[Aboriginal] musl and kernel headers [was Re: system-images 1.4.2: od is broken; bzip2 is missing]

[Rob Landley]

On 10/05/2015 08:44 PM, Rich Felker wrote:
> On Mon, Oct 05, 2015 at 10:08:10AM -0500, Rob Landley wrote:
> The cleaner approach is just avoiding including both the kernel
> headers and libc/userspace headers for the same things in the same
> file. In theory this may be hard in some cases, but I find that I can
> almost always fix these sorts of errors during a build by commenting
> out one or two #include lines.

I am _deeply_ curious how you'd get linux/loop.h on a platform where you
need the 32 bit loopback structure definition without including the
kernel header. I struggled with that one a lot back in the busybox days.
(For the 64 bit version you can block copy the structure out of the
header into your program, just like you can block copy everything out of
headers and never actually #include anything, in the name of portability!)

Sadly, the kernel headers are exported for a _reason_. If I need to
syscall something you haven't wrapped, I need the _NR_ and it varies per
target. It's a thing.

Rob