Dear Peter Tyser, In message <1286167382.22760.19.ca...@ptyser-laptop> you wrote: > > > Peter, could you please fill in the details of that old story? > > I haven't been following the ARM relocation thread very closely, but a > summary of the PPC relocation is: > - Prior to commit 858290178f222d998b6425d85cf06822467918f3 PPC supported > basic relocation, but didn't relocate static pointers, eg pointers in a > structure, such as the strings in the cmd_pca953x[] table. So we had to > use the hokey "struct->field += gd->reloc_off" fixups that we still have > for some arches. > > - Adding "-mrelocatable" to the gcc's flags would add additional > relocation info into the ".fixup" section that allowed us to properly > fixup static pointers and get rid of the "+= gd->reloc_off" fixups. The > additional fixup code was relatively small, in the 1-2% ballpark I > think. > > - Unfortunately "-mrelocatable" is PPC specific. I remember dabbling > with other, more general relocation flags like -fPIC, pie, etc, but went > with -mrelocatable mainly because it was a smaller, easier change. We > could share the already-used relocation fixup code in many PPC arch's > start.S, so it wasn't too hard to get working unlike the other > relocation schemes. > > - Graeme Russ was working on relocation for x86 near the same time. He > started this thread which may provide useful info: > http://www.mail-archive.com/u-boot@lists.denx.de/msg23347.html He > discusses the impact of other compile flags, most of which were generic > so could apply to this ARM discussion hopefully.
Thanks alot for the summary. Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, MD: Wolfgang Denk & Detlev Zundel HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: w...@denx.de Q: How do you spell "onomatopoeia"? A: The way it sounds. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
