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发信人: reden (鱼 ～ 看流星和她的故事), 信区: Linux
标 题: Linux Remote-Boot mini-HOWTO(6/7)
发信站: BBS 水木清华站 (Sun Oct 18 20:54:17 1998) WWW-POST
5. Remote-Boot Tools Reference Manual
This section provides detailled informations on the use of the tools we
developped at the CUI, University of Geneva for this
remote-boot configuration.
5.1 BpBatch, MrBatch and MrZip
These three names stand for three variants of the same program, with the
following characteristics:
BpBatch is a special program that can be started from the BootProm
before the operating system is loaded. It is made of
two parts: bpbatch.P, the dynamic loader, and bpbatch.ovl, the program
itself. BpBatch has full disk I/O
capabilities through our own implementation of FAT16, FAT32 and Ext2fs,
as well as remote network I/O capabilities
through the BootProm TFTP API. BpBatch was compiled under DOS using
Borland C 5.0 and Turbo Assembler 3.2.
MrBatch is the DOS/Linux version of BpBatch. All commands recognized by
BpBatch are recognized by MrBatch
and vice versa. This is very usefull if you want to test your batch
scripts from a DOS/Linux session. Under DOS,
MrBatch emulates remote I/O by OS-based file access if the bootprom is
not available. Under Linux, the bootprom
cannot be seen anymore but MrBatch can emulate it using Linux IP
support, or use OS-based file access. MrBatch was
compiled under Linux using GCC 2.7.2.1 and under DOS using Borland C 5.0
and Turbo Assembler 3.2.
MrZip is an interpreter that recognizes a superset of MrBatch language,
and that serves to build disk images. In MrZip,
the limited remote file I/O is replaced by a full-featured OS-based file
access. MrZip does not include VESA support.
MrZip was compiled under Linux using GCC 2.7.2.1 and under DOS using
Borland C 5.0 and Turbo Assembler 3.2.
Command Line Arguments
All programs accept the same syntax of arguments. MrBatch and MrZip take them
from the command line, while BpBatch
look for them in the BOOTP option 155 (decimal). Here is the syntax of the
arguments:
[-x] [-l] [-b] [-v] [-w] [-i] [script-basename]
where:
-x disable the use of extended memory
-l disable the use of ISO-latin-8859-1 as default character set
-b cancel the bootprom detection (which cause a floppy seek under DOS)
-v cancel the VESA detection (which cause a switch to full screen under
Windows 95)
-w enable direct disk write access (disabled by default under DOS and
Linux)
-i enable interactive mode even if a script name is provided
The script-basename is optional. If provided, MrBatch and BpBatch load the
file with the .bpb extension, and MrZip
loads the file with the .mrz extension. If not provided, MrBatch and MrZip
run in interactive mode while BpBatch loads the
file with the same basename as the BOOTP Boot file and a .bpb extension.
Syntax rules
The following rules apply when BpBatch parses an input line.
Commands are parsed line by line. Lines are separated by CR and/or LF.
The maximal line length is currently 255 characters.
Keywords and variable names are case-insensitive.
" is interpreted as the special string delimiter
When ${variable} or $variable is encountred, it is substituted by the
value of the variable, or by an empty string if the
variable is undefined. The substitution also occurs within a string.
Moreover, the resulting substituted value must be
explicitely enclosed between double quotes if used as a string value
(ie. one should merely speak of macro expansion than
of a variables).
\a is substituted by the audible-bell character (ASCII 7)
\b is substituted by the backspace character (ASCII 8)
\n is substituted by the newline character (ASCII 10)
\r is substituted by the return character (ASCII 13)
\t is substituted by the tabulation character (ASCII 9)
\v is substituted by the vertical-tab character (ASCII ...)
\nnn where n is a 3-digit octal number between 000 and 377 is
substituted by the character with ascii code
specified
\X where X is any other character not listed above is substituted by
X itself. In particular,
\" is substituted by a regular double-quote (not a
string-delimiter)
\$ is substituted by a regular dollar sign (not variable
substitution)
\\ is substituted by a regular backslash (not a special
character)
The character "end of string" (ASCII code 0) CANNOT be used anywhere as
it is used internally as end-of-string delimiter
The character "floating diaeresis" (ASCII code dec 249, hex F9, octal
371) CANNOT be used in any string as it is used
internally as string delimiter in the input parsing routine.
