mis-elf-as : local/global symbol order in symbol table

[Pierre Habraken]

Thanks a lot Jim for the story of mips elf and your detailed 
explanations. Now things are clear to me. I just have to rebuild 
binutils with mips-sde-elf in order to get traditional ELF assembler and 
linker.
But will I have to rebuild also gcc, newlib and gdb ?

Pierre


Jim Wilson wrote:
> On 04/25/2010 01:20 PM, Pierre Habraken wrote:
>> I have to precise that I am not a mips programmer. I just supervise a
>> student project in which students have to program an assembler or a
>> simulator. The mips architecture was choosen for educational reasons
>> (not for technical reasons). Several students ask us why the "official"
>> assembler (mips-elf-as !) does not conform to the ELF specification
>> (this is rather confusing for them). Hence my post.
> 
> To expand a little on what Ian said...
> 
> ELF was invented by AT&T and Sun.  SGI started from the ELF docs and 
> wrote their own toolchain.  The result is something that is technically 
> ELF, but not entirely compatible with the original AT&T and Sun ELF 
> toolchains, because SGI interpreted many things differently than AT&T 
> and Sun did.  Because the early GNU toolchain ports were for SGI 
> workstations, this alternative ELF implementation was used as the basis 
> for the mips-elf target.
> 
> Linux wanted traditional ELF support, so the GNU MIPS toolchains now 
> actually support two different kinds of ELF object files.  There is the 
> "traditional ELF" support which is compatible with AT&T/Sun ELF files, 
> and then there is the SGI ELF support which is compatible with SGI Irix5 
> and Irix6.  SGI ELF is used by default for mips-sgi-irix* targets and 
> mips*-elf.  Traditional ELF is used for mips-linux, mips-*bsd, etc.
> 
> It might be nice to change mips-elf to use traditional ELF instead of 
> SGI ELF, which is becoming obsolete.  However, the mips-elf target has 
> used SGI ELF for so long that this is likely to cause too much trouble 
> for too many people, so it isn't clear when if ever we can make this 
> change.  In the meantime, there is the mips-sde-elf workaround though. 
> The mips-sde-elf target does default to traditional ELF, and is very 
> similar to the mips-elf target, except that it uses traditional ELF 
> instead of SGI ELF.
> 
> Jim
-- 
Pierre HABRAKEN - mailto:Pierre.Habraken@imag.fr
Tél: 04 76 63 59 94 - Fax: 04 76 51 47 93