syslinux.doc

Windows上的精简Linux系统

			       SYSLINUX

              A bootloader for Linux using MS-DOS floppies

		Copyright (C) 1994-2003 H. Peter Anvin

This program is provided under the terms of the GNU General Public
License, version 2 or, at your option, any later version.  There is no
warranty, neither expressed nor implied, to the function of this
program.  Please see the included file COPYING for details.

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      SYSLINUX now has a home page at http://syslinux.zytor.com/

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SYSLINUX is a boot loader for the Linux operating system which
operates off an MS-DOS/Windows FAT filesystem.  It is intended to
simplify first-time installation of Linux, and for creation of rescue-
and other special-purpose boot disks.

SYSLINUX can be used, when properly set up, completely eliminate the
need for distribution of raw diskette images for boot floppies.  A
SYSLINUX floppy can be manipulated using standard MS-DOS (or any other
OS that can access an MS-DOS filesystem) tools once it has been
created.


   ++++ WHAT SYSLINUX IS NOT ++++

SYSLINUX is probably not suitable as a general purpose boot loader.
It can only boot Linux from a FAT filesystem, and not, for example,
ext2.  Since a native Linux implementation will typically use ext2,
another boot loader (e.g. LILO) is probably more suitable.  In a
system which actually contains DOS or Windows, LOADLIN may be simpler
to use.

However, SYSLINUX has shown itself to be quite useful in a number of
special-purpose applications.


   ++++ CREATING A BOOTABLE LINUX FLOPPY +++

In order to create a bootable Linux floppy using SYSLINUX, prepare a
normal MS-DOS formatted floppy.  Copy one or more Linux kernel files to
it, then execute the DOS command:

        syslinux [-s] a:

(or whichever drive letter is appropriate; the [] meaning -s is optional) 

If you're running in a Win95/98/ME DOS box, you should execute the
command "lock a:" first.  If you're running in a WinNT/2K DOS box, you
will probably get a dialog box about not getting exclusive access and
with Abort/Retry/Ignore buttons; people have reported that selecting
"Ignore" makes the command complete correctly.

Under Linux, execute the command:

	syslinux [-s] [-o offset] /dev/fd0

(or, again, whichever device is the correct one.)

This will alter the boot sector on the disk and copy a file named
LDLINUX.SYS into its root directory.

The -s option, if given, will install a "safe, slow and stupid"
version of SYSLINUX.  This version may work on some very buggy BIOSes
on which SYSLINUX would otherwise fail.  If you find a machine on
which the -s option is required to make it boot reliably, please send
as much info about your machine as you can, and include the failure
mode.

The -o option is used with a disk image file and specifies the byte
offset of the filesystem image in the file.

On boot time, by default, the kernel will be loaded from the image named
LINUX on the boot floppy.  This default can be changed, see the section
on the SYSLINUX config file.

If the Shift or Alt keys are held down during boot, or the Caps or Scroll
locks are set, SYSLINUX will display a LILO-style "boot:" prompt.  The
user can then type a kernel file name followed by any kernel parameters.
The SYSLINUX loader does not need to know about the kernel file in
advance; all that is required is that it is a file located in the root
directory on the disk.


   ++++ CONFIGURATION FILE ++++

All the configurable defaults in SYSLINUX can be changed by putting a
file called SYSLINUX.CFG in the root directory of the boot floppy.  This
is a text file in either UNIX or DOS format, containing one or more of
the following items (case is insensitive for keywords; upper case is used
here to indicate that a word should be typed verbatim):

All options here applies to PXELINUX as well as SYSLINUX unless
otherwise noted.  See pxelinux.doc for additional information on
PXELINUX.

# comment
	A comment line.  The whitespace after the hash mark is mandatory.

DEFAULT kernel options...
        Sets the default command line.  If SYSLINUX boots automatically,
        it will act just as if the entries after DEFAULT had been typed
        in at the "boot:" prompt.

        If no configuration file is present, or no DEFAULT entry is
        present in the config file, the default is "linux auto".

	NOTE: Earlier versions of SYSLINUX used to automatically
	append the string "auto" to whatever the user specified using
	the DEFAULT command.  As of version 1.54, this is no longer
	true, as it caused problems when using a shell as a substitute
	for "init."  You may want to include this option manually.

