[U-Boot-Users] Relocation of symbols?

[Grant Likely]

On 6/27/05, Wolfgang Denk <wd at denx.de> wrote:
> Dear Andreas,
> 
> in message <3YJEA6HGSNLF3264765ZTQSQYSRNJI43.42bffa31 at pc-block> you wrote:

> 
> It's just that not many people really understand all the details  how
> the relocation works.

<stuff deleted>

> I guess you can probably tell  GCC  to  add  GOT  entries  for  these
> pointers,  but  I have to admit that I don't know off-hand what's the
> most efficient way.
> 
Just to satisfy my curiosity...

What is the design decision behind u-boot building as a single
relocatable binary (with all the complexities associated with
relocation)?  As opposed to a a two stage process with a small chunk
of bootstrap code encapsulating the main u-boot image.  The bootstrap
code being linked seperatly from the main image so each image runs in
the address space it is linked to.  (like a Linux zImage; bootstrap
code only responsible for initializing RAM, copying the main image and
jumping to it).

I can see that a two stage scheme would sidestep the relocation issues
mentioned above and should make probing with a debugger simpler.  What
are the advantages of the single binary approach?  Image size perhaps?

Cheers,
g.