pxelinux-options

Configuration files are typically named `default`, `01-mac-address`, `ip-address`, or are named using hexadecimal representation of IP address. The syntax involves keyword-value pairs.
Example: `LABEL my_os`
`KERNEL vmlinuz`
`APPEND initrd=initrd.img root=/dev/sda1`

LABEL label_name
    Defines a menu entry with the specified label. This is the human-readable name shown in the boot menu.

KERNEL kernel_file
    Specifies the kernel file to load.
Example: `KERNEL vmlinuz-5.15.0-76-generic`

APPEND options
    Adds kernel command-line parameters.
Example: `APPEND root=/dev/sda1 ro quiet splash`

INITRD initrd_file
    Specifies the initial RAM disk (initrd) file to load.
Example: `INITRD initrd.img`

MENU LABEL menu_label
    Specifies the label displayed for the menu item.

TIMEOUT timeout_value
    Sets the timeout (in tenths of a second) before the default entry is automatically booted. 0 disables the timeout. Global setting.

DEFAULT label_name
    Specifies the default menu entry to boot if the timeout expires. Global setting.

MENU DEFAULT
    Highlights this entry as default in the menu. Typically, assigned to one LABEL

MENU HIDE
    Hides a menu entry if some condition is met.

PROMPT prompt_value
    Determines whether the boot prompt is displayed. Set to 1 to display, 0 to hide. Global setting

LOCALBOOT type
    Boots from a local disk. `type` can be 0 (floppy), 1-3 (hard disk partitions)

The `pxelinux-options` command is not a standard Linux command. It refers to the configuration options used within the PXELINUX bootloader, which is part of the SYSLINUX bootloader suite. PXELINUX allows computers to boot from a network server using the Preboot Execution Environment (PXE) protocol. Configuration of PXELINUX involves creating or modifying configuration files on the TFTP server, usually located in `/tftpboot/pxelinux.cfg`. These configuration files dictate the boot menu presented to the user and the subsequent actions taken, such as loading a kernel and initrd or launching a bootable image. This command refers to options used in that configuration file.

PXELINUX configuration requires a functional TFTP server. Correct network configuration (DHCP, IP addressing) is crucial for PXE booting to work. The specific options and features available may vary slightly depending on the version of SYSLINUX/PXELINUX used.

PXELINUX searches for configuration files in a specific order. It first checks for a file named after the client's MAC address (prefixed with '01-'). If not found, it checks for a file named after the client's IP address (in hexadecimal). If neither is found, it uses the 'default' file. This hierarchy allows for specific configurations for individual machines, or a general default configuration.

PXELINUX menus can be customized extensively using various `MENU` options. These include setting the title, colors, and specific entries displayed based on certain conditions. This allows for a user-friendly and tailored boot experience.

``` DEFAULT linux TIMEOUT 300 LABEL linux MENU LABEL Boot Linux KERNEL vmlinuz APPEND initrd=initrd.img root=/dev/sda1 ro quiet splash LABEL memtest MENU LABEL Run Memtest86+ KERNEL memtest ```

PXELINUX evolved as part of the SYSLINUX project, created to allow booting Linux from non-disk media. PXELINUX specifically addresses network booting using PXE. It became widely adopted for deploying operating systems across networks, especially in large environments where manual installation on each machine is impractical.

dhcpd(8), tftpd(8)