Sets the default kernel command line. If PXELINUX boots automatically, it acts as if the entries after DEFAULT had been typed in at the boot prompt, except the auto option is automatically added, indicating an automatic boot.

If no configuration file is present or no DEFAULT entry is present in the configuration file, the default is the kernel name “linux” with no options.

Add one or more options to the kernel command line. These are added for both 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.

Indicates that if label is entered as the kernel to boot, PXELINUX should instead boot image and the specified APPEND 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 128 LABEL entries are permitted.

Note that GRUB uses the following syntax:

title mytitle 
  kernel my_kernel my_kernel_options 
  initrd myinitrd

while PXELINUX uses the following syntax:

label mylabel 
  kernel mykernel 
  append myoptions
      

Labels are mangled as if they were filenames and they must be unique after mangling. For example, the two labels “v2.1.30” and “v2.1.31” would not be distinguishable under PXELINUX because both mangle to the same DOS filename.

The kernel does not have to be a Linux kernel; it can be a boot sector or a COMBOOT file.

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

On PXELINUX, specifying LOCALBOOT 0 instead of a KERNEL option means invoking this particular label and causes a local disk boot instead of a kernel boot.

All other values are undefined. If you do not know what the UNDI or PXE stacks are, specify 0.

Indicates how long to wait at the boot prompt until booting automatically, in units of 1/10 second. The time-out is cancelled as soon as the user types anything on the keyboard, the assumption being that the user completes the command begun. A time-out of zero disables the time-out completely (this is also the default).

The maximum possible time-out value is 35996 (just less than one hour).

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

 
F2  filename
F1  filename 
..etc... 
F9  filename
F10 filename

Displays the indicated file on the screen when a function key is pressed at the boot prompt. This can be used to implement preboot online help (presumably for the kernel command line options.) For backward compatibility with earlier releases, F10 can be also entered as F0. Note that there is currently no way to bind filenames to F11 and F12.