.TH 9BOOT 8
.SH NAME
9bootfat, 9bootiso, 9bootpxe \- bootloaders for pc FAT, ISO and PXE network booting
.SH SYNOPSIS
started by BIOS or chainloaded by partition bootsector
.SH DESCRIPTION
The bootloader is responsible for reading the
.IR plan9.ini (8)
boot parameters and booting a kernel. It interprets the
.B bootfile=
parameter as a file path on the current boot media
to locate the kernel image. The path should be in all
lower case except for
.IR 9bootpxe
wich supports case sensitive file names. Read parameters
are echoed on the console. The boot procedure
can be interrupted by pressing any key after the configuration
was read. The interactive boot console is indicated with a
.B >
prompt. The syntax of the boot console is the same as in
the
.IR plan9.ini (8)
file. The word
.B clear
will reset all current parameters. The word
.B boot
will end the console and resume booting the kernel. The boot
console is entered automatically when: boot failed, no
.B bootfile=
parameter was specified or no 
.IR plan9.ini (8)
was found.
.SH FAT BOOTING
The
.IR 9bootfat
program is responsible for loading the kernel from
the
.IR 9fat
partition into memory and passing it the
.IR plan9.ini (8)
boot parameters. It is chainloaded by
.IR pbs,
wich locates it in the root of the active
FAT partition. The
.IR plan9.ini (8)
file is read from the root directory of the FAT
filesystem.
.SH CD-ROM BOOTING
Booting from CD-ROM requires
.IR 9bootiso
to be included in the ISO-9660 image under
.B 386/9bootiso,
set as a non emulation bootblock (see
.IR mk9660 (8)).
The BIOS loads the first 2K of 
.B 386/9bootiso
into memory and then executes the program. The remainder
of the file is then read to complete the chainloading process.
Boot parameters are read from
.B cfg/plan9.ini.
.SH NETWORK BOOTING
With a PXE capable BIOS and network card it is possible for
a machine to download
.IR 9bootpxe
and a kernel from a tftp server. The location of
.IR 9bootpxe
is defined by the
.B bootf=/386/9bootpxe
line in the tftp server's
.IR ndb (6)
entry.
.BR
Once started,
.IR 9bootpxe
will read the file
.B /cfg/pxe/$ether
from the tftp server, where
.B $ether
is the MAC address of the client's network card
in lower case hex, and use this as its
.IR plan9.ini (8)
file.
.SH SOURCE
.BR /sys/src/boot/pc .