[SOLVED] Slackware 14.2 , UEFI, Dual Booting

swider · 07-04-2016, 05:29 PM

After few years of not using linux, I decided to come back to Slackware. I successfully installed new version, but I discovered that LILO is no longer option for me, as I have UEFI. I installed and configured grub using this video: https://www.youtube.com/watch?v=kBIWSEoWIkw ( important part starts at 10:00). The problem is when I try to load windows 10, I get two errors: no assignment and the other one that the file /EFI/Microsoft/Boot/bootmgfw.efi doesn't exist.
I tried to google the solution, but unfortunatelly I couldn't find anything useful, also I have never used grub, so I cannot figure out what is a problem ( btw. I tried to change number of a partition from 1-3 and that didn't help).

sodamnmad · 07-06-2016, 02:13 AM

i'm by no means an expert when it comes to efi but i discovered that after a typical slackware install you'll have /boot/efi/EFI/* and from the bios config screen you can add boot options. most likely it won't create a menu that you select from on each boot like lilo/grub add but during boot you can hit f12 and get a list of boot options. if you still have your windows efi stuff you might be able to get around that way. i haven't used windows in years so that's about as much as i can help you with.

notKlaatu · 07-06-2016, 04:04 AM

I don't boot into other OS's, so I'm speaking somewhat theoretically here (although I have done this with other distros), but essentially you should be using elilo (not lilo). I mean you can use GRUB, but I know nothing about that, so I'll keep going with elilo.

Information is here:
http://docs.slackware.com/howtos:sla...uefi_and_elilo

Once you have installed elilo, you can add an entry to point to your Windows partition or drive as an 'other' entry:

Code:

other = /dev/sda3
    label = windows

which basically just tells elilo to shove the boot responsibilities over to that drive/partition. Windows's boot loader or equivalent can take it from there.

JamesGT · 07-06-2016, 08:38 AM

My system is UEFI as well, but I changed the BIOS to allow legacy booting as well as disabling security boot...and everything installed and works as it should.

swider · 07-06-2016, 02:27 PM

There was a long-ish delay between me asking question and this topic appearing on boards, in the meantime I solved my problem. All enries in my grub file had: hd0 as a disk and everything was working properly for slackware , but not windows. I entered grub console after another unsuccessful booting, I used ls -l command and it turned out that grub saw my disks as hd1, I changed the entry for windows and it works (I left it as hd0 for slackware and it also works, although both systems are on the same disk). Thanks for replays guys.

sombragris · 07-06-2016, 03:43 PM

My machine is dual boot, win10 and slack-current. I use grub.

To recognize the windows partition, I edited /etc/grub.d/40_custom in this way:

Code:

[eduardo:/etc/grub.d]$ cat 40_custom 
#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

menuentry "Windows 10" {
    set root='(hd0,gpt2)'
    chainloader /EFI/microsoft/Boot/bootmgfw.efi
}

[eduardo:/etc/grub.d]$

Then, after each kernel upgrade, I run the following command (as root):

Code:

# grub-mkconfig -o /boot/grub/grub.cfg

The problem with this setup is that it is relative. That is, if you happen to boot your system with a USB drive connected, for example, and you're screwed. Windows won't boot. Make sure any USB external storage drive is unplugged before booting. I may make it absolute yet, but that would mean using these outrageous UUID numbers which are loathsome in extreme.

Hope this helps. I have been planning to write about how to set up a win10/slack dual boot box for some time by using UEFI. The fact is that documentation on ELILO and GRUB2 are sorely lacking in clarity. The best you can get is the Arch Linux docs, but even they are seriously obtuse to say the least.

slackb0t · 07-06-2016, 06:48 PM

I did not add the microsoft info to elilo because I do not use it often. This is not a solution to your problem but it might get you into windows at least until you figure it out.

when I want to get into windows I do the following:
Power on
Hit enter right away to interrupt the boot process
Hit f12 to select boot options
Choose Microsoft boot loader (or something like that)

