Linux on Pipistrello
Pipistrello is an excellent board for running embedded Linux, using the Microblaze soft processor.
On a Spartan-6 LX45 using speed grade -3, the processor will run at 100 Mhz with Linux performance settings (MMU, 64-bit multiplier, barrel-shifter etc.) and use about 25% of the slices without the Ethernet block.
This project is using mainline Linux kernel 3.14.4 with MMU. It's reported having 49.56 BogoMips.
The Linux kernel and root file system is stored in flash memory (after the bit file) and loaded into memory by the ELF bootloader.
Files needed to compile and run your own kernel on Pipistrello
The Workspace directory is a workspace for Xilinx SDK with pre-built Microblaze hardware from EDK. It includes code examples for memory and peripheral tests. The director mb_system_hw_platform has bit files and a make file for downloading the Linux bit file to Pipistrello. It also includes a Linux kernel using the Xilinx prebuilt initramfs_minimal.cpio.gz ramdisk image (simpleImage.Pipistrello_LX45_axi_Linux.unstrip).
The file Pipistrello_LX45_axi_Linux.dts is the device-tree file describing the Microblaze hardware, this file is needed when rebuilding the Linux kernel from scratch. See links below.