Excerpts of some important descriptions about Syslinux

The following resources are from official documents, excerpts from the original

The SYSLINUX suite contains the following boot loaders ("derivatives"), for their respective boot media:

SYSLINUX -ms-dos/windows FAT filesystem

pxelinux -PXE network booting

isolinux -ISO9660 CD-ROM

extlinux -Linux ext2/ext3 filesystem

For historical reasons, some of the sections in this document applies to the FAT loader only

Options

These is the options common to all versions of Syslinux:

-S Safe, slow, stupid; Uses simpler code that boots better

-F Force installing

These is only in the Windows version:

-M MBR; Install a bootable MBR sector to the beginning of the drive.

-A Active; Marks the partition used active (=bootable)

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 [-sfma][-d directory] A:

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

Use "syslinux.com" (in the DOS subdirectory of the distribution) for plain DOS (MS-DOS, Dr-dos, Pc-dos, FreeDOS ...) or Win 9x/me.

Use ' Syslinux.exe ' (in the Win32 subdirectory of the distribution) for WINNT/2000/XP.

Under Linux, execute the command:

syslinux [-sf][-d directory][-o offset]/dev/fd0

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

This would alter the boot sector on the disk and copy a file named Ldlinux. SYS into it root directory (or a subdirectory, if the-d option is specified.)

The-s option, if given, would install a "safe, slow and stupid" version of SYSLINUX. This version could work on some very buggy bioses on which SYSLINUX would otherwise fail. If you find a in which the-s option is required to make it boot reliably, please send as much info about your Mac Hine 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.

For the DOS and Windows installers, the-m and-a options can is used on hard drives to write a Master Boot Record (MBR), And to mark the specific partition active.

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

If the Shift or Alt keys is held down during boot, or the Caps or Scroll locks is SE T, SYSLINUX would 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 on the kernel file in advance; All this is required are that it's a file located in the root directory on the disk.

There is the versions of the Linux installer; One in the ' mtools ' directory which requires no special privilege (other than write permission to the device where is Installing) but requires the Mtools program suite to being available, and one in the "UNIX" directory which requires root PR Ivilege.

CONFIGURATION FILE

All the configurable defaults in SYSLINUX can is changed by putting a file called "Syslinux.cfg" in the root directory of The boot disk.

This was a text file in either UNIX or DOS format, containing one or more of the following items (case was insensitive for K Eywords; Uppercase is used here to indicate this a word should be typed verbatim):

Starting with version 3.35, the configuration file can also is in either The/boot/syslinux or/syslinux directories (Sear Ched in that order.) If that's the case and then all filenames is assumed to be relative to that same directory, unless preceded with a slash or Backslash.

All options here applies to Pxelinux, Isolinux and Extlinux as well as SYSLINUX unless otherwise noted. See the respective. txt files.

# Comment

A Comment Line. The whitespace after the hash mark is mandatory.

INCLUDE filename

Inserts the contents of another file at the the the configuration file. Files can currently be nested-to-levels deep, but it's not guaranteed-more than 8 levels would be supported in The future.

DEFAULT Kernel Options ...

Sets the default command line. If SYSLINUX boots automatically, it would 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 are present in the config file, and the default is "Linux Auto".

Note: Earlier versions of SYSLINUX used to automatically append the string "Auto" to whatever the user specified using the Defau LT command. As of version 1.54, this is no longer true, as it caused problems if using a shell as a substitute for "init." Want to include this option manually.

APPEND Options ...

ADD one or more options to the kernel command line. These is added both for automatic and manual boots. The options is added at the very beginning of the kernel command line, usually permitting explicitly entered kernel Optio NS 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

1:indicates that an option of the following format should is 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 was not RECOMMENDED. If you had to use it, it was probably an indication the your network configuration is broken. Using just "ip=dhcp" on the kernel command line was a preferrable option, or, better yet, run Dhcpcd/dhclient, from an init Rd if necessary.

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

Bootif=

... in dash-separated hexadecimal with leading hardware type

(Same as for the configuration file; see Pxelinux.txt.)

This allows a 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" was entered as the kernel to boot, SYSLINUX should instead boot "image", and th E specified APPEND and ipappend options should be used instead of the ones specified in the global section of the The file Fore the first LABEL command.) The default for 'image' is the same as 'label', and if no APPEND is given the default was to use the Glob Al entry (if any).

Starting with version 3.62, the number of the LABEL statements is virtually unlimited.

Note that LILO uses the syntax:

Image = Mykernel

Label = MyLabel

Append = "Myoptions"

... whereas SYSLINUX uses the syntax:

Label MyLabel

Kernel Mykernel

Append myoptions

Note: The "kernel" doesn ' t has to be a Linux kernel; It can be a boot sector or a comboot file (see below.)

Since version 3.32 label names is no longer mangled into DOS format (for SYSLINUX.)

The following commands is available after a LABEL statement:

LINUX image -Linux kernel image (default)

BOOT Image -Bootstrap program (. BS,. bin)

BSS Image -BSS image (. BSS)

PXE Image -PXE Network Bootstrap program (. 0)

Fdimage image -Floppy disk image (. img)

Comboot Image -comboot program (. com,. CBT)

COM32 Image -COM32 program (. C32)

CONFIG Image -New configuration file

Using One of these keywords instead of KERNEL forces the filetype, regardless of the filename.

CONFIG means restart the boot loader using a different configuration file.

APPEND -

Append nothing. APPEND with a, 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 would cause a local Disk boot instead of booting a kernel.

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

On Isolinux, the 'type' Specifies the ' local drive ' number to boot from; 0x00 are the primary floppy drive and 0x80 are 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 boo T device in the boot sequence should is activated.

INITRD Initrd_file

Starting with version 3.71, an INITRD can is specified in a separate statement (INITRD) instead of as part of the APPEND s Tatement; This functionally appends "initrd=initrd_file" to the kernel command line.

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 I s set (this is the default). If flag_val is 1, always display the boot:prompt.

Excerpts of some important descriptions about Syslinux