syslinux.doc

Windows上的精简Linux系统

	the help screens, e.g. <Ctrl-F><2> to get to the F2 screen,
	and <Ctrl-F><0> for the F10 one.

Blank lines are ignored.

Note that the configuration file is not completely decoded.  Syntax
different from the one described above may still work correctly in this
version of SYSLINUX, but may break in a future one.


   ++++ LARGE KERNELS AND INITIAL RAMDISK SUPPORT ++++

This version of SYSLINUX supports large kernels (bzImage format),
eliminating the 500K size limit of the zImage kernel format.  bzImage
format kernels are detected automatically and handled transparently to
the user.

This version of SYSLINUX also supports a boot-time-loaded ramdisk
(initrd).  An initrd is loaded from a DOS file if the option
"initrd=filename" (where filename is the filename of the initrd image;
the file must be located in the root directory on the boot floppy) is
present on the processed command line (after APPEND's have been added,
etc.).  If several initrd options are present, the last one has
precedence; this permits user-entered options to override a config
file APPEND.  Specifying "initrd=" without a filename inhibits initrd
loading.  The file specified by the initrd= option will typically be a
gzipped filesystem image.

NOTE: One of the main advantages with SYSLINUX is that it makes it
very easy to support users with new or unexpected configurations,
especially in a distribution setting.  If initrd is used to
extensively modularize the distribution kernel, it is strongly
recommended that a simple way of adding drivers to the boot floppy be
provided.  The suggested manner is to let the initrd system mount the
boot floppy and look for additional drivers in a predetermined
location.

To bzImage and recent zImage kernels, SYSLINUX 1.30 and higher will
identify using the ID byte 0x31.  PXELINUX identifies using the ID
byte 0x32, and ISOLINUX 0x33.  The ID range 0x34-0x3f is reserved for
future versions or derivatives of SYSLINUX.


   ++++ DISPLAY FILE FORMAT ++++

DISPLAY and function-key help files are text files in either DOS or UNIX
format (with or without <CR>).  In addition, the following special codes
are interpreted:

<FF>                                    <FF> = <Ctrl-L> = ASCII 12
        Clear the screen, home the cursor.  Note that the screen is
        filled with the current display color.

<SI><bg><fg>                            <SI> = <Ctrl-O> = ASCII 15
        Set the display colors to the specified background and
        foreground colors, where <bg> and <fg> are hex digits,
        corresponding to the standard PC display attributes:

        0 = black               8 = dark grey
        1 = dark blue           9 = bright blue
        2 = dark green          a = bright green
        3 = dark cyan           b = bright cyan
        4 = dark red            c = bright red
        5 = dark purple         d = bright purple
        6 = brown               e = yellow
        7 = light grey          f = white

        Picking a bright color (8-f) for the background results in the
        corresponding dark color (0-7), with the foreground flashing.

	Colors are not visible over the serial console.

<CAN>filename<newline>			<CAN> = <Ctrl-X> = ASCII 24
	If a VGA display is present, enter graphics mode and display
	the graphic included in the specified file.  The file format
	is an ad hoc format called LSS16; the included Perl program
	"ppmtolss16" can be used to produce these images.  This Perl
	program also includes the file format specification.

	The image is displayed in 640x480 16-color mode.  Once in
	graphics mode, the display attributes (set by <SI> code
	sequences) work slightly differently: the background color is
	ignored, and the foreground colors are the 16 colors specified
	in the image file.  For that reason, ppmtolss16 allows you to
	specify that certain colors should be assigned to specific
	color indicies.

	Color indicies 0 and 7, in particular, should be chosen with
	care: 0 is the background color, and 7 is the color used for
	the text printed by SYSLINUX itself.

<EM>					<EM> = <Ctrl-Y> = ASCII 25
	If we are currently in graphics mode, return to text mode.

