These weakly defined empty functions prevent the strong definition from being linked in.
For example, libarm.a contains a weak symbol 'red_LED_on', which is expected to be defined (strongly) in the board library. Because archive libraries are being used, this fails (testing with binutils 2.20.1), and only the empty __red_LED_on stub is linked in; the red_LED_on definition in the board library is throw away. This behavior is documented and it is the intended one; from http://www.sco.com/developers/gabi/latest/ch4.symtab.html: > When the link editor searches archive libraries [see ``Archive > File'' in Chapter 7], it extracts archive members that contain > definitions of undefined global symbols. > The member's definition may be either a global or a weak symbol. > The link editor does not extract archive members to resolve > undefined weak symbols. Unresolved weak symbols have a zero value. Empty weak definitions would have to be supplied to the linker only _after_ the strong definitions have been provided. Leaving undefined weak symbols and testing for NULL-ity at call sites seems to be a more robust approach. Note that with some ld versions (at least with 2.20.1), ld creates PLT entries for undefined weak symbols and crashes when the PLT-related sections (.plt, .got.plt, and .rel.plt) are discarded... -- Sebastien Carlier _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
