[U-Boot] reloacting uboot

[Ulf Samuelsson]

Wolfgang Denk skrev:
> 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
> 

Very few boards based on the SAM9263 store u-boot in parallel flash
and if they are stored in SPI dataflash or in NAND flash it makes
little sense to link the u-boot to the flash address.

Fix at91bootstrap to load where you want it to load.

BR
Ulf Samuelsson