boot_alpha8

Cold starts

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”.

Warm starts

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 bootdef_dev variable. A list of the recognized SRM devices can be obtained with the command 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.