Re: problems dual booting Ubuntu 16.04 and Windows 10

[Pascal Hambourg]

Le 12/05/2018 à 21:51, David Collier a écrit :
> On Sat, May 12, 2018 at 12:41 AM Pascal Hambourg <address@hidden>
> wrote:
>
> > The
> > one you need first is grub-efi-amd64-bin. It won't run grub-install
> > automatically. After all is fine, you can install grub-efi-amd64 which
> > replaces grub-pc and runs grub-install automatically.
> >
> > Make sure you run grub-install from the distribution, not the one you
> > built from source.
>
> Ok, I uninstalled locally built grub and installed both grub and

This is not what I said. I did not say to install package grub. grub is 
a virtual package provided by package grub-legacy, the obsolete version 
of GRUB (aka GRUB 1). It does not support EFI boot.

> grub-efi-amd64

Do you mean grub-efi-amd64-bin ? I said to install grub-efi-amd64-bin at 
first, not grub-efi-amd64. Also grub-efi-amd64 conflicts with grub-legacy.

> from ubuntu, then again booted from USB stick in EFI mode and entered
> chroot.
>
> This time grub-install would not recognize the --target command line option:
(...)
> address@hidden:/# grub-install -v
> grub-install (GNU GRUB 0.97)
                         ^^^^
This is GRUB 1 aka GRUB legacy, from package grub-legacy.

> at this point I decided to run grub-install from the locally built
> directory,

Didn't you say that you uninstalled the locally built GRUB ?

> it did accept --target command line option, but still complained
> about  /usr/local/lib/grub/x86_64_efi/modinfo.sh not existing, so I mapped
> /usr/lib/grub/x86_64_efi into /usr/local/lib/grub and at that point
> grub-install invocation finally succeeded and created that path in
> /boot/efi you mentioned earlier.

A lot of trouble and hack just to correct your mistake.

> I am still at loss though  - what do I do next, to get Windows showing as
> an entry in the grub boot menu?

Why should I waste time writing instructions if you don't follow them ?

Uninstall grub-legacy and check that you have at least grub2-common and 
grub-efi-amd64-bin installed. Or just install grub-efi-amd64.
After EFI boot, run os-prober to check that Windows is detected.
Run update-grub to include it in GRUB's menu.