The boot loader configuration file boot.cfg specifies the kernel, the kernel options, and the boot modules that the mboot.c32 boot loader uses in an ESXi installation.

The boot.cfg file is provided in the ESXi installer. You can modify the kernelopt line of the boot.cfg file to specify the location of an installation script or to pass other boot options.

The boot.cfg file has the following syntax:
# boot.cfg -- mboot configuration file
# Any line preceded with '#' is a comment.

modules=FILEPATH1 --- FILEPATH2... --- FILEPATHn

# Any other line must remain unchanged.

The commands in boot.cfg configure the boot loader.

Table 1. Commands in boot.cfg.
Command Description
title=STRING Sets the boot loader title to STRING.
kernel=FILEPATH Sets the kernel path to FILEPATH.
kernelopt=STRING Appends STRING to the kernel boot options.
modules=FILEPATH1 --- FILEPATH2... --- FILEPATHn Lists the modules to be loaded, separated by three hyphens (---).

For example, to modify the boot.cfg file with information for an HTTP server, see PXE Boot the ESXi Installer Using gPXE.

See also Create an Installer ISO Image with a Custom Installation or Upgrade Script, PXE Boot the ESXi Installer by Using PXELINUX and a PXE Configuration File, PXE Boot the ESXi Installer by Using PXELINUX and an isolinux.cfg PXE Configuration File, and PXE Booting the ESXi Installer.