This method works for my thinkpad... might be slightly different for others.

swider · 07-06-2016, 07:03 PM

Thanks guys for you replays, I already solved my problem and described what I had to do in the other thread, as I am new user apparently my threads and posts are checked by moderators before being visible for everybody( I thought I pressed wrong button and created a thread again) I will link the solution here as soon as the other one re-appears. (Short version, grub seems to be bugged, it auto-detects all partitions as partitions of disk hd0, but during booting it sees a disk as hda1, what is weird is the fact that all entries in the grub for linux have hd0 and it loads Slackware properly, but for Widnows I had to change disk to hd1 and I have only one hard disk in my laptop, very weird).

frushiyama · 08-03-2016, 09:32 AM

With this custom file and instruction from SlackDocs i did a fresh install of Slack 14.2 dual boot with a existing install of W10.
All working fine.

Quote:

Originally Posted by sombragris

My machine is dual boot, win10 and slack-current. I use grub.

To recognize the windows partition, I edited /etc/grub.d/40_custom in this way:

Code:

[eduardo:/etc/grub.d]$ cat 40_custom 
#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

menuentry "Windows 10" {
    set root='(hd0,gpt2)'
    chainloader /EFI/microsoft/Boot/bootmgfw.efi
}

[eduardo:/etc/grub.d]$

Then, after each kernel upgrade, I run the following command (as root):

Code:

# grub-mkconfig -o /boot/grub/grub.cfg

The problem with this setup is that it is relative. That is, if you happen to boot your system with a USB drive connected, for example, and you're screwed. Windows won't boot. Make sure any USB external storage drive is unplugged before booting. I may make it absolute yet, but that would mean using these outrageous UUID numbers which are loathsome in extreme.

Hope this helps. I have been planning to write about how to set up a win10/slack dual boot box for some time by using UEFI. The fact is that documentation on ELILO and GRUB2 are sorely lacking in clarity. The best you can get is the Arch Linux docs, but even they are seriously obtuse to say the least.

sombragris · 08-03-2016, 05:32 PM

Quote:

Originally Posted by frushiyama

With this custom file and instruction from SlackDocs i did a fresh install of Slack 14.2 dual boot with a existing install of W10.
All working fine.

Glad to be of help!

dsanmartins · 11-25-2017, 05:26 PM

Windows 8.1 and Slackware 14.2 (GPT partitions in different HD) and GRUB 2.0

-Windows is in /dev/sda and Linux in /dev/sdb

(1) Check uuid: where is Windows EFI (grub-probe --target=fs_uuid /mnt/EFI/Microsoft/Boot/bootmgfw.efi) remember to mount the partition, in this case in mnt (mount /dev/sda2 /mnt).

(2) Check hint_strings: grub-probe --target=hints_string /mnt/EFI/Microsoft/Boot/bootmgfw.efi

Then, edit the following file /etc/grub.d/40-custom and add these lines:

Code:

menuentry "Microsoft Windows 8.1" {
	insmod part_gpt
	insmod fat
	insmod search_fs_uuid
	insmod chain
	search --fs-uuid --no-floppy --set=root THE RESULT FROM (2) UUID_NUMBER FROM (1)
	chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}

In my case the result from (2) was

Code:

--hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2

Save the changes and run this command:

Code:

grub-mkconfig -o /boot/grub/grub.cfg

That's all!, restart and go into windows.

FlinchX · 11-27-2017, 08:11 AM

Quote:

Originally Posted by swider

After few years of not using linux, I decided to come back to Slackware...

I have never used grub

Same here, I have never used grub, because Slackware always used lilo and I've never needed to boot Windows as well, until this new computer that came with it preinstalled and I've decided to keep Windows as secondary toy OS. I installed Slackware64-14.2 in addition to Windows 10 (both in UEFI mode, Slackware installed elilo) and from Slackware I have installed rEFInd (you can find it on slackbuilds.org). rEFInd boots both systems fine, I did not have to make any manual settings.