This symbol is needed to inform the (static) linker about the dependency
of the component-startup code from the program's main function. Without
the symbol, the use of gc-sections during linking may discard the actual
application code.
This patch contains changes to the libSDL port that were needed to build
the Hatari emulator using cmake.
- Since SDL programs cannot use the posix library (because sdl's init
function needs a way to get hold of the Genode env), the sdl_main
library must be used instead of the posix library. The sdl_main
code implements the Libc::Component::construct function for the
final binary. However, 3rd-party build systems are not aware of this
Genode-specific peculiarity and thereby create binaries that leave
libsdl uninitialized. This patch adds the sdl_main to libsdl by
default and thereby eliminates the need for specifying the extra
sdl_main library. Customizing the Libc::Component::construct is
still possible by overriding the library-provided implementation
in the main program.
- A few missing config definitions are added to compile Hatari
successfully.
- Avoid reliance on the include/SDL convention in SDL_config.h
- Cmake relies on the upper-case naming of the library with no way
to tweak this convention. So we install an symlink named `SDL.lib.so`
when installing the library into the <build-dir>/bin/ directory.
Fixes#161