The character "block space" (ASCII code dec 255, hex FF, octal 377)
CANNOT be used in any variable value as it is used
internally as variable delimiter.
Empty lines are ignored. Lines starting with a sharp (#) are treated as
comments and are not interpreted. Lines starting with a
column (:) are treated as labels and are not interpreted.
String expressions
Strings are delimited by opening and closing double-quotes:
"Hello world"
To include double-quotes within a string, quote them using a backslash:
"I said: \"Hello world\""
Strings can be postfixed with a few operators.
The character substitution operator:
"Hello world"/o=u/ == "Hellu wurld"
"198.76.54.32"/.= / == "198 76 54 32"
The word selection operator (zero-based):
"Hello world"{0} == "Hello"
"198 76 54 32"{1-3} == "76 54 32"
The substring selection operator (zero-based):
"Hello world"[4] == "o"
"Hello world"[4-7] == "o wo"
Operators can be chained by postfixing one after the other. For
informations about the string length and word count
operators, see under "Numerical expressions".
Numerical expressions
Numerical expressions work on 32-bits integer numbers (from
-2,147,483,646 to 2,147,483,647). Hexadecimal octal and
binary numbers are not understood. Whenever a numerical expression is
expected, the following are recognized:
A positive or negative integer number
An expression in the form (expr1 op expr2) where op can be either +,
-, * (multiply), / (divide) or % (modulo) and
expr is a numerical expression. Note that EACH operation MUST be
enclosed between parenthesis :
((3 * 5)+2) == 17
The string-length operator (@), followed by a string :
@"Hello world" == 11
The word-count operator (#) followed by a string :
#"Hello world" == 2
Durations
A few commands expect durations as arguments. Durations are measured in
seconds, with a precision of up to a tenth of
second:
Delay 3 waits for 3 seconds
Delay 0.3 waits for 3/10 seconds
Colors
Whenever a color is expected, you can either use the numeric value of
the color or its symbolic name (case-insensitive).
The following colors are recognized
Black 0
Blue 1
Green 2
Cyan 3
Red 4
Magenta 5
Brown 6
LightGray 7
DarkGray 8
LightBlue 9
LightGreen 10
LightCyan 11
LightRed 12
LightMagenta 13
Yellow 14
White 15
File References
File names are strings. They must therefore always be enclosed between
double-quotes. File names are case-sensitive on
case-sensitive filesystems, case-insensitive on case-insensitive
filesystems. Slash and backslash can be freely used one in
place of the other. Do not forget to double backslash since a single
backslash is an escape character.
There are two kinds of file references:
Direct disk files
Foreign files
Direct disk files are referenced using the following notation:
"{disk:partition}/absolute/filename"
The disk number can be omitted and defaults to zero. For instance,
"{:1}/usr/bin" points to /usr/bin assuming
there is such a directory on the first partition. Direct file I/O is
solely based on our own file access routines (we do not use
the operating system).
There are two special partitions. Partition zero corresponds to the hard
disk master boot record (MBR) and has a pseudo
file-system which let you access the boot code. Partition minus-one (-1)
corresponds to the cache filesystem (see below).
Under BpBatch/MrBatch, foreign files correspond to remote files on the
TFTP server when the BootProm is available:
"help.bpb" is the file help.bpb in the /tftpboot
directory
"gifs/MyImage.gif" is a file in /tftpboot/gifs
Other TFTP servers can be referenced :
"198.76.54.32:help.bpb"
If the other server is behind a gateway :
"198.70.0.1/198.76.54.31:help.bpb"
One can also specify a specific port for the TFTP connection :
"198.76.54.32@89:getpasswd/smith"
There can be only one open remote file at a time. If the BootProm is not
available, remote files are emulated using the
operating system file I/O, but the same restriction apply.
Under MrZip, foreign files correspond to files as seen by the operating
system. There is no limitation, and foreign files can
be used wherever direct disk files can be. Foreign files are usually
faster than direct disk files, because the operating
system has more buffers. Foreign files can refer to network files if
supported by the operating system.
"C:\\autoexec.bat"
"C:/config.sys"
"/mnt/net/usr"
The Cache Filesystem
In order to reduce network load and to fasten the boot process, disk
archives, linux kernels and possibly other files are cached on
the hard disk. This disk cache is located at the end of the hard disk,
between the last cylinder allocated in the partition table and
the last physical cylinder of the disk (out of any allocated partition).
