IBM has open sourced the POWER Instruction Set Architecture (ISA), which is used in its Power Series chips and in many embedded devices by other manufacturers. In addition, the OpenPOWER Foundation will become part of The Linux Foundation to further open governance.
IBM created the OpenPOWER Foundation in 2013 with the aim to make it easier for server vendors to build customized servers based on IBM Power architecture. By joining the OpenPOWER Foundation, vendors had access to processor specifications, firmware, and software and were allowed to manufacture POWER processors or related chips under a liberal license. With IBM latest announcement, vendors can create chips using the POWER ISA without paying any royalties and have full access to the ISA definition. As IBM OpenPOWER general manager Ken King highlights, open sourcing the POWER ISA enables the creation of computers that are completely open source, from the foundation of the hardware, including the processor instruction set, firmware, boot code, and so on up to the software stack.
IBM is also contributing a softcore implementation of the POWER ISA, which is fully implemented using programmable logic on an FPGA architecture. This is especially relevant for embedded system manufacturers, which often need to integrate a processor along with other components on the same custom chip.
As mentioned, POWER-based chips are used mostly in high-end servers, including IBM recent POWER9 series, and in embedded devices. Nevertheless, OpenPOWER-based chips are also used in desktop-class workstations.
IBM POWER is not the only open-source ISA available to manufacturers. Besides 34-year-old MIPS, it is worth mentioning RISC-V, which has been seeing a growing adoption in the last year. The RISC-V architecture is mostly geared toward low-power IoT use cases, as opposed to POWER being used in high-performance scenarios, but Alibaba has recently come up with a high-performance RISC-V design and introduced a high-end RISC-V processor
