AWAN is a hardware accelerator composed of programmable gate arrays that can emulate a POWER logic core. The AWAN environment can be used to run hardware procedures or test binaries on the logic, before hardware is available or when hardware is scarce.
The AWAN environment is slow compared to Mambo and QEMU. Each timebase tick is equivalent to 8 simclocks, and simclock is slow. For example, on the core model we get through Skiboot in about 6 million simclock cycles and that takes approximately 1 minute wall-clock time to complete.
To run in AWAN, you need a an initial checkpoint, a loader, and a method to read memory.
The high-level sequence for running in AWAN is:
Load an initial checkpoint provided by the person that built the model
Load a stripped vmlinux at 0
Load an initramfs at 0x28200000
Load skiboot.lid at 0x30000000
Load a small piece of start code at 0x100 that tells skiboot where to find the device tree blob
Load a compiled device tree blob at 0x1f00000
Run “simclock 5000000” and check the console buffer for the Skiboot log by reading memory at 784MB.