[U-Boot] [RFC][PATCH 00/21] [x86] 'Comming of Age'

Joakim Tjernlund joakim.tjernlund at transmode.se
Sat Mar 27 16:48:40 CET 2010



Graeme Russ <graeme.russ at gmail.com> wrote on 2010/03/27 12:54:03:
>
> Joakim Tjernlund wrote:
> >> In the near future, I intend to make it 100% relocatable (i.e. does not
> >> need to be loaded at TEXT_BASE) and maybe even add the ability to specify
> >> the relocation address.
> >
> > I did a few months ago for MPC83xx and sent it to the list. There was some
> > discussion but in the end it wasn't applied because it was too invasive.
> > PPC is especially bad as it needs to relocate string literals too.
> >
> > Search for LINK_OFF if you want to see what I did
> >
>
> Yes, I saw a bit of that thread and you patches an I would agree that they
> were too invasive. x86 is not that great for relocation either (all calls
> are absolute as well as references to .text). Have a look at board_init_f()
> in lib_i386\board.c - it has a very basic parsing of the ELF relocation
> information.
>
> I tried to champion this as a cross-platform method of achieving full
> relocation and the killing off of all those ugly reloc_off hacks all over
> the place. Unfortunately, I think the code size and time penalty may have
> been too great in the end.
>
> To implement full relocation, I simply need to add an additional parameter
> to this function which provides the 'link versus load' offset which will
> get applied to the 'load versus run' offset calculation

Are we talking about the same thing? when you say "does not
need to be loaded at TEXT_BASE" you need something like my LINK_OFF patch,
otherwise I don't see how you can boot out of flash otherwise.

 Jocke



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