APPEND options...
        Add one or more options to the kernel command line.  These are
        added both for automatic and manual boots.  The options are
        added at the very beginning of the kernel command line,
        usually permitting explicitly entered kernel options to override
        them.  This is the equivalent of the LILO "append" option.

IPAPPEND flag_val			[PXELINUX only]
	The IPAPPEND option is available only on PXELINUX.  The
	flag_val is an OR of the following options:

	1: indicates that an option of the following format
	should be generated and added to the kernel command line:

		ip=<client-ip>:<boot-server-ip>:<gw-ip>:<netmask>

	... based on the input from the DHCP/BOOTP or PXE boot server.

	THE USE OF THIS OPTION IS NOT RECOMMENDED.  If you have to use
	it, it is probably an indication that your network configuration
	is broken.  Using just "ip=dhcp" on the kernel command line
	is a preferrable option, or, better yet, run dhcpcd/dhclient,
	from an initrd if necessary.

	2: indicates that an option of the following format
	should be generated and added to the kernel command line:

		BOOTIF=<hardware-address-of-boot-interface>

	... in dash-separated hexadecimal with leading hardware type
	(same as for the configuration file; see pxelinux.doc.)

	This allows an initrd program to determine from which
	interface the system booted.

LABEL label
  KERNEL image
  APPEND options...
  IPAPPEND flag_val			[PXELINUX only]
	Indicates that if "label" is entered as the kernel to boot,
        SYSLINUX should instead boot "image", and the specified APPEND
	and IPAPPEND options should be used instead of the ones
        specified in the global section of the file (before the first
        LABEL command.)  The default for "image" is the same as
        "label", and if no APPEND is given the default is to use the
        global entry (if any).  Up to 64 LABEL entries are permitted
	(for SYSLINUX, 128 LABEL entries.)

        Note that LILO uses the syntax:
        image = mykernel
          label = mylabel
          append = "myoptions"

        ... whereas SYSLINUX uses the syntax:
        label mylabel
          kernel mykernel
          append myoptions

	Notes:	Labels are mangled as if they were filenames, and must be
		unique after mangling.  For example, two labels
		"v2.1.30" and "v2.1.31" will not be distinguishable
		under SYSLINUX, since both mangle to the same DOS filename.

		The "kernel" doesn't have to be a Linux kernel; it can
		be a boot sector or a COMBOOT file (see below.)

  APPEND -
        Append nothing.  APPEND with a single hyphen as argument in a
        LABEL section can be used to override a global APPEND.

  LOCALBOOT type			[ISOLINUX, PXELINUX]
	On PXELINUX, specifying "LOCALBOOT 0" instead of a "KERNEL"
	option means invoking this particular label will cause a local
	disk boot instead of booting a kernel.

	The argument 0 means perform a normal boot.  The argument 4
	will perform a local boot with the Universal Network Driver
	Interface (UNDI) driver still resident in memory.  Finally,
	the argument 5 will perform a local boot with the entire PXE
	stack, including the UNDI driver, still resident in memory.
	All other values are undefined.  If you don't know what the
	UNDI or PXE stacks are, don't worry -- you don't want them,
	just specify 0.

	On ISOLINUX, the "type" specifies the local drive number to
	boot from; 0x00 is the primary floppy drive and 0x80 is the
	primary hard drive.  The special value -1 causes ISOLINUX to
	report failure to the BIOS, which, on recent BIOSes, should
	mean that the next boot device in the boot sequence should be
	activated.

IMPLICIT flag_val
        If flag_val is 0, do not load a kernel image unless it has been
        explicitly named in a LABEL statement.  The default is 1.

ALLOWOPTIONS flag_val
	If flag_val is 0, the user is not allowed to specify any
	arguments on the kernel command line.  The only options
	recognized are those specified in an APPEND statement.  The
	default is 1.

TIMEOUT timeout
        Indicates how long to wait at the boot: prompt until booting
        automatically, in units of 1/10 s.  The timeout is cancelled as
        soon as the user types anything on the keyboard, the assumption
        being that the user will complete the command line already
        begun.  A timeout of zero will disable the timeout completely,
        this is also the default.

