Dear "J. William Campbell", In message <[email protected]> you wrote: > > Yes, I think Wolfgang is correct. This is not going to be easy to do in > general. To run anywhere, the code must be true Position Independent > code. If you intend to use any C code in the initialization, this will > result in needing -fPIC for at least that code. I am not sure you can > mix -fPIC and non -fPIC code in the same link, but I expect not. I am a > bit surprised that it is possible to get even the initialization code to > be Position Independent, but it appears that on at least some PPC it is > possible/has been done.
Not really. On PowerPC, only the first 20 or 30 lines of assembler code in start.S are position independent; then we compute the link (resp. execution) address and branch to it. From then, we run from the very address range we were linked for (starting at TEXT_BASE). > Albert is doing now, and Graeme did before, is the first option, > creating a loader that understands ELF. This has the advantage that it > will work on all architectures. However, once this understanding is in > place, it would be easy to write a small post-processing program that > would reduce the size of the relocation entries, much like -mrelocatable > does. This may or may not be necessary, but it is certainly possible. Eventually we might even add -mrelocatable support for the other architectures to the tool chain. 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: [email protected] Its always easier short term to pee in the pond than install a toilet - it's just not a good long term plan. - Alan Cox in <[email protected]> _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
