Download and boot an executable image

  chain [--name <name>] [--timeout <timeout>] [--autofree] [--replace]
        [<uri|image>] [<arguments>...]

or

  imgexec [--name <name>] [--timeout <timeout>] [--autofree] [--replace]
          [<uri|image>] [<arguments>...]

or

  boot [--name <name>] [--timeout <timeout>] [--autofree] [--replace]
       [<uri|image>] [<arguments>...]

  chain http://boot.ipxe.org/demo/boot.php

  chain pxelinux.0

  initrd http://192.168.0.1/initrd.img
  chain http://192.168.0.1/vmlinuz vga=788 console=ttyS0,115200n8 console=tty0

  chain --autofree http://10.0.0.1/scripts/menu.ipxe

  chain --replace http://10.0.0.1/scripts/script.ipxe

  boot

Download and boot an executable image from the specified URI. A name for the downloaded image can be specified using the --name option. A download progress timeout can be specified (in milliseconds) using the --timeout option. Any remaining arguments will be passed directly to the booted image.

If no image is explicitly specified, iPXE will boot the currently-selected image (as reported by the imgstat command).

An image that has already been downloaded (e.g. by the imgfetch command) can be specified by using the image's name instead of a URI. For example:

  imgfetch http://192.168.0.1/vmlinuz
  boot vmlinuz

If this command is executed from within an iPXE script, then the URI will be interpreted as being relative to the URI of the script itself. For example, if the script http://boot.ipxe.org/demo/boot.php contains the line

  chain pxelinux.0

then iPXE will download and boot http://boot.ipxe.org/demo/pxelinux.0.

If the --autofree option is specified then the image will be freed automatically after terminating. Otherwise, the image will remain present and can be freed using imgfree.

If the --replace option is specified then the image will replace the currently executing script (similar to the Unix exec() system call). Otherwise, the current script will continue execution once the image returns.

It is unusual for this command to return successfully, since if the boot is successful then control will not return to iPXE.

• imgstat
• imgfetch
• kernel
• imgfree
• List of all iPXE commands

There is no difference between the commands chain, imgexec and boot.

If your script will exit immediately after the chain command then you can use the --replace option to minimise memory usage.

If you have a series of scripts that jump to each other and do not ever return (such as a menu system implemented as several separate iPXE script files) then you can use both --autofree and --replace to avoid running out of memory.

In older versions of iPXE, you must use chain when you want to download and boot a new image from a URI, and you must use imgexec or boot when you want to boot an image that has already been downloaded.