cross armhf tangle

[Gary E. Miller]

Yo Hal!

On Tue, 04 Feb 2025 01:04:55 -0800
Hal Murray <halmurray at sonic.net> wrote:

> I don't have a cross build setup working yet.

And when you do, keeping it running is even harder.

> It looks to me like the CI stuff uses the same headers from
> /usr/include/. Looking in the header files, they are doing a lot of
> ifdefs on symbols that come from the compiler.  It sure looks to me
> like the same headers will work on both normal and cross builds.

Once again: ONLY if your host and target OS are the same distro.

> The thing that started this for me was a long long where I expected a 
> long, and that hapened while cross compiling on a system where
> non-cross worked OK.  Digging deeper, I found some #if-s.

Yup, an ugly mess.

> There are a few header file provided by the compiler.

Way more than a few.

> For example,
> locate finds thee:

There are a lot more.

> There are a whole bunch of header files in
> /usr/lib/gcc/x86_64-linux-gnu/14 /include/
> Most of them I don't recognize.

What do you not recognize?  Each for a different ABI and toolchain
combination.

> That's really only half-cross.  You are building the same distro and 
> version, just another march.  If you want to build, say, say FreeBSD,
> on a Linux box you would need different headers.

Yup.  Gentoo used to have a wiki for that too.  But got tired of answering
questions about crossing to other distros.

> You also have to get libraries that are built for the target arch.

Yup. Like lic and libm You can find them the same way you found the
stdbool.h.

RGDS
GARY
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Gary E. Miller Rellim 109 NW Wilmington Ave., Suite E, Bend, OR 97703
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