I use a computer that has to have Linux and Windows 10 installed in parallel. Windows came pre-installed and requires UEFI… Therefore I went through Slackware’s instructions “To use UEFI, or not to use UEFI?” before installing Slackware. I told the installer to use ELILO and upon reboot, the system booted straight to Slackware. I installed Slackware -current, but that’s a separate story… Now I want to have the option to dual boot Windows and Linux.

Unfortunatelly elilo.conf, found in /boot/efi/EFI/Slackware/ is poorly commented and I could not figure out right away what I needed to do. I googled around and found this blog post about ELILO.

I copied my kernel image and its corresponding initrd file from /boot to /boot/efi/EFI/Slackware. Then I modified elilo.conf as follows:

chooser=simple
delay=100
timeout=100
default=Windows
#
image=vmlinuz
        label=vmlinuz
        read-only
        append="root=/dev/sda5 vga=normal ro"

image=vmlinuz-generic-4.14.17
	label=gen
	initrd=initrd-4.14.17.gz
	append="root=/dev/sda5 vga=normal vt.default_utf8=1 ro"

image=vmlinuz-generic-4.15.0-rc9
        label=rc
        initrd=initrd-4.15.0-rc9.gz
        append="root=/dev/sda5 vga=normal vt.default_utf8=1 ro"

image=dummy
	label=Windows

I could not find an easy way to make Windows bootable. However. I noticed that when I had some menu entry that was not correct (e.g. image= pointing to a non existing kernel image), the computer would boot to Windows if I did nothing at the ELILO .......... step. That’s why I made the dummy boot option there with label=Windows and specified it as default boot option. Not the most elegant solution, but it does the job.

For now, I am going to leave things like this.