There MUST be room between the last partition and the end
of the disk if you want the cache filesystem to work. The cache filesystem
MUST work if you want to restore a disk image.
The disk cache is organised in a volatile, CRC-validated filesystem : Each
directory entry and each 32 KB data block is validated
by a 32-bits CRC. Whenever a directory entry or a data block unexpectedly
changes, the file is automatically removed from the
cache and downloaded again upon the next request.
You can freely access the cache filesystem from within BpBatch, MrBatch and
MrZip using direct disk access on the special
partition "{:-1}". To see the content of the cache, just type :
logdir "{:-1}"
If the cache ever gets corrupted and is not automatically cleaned (which
should never occurs), you can either type :
clean -1
(in interactive mode) or hold both shifts down when BpBatch access the cache
for the first time.
Special variables
Some variable are initially set and/or have special meanings. Some of them
exist within all programs, other are only available under
MrZip and other are only available when a BOOTP/DHCP reply has been
received.
General variables
$Program is set to "BpBatch" within BpBatch, "MrBatch" within
MrBatch and "MrZip" within MrZip
$Basename is set to the basename of the script on which the batch
interpreter was started
$HelpFile is the name of the file loaded when Help is invoked.
Default: "${Basename}.hlp"
$BOOTP-... are variables set from the BOOTP/DHCP reply (see the
paragraph on BOOTP/DHCP variables for
more details)
$DHCP-... are variables set from the DHCP reply (see the paragraph
on BOOTP/DHCP variables for more
details)
$Disks is set to the space-separated list of sizes for each disk.
That means, #"$Disks" represent the number of
disks and "$Disks"{0} is the size of the first disk
$Keypressed is set to the next ready-to-read key available in the
keyboard buffer (if available)
$LBA controls the use of LBA to access disks > 2Gb. Default: "ON"
$FDA controls the use of fast disk access (write accross cylinders).
Default: "ON"
$VESA controls the use of VESA graphics. Default: "ON" if available
$VESA-Modes gives the list of all available VESA modes. The first
entry of the list is the default mode, which is
used when no parameter is given to InitGraph. Note: if VESA="OFF",
this variable is blank
$APM is set to "ON" if your computer supports Avanced Power
Management. If $APM is "ON", you can use the
command PowerOff to turn your computer off. Default: depends on your
hardware
$Trace controls the display of each command before execution. It
also controls the display of file names when
creating new archives. Default: "OFF"
$AutoShowLog controls the automatic switch to the text log whenever
the ESC key is pressed. Default: "ON"
$PauseLog controls the pause between each page of log when the log
is visible. Default: "ON"
$CacheDisk is set to the disk used for caching remote files.
Default: empty == 0, the first hard disk
$CacheAlways controls the automatic caching of remote files copied,
patched or drawn as GIF. Default: "OFF"
$CacheNever prevents any file from being cached. Turn this variable
on for diskless Linux boot. Default: "OFF"
$CacheReserve controls the preventive allocation of 25 percent more
space than necessary in the cache
partition, to let the files grow. Turn this variable off if you are
short of disk space. Default: "ON"
$ExtMemory controls the use of Extended Memory (or XMS). Once
deactivated, extended memory cannot be
reactivated. Default: "ON" if available
$IsoLatin controls the interpretation of upper ASCII codes in
included and patched files. The IsoLatin settings
are processed at the time the file is loaded, not at the time the
file is processed. Default: "ON"
$ProgressX and $ProgressY controls the position of the progress
window displayed in VESA graphics during
archive download and decompression. Default: 200 200
$EXT2-Backup controls the update of superblock backups in Linux ext2
filesystem. Superblock backups take a
few seconds to do and are never used by current kernels (only by
e2fsck).
$Security-Gateway controls the gateway-server used for user
authentication. Our special authentication
gateway must be running on the target computer. Default:
"${BOOTP-Server-IP}@89" (ie. the TFTP server,
on port 89)
$Security-Check contains the answer of the security server for the
last check performed, either PASSED or
FAILED. Default: "FAILED"
$Security-Passwd, $HelpTopic, $OnExit, $OnKey-... are used
internally.
See also BOOTP variables and MrZip-specific variables.
MrZip-specific variables
The following variables are only used within MrZip.
