Alpha system bootstrapping
When powered on, the SRM firmware will proceed to its initialization, and will boot an operating system if the auto_action variable is set to “boot” or “restart”, or will wait for interactive commands if set to “halt”.
After a panic, or if the system is rebooted via reboot(8) or shutdown(8), the SRM console will only restart the system if the auto_action variable is set to “boot”.
Boot process options
The SRM console will attempt to boot from the device listed in the
variable. A list of the recognized SRM devices can be obtained with the
show dev at the SRM prompt.
The OpenBSD alpha boot loader program is extensively described in a separate document, boot(8).
Abnormal system termination
In case of system crashes, the kernel will usually enter the kernel debugger, ddb(4), unless it is not present in the kernel, or it is disabled via the ddb.panic sysctl. Upon leaving ddb, or if ddb was not entered, the kernel will halt the system if it was still in device configuration phase, or attempt a dump to the configured dump device, if possible. The crash dump will then be recovered by savecore(8) during the next multi-user boot cycle. It is also possible to force other behaviours from ddb.
- default system kernel
- standalone installation kernel, suitable for disaster recovery
- primary bootstrap for “ffs” file system
- secondary bootstrap (usually also installed as /boot)
- network bootstrap
ddb(4), boot(8), boot_config(8), halt(8), init(8), installboot(8), reboot(8), savecore(8), setnetbootinfo(8), shutdown(8)
Alpha Architecture Reference Manual Third Edition, Digital Press, Alpha Architecture Committee, 1998.
The device names used by OpenBSD/alpha and the SRM Console often have no relation to each other.