This is an open hardware SBC module around AT91RM9200 with 64MB SDRAM. It's built with nonBGA parts and is capable of running mainline Linux
Boot mode is usually set using the BMS pin on the AT91SAM9 series processors. When pulled down, it boots a NAND flash on the EBI bus. As NAND is expensive and takes a considerable area on the board, the boot strategy was devised relaying on the internal BootROM and a small NVM memory attached to SPI0.
The U-Boot bootloader and a small Busybox are stored there ( for fallback puroposes). U-Boot tries to load the kernel and rootfs from microSD if present, or falls back to the NVM environment if not present.
This module is part of a bigger project, Apollo IoT. It was born as an idea from observing the Arduino and the Raspberry ecosystem. The goal is to have a set of boards with standard features exposed in predefined locations in order to ease product development.
The processing boards feature uCs ranging from small STM32s to quad core processors capable of running full Linux distributions..
To enable real world applications, a set of capes was designed which adhere to the standard interconnect means and dimensions.
More information about the project can be found on Github https://github.com/vd-rd/apollo.iot