On Thu, 24 Jul 2008 19:12:20 +0200 Kenneth Johansson kenneth@southpole.se wrote:
We could build u-boot as a shared library I guess, but that feels a bit weird...
What do you mean by that ? u-boot is already compiled with the -fPIC option.
If that's sufficient, why would you need the -mrelocatable option on PowerPC?
-fPIC makes the compiler generate position-independent code, which is necessary but not sufficient in order to get a fully relocatable binary. The second part of the puzzle is dynamic relocations. Shared libraries have them, and apparently, PowerPC binaries have them if you link with -mrelocatable.
Currently u-boot is compiled with -fPIC, so the result is almost fully relocatable. We work around the lack of dynamic relocations by manually fixing up a handful of pointers at runtime.
Haavard