aboutsummaryrefslogblamecommitdiffstats
path: root/Documentation/nbd.txt
blob: aeb93ffe64163173e37cf099a63451b6540551d0 (plain) (tree) 
1da177e4c3f4















































1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47















































                                                                          
                      Network Block Device (TCP version)
                                       
   What is it: With this compiled in the kernel (or as a module), Linux
   can use a remote server as one of its block devices. So every time
   the client computer wants to read, e.g., /dev/nb0, it sends a
   request over TCP to the server, which will reply with the data read.
   This can be used for stations with low disk space (or even diskless -
   if you boot from floppy) to borrow disk space from another computer.
   Unlike NFS, it is possible to put any filesystem on it, etc. It should
   even be possible to use NBD as a root filesystem (I've never tried),
   but it requires a user-level program to be in the initrd to start.
   It also allows you to run block-device in user land (making server
   and client physically the same computer, communicating using loopback).
   
   Current state: It currently works. Network block device is stable.
   I originally thought that it was impossible to swap over TCP. It
   turned out not to be true - swapping over TCP now works and seems
   to be deadlock-free, but it requires heavy patches into Linux's
   network layer.
   
   For more information, or to download the nbd-client and nbd-server
   tools, go to http://nbd.sf.net/.

   Howto: To setup nbd, you can simply do the following:

   First, serve a device or file from a remote server:

   nbd-server <port-number> <device-or-file-to-serve-to-client>

   e.g.,
	root@server1 # nbd-server 1234 /dev/sdb1

	(serves sdb1 partition on TCP port 1234)

   Then, on the local (client) system:

   nbd-client <server-name-or-IP> <server-port-number> /dev/nb[0-n]

   e.g.,
	root@client1 # nbd-client server1 1234 /dev/nb0

	(creates the nb0 device on client1)

   The nbd kernel module need only be installed on the client
   system, as the nbd-server is completely in userspace. In fact,
   the nbd-server has been successfully ported to other operating
   systems, including Windows.
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-24 18:24:50 -0500
id='n115' href='#n115'>115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 







































































































































































































































































































































































































                                                                                
* NOTE - This is an unmaintained driver.  Lantronix, which bought Stallion
technologies, is not active in driver maintenance, and they have no information
on when or if they will have a 2.6 driver.

James Nelson <james4765@gmail.com> - 12-12-2004

Stallion Multiport Serial Driver Readme
---------------------------------------

Copyright (C) 1994-1999,  Stallion Technologies.

Version:   5.5.1
Date:      28MAR99



1. INTRODUCTION

There are two drivers that work with the different families of Stallion
multiport serial boards. One is for the Stallion smart boards - that is
EasyIO, EasyConnection 8/32 and EasyConnection 8/64-PCI, the other for
the true Stallion intelligent multiport boards - EasyConnection 8/64
(ISA, EISA, MCA), EasyConnection/RA-PCI, ONboard and Brumby.

If you are using any of the Stallion intelligent multiport boards (Brumby,
ONboard, EasyConnection 8/64 (ISA, EISA, MCA), EasyConnection/RA-PCI) with
Linux you will need to get the driver utility package.  This contains a
firmware loader and the firmware images necessary to make the devices operate.

The Stallion Technologies ftp site, ftp.stallion.com, will always have
the latest version of the driver utility package.

ftp://ftp.stallion.com/drivers/ata5/Linux/ata-linux-550.tar.gz

As of the printing of this document the latest version of the driver
utility package is 5.5.0. If a later version is now available then you
should use the latest version.

If you are using the EasyIO, EasyConnection 8/32 or EasyConnection 8/64-PCI
boards then you don't need this package, although it does have a serial stats
display program.

If you require DIP switch settings, EISA or MCA configuration files, or any
other information related to Stallion boards then have a look at Stallion's
web pages at http://www.stallion.com.



2. INSTALLATION

The drivers can be used as loadable modules or compiled into the kernel.
You can choose which when doing a "config" on the kernel.

All ISA, EISA and MCA boards that you want to use need to be configured into
the driver(s). All PCI boards will be automatically detected when you load
the driver - so they do not need to be entered into the driver(s)
configuration structure. Note that kernel PCI support is required to use PCI
boards.

There are two methods of configuring ISA, EISA and MCA boards into the drivers.
If using the driver as a loadable module then the simplest method is to pass
the driver configuration as module arguments. The other method is to modify
the driver source to add configuration lines for each board in use.

