Porting to Alpine Linux aarch64 Raspberry Pi 3B

 Greetings,

I am too lazy to do bare metal, but found a very light weight Linux
distro which uses Musl and Busybox.  Thought was to get basic port up
using XFCE desktop then switch to direct framebuffer and not use the
desktop.  Let someone else do usb and net drivers et al.

Unfortunately, I gave away all my C references and it has been a couple
of decades since I did anything serious in C.

I added -D_GNU_SOURCES to the CFLAGS but am getting a wierd (to me)
error.

Apparently FILE is #defined as some kind of opaque type?

Anyway, breakage in
   platforms/Cross/vm/sqVirtualMachine.c

   for pushOutputFile()

Can some kind soul help me out with a workaround for this?

Thanks a bunch!
-KenD

> I would try two things.  One is to find out where FILE is defined by
> searching the system's include files.  There has to be some kind of
> definition because e.g. open answers a FILE *.  So one /has/ to be able
> to
> write e.g.
>   FILE *f = open("foo.txt",...
>
> and that's all the code is doing, trying to declare a small array of
> FILE
> *'s.

Ya.  Attached.

The code array uses 'FILE', not 'FILE *', btw.
   static FILE stdoutStack[STDOUT_STACK_SZ];

Hey, I once used '***' in EPROM boot code -- because I had to!

My ol' brain has now rotted and no longer does cdecl.  Back to the
'80's.

I am just confused by this. I don't know enough memory usage context to
safely convert to 'FILE *'

> The second thing would be to commit a change to sqVirtualMachine.c
> which
> simply ifdef's out push/popOutputFile if some manifest constant, such
> as
> CANT_USE_FILE_STAR or DONT_USE_FILE_STAR is defined in the makefile (so
> that files are compiled with -DDONT_USE_FILE_STAR=1 or some such).

I will continue to play around.  Thanks!

Part of my confusion is lack of understanding as to why pushOutputFile()
side-effects stdout rather than using a global 'output' variable
universally.
   *stdout = *output
Just initialize 'output' global on startup an side effect that.

Thanks again much for all,
-KenD