KERNEL(8) Maintenance Commands and Procedures KERNEL(8)

NAME

kernel - UNIX system executable file containing basic operating
system services

SYNOPSIS

kernel-name [-asrvx] [-m smf_options] [-i altinit]

DESCRIPTION

The operating system image, or kernel, is the collection of software
comprising the image files (unix and genunix) and the modules loaded
at any instant in time. The system will not function without a kernel
to control it.


The kernel is loaded by the boot(8) command in a machine-specific
way. The kernel may be loaded from disk, CD-ROM, or DVD (diskfull
boot) or over the network (diskless boot). In either case, the
directories under /platform and /kernel must be readable and must
contain executable code which is able to perform the required kernel
service. If the -a flag is given, the user is able to supply
different pathnames for the default locations of the kernel and
modules. See boot(8) for more information on loading a specific
kernel.


The moddir variable contains a list of module directories separated
by whitespace. moddir can be set in the /etc/system file. The minimal
default is:

/platform/platform-name/kernel /kernel /usr/kernel


This default can be supplemented by a specific platform. It is common
for many SPARC systems to override the default path with:

/platform/platform-name/kernel:/platform/hardware-class-name\
/kernel:/kernel:/usr/kernel


where platform-name can be found using the -i option of uname(1), and
hardware-class-name can be found using the -m option of uname(1).


The kernel configuration can be controlled using the /etc/system file
(see system(5)).


genunix is the platform-independent component of the base kernel.

OPTIONS

The following options are supported:

-a

Asks the user for configuration information, such as where to
find the system file, where to mount root, and even override the
name of the kernel itself. Default responses will be contained in
square brackets ([ ]), and the user may simply enter RETURN to
use the default response (note that RETURN is labeled ENTER on
some keyboards). To help repair a damaged /etc/system file, enter
/dev/null at the prompt that asks for the pathname of the system
configuration file. See system(5).


-i altinit

Select an alternative executable to be the primordial process.
altinit must be a valid path to an executable. The default
primordial process is init(8).


-m smf_options

The smf_options include two categories of options to control
booting behavior of the service management facility: recovery
options and messages options.

Message options determine the type and amount of messages that
smf(7) displays during boot. Service options determine the
services which are used to boot the system.

Recovery options

debug

Prints standard per-service output and all svc.startd
messages to log.


milestone=[milestone]

Boot with some SMF services temporarily disabled, as
indicated by milestone. milestone can be "none", "single-
user", "multi-user", "multi-user-server", or "all". See the
milestone subcommand of svcadm(8).

Messages options

quiet

Prints standard per-service output and error messages
requiring administrative intervention.


verbose

Prints standard per-service output with more informational
messages.


-r

Reconfiguration boot. The system will probe all attached hardware
devices and configure the logical namespace in /dev. See
add_drv(8) and rem_drv(8) for additional information about
maintaining device drivers.


-s

Boots only to init level 's'. See init(8).


-v

Boots with verbose messages enabled. If this flag is not given,
the messages are still printed, but the output is directed to the
system logfile. See syslogd(8).


-x

Does not boot in clustered mode. This option only has an effect
when a version of Sun Cluster software that supports this option
has been installed.

EXAMPLES

See boot(8) for examples and instructions on how to boot.

FILES

/kernel

Contains kernel components common to all platforms within a
particular instruction set that are needed for booting the
system. of the core image file.


/platform/platform-name/kernel

The platform-specific kernel components.


/platform/hardware-class-name/kernel

The kernel components specific to this hardware class.


/usr/kernel

Contains kernel components common to all platforms within a
particular instruction set.


The directories in this section can potentially contain the following
subdirectories:

drv

Loadable device drivers


exec

The modules that execute programs stored in various file formats.


fs

File system modules


misc

Miscellaneous system-related modules


sched

Operating system schedulers


strmod

System V STREAMS loadable modules


sys

Loadable system calls

SPARC

cpu

Processor specific modules


tod

Time-Of-Day hardware interface modules


As only 64-bit SPARC platforms are supported, all SPARC executable
modules are contained within sparcv9 directories in the directories
listed above.

x86
mach

x86 hardware support


Modules comprising the 32-bit x86 kernel are contained in the above
directories, with the 64-bit x86 kernel components contained within
amd64 subdirectories.

SEE ALSO

isainfo(1), uname(1), devfs(4FS), system(5), attributes(7), smf(7),
add_drv(8), boot(8), init(8), kadb(8), rem_drv(8), savecore(8),
svc.startd(8), svcadm(8), syslogd(8)

DIAGNOSTICS

The kernel gives various warnings and error messages. If the kernel
detects an unrecoverable fault, it will panic or halt.

NOTES

Reconfiguration boot will, by design, not remove /dev entries for
some classes of devices that have been physically removed from the
system.

March 6, 2023 KERNEL(8)