If you have pre-built Stallion driver modules then the module argument
configuration method should be used. A lot of Linux distributions come with
pre-built driver modules in /lib/modules/X.Y.Z/misc for the kernel in use.
That makes things pretty simple to get going.


2.1 MODULE DRIVER CONFIGURATION:

The simplest configuration for modules is to use the module load arguments
to configure any ISA, EISA or MCA boards. PCI boards are automatically
detected, so do not need any additional configuration at all.

If using EasyIO, EasyConnection 8/32 ISA or MCA, or EasyConnection 8/63-PCI
boards then use the "stallion" driver module, Otherwise if you are using
an EasyConnection 8/64 ISA, EISA or MCA, EasyConnection/RA-PCI, ONboard,
Brumby or original Stallion board then use the "istallion" driver module.

Typically to load up the smart board driver use:

    modprobe stallion

This will load the EasyIO and EasyConnection 8/32 driver. It will output a
message to say that it loaded and print the driver version number. It will
also print out whether it found the configured boards or not. These messages
may not appear on the console, but typically are always logged to
/var/adm/messages or /var/log/syslog files - depending on how the klogd and
syslogd daemons are setup on your system.

To load the intelligent board driver use:

    modprobe istallion

It will output similar messages to the smart board driver.

If not using an auto-detectable board type (that is a PCI board) then you
will also need to supply command line arguments to the modprobe command
when loading the driver. The general form of the configuration argument is

    board?=<name>[,<ioaddr>[,<addr>][,<irq>]]

where:

    board?  -- specifies the arbitrary board number of this board,
               can be in the range 0 to 3.

    name    -- textual name of this board. The board name is the common
               board name, or any "shortened" version of that. The board
               type number may also be used here.

    ioaddr  -- specifies the I/O address of this board. This argument is
               optional, but should generally be specified.

    addr    -- optional second address argument. Some board types require
               a second I/O address, some require a memory address. The
               exact meaning of this argument depends on the board type.

    irq     -- optional IRQ line used by this board.

Up to 4 board configuration arguments can be specified on the load line.
Here is some examples:

    modprobe stallion board0=easyio,0x2a0,5

This configures an EasyIO board as board 0 at I/O address 0x2a0 and IRQ 5.

    modprobe istallion board3=ec8/64,0x2c0,0xcc000

This configures an EasyConnection 8/64 ISA as board 3 at I/O address 0x2c0 at
memory address 0xcc000.

    modprobe stallion board1=ec8/32-at,0x2a0,0x280,10

This configures an EasyConnection 8/32 ISA board at primary I/O address 0x2a0,
secondary address 0x280 and IRQ 10.

You will probably want to enter this module load and configuration information
into your system startup scripts so that the drivers are loaded and configured
on each system boot. Typically the start up script would be something like
/etc/modprobe.conf.


2.2 STATIC DRIVER CONFIGURATION:

For static driver configuration you need to modify the driver source code.
Entering ISA, EISA and MCA boards into the driver(s) configuration structure
involves editing the driver(s) source file. It's pretty easy if you follow
the instructions below. Both drivers can support up to 4 boards. The smart
card driver (the stallion.c driver) supports any combination of EasyIO and
EasyConnection 8/32 boards (up to a total of 4). The intelligent driver
supports any combination of ONboards, Brumbys, Stallions and EasyConnection
8/64 (ISA and EISA) boards (up to a total of 4).

To set up the driver(s) for the boards that you want to use you need to
edit the appropriate driver file and add configuration entries.

If using EasyIO or EasyConnection 8/32 ISA or MCA boards,
   In drivers/char/stallion.c:
      - find the definition of the stl_brdconf array (of structures)
        near the top of the file
      - modify this to match the boards you are going to install
	(the comments before this structure should help)
      - save and exit

If using ONboard, Brumby, Stallion or EasyConnection 8/64 (ISA or EISA)
boards,
   In drivers/char/istallion.c:
      - find the definition of the stli_brdconf array (of structures)
        near the top of the file
      - modify this to match the boards you are going to install
	(the comments before this structure should help)
      - save and exit

Once you have set up the board configurations then you are ready to build
the kernel or modules.

When the new kernel is booted, or the loadable module loaded then the
driver will emit some kernel trace messages about whether the configured
boards were detected or not. Depending on how your system logger is set
up these may come out on the console, or just be logged to
/var/adm/messages or /var/log/syslog. You should check the messages to
confirm that all is well.


