On Mon, Jan 07, 2002 at 01:16:04PM -0800, H . J . Lu wrote: > > I know, but from what I understood, quickstart e.g. just assumes there won't > > be conflicts and if there are, their handling is very costly (their > > conflicts are just symbol indices which need to be checked out). > > prelink conflicts are ElfW(Rela) relocs against r_symndx 0. > > > > To port prelink to a new architecture, you need basically: > > 1) determine what you need to do with relocations and special CPU sections > > when relocating a shared library from one address to another one > > (e.g. you can link a shared libs once at VMA 0, once at VMA 0xdeadb000 > > and see what changed) - these are *_adjust_* functions > > 2) write routines which apply relocs (*_prelink_rel*) > > 3) write routines which create conflict relocs > > 4) as MIPS is rel, it needs to be figured out when it is needed to convert > > from Rel to Rela (in i386/arm case in most cases it can be avoided, > > the only relocs which require it are (on i386): R_386_32 with nonzero > > addend (otherwise R_386_GLOB_DAT does exactly the same thing) and > > R_386_PC32). This is needed, because otherwise the information about the > > original addend is lost when the final relocated value is stored at > > r_offset address. Original addend is needed, if prelink cannot be used, > > during dynamic linking. If MIPS has some place where it stashes this > > for Quickstart, then it could be reused, otherwise I'm afraid REL->RELA will > > happen more often on MIPS than on IA-32/ARM. > > 5) write routines which apply relocs to a buffer or apply a conflict > > to a buffer (these are used when doing comparisons on relocated content) > > > > As I unsterstand, MIPS only has R_MIPS_REL32 for GOT in DSO and EXE. Do you > have any suggestions? The ld.so relocates R_MIPS_REL32 using GOT which is relocated first by a special rule. There is no relocation information for GOT. Also there is no symbol lookup for relocating R_MIPS_REL32. I am not sure how it will work with the current prelink. H.J.
