On 04/10/10 19:28, Albert ARIBAUD wrote: > Le 04/10/2010 09:27, Reinhard Meyer a écrit : >> Dear Albert ARIBAUD, >>> >>> Right now I can build (not run, mind you) u-boot for edminiv2 without >>> -fPIC/-fPIE, with -pie and a modified u-boot.lds and start.S. Almost all
Any reason to do it in assembler? Have a look at arch/i386/lib/board.c board_init_f() (especially if you apply my latest patch series) >>> of the .rel.dyn fixup entries are type 23, that is, relative to the base >>> address, which is good. However, here are about ten at the end which are >>> type 2 -- symbol-relative -- and I am studying them in order to see if >>> they are needed. Hmm, for x86 they are all type 8 (R_386_RELATIVE) which are a simple Base + Addend (B + A) entries Type 23 is R_ARM_RELATIVE which are also B + A (although they can also by S + A whatever that means) >>> If type 23 relocations are all that is needed, then a first ARM ELF >>> relocation implementation should 'simply' trade GOT vs .rel.dyn >>> relocation in start.S (I am almost there) and remove fixups in Removing fixups - sweet, oh so sweet ;) >>> board_init_r. Start.S would apply type 23 fixups only and ignore the >>> rest. Later on we could add a build stage to rewrite the .rel.dyn >>> section as suggested, by filtering out non-type-23 relocs and keeping >>> only the address part of type-23 ones, reducing the .rel.dyn table >>> roughly by half. Also non type-8 for x86 - If all arches reduce down to a single relocation type in .rel.dyn then we can ignore the type and simply strip all the 'type' fields. [snip] > >> A rather wild, but quite arch independant additional "build stage" for >> relocation would be to link u-boot for two different TEXT_BASE values >> e.g. TEXT_BASE (as desired) and TEXT_BASE+0x00010010. A special "diff" >> tool should find the 32 bit places where relocation is required and >> add a table to the end of u-boot.bin... (Just a rough idea) I don't think we need to - everything should be handled by .rel.dyn. I wrote a diff tool to do as you suggest, but I have no need for it now Looks like we could be onto a winner :) Regards, Graeme _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot