NetBSD/share/man/man4/kloader.4

.\"	$NetBSD: kloader.4,v 1.3 2009/12/05 16:29:11 pooka Exp $
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.\" Copyright (c) 2004 Valeriy E. Ushakov
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.Dd April 3, 2004
.Dt KLOADER 4
.Os
.Sh NAME
.Nm kloader
.Nd in-kernel bootloader
.Sh SYNOPSIS
.Cd options KLOADER
.Cd options KLOADER_KERNEL_PATH="\e"/netbsd\e""
.Sh DESCRIPTION
The
.Nm
is the in-kernel bootloader for platforms that do not have a proper
firmware.
.Pp
Some platforms supported by
.Nx
do not have a firmware that can boot the
.Nx
kernel.
Examples are game consoles (dreamcast port), and
handhelds (hpcarm, hpcmips, and hpcsh ports).
On such platforms the bootloader is usually a host program that runs
under the native OS.
This means that rebooting
.Nx
is a lengthy process of booting into the native OS first,
launching the bootloader program, and finally booting
.Nx
again.
This problem is addressed by
.Nm ,
which allows the currently running kernel to serve as a bootloader
for the kernel being booted, thus avoiding the burden of booting
into the native OS first.
.Pp
When
.Nm
is configured into the kernel, a call to
.Xr reboot 2
causes the
.Nm
to load the new kernel into memory, and arrange for control to be
passed to the new kernel \(em just like a standalone bootloader does.
The new kernel then boots in the ordinary manner.
.Sh SEE ALSO
.Xr reboot 2 ,
.Xr boot 8 ,
.Xr reboot 8
.Sh HISTORY
.Nm
first appeared in
.Nx 1.6 .
.Sh BUGS
.Nm
ignores
.Fa howto
and
.Fa bootstr
arguments passed to the
.Xr reboot 2
system call, and reboots the system with the previous boot settings.
.Pp
.Nm
doesn't support booting compressed kernels.
.Pp
The hpcarm port doesn't support
.Nm
yet.