<DLE>..<ETB>				<Ctrl-P>..<Ctrl-W> = ASCII 16-23
	These codes can be used to select which modes to print a
	certain part of the message file in.  Each of these control
	characters select a specific set of modes (text screen,
	graphics screen, serial port) for which the output is actually
	displayed:

	Character			Text	Graph	Serial
	------------------------------------------------------
	<DLE> = <Ctrl-P> = ASCII 16	No	No	No
	<DC1> = <Ctrl-Q> = ASCII 17	Yes	No	No
	<DC2> = <Ctrl-R> = ASCII 18	No	Yes	No
	<DC3> = <Ctrl-S> = ASCII 19	Yes	Yes	No
	<DC4> = <Ctrl-T> = ASCII 20	No	No	Yes
	<NAK> = <Ctrl-U> = ASCII 21	Yes	No	Yes
	<SYN> = <Ctrl-V> = ASCII 22	No	Yes	Yes
	<ETB> = <Ctrl-W> = ASCII 23	Yes	Yes	Yes

	For example:

	<DC1>Text mode<DC2>Graphics mode<DC4>Serial port<ETB>
	
	... will actually print out which mode the console is in!

<SUB>                                   <SUB> = <Ctrl-Z> = ASCII 26
        End of file (DOS convention).


   ++++ COMBOOT IMAGES AND OTHER OPERATING SYSTEMS ++++

This version of SYSLINUX supports chain loading of other operating
systems (such as MS-DOS and its derivatives, including Windows 95/98),
as well as COMBOOT-style standalone executables (a subset of DOS .COM
files; see separate section below.)

Chain loading requires the boot sector of the foreign operating system
to be stored in a file in the root directory of the filesystem.
Because neither Linux kernels, boot sector images, nor COMBOOT files
have reliable magic numbers, SYSLINUX will look at the file extension.
The following extensions are recognized (case insensitive):

  none or other	Linux kernel image
  .0		PXE bootstrap program (NBP) [PXELINUX only]
  .bin		"CD boot sector" [ISOLINUX only]
  .bs		Boot sector [SYSLINUX only]
  .bss		Boot sector, DOS superblock will be patched in [SYSLINUX only]
  .c32		COM32 image (32-bit COMBOOT)
  .cbt		COMBOOT image (not runnable from DOS)
  .com		COMBOOT image (runnable from DOS)
  .img		Disk image [ISOLINUX only]

For filenames given on the command line, SYSLINUX will search for the
file by adding extensions in the order listed above if the plain
filename is not found.  Filenames in KERNEL statements must be fully
qualified.


      ++++ BOOTING DOS (OR OTHER SIMILAR OPERATING SYSTEMS) ++++

This section applies to SYSLINUX only, not to PXELINUX or ISOLINUX.
See isolinux.doc for an equivalent procedure for ISOLINUX.

This is the recommended procedure for creating a SYSLINUX disk that
can boot either DOS or Linux.  This example assumes the drive is A: in
DOS and /dev/fd0 in Linux; for other drives, substitute the
appropriate drive designator.

   ---- Linux procedure ----

1. Make a DOS bootable disk.  This can be done either by specifying
   the /s option when formatting the disk in DOS, or by running the
   DOS command SYS (this can be done under DOSEMU if DOSEMU has
   direct device access to the relevant drive):

	format a: /s
   or
	sys a:

2. Boot Linux.  Copy the DOS boot sector from the disk into a file:

	dd if=/dev/fd0 of=dos.bss bs=512 count=1

3. Run SYSLINUX on the disk:

	syslinux /dev/fd0

4. Mount the disk and copy the DOS boot sector file to it.  The file
   *must* have extension .bss:

	mount -t msdos /dev/fd0 /mnt
	cp dos.bss /mnt

5. Copy the Linux kernel image(s), initrd(s), etc to the disk, and
   create/edit syslinux.cfg and help files if desired:

	cp vmlinux /mnt
	cp initrd.gz /mnt

6. Unmount the disk (if applicable.)

	umount /mnt
 
   ---- DOS/Windows procedure ----

To make this installation in DOS only, you need the utility copybs.com
(included with SYSLINUX) as well as the syslinux.com installer.  If
you are on an WinNT-based system (WinNT, Win2k, WinXP or later), use
syslinux.exe instead.