2.3 SHARING INTERRUPTS

It is possible to share interrupts between multiple EasyIO and
EasyConnection 8/32 boards in an EISA system. To do this you must be using
static driver configuration, modifying the driver source code to add driver
configuration. Then a couple of extra things are required:

1. When entering the board resources into the stallion.c file you need to
   mark the boards as using level triggered interrupts. Do this by replacing
   the "0" entry at field position 6 (the last field) in the board
   configuration structure with a "1". (This is the structure that defines
   the board type, I/O locations, etc. for each board). All boards that are
   sharing an interrupt must be set this way, and each board should have the
   same interrupt number specified here as well. Now build the module or
   kernel as you would normally.

2. When physically installing the boards into the system you must enter
   the system EISA configuration utility. You will need to install the EISA
   configuration files for *all* the EasyIO and EasyConnection 8/32 boards
   that are sharing interrupts. The Stallion EasyIO and EasyConnection 8/32
   EISA configuration files required are supplied by Stallion Technologies
   on the EASY Utilities floppy diskette (usually supplied in the box with
   the board when purchased. If not, you can pick it up from Stallion's FTP
   site, ftp.stallion.com). You will need to edit the board resources to
   choose level triggered interrupts, and make sure to set each board's
   interrupt to the same IRQ number.

You must complete both the above steps for this to work. When you reboot
or load the driver your EasyIO and EasyConnection 8/32 boards will be
sharing interrupts.


2.4 USING HIGH SHARED MEMORY

The EasyConnection 8/64-EI, ONboard and Stallion boards are capable of
using shared memory addresses above the usual 640K - 1Mb range. The ONboard
ISA and the Stallion boards can be programmed to use memory addresses up to
16Mb (the ISA bus addressing limit), and the EasyConnection 8/64-EI and
ONboard/E can be programmed for memory addresses up to 4Gb (the EISA bus
addressing limit).

The higher than 1Mb memory addresses are fully supported by this driver.
Just enter the address as you normally would for a lower than 1Mb address
(in the driver's board configuration structure).



2.5 TROUBLE SHOOTING

If a board is not found by the driver but is actually in the system then the
most likely problem is that the I/O address is wrong. Change the module load
argument for the loadable module form. Or change it in the driver stallion.c
or istallion.c configuration structure and rebuild the kernel or modules, or
change it on the board.

On EasyIO and EasyConnection 8/32 boards the IRQ is software programmable, so
if there is a conflict you may need to change the IRQ used for a board. There
are no interrupts to worry about for ONboard, Brumby or EasyConnection 8/64
(ISA, EISA and MCA) boards. The memory region on EasyConnection 8/64 and
ONboard boards is software programmable, but not on the Brumby boards.



3. USING THE DRIVERS

3.1 INTELLIGENT DRIVER OPERATION

The intelligent boards also need to have their "firmware" code downloaded
to them. This is done via a user level application supplied in the driver
utility package called "stlload". Compile this program wherever you dropped
the package files, by typing "make". In its simplest form you can then type

    ./stlload -i cdk.sys

in this directory and that will download board 0 (assuming board 0 is an
EasyConnection 8/64 or EasyConnection/RA board). To download to an
ONboard, Brumby or Stallion do:

    ./stlload -i 2681.sys

Normally you would want all boards to be downloaded as part of the standard
system startup. To achieve this, add one of the lines above into the
/etc/rc.d/rc.S or /etc/rc.d/rc.serial file. To download each board just add
the "-b <brd-number>" option to the line. You will need to download code for
every board. You should probably move the stlload program into a system
directory, such as /usr/sbin. Also, the default location of the cdk.sys image
file in the stlload down-loader is /usr/lib/stallion. Create that directory
and put the cdk.sys and 2681.sys files in it. (It's a convenient place to put
them anyway). As an example your /etc/rc.d/rc.S file might have the
following lines added to it (if you had 3 boards):

    /usr/sbin/stlload -b 0 -i /usr/lib/stallion/cdk.sys
    /usr/sbin/stlload -b 1 -i /usr/lib/stallion/2681.sys
    /usr/sbin/stlload -b 2 -i /usr/lib/stallion/2681.sys

The image files cdk.sys and 2681.sys are specific to the board types. The
cdk.sys will only function correctly on an EasyConnection 8/64 board. Similarly
the 2681.sys image fill only operate on ONboard, Brumby and Stallion boards.
If you load the wrong image file into a board it will fail to start up, and
of course the ports will not be operational!

If you are using the modularized version of the driver you might want to put
the modprobe calls in the startup script as well (before the download lines
obviously).


