Booting Grml via iPXE
iPXE is a network boot firmware that allows you to boot ISO images over http. It’s actually part of the Grml ISO and you can find it under Addons in the boot menu. Alternatively you can download it from the iPXE website. All you need is an ISO image and the memdisk binary stored on a webserver. The ISO image needs to support the memdiskfind approach, more details can be found on the syslinux website. Grml supported it for a while, unfortunately it was broken in the last stable release but it’s working in the daily built images again.
To boot over http you need to run iPXE and press Ctrl-B after an IP address was assigned. This will give you a shell where you need to type in the following commands:
initrd http://download.grml.org/devel/grml64-small_20160415_netboot_xyz.iso chain http://download.grml.org/devel/memdisk iso
The first one will download the ISO and the next one will download memdisk and chainboot the ISO, which is the daily build of Grml-small on the 15th of April. There’s also another ISO if you prefer Grml-full:
initrd http://download.grml.org/devel/grml64-full_20160415_netboot_xyz.iso chain http://download.grml.org/devel/memdisk iso
If you want to boot newer daily builds, just replace the first line with the correct URL.
There’s also an easier way using iPXE menus and it only requires one command instead of two:
chain http://download.grml.org/devel/menu.ipxe
This will present you a menu where you can choose which flavor to boot.
The file menu.ipxe contains:
#!ipxe
set menu-default small
:start
menu iPXE boot menu for Grml
item --key f full Boot Grml Full
item --key s small Boot Grml Small
choose --default ${menu-default} selected
goto ${selected}
:full
echo Booting Grml Full over http
initrd http://download.grml.org/devel/grml64-full_20160415_netboot_xyz.iso
chain http://download.grml.org/devel/memdisk iso
:small
echo Booting Grml Small over http
initrd http://download.grml.org/devel/grml64-small_20160415_netboot_xyz.iso
chain http://download.grml.org/devel/memdisk iso
If you want to test this on your own webserver just copy your choice of ISOs, the memdisk binary and the file menu.ipxe to the root directory.
