boot_alpha - Alpha system bootstrapping procedures
When powered on, the SRM firmware will proceed to its initialization, and
will boot an operating system if the auto_action variable is
``boot'' or ``restart'', or will wait for interactive commands if set to
Warm starts [Toc] [Back]
After a panic, or if the system is rebooted via reboot(8) or
the SRM console will only restart the system if the
is set to ``boot''.
Boot process options [Toc] [Back]
The SRM console will attempt to boot a kernel named from the
environment variable, on the device listed in the
A list of the recognized SRM devices can be obtained with
show dev at the SRM prompt. If the boot_file variable is
not set or empty,
/bsd will be used by default.
The kernel will be passed the options listed in the
Option letters are case insensitive. The following
a Boot the system multi-user.
b Enter the debugger, ddb(4), as soon as the kernel
c Enter the ``User Kernel Configuration'' mode upon
d Create a kernel crash dump immediately after the
been configured. This option is only available
compiled with "option DEBUG".
h On the next system reboot, always halt the system, even if a
reboot is required.
n Prompt for the root filesystem device after the
s Boot the system single-user. This is the default
the kernel if no flags are specified.
Abnormal system termination [Toc] [Back]
In case of system crashes, the kernel will usually enter the
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
the kernel will halt the system if it was still in device
phase, or attempt a dump to the configured dump device, if
crash dump will then be recovered by savecore(8) during the
boot cycle. It is also possible to force other behaviours from ddb.
/bsd default system kernel
/usr/mdec/bootxx primary bootstrap for ``ffs'' file system
/usr/mdec/boot secondary bootstrap (usually also installed as /boot)
/usr/mdec/netboot network bootstrap
ddb(4), boot_config(8), halt(8), init(8), installboot(8),
savecore(8), setnetbootinfo(8), shutdown(8)
Alpha Architecture Reference Manual Third Edition, Digital
Architecture Committee, 1998.
The device names used by OpenBSD /alpha and the SRM Console
often have no
relation to each other.
OpenBSD 3.6 October 2, 2002
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