---
name: "boot_alpha"
section: "8"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/boot_alpha"
---

# boot\_alpha(8)

Alpha system bootstrapping procedures

## NAME

**boot\_alpha** – Alpha system bootstrapping procedures

## DESCRIPTION

### 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)](/reboot/8.md) or [shutdown(8)](/shutdown/8.md), 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)](/boot/8.md).

### Abnormal system termination

In case of system crashes, the kernel will usually enter the kernel debugger, [ddb(4)](/ddb/4.md), 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)](/savecore/8.md) during the next multi-user boot cycle. It is also possible to force other behaviours from ddb.

## FILES

- */bsd*

  default system kernel

- */bsd.rd*

  standalone installation kernel, suitable for disaster recovery

- */usr/mdec/bootxx*

  primary bootstrap for “ffs” file system

- */usr/mdec/boot*

  secondary bootstrap (usually also installed as */boot*)

- */usr/mdec/netboot*

  network bootstrap

## SEE ALSO

[ddb(4)](/ddb/4.md), [boot(8)](/boot/8.md), [boot\_config(8)](/boot_config/8.md), [halt(8)](/halt/8.md), [init(8)](/init/8.md), [installboot(8)](/installboot/8.md), [reboot(8)](/reboot/8.md), [savecore(8)](/savecore/8.md), [setnetbootinfo(8)](/setnetbootinfo/8.md), [shutdown(8)](/shutdown/8.md) *Alpha Architecture Reference Manual Third Edition*, Digital Press, Alpha Architecture Committee, 1998.

## BUGS

The device names used by OpenBSD/alpha and the SRM Console often have no relation to each other.