This release supports the following platforms:
- ST Micro STM32F2
- NXP LPC17XX
- Actel SmartFusion
- Freescale Kinetis
You can check the source code as follows:
- uCLinux: git clone git://github.com/EmcraftSystems/linux-emcraft.git
- U-boot: git clone git://github.com/EmcraftSystems/u-boot.git
The company has also designed systems on module (SoM) with enough memory to run Linux with Cortex M3/M4 micro-controllers:
You might find more details on building/using u-boot or uClinux on EmCraft documentation page (especially linux-cortexm-um-1.4.1.pdf) and you may want to check EmCraft website for details on available hardware and BSP for Cortex M3/M4 solutions.