When it comes to obtaining an embedded Linux devices like the Raspberry Pi and BeagleBone for a project, most Makers would simply head online and purchase one. That is unless you’re “hak8or,” who decided to produce his own uber mini board based on an Atmel SMART AT91SAM9N12 that runs Linux off of a USB drive.
Inspired by Henrik Forstén’s recent device, hak8or’s system measures just two square inches in size, features 64 MB of DDR2 DRAM, a USB host and OTG port on-board.
“NAND Flash doesn’t work for some reason, so dataflash is used instead. The dataflash chip is attached to the SPI bus from the chip to the SPI bus pads while also using it’s own board. DRAM is also underclocked to 100 Mhz instead of 133 Mhz via the main system bus downclock, causing the processor to run at 300 Mhz instead of 400 Mhz. AT91 Bootstrap and U-Boot are located on dataflash at0x00 and 0x8400 respectivly, with U-Boot pulling the kernel from a flash drive connected via USB OTG as well. The kernel then pulls the rootfs off the flash drive in a dedicated ext2 rootfs as rw (read write). GCC has been cross compiled to this board and compiles programs correctly, so this board was used for completion of the project,” hak8or notes.
Those wishing to delve deeper can head over to the project’s Github page, where the Maker has provided an elaborate readme.md covering the boot process, the root filesystem and the toolchain. He also goes on to list a slew of useful resources for anyone looking to boot Linux on the chips.
Really great . The welds really seems to have was made by hand. Excellent , I love !