Re: Help needed - defining the output section order

[Nick Clifton <nickc at redhat dot com>]

Hi Simon,

> Now the big questions is: Is there any way to force ld to put the fpc.resspare
> section after fpc.resdata?

Yes - use the SECTIONS command in the linker script...

> From reading the docs it appeared to me that possibly using a SECTIONS
> command in the linker script might do the trick - so added the
> following to the end of the linker script:
>
> SECTIONS{
>   fpc.ressym    : { *(fpc.ressym) }
>   fpc.resstr    : { *(fpc.resstr) }
>   fpc.reshash   : { *(fpc.reshash) }
>   fpc.resdata   : { *(fpc.resdata) }
>   fpc.resspare  : { *(fpc.resspare) }
> }
>
> Sadly this only results in
> "Not enough room for program headers (allocated 5, need 6)" and "final
> link failed: Bad value".

Ah well, that is because your new linker script is too simple.  There is 
a section in the linker documentation that talks about this problem:

  When producing an ELF output file, if the linker script uses
  the SIZEOF_HEADERS builtin function, the linker must compute
  the number of program headers before it has determined all
  the section addresses and sizes.  If the linker later
  discovers that it needs additional program headers, it will
  report an error "not enough room for program headers".  To
  avoid this error, you must avoid using the SIZEOF_HEADERS
  function, or you must rework your linker script to avoid
  forcing the linker to use additional program headers, or
  you must define the program headers yourself using the
  PHDRS command.

So what you probably need to do is to add a PHDRS command to your linker 
script.

Plus what you probably really want to do is to find out the default 
script used by the linker (by running ld --verbose) and then take the 
SECTIONS command from there and merge in your fpc.* sections.  The 
SECTIONS command in the default script will probably be a lot more 
comprehensive than the one that you are currently using.

Cheers
  Nick