PLAN9.INI(8)
NAME
plan9.ini − configuration file for PCs
SYNOPSIS
none
DESCRIPTION
When booting Plan 9 on a PC, the DOS program 9load(8) first reads a DOS file containing configuration information from the boot disk. This file, plan9.ini, looks like a shell script containing lines of the form
name=value
each of which defines a kernel or device parameter.
For devices, the generic format of value is
type=TYPE [port=N] [irq=N] [mem=N] [size=N] [dma=N] [ea=N]
specifying the controller type, the base I/O port of the interface, its interrupt level, the physical starting address of any mapped memory, the length in bytes of that memory, the DMA channel, and for Ethernets an override of the physical network address. Not all elements are relevant to all devices; the relevant values and their defaults are defined below in the description of each device.
The file is used by 9load and the kernel to configure the hardware available. The information it contains is also passed to the boot process, and subsequently other programs, as environment variables (see boot(8)). However, values whose names begin with an asterisk ∗ are used by the kernel and are not converted into environment variables.
The following sections describe how variables are used.
etherX=value
This defines an Ethernet interface. X, a unique monotonically increasing number beginning at 0, identifies an Ethernet card to be probed at system boot. Probing stops when a card is found or there is no line for etherX+1.
Some cards are software configurable and do not require all options. Unspecified options default to the factory defaults.
Known types are
ne2000
Not software configurable. 16-bit card. Defaults are
port=0x300 irq=2 mem=0x04000 size=0x4000
The option (no value) nodummyrr is needed on some (near) clones to turn off a dummy remote read in the driver.
amd79c970
The AMD PCnet PCI Ethernet Adapter (AM79C970). Completely configurable, no options need be given.
wd8003
Includes WD8013 and SMC Elite and Elite Ultra cards. There are varying degrees of software configurability. Cards may be in either 8-bit or 16-bit slots. Defaults are
port=0x280 irq=3 mem=0xD0000 size=0x2000
BUG: On many machines only the 16 bit card works.
elnk3
The 3COM Etherlink ||| series of cards including the 5x9, 59x, and 905 and 905B. Completely configurable, no options need be given. The media may be specified by setting media= to the value 10BaseT, 10Base2, 100BaseTX, 100BaseFX, aui, and mii. If you need to force full duplex, because for example the Ethernet switch does not negotiate correctly, just name the word (no value) fullduplex or 100BASE-TXFD. Similarly, to force 100Mbit operation, specify force100. Port 0x110 is used for the little ISA configuration dance.
3c589
The 3COM 3C589 series PCMCIA cards. There is no support for the modem on the 3C562. Completely configurable, no options need be given. Defaults are
port=0x240 irq=10
The media may be specified as media=10BaseT or media=10Base2.
ec2t The Linksys Combo PCMCIA EthernetCard (EC2T), EtherFast 10/100 (PCMPC100) PCMCIA cards and the Accton EtherPair-PCMCIA (EN2216). Completely configurable, no options need be given. Defaults are
port=0x300 irq=9
These cards are NE2000 clones. Other NE2000 compatible PCMCIA cards may be tried with the option
id=string
where string is a unique identifier string contained in the attribute memory of the card (see pcmcia(8)); unlike most options in plan9.ini, this string is case-sensitive. The option dummyrr=[01] can be used to turn off (0) or on (1) a dummy remote read in the driver in such cases, depending on how NE2000 compatible they are.
i82557
Cards using the Intel 8255[789] Fast Ethernet PCI Bus LAN Controller such as the Intel EtherExpress PRO/100B. Completely configurable, no options need be given. If you need to force the media, specify one of the options (no value) 10BASE-T, 10BASE-2, 10BASE-5, 100BASE-TX, 10BASE-TFD, 100BASE-TXFD, 100BASE-T4, 100BASE-FX, or 100BASE-FXFD.
21114x
Cards using the Digital Equipment (now Intel) 2114x PCI Fast Ethernet Adapter Controller. Completely configurable, no options need be given. Media can be specified the same was as for the i82557. Some cards using the PNIC and PNIC2 near-clone chips may also work.
scsiX=value
This defines a SCSI interface which cannot be automatically detected by the kernel.
Known types are
aha1542
The Adaptec 154x series of controllers (and clones). Almost completely configurable, only the
port=0x300
option need be given.
serialX=value
This defines add on serial ports and cards. Multiple cards can share the same IRQ. Unfortunately, many PC’s allow only the built in UARTs on the COM1 and COM2 IRQ’s (3 & 4) so beware.
Known types are
mp008
The TTC 8 serial line card. The mem parameter is the port number of the interrupt polling port. Size is the number of UARTs, default 8. Port is the port number of the first UART.
a100i a200i a16i AvanstarXp
The Star Gate Avanstar series of intelligent serial boards.
generic
Any set of 16450 compatible serial lines with consecutive port addresses. Size is the number of UARTs, default 1. Port is the port number of the first UART.
eiaX=disabled
By default, eia0 is initialized as port 0x3F8, IRQ 4 (DOS’s COM1) and eia1 as port 0x2F8, IRQ 3 (DOS’s COM2). Such a line disables this default initialization, usually in order to reuse the IRQ for another device.
mouseport=value
This specifies where the mouse is attached. Value can be
ps2 the PS2 mouse/keyboard port. The BIOS setup procedure should be used to configure the machine appropriately.