1. Make a DOS bootable disk.  This can be done either by specifying
   the /s option when formatting the disk in DOS, or by running the
   DOS command SYS:

	format a: /s
   or
	sys a:

2. Copy the DOS boot sector from the disk into a file.  The file
   *must* have extension .bss:

	copybs a: a:dos.bss

3. Run SYSLINUX on the disk:

	syslinux a:

4. Copy the Linux kernel image(s), initrd(s), etc to the disk, and
   create/edit syslinux.cfg and help files if desired:

	copy vmlinux a:
	copy initrd.gz a:

 
   ++++ COMBOOT EXECUTABLES ++++

SYSLINUX supports simple standalone programs, using a file format
similar to DOS ".com" files.  A 32-bit version, called COM32, is also
provided.  A simple API provides access to a limited set of filesystem
and console functions.

See the file comboot.doc for more information on COMBOOT and COM32
programs.


   ++++ NOVICE PROTECTION ++++

SYSLINUX will attempt to detect if the user is trying to boot on a 286
or lower class machine, or a machine with less than 608K of low ("DOS")
RAM (which means the Linux boot sequence cannot complete).  If so, a
message is displayed and the boot sequence aborted.  Holding down the
Ctrl key while booting disables this feature.

The compile time and date of a specific SYSLINUX version can be obtained
by the DOS command "type ldlinux.sys".  This is also used as the
signature for the LDLINUX.SYS file, which must match the boot sector.

Any file that SYSLINUX uses can be marked hidden, system or readonly if
so is convenient; SYSLINUX ignores all file attributes.  The SYSLINUX
installed automatically sets the readonly attribute on LDLINUX.SYS.


   ++++ NOTES ON BOOTABLE CD-ROMS ++++

SYSLINUX can be used to create bootdisk images for El
Torito-compatible bootable CD-ROMs.  However, it appears that many
BIOSes are very buggy when it comes to booting CD-ROMs.  Some users
have reported that the following steps are helpful in making a CD-ROM
that is bootable on the largest possible number of machines:

	a) Use the -s (safe, slow and stupid) option to SYSLINUX;
	b) Put the boot image as close to the beginning of the
	   ISO 9660 filesystem as possible.

A CD-ROM is so much faster than a floppy that the -s option shouldn't
matter from a speed perspective.

Of course, you may want to use ISOLINUX instead.  See isolinux.doc.


   ++++ BOOTING FROM A FAT FILESYSTEM PARTITION ON A HARD DISK ++++

SYSLINUX can boot from a FAT12 or FAT16 filesystem partition on a hard
disk (FAT32, introduced in Windows 95 OSR-2, is not supported,
however.)  The installation procedure is identical to the procedure
for installing it on a floppy, and should work under either DOS or
Linux.  To boot from a partition, SYSLINUX needs to be launched from a
Master Boot Record or another boot loader, just like DOS itself would.

Under DOS, you can install a standard simple MBR on the primary hard
disk by running the command:

	FDISK /MBR

Then use the FDISK command to mark the appropriate partition active.

A simple MBR, roughly on par with the one installed by DOS (but
unencumbered), is included in the SYSLINUX distribution


   ++++ KNOWN BUGS ++++

SYSLINUX is unsafe to use on any filesystem that extends past cylinder
1024.  This is a fundamental limitation of the standard BIOS API.  The
"extended" BIOS API can *sometimes* be used to work around it, but
there simply is not enough space in the SYSLINUX boot sector to
support both APIs.

SYSLINUX will not work (and will refuse to install) on filesystems
with a cluster size of more than 16K (typically means a filesystem of
more than 1 GB.)


   ++++ HARDWARE INFORMATION +++

I have started to maintain a web page of hardware with known
problems.  There are, unfortunately, lots of broken hardware out
there; especially early PXE stacks (for PXELINUX) have lots of
problems.

A list of problems, and workarounds (if known), is maintained at:

	http://syslinux.zytor.com/hardware.php


   ++++ BUG REPORTS ++++

I would appreciate hearing of any problems you have with SYSLINUX.  I
would also like to hear from you if you have successfully used SYSLINUX,
*especially* if you are using it for a distribution.

If you are reporting problems, please include all possible information
about your system and your BIOS; the vast majority of all problems
reported turn out to be BIOS or hardware bugs, and I need as much
information as possible in order to diagnose the problems.

There is a mailing list for discussion among SYSLINUX users and for
announcements of new and test versions.  To join, or to browse the
archive, go to:

   http://www.zytor.com/mailman/listinfo/syslinux

Please DO NOT send HTML messages or attachments to the mailing list
(including multipart/alternative or similar.)  All such messages will
be bounced.