        NOTE: The maximum possible timeout value is 35996; corresponding to
        just below one hour.

ONTIMEOUT kernel options...
	Sets the command line invoked on a timeout.  Normally this is
	the same thing as invoked by "DEFAULT".  If this is specified,
	then "DEFAULT" is used only if the user presses <Enter> to
	boot.

ONERROR kernel options...
	If a kernel image is not found (either due to it not existing,
	or because IMPLICIT is set), run the specified command.  The
	faulty command line is appended to the specified options, so
	if the ONERROR directive reads as:

		ONERROR xyzzy plugh

	... and the command line as entered by the user is:

		foo bar baz

	... SYSLINUX will execute the following as if entered by the
	user:
	
		xyzzy plugh foo bar baz

SERIAL port [[baudrate] flowcontrol]
	Enables a serial port to act as the console.  "port" is a
	number (0 = /dev/ttyS0 = COM1, etc.) or an I/O port address
	(e.g. 0x3F8); if "baudrate" is omitted, the baud rate defaults
	to 9600 bps.  The serial parameters are hardcoded to be 8
	bits, no parity, 1 stop bit.

	"flowcontrol" is a combination of the following bits:
	0x001 - Assert DTR
 	0x002 - Assert RTS
	0x010 - Wait for CTS assertion
	0x020 - Wait for DSR assertion
	0x040 - Wait for RI assertion
	0x080 - Wait for DCD assertion
	0x100 - Ignore input unless CTS asserted
	0x200 - Ignore input unless DSR asserted
	0x400 - Ignore input unless RI asserted
	0x800 - Ignore input unless DCD asserted

	All other bits are reserved.

	Typical values are:

	    0 - No flow control (default)
	0x303 - Null modem cable detect
	0x013 - RTS/CTS flow control
	0x813 - RTS/CTS flow control, modem input
	0x023 - DTR/DSR flow control
	0x083 - DTR/DCD flow control

	For the SERIAL directive to be guaranteed to work properly, it
	should be the first directive in the configuration file.

	NOTE: "port" values from 0 to 3 means the first four serial
	ports detected by the BIOS.  They may or may not correspond to
	the legacy port values 0x3F8, 0x2F8, 0x3E8, 0x2E8.

FONT filename
	Load a font in .psf format before displaying any output
	(except the copyright line, which is output as ldlinux.sys
	itself is loaded.)  SYSLINUX only loads the font onto the
	video card; if the .psf file contains a Unicode table it is
	ignored.  This only works on EGA and VGA cards; hopefully it
	should do nothing on others.

KBDMAP keymap
	Install a simple keyboard map.  The keyboard remapper used is
	*very* simplistic (it simply remaps the keycodes received from
	the BIOS, which means that only the key combinations relevant
	in the default layout -- usually U.S. English -- can be
	mapped) but should at least help people with AZERTY keyboard
	layout and the locations of = and , (two special characters
	used heavily on the Linux kernel command line.)

	The included program keytab-lilo.pl from the LILO distribution
	can be used to create such keymaps.  The file keytab-lilo.doc
	contains the documentation for this program.

DISPLAY filename 
	Displays the indicated file on the screen at boot time (before
        the boot: prompt, if displayed).  Please see the section below
        on DISPLAY files.

        NOTE: If the file is missing, this option is simply ignored.

SAY message
	Prints the message on the screen.

PROMPT flag_val
        If flag_val is 0, display the boot: prompt only if the Shift or Alt
        key is pressed, or Caps Lock or Scroll lock is set (this is the
        default).  If flag_val is 1, always display the boot: prompt.

F1 filename
F2 filename
   ...etc...
F9 filename
F0 filename
        Displays the indicated file on the screen when a function key is
        pressed at the boot: prompt.  This can be used to implement
        pre-boot online help (presumably for the kernel command line
        options.)  Note that F10 MUST be entered in the config file as
        "F0", not "F10", and that there is currently no way to bind
        file names to F11 and F12.  Please see the section below on
        DISPLAY files.

	When using the serial console, press <Ctrl-F><digit> to get to