OpenBMC/StepsToIPL

The BMC takes a number of steps to start the IPL process and boot the main CPU. Due to OpenBMC's complex boot procedure that relies on a tangled mess of systemd targets and dbus, the exact steps taken to boot and their ordering is not always clear. This page attempts to clearly document them.

poweron

1. Disable OCC
   1. occ_active.sh disable
2. Bind FSI Driver (once per BMC boot)
3. ScanFSI
   1. openpower-proc-control's ScanFSI procedure is run
4. CFAMOverride
   1. openpower-proc-control's CFAMOverride procedure is run
5. Fan daemon is started
6. AVSBus stuff
   1. avsbus_workaround.sh
   2. avsbus_disable.sh
   3. vrm_control.sh
   4. avsbus_enable.sh
7. startHost
   1. openpower-proc-control's startHost procedure is run
8. Wait for IPL
9. Enable OCC
   1. occ_active.sh watchdog