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.\" Copyright (c) 2000, 2001 Ben Harris
.\" Copyright (c) 2004 Reinoud Zandijk
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.Dd September 4, 2009
.Dt BOOT32 8 acorn32
.Os
.Sh NAME
.Nm boot32
.Nd Bootloader for
.Nx Ns /acorn32
.Sh SYNOPSIS
.Nm *boot32
.Op Fl acdqsv
.Op Ar root=rootdir
.Op Ar file
.Sh DESCRIPTION
.Nm
is a program that runs under
.Tn RISC OS
and launches the
.Nx Ns /acorn32
kernel.
It needs to be installed in a RISC OS filesystem and given file
type FFA (Module).
The kernel it is to load also needs to be stored in a
.Tn RISC OS
filesystem.
.Pp
It takes the following standard
.Nx
options, which set flags in the
.Va boothowto
variable in the booted kernel (see
.Xr boothowto 9 ) .
Not all flags may be effective.
.Bl -tag -width Fl
.It Fl a
.Pq Dv RB_ASKNAME
Cause the kernel to prompt the user for the name of the device containing the
root filesystem.
This also causes
.Nm
to prompt for the name of the kernel to be loaded.
.It Fl s
.Pq Dv RB_SINGLE
Cause the kernel to ask
.Nm init
to boot into single-user mode.
.It Fl d
.Pq Dv RB_KDB
Cause the kernel to enter the kernel debugger as soon as possible.
.It Fl c
.Pq Dv RB_USERCONF
Enter the in-kernel device configuration manager before attaching any
devices.
.It Fl q
.Pq Dv AB_QUIET
Cause the kernel to emit fewer messages than normal while starting up.
.It Fl v
.Pq Dv AB_VERBOSE
Cause the kernel to emit more messages than normal while starting up.
.El
.Pp
.Nm
attempts to load the kernel from the RISC OS file specified as
.Ar file ,
or from
.Pa netbsd
if
.Ar file
is not specified.
The file must be an ELF image, and may have been compressed using
.Xr gzip 1 .
.Ss Use as a module
.Nm
is implemented as a RISC OS relocatable module.
It can be loaded into memory by running
.Ql *RMLoad boot32 .
After this,
.Nx
can be booted by running
.Ql *boot32
as usual, but the command will be handled by the module.
.Pp
It should also be possible to arrange for
.Nm
to be loaded from ROM (e.g., from the ROM on an expansion card), in which case
.Nx
could be made to boot automatically by making
.Nm
the configured language using
.Ql *Configure Language .
.Ss Screen display
When it starts up,
.Nm
displays the number of 4 kilobyte memory pages it has been delegated by RISC-OS
and gives a summary about the memory map as reported by RISC-OS followed by a
table of physical memory ranges available to the bootloader.
All this information is mainly for bughunting booting problems.
.Pp
It then checks its internal structures and kicks out RISC-OS, relocates all
memory pages loaded in to their final destinations and kickstarts
.Nm .
.Sh FILES
.Bl -tag -width Pa
.It Pa /usr/mdec/boot32,ffa
The location of
.Nm
in the
.Nx
filesystem.
.El
.Sh SEE ALSO
.Xr gzip 1 ,
.Xr reboot 2 ,
.Xr ddb 4 ,
.Xr userconf 4 ,
.Xr init 8 ,
.Xr boothowto 9
.Sh HISTORY
.Nm
was introduced in
.Nx 1.6
as a replacement for the original
.Nx Ns /arm32
bootloader, which was written in BBC BASIC.
.Sh BUGS
.Nm
cannot load kernels from a
.Nx
filesystem.