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Revision as of 15:20, 3 March 2023 by JeremyRand (talk | contribs) (→Components: CME HCODE upstream source)
OpenPOWER Firmware is an open-source alternative to OpenFirmware and proprietary IBM firmware used on Power machines. It is a general name for many separate pieces of software used to start recent Power Architecture chips made by IBM.
OpenBMC is a separate project that creates firmware for the Baseboard Management Controller.
|Firmware||Executed on||Loaded from||Function|
|SBE - OTPROM||SBE core (on CPU)||OTPROM (on CPU die)||The portion of Self-Boot Engine (SBE) firmware permanently written via eFuses into the POWER9 silicon's OTPROM
|SBE - SEEPROM||SBE core (on CPU)||SBE SEEPROM (on CPU)||The portion of Self-Boot Engine (SBE) firmware run from rewritable SEEPROM
|Hostboot Bootloader (HBBL)||CPU core||SBE SEEPROM (on CPU)||
|Hostboot||CPU core||PNOR (SPI Flash)||
|Skiboot||CPU core||PNOR (SPI Flash)||
Skiroot Linux Config Source (Talos II)
|CPU core||PNOR (SPI Flash)|
|OCC firmware||OCC core (on CPU)||PNOR (SPI Flash)||The On-Chip Controller (OCC) manages:
|CME HCODE||CME cores (on CPU)||PNOR (SPI Flash)||The Core Management Engines (CME) are auxillary cores used for power management purposes. They are ultimately responsible to the OCC.
|SGPE and PGPE HCODE||SGPE and PGPE cores (on CPU)||PNOR (SPI Flash)||General Purpose Engine (GPE) cores which assist, and are managed by, the OCC.
|IOPPE HCODE||IOPPE cores (on CPU)||PNOR (SPI Flash)||
|OpenBMC||BMC chip||BMC SPI Flash||
(This is not part of OpenPOWER firmware, but is mentioned to give a picture of the division of responsibilities. Not all POWER9 systems use a BMC; IBM systems use a FSP.)
- OpenBMC uses FSI interface to start SBE
- SBE executes OTPROM, which loads SEEPROM firmware into SBE PIBMEM
- SBE executes SEEPROM firmware
- SBE loads Hostboot
- Hostboot loads Skiboot
- Skiboot loads OCC, Skiroot
- Petitboot application within Skiroot loads the operating system
- OS talks to firmware through OPAL
- ↑ Kerr, Jeremy. OpenPOWER: building an open-source software stack from bare metal. LCA 2015 - video on YouTube
- ↑ Smith, Stewart. Adventures in OpenPOWER Firmware. LCA 2016 - video on YouTube
- OpenPOWER firmware source code on GitHub
- For a better understanding of OpenPOWER firmware and boot processes, see:
- Bug tracker for firmware issues specific to Raptor CS products: https://bugs.raptorengineering.com/