[U-Boot] [PATCH] arm: Add option to disable code relocation

[Dirk Behme]

On 08.02.2012 00:36, Wolfgang Denk wrote:
> Dear Graeme Russ,
> 
> In message <CALButCKfG+guStJP+M5E=NSr34VPhzgbREbxQuXD6028sw6x6A at mail.gmail.com> you wrote:
>>> If SPL was to determing the relocation address, it would also have to
>>> read the environment, because there are a number of environment
>>> variables which can cause (dynamically) the relocation address to
>>> change.
>> But this is not neccessarily the case for every board (or even every arch)
> 
> Not neccessarily, but possible.
> 
>> For those boards/arches which CAN calculate the relocation address (either
>> because it is fixed do to npn-variable RAM size, or fixed in relation to
>> the maximum RAM address) why should we prohibit a method of skipping the
>> redundant copy operation in a way which is 100% transparent to everyone
>> else?
> 
> Can we please focus on unifying the boot process first, before we try
> to come up with micro-optimizations?
> 
> Most of the people who complain here that they need to skip
> relocation are probably wrong in at least two accounts:
> 
> - They are not actually talking about relocation at all.
> - They don