Mark H Weaver (2015-05-22 20:31 +0300) wrote:

> ludo@gnu.org (Ludovic Courtès) writes:
>
>> Alex Kost <alezost@gmail.com> skribis:
[...]
>>> So I'm wondering is there a way to init a 64-bit system from a 32-bit
>>> one or perhaps it's just not possible?
>>
>> It actually is possible, but a little bit trickier.  Mark did it a few
>> weeks ago, though in a slightly different context.  The following should
>> work:
>>
>>   1. Install an i686 GuixSD, simply with ‘guix system init’, but use an
>>      x86_64 kernel.  To do that, you need to explicitly ask for an
>>      x86_64 kernel and Guix (so that the daemon accepts to build x86_64
>>      things) in the OS config:
>>
>>        (define linux-libre-x86_64
>>          (package (inherit linux-libre)
>>            (arguments `(#:system "x86_64-linux"
>>                         ,@(package-arguments linux-libre)))))
>
> I think this is not sufficient, because it would still use the kernel
> config for i686.  Here's what I used for the kernel:
[...]
> diff --git a/gnu/packages/linux.scm b/gnu/packages/linux.scm
> index 26e9aa9..c42919d 100644
> --- a/gnu/packages/linux.scm
> +++ b/gnu/packages/linux.scm
> @@ -64,6 +64,7 @@
>    #:use-module (guix build-system cmake)
>    #:use-module (guix build-system python)
>    #:use-module (guix build-system trivial)
> +  #:use-module ((guix build utils) #:select (alist-replace))
>    #:use-module (srfi srfi-26)
>    #:use-module (ice-9 match))
>  
> @@ -308,6 +309,15 @@ It has been modified to remove all non-free binary blobs.")
>      (license gpl2)
>      (home-page "http://www.gnu.org/software/linux-libre/"))))
>  
> +(define linux-libre-64
> +  (package (inherit linux-libre)
> +    (arguments
> +     `(#:system "x86_64-linux"
> +       ,@(package-arguments linux-libre)))
> +    (native-inputs
> +     (alist-replace "kconfig" (list (kernel-config "x86_64-linux"))
> +                    (package-native-inputs linux-libre)))))
> +

Thanks Ludovic and Mark!  I tried to follow your advices but eventually
I got the same error:

  guix system: error: build failed: a `x86_64-linux' is required to build `/gnu/store/zh42mbm0wvbsz05zr798nchyd3bc7fh6-guix-0.8.2.c2ee19e.drv', but I am a `i686-linux'

I used the following command:

  guix system init --no-grub config-64-simple.scm /mnt/guix

I'm attaching the OS config I used.  Did I miss anything?