$TempPath controls the directory where temporary files will be
stored. Default: <empty> == current directory
$DumpFormat controls the way archives are dumped to the log when
requested. It is a string containing
"h"/"H" to display the archive header
"b"/"B" to summarize/dump boot sectors
"s"/"S" to display a short/long allocation summary
"d"/"D" to display a short/long directory listing
"f"/"F" to summarize/dump files
Default: "hbD"
$FragmentSize controls the size of archive pieces. If you do not use
InCom's extended TFTP server, you
should set this to "30 MB". Default: "87 MB"
$SourceArchive, $DestArchive, $Filter... are used internally.
BOOTP variables
The following BOOTP-... and DHCP-... variables are recognized, as long
as a BOOTP/DHCP reply has been received
(TCP/IP Bootprom must be reported as detected):
$BOOTP-Client-ID
$BOOTP-Your-IP
$BOOTP-Server-IP
$BOOTP-Gateway-IP
$BOOTP-Bootfile
$BOOTP-Server-Name
$BOOTP-Subnet-Mask
$BOOTP-Time-Offset
$BOOTP-Routers
$BOOTP-Time-Servers
$BOOTP-Name-Servers
$BOOTP-Domain-name-Servers
$BOOTP-BOOTP-Log-Servers
$BOOTP-Cookie-Servers
$BOOTP-Lpr-Servers
$BOOTP-Impress-Servers
$BOOTP-Resource-Location-Servers
$BOOTP-Host-Name
$BOOTP-Boot-Size
$BOOTP-Merit-Dump
$BOOTP-Domain-Name
$BOOTP-Swap-Servers
$BOOTP-Root-Path
$BOOTP-Extensions-Path
$BOOTP-IP-Forwarding
$BOOTP-Interface-MTU
$BOOTP-All-Subnets-Are-Local
$BOOTP-Broadcast-Address
$BOOTP-NIS-Domain
$BOOTP-NIS-Servers
$BOOTP-NTP-Servers
$BOOTP-Font-Servers
$BOOTP-X-Display-Manager
$DHCP-IP-Address-Lease-Time
$DHCP-Message-Type
$DHCP-Server-Identifier
$DHCP-Message
$DHCP-Renewal-Time
$DHCP-Rebinding-Time
$BOOTP-NIS+-Domain
$BOOTP-NIS+-Servers
$BOOTP-Server-Name
$BOOTP-Bootfile
$BOOTP-Mobile-IP-Agent
$BOOTP-SMTP-Servers
$BOOTP-POP3-Servers
$BOOTP-NNTP-Servers
$BOOTP-WWW-Servers
$BOOTP-Finger-Servers
$BOOTP-IRC-Servers
$BOOTP-StreetTalk-Servers
$BOOTP-STDA-Servers
Other BOOTP/DHCP parameters can be used under the name
$BOOTP-Option-n
where n is the decimal representation of the BOOTP option number.
Do not mix-up BOOTP-Gateway-IP, which is the gateway to use for TFTP and
should be 0.0.0.0 if the TFTP server is
in the same subnet, and BOOTP-Routers, which contains the default IP
gateway(s). The TCP/IP Bootprom sometimes
seems to set the value of BOOTP-Gateway-IP from the value in
BOOTP-Routers, causing each TFTP ack packet to
be sent to the router first. To avoid such behaviour, if your TFTP
server is in the same subnet as the client, force
BOOTP-Gateway-IP to 0.0.0.0 (thanks to Maciek Uhlig for having pointed
out this problem).
Monitoring commands
This section lists commands for monitoring the system state. Optional
arguments are listed between parenthesis (I would have
prefered square brackets, but LaTeX do not like them at this place...)
Interact
Show the log and turn to interactive mode until QUIT or EXIT is entered.
Type HideLog before quitting if you want to
avoid disturbing log messages during batch execution.
Help (topic)
Load the on-line help file (bpbatch.hlp) and display the description of
the given topic. If no topic is provided, or if the
topic is unknown, display the help index.
--
白马带著她一步步的回到中原。白马已经老了，只能慢慢的走，
但终是能回到中原的。江南有杨柳、桃花，有燕子、金鱼……
汉人中有的是英俊勇武的少年，倜傥潇洒的少年……但这个美
丽的姑娘就像古高昌国人那样固执:
「那都是很好很好的，可是我偏不喜欢。」
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