[Nix-dev] NixOS on MacBook dual boot

[Paul Colomiets]

Hi Alexey,

On Tue, Aug 12, 2014 at 10:47 PM, Alexey Muranov
<alexey.muranov at gmail.com> wrote:
> Hello Paul,
>
> On 12 août 2014, at 22:27, Paul Colomiets <paul at colomiets.name> wrote:
>
>> I think it should just work. IIRC, you
>> need to bless the nixos kernel from mac os. You don't need another EFI
>> partition, nixos should put it's own kernel into existing EFI
>> partition, just mount it as /boot.
>
> thank you for the answer, i suspected it might work like that.  However, according to what i've read in Wikipedia, Apple firmware updates use the EFI System Partition, so i am worried that a firmware update may break the NixOS boot loader.  (Maybe this is not a big deal, but it would not look like a proper way to do it.)  Do you know anything about it by any chance?

I never had broken EFI partition on Mac OS. But I didn't try to run
mayor system upgrade (probably new versions of Mac OS are not so
frequent, so it's not big deal if it breaks).

> Also, the recommeded ESP partition size was 500 MB, but mine is 200 MB, so i imagine a firmware update might not have enough space to work.
>
> As i am not particualrly exeprienced, could you tell me please how the nixos kernel will be named?
>

I have three different nixos kernels installed and they occupy 29Mb.
So I don't think it might be a problem. Kernels are named like this:
/boot/EFI/nixos/ywzply87h2357ahidlq0ggxs57pidnxp-linux-3.15.5-bzImage.efi

> What would you recommend as a boot manager?  Do i need to set `boot.loader.gummiboot.enable = true`?
>

Well, it seems to be hard to use nixos with EFI without gummiboot (or
I didn't try hard enough), so yes, I recommend enable it, and make
gummiboot the default. I believe you can start Mac OS from gummiboot,
but I failed to do the reverse (i.e. I tried to boot nixos from
refind, the problem is that older generations of nixos are not added
to refind, so it's hard to rollback in case of trouble).

Also it may be that you actually need to "bless" the gummiboot not the
kernel, I don't remember correctly, but there are plenty of
instructions of installing linux on mac. (Gummyboot is at
/boot/EFI/gummiboot/gummibootx64.efi)

-- 
Paul