A Linux-based tool for hardware bring up, Linux development, and manufacturing

In this paper we describe Bare Metal Linux (BML), a cut-down version of Linux® 2.6 that requires no firmware, has an in-memory root file system, and runs without a virtualization layer. We designed and implemented BML in order to accelerate the bring up of POWER5™-based systems. The use of BML allows testing and validation of the POWER5-based system to be conducted in parallel with the standard path, which involves the bring up of a hypervisor, the partition firmware, and the operating system. BML, which has fast boot times and can be modified quickly, is used in fault detection during chip manufacturing, POWER5 chip verification, system-board verification, and benchmarking for performance. BML is also used to reproduce and resolve problems in Linux.