Building programs with MODE=shared in L4Re

[Paul Boddie]

On Monday 14. May 2018 21.18.04 Adam Lackorzynski wrote:
> 
> You can set LD_DEBUG=1 in the environment of your program to make the
> dynamic loader tell you something. LD_TRACE_LOADED_OBJECTS=1 might also
> be of help. Add enviroment variable settings after the program's
> cmdline: ...:start({ ...}, "rom/myprog arg", { LD_DEBUG=1, ... });

So, with the help of fbterminal (mentioned in my last message), I managed to 
get some debugging information out of the loader:

L4Re: rom/ex_hello_shared: Unhandled exception: PC=0x800000 PFA=8d7a LdrFlgs=0

This appears to be generated in pkg/l4re-core/l4re_kernel/server/src/region.cc 
inside the Region_map::op_exception method. I'm not really sure what I can do 
with this information, though.

Alongside ex_hello_shared and the stack of programs supporting the framebuffer 
environment, I have the following libraries included in the modules.list:

module lib4re.so
module lib4re-util.so
module libc_be_l4refile.so
module libc_be_l4re.so
module libc_be_socket_noop.so
module libc_support_misc.so
module libdl.so
module libl4sys-direct.so
module libl4sys.so
module libl4util.so
module libld-l4.so
module libpthread.so
module libsupc++.so
module libuc_c.so

This being for reference, since my first guess would be that the loader is 
failing before even considering any of the libraries.

Paul