[U-Boot-Users] U-Boot-NG ?

Sascha Hauer
2007-07-03T00:09:10Z

On Tue, Jul 03, 2007 at 01:39:29AM +0200, Wolfgang Denk wrote:
> In message <20070702184259.GA2533@pengutronix.de> you wrote:
> >
> > bigger if you enable the same features. But on Arm you do not need zlib,
> > which is configurable now. This saves you around 15k.
>
> You don't? How do you uncompress an image then?

On Arm by default zImages are used to generate the uImage, so the kernel
decompresses itself.

>
> > The PowerPC images got smaller than before. The code is not position
> > independent anymore, this saves around 10% of binary space.
>
> The code has never been position independent; it gets relocated.

The code itself would have been position independent because it was
compiled with -fPIC.

>
> Do you mean you don't relocate the code any more?

It still gets copied from the address U-Boot starts (Flash) to RAM, but
pointer offsets are not recalculated. This means that you must not use
statically initialized pointers during startup since the code is not
running at its link address.
The Arm part has done this for years. On PowerPC we have the luxury of
having SRAM, so we can setup a stack and do SDRAM initialization in C
before jumping to RAM.

Regards
Sascha

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