[U-Boot] reloacting uboot

[Wolfgang Denk]

Dear E Robertson,

In message <200908251428.55255.e.robertson.svg at gmail.com> you wrote:
>
> > In message <200908251403.20809.e.robertson.svg at gmail.com> you wrote:
> > > I am using the at91sam9263 device from which the bootstrap code load
> > > u-boot to the desired ram address. However, I would like to re-relocate
> > > this at the different address based on memory availability. Can / or
> > > should this be done?
> >
> > Yes, it can be done, and it should be done. The fact that we don't do
> > it so far is due to the fact that the guys who did the original ARM
> > code found this too complicated (even though they had a working
> > example in the PowerPC code) and not worth the effort. We're suffering
> > since from this misconception.
> >
> > But there is no reason why you would have to copy the  code  again  -
> > just copy it to the correct address right from the beginning, like we
> > do in PowerPC.
> 
> I don't follow: Yes, but no reason to do so?

You wrote: "re-relocate". This is bogus. Just relocate it once, to the
correct address.

> On the 9263, it's copied once to ram at boot. Are you saying their is no 
> reason to copy it again? If so, yes, in most cases that would be true but I 
> would like to move it again after that initial relocation. Since I've already 
> specified my start address, I wasn't sure about.

Fix the ARM relocating scheme such that it works like in PowerPC: link
the image not for a RAM address, but for the address in flash. Then,
after determining the RAM size, copy & relocate the code once to RAM.
Only one copy. Not two.

Best regards,

Wolfgang Denk

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