skiboot ------- Firmware for OpenPower systems https://github.com/open-power/skiboot OPAL firmware (OpenPower Abstraction Layer) comes in several parts. A simplified flow of what happens when the power button is pressed is: 1) The baseboard management controller (BMC) powers the system on. 2) The BMC selects the master chip and releases the self-boot engines (SBEs) on the POWER8 chips, master last. 3) The BMC relinquishes control of the flexible service interface (FSI) SCAN/SCOM engines. 4) The hostboot firmware IPLs the system. It initiates a secondary power-on sequence through a digital power systems sweep (DPSS). 5) The hostboot firmware loads the OPAL image and moves all processors to their execution starting points. Here, the OPAL image is three parts: 1) skiboot (includes OPAL runtime services) 2) skiroot - the bootloader environment a) kernel b) initramfs (containing petitboot bootloader) They may be all part of one payload or three separate images (depending on platform). The bootloader will kexec a host kernel (probably linux). The host OS can make OPAL calls. A TODO item is to extensively document this API. See doc/overview.txt for a more in depth overview of skiboot. Hacking ------- You will need a C compiler (gcc 4.8) for ppc64 (big endian). You will need a POWER8 system that you can deploy new firmware to. License ------- See LICENSE