Bug 704466 – sys-kernel/genkernel-4.0.1 lost --override-arch option

• Status: RESOLVED INVALID
• Product: Gentoo Hosted Projects

[Description Joakim Tjernlund 2020-01-01 14:27:10 UTC]

how to build 64 bit kernels on 32 bit userland?

[Comment 1 Thomas Deutschmann (RETIRED) 2020-01-01 16:49:27 UTC]

You are cross-compiling. You must use new --cross-compile command-line parameter. See man page for more details.

[Comment 2 Joakim Tjernlund 2020-01-01 19:47:44 UTC]

this cross-compile option implies I have to build a cross compiler
just to build x864-64 kernel on 32 bits user land.
Have I missed anything?

[Comment 3 Thomas Deutschmann (RETIRED) 2020-01-01 21:13:43 UTC]

Well, I implemented Gentoo's multilib behavior in genkernel: To compile for x86 on amd64 you would set --cross-compile=i686-pc-linux-gnu and genkernel would understand that it will have to use "x86_64-pc-linux-gnu-gcc -m32" for example, see https://gitweb.gentoo.org/proj/genkernel.git/tree/gen_funcs.sh?h=v4.0.1#n1116.

You are asking for the other way which is not supported without proper crossdev toolchain.

[Comment 4 Joakim Tjernlund 2020-01-02 12:00:27 UTC]

(In reply to Thomas Deutschmann from comment #3)
> Well, I implemented Gentoo's multilib behavior in genkernel: To compile for
> x86 on amd64 you would set --cross-compile=i686-pc-linux-gnu and genkernel
> would understand that it will have to use "x86_64-pc-linux-gnu-gcc -m32" for
> example, see
> https://gitweb.gentoo.org/proj/genkernel.git/tree/gen_funcs.sh?h=v4.0.
> 1#n1116.
> 
> You are asking for the other way which is not supported without proper
> crossdev toolchain.

I used to work with --override-arch option so I figure it could work using
i686-pc-linux-gnu -m64 ?