0 for COM1
1 for COM2
modemport=value
Picks the UART line to call out on. This is used when connecting to a file server over an async line. Value is the number of the port.
pcmciaX=type=XXX irq=value
If the default IRQ for the PCMCIA is correct, this entry can be omitted. The value of type is ignored.
console=value
baud=value
These are used to specify the console device. The default console value is cga. Values of 0 or 1 specify COM1 or COM2 respectively, in which case baud is used to initialize the port.
bootfile=value
This is used to direct the actions of 9load(8) by naming the device and file from which to load the kernel.
rootdir=dir
rootspec=spec
These are used by 9load(8) to identify the directory dir to make the root directory for the kernel, and the and file system specifier spec (see mount in bind(2)) on which it can be found. These are usually used to test variant file systems for distributions, etc.
bootargs=value
The value of this variable is passed to boot(8) by the kernel as the name of the root file system. For example, if the system is to run from a local kfs(4) partition, the definition might read bootargs=local!#S/sdC0/fs.
cfs=value
This gives the name of the file holding the disk partition for the cache file system, cfs(4). Extending the bootargs example, one would write cfs=#S/sdC0/cache.
bootdisk=value
This deprecated variable was used to specify the disk used by the cache file system and other disk-resident services. It is superseded by bootargs and cfs.
partition=value
This defines the partition table 9load(8) will examine to find disk partitioning information. By default, a partition table in a Plan 9 partition is consulted; if no such table is found, an old-Plan 9 partition table on the next-to-last or last sector of the disk is consulted. A value of new consults only the first table, old only the second.
∗maxmem=value
This defines the maximum physical address that the system will scan when sizing memory. By default the operating system will scan up to 768 megabytes, but setting ∗maxmem will limit the scan. If the system has more than 768 megabytes, you must set ∗maxmem for the kernel to find it. ∗maxmem must be less than 1.75 gigabytes.
∗kernelpercent=value
This defines what percentage of available memory is reserved for the kernel allocation pool. The remainder is left for user processes. The default value is 30. This deprecated option is rarely necessary in newer kernels.
∗nomp=value
A multiprocessor machine will enable all processors by default. Setting ∗nomp restricts the kernel to starting only one processor and using the traditional interrupt controller.
∗pcimaxbno=value
This puts a limit on the maximum bus number probed on a PCI bus (default 255). For example, a value of 1 should suffice on a ’standard’ motherboard with an AGP slot. This, and ∗pcimaxdno below are rarely used and only on troublesome or suspect hardware.
∗pcimaxdno=value
This puts a limit on the maximum device number probed on a PCI bus (default 31).
monitor=value
vgasize=value
These are used not by the kernel but by vga(8).
nvr=value
This is used by a file server kernel to locate a file holding information to configure the file system. The file cannot live on a SCSI disk. The default is fd!0!plan9.nvr (sic), unless bootfile is set, in which case it is plan9.nvr on the same disk as bootfile. The syntax is either fd!unit!name or hd!unit!name where unit is the numeric unit id. This variant syntax is a vestige of the file server kernel’s origins.
audioX=value
This defines a sound interface.
Known types are
sb16 Sound Blaster 16. ess1688 A Sound Blaster clone.
The DMA channel may be any of 5, 6, or 7. The defaults are
port=0x220 irq=7 dma=5
fs=a.b.c.d
auth=a.b.c.d
These specify the IP address of the file and authentication server to use when mounting a network-provided root file system. They are used only if the addresses cannot be determined via DHCP.
EXAMPLES
A representative plan9.ini:
% cat /n/c:/plan9.ini
ether0=type=3C509
mouseport=ps2
modemport=1
serial0=type=generic port=0x3E8 irq=5
monitor=445x
vgasize=1600x1200x8
%
Minimum CONFIG.SYS and AUTOEXEC.BAT files to use COM2 as a console:
% cat /n/c:/config.sys
SHELL=COMMAND.COM COM2 /P
% cat /n/c:/autoexec.bat
@ECHO OFF
PROMPT $p$g
PATH C:\DOS;C:\BIN
mode com2:96,n,8,1,p
SET TEMP=C:\TMP
%
SEE ALSO
BUGS
Being able to set the console device to other than a display is marginally useful on file servers; MS-DOS and the programs which run under it are so tightly bound to the display that it is necessary to have a display if any setup or reconfiguration programs need to be run. Also, the delay before any messages appear at boot time is disconcerting, as any error messages from the BIOS are lost.
This idea is at best an interesting experiment that needs another iteration.
Plan 9 — July 29, 2000