3.2 USING THE SERIAL PORTS

Once the driver is installed you will need to setup some device nodes to
access the serial ports. The simplest method is to use the /dev/MAKEDEV program.
It will automatically create device entries for Stallion boards. This will
create the normal serial port devices as /dev/ttyE# where# is the port number
starting from 0. A bank of 64 minor device numbers is allocated to each board,
so the first port on the second board is port 64,etc. A set of callout type
devices may also be created. They are created as the devices /dev/cue# where #
is the same as for the ttyE devices.

For the most part the Stallion driver tries to emulate the standard PC system
COM ports and the standard Linux serial driver. The idea is that you should
be able to use Stallion board ports and COM ports interchangeably without
modifying anything but the device name. Anything that doesn't work like that
should be considered a bug in this driver!

If you look at the driver code you will notice that it is fairly closely
based on the Linux serial driver (linux/drivers/char/serial.c). This is
intentional, obviously this is the easiest way to emulate its behavior!

Since this driver tries to emulate the standard serial ports as much as
possible, most system utilities should work as they do for the standard
COM ports. Most importantly "stty" works as expected and "setserial" can
also be used (excepting the ability to auto-configure the I/O and IRQ
addresses of boards). Higher baud rates are supported in the usual fashion
through setserial or using the CBAUDEX extensions. Note that the EasyIO and
EasyConnection (all types) support at least 57600 and 115200 baud. The newer
EasyConnection XP modules and new EasyIO boards support 230400 and 460800
baud as well. The older boards including ONboard and Brumby support a
maximum baud rate of 38400.

If you are unfamiliar with how to use serial ports, then get the Serial-HOWTO
by Greg Hankins. It will explain everything you need to know!



4. NOTES

You can use both drivers at once if you have a mix of board types installed
in a system. However to do this you will need to change the major numbers
used by one of the drivers. Currently both drivers use major numbers 24, 25
and 28 for their devices. Change one driver to use some other major numbers,
and then modify the mkdevnods script to make device nodes based on those new
major numbers. For example, you could change the istallion.c driver to use
major numbers 60, 61 and 62. You will also need to create device nodes with
different names for the ports, for example ttyF# and cuf#.

The original Stallion board is no longer supported by Stallion Technologies.
Although it is known to work with the istallion driver.

Finding a free physical memory address range can be a problem. The older
boards like the Stallion and ONboard need large areas (64K or even 128K), so
they can be very difficult to get into a system. If you have 16 Mb of RAM
then you have no choice but to put them somewhere in the 640K -> 1Mb range.
ONboards require 64K, so typically 0xd0000 is good, or 0xe0000 on some
systems. If you have an original Stallion board, "V4.0" or Rev.O, then you
need a 64K memory address space, so again 0xd0000 and 0xe0000 are good.
Older Stallion boards are a much bigger problem. They need 128K of address
space and must be on a 128K boundary. If you don't have a VGA card then
0xc0000 might be usable - there is really no other place you can put them
below 1Mb.

Both the ONboard and old Stallion boards can use higher memory addresses as
well, but you must have less than 16Mb of RAM to be able to use them. Usual
high memory addresses used include 0xec0000 and 0xf00000.

The Brumby boards only require 16Kb of address space, so you can usually
squeeze them in somewhere. Common addresses are 0xc8000, 0xcc000, or in
the 0xd0000 range. EasyConnection 8/64 boards are even better, they only
require 4Kb of address space, again usually 0xc8000, 0xcc000 or 0xd0000
are good.

If you are using an EasyConnection 8/64-EI or ONboard/E then usually the
0xd0000 or 0xe0000 ranges are the best options below 1Mb. If neither of
them can be used then the high memory support to use the really high address
ranges is the best option. Typically the 2Gb range is convenient for them,
and gets them well out of the way.

The ports of the EasyIO-8M board do not have DCD or DTR signals. So these
ports cannot be used as real modem devices. Generally, when using these
ports you should only use the cueX devices.

The driver utility package contains a couple of very useful programs. One 
is a serial port statistics collection and display program - very handy
for solving serial port problems. The other is an extended option setting
program that works with the intelligent boards.



5. DISCLAIMER

The information contained in this document is believed to be accurate and
reliable. However, no responsibility is assumed by Stallion Technologies
Pty. Ltd. for its use, nor any infringements of patents or other rights
of third parties resulting from its use. Stallion Technologies reserves
the right to modify the design of its products and will endeavour to change
the information in manuals and accompanying documentation accordingly.
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-24 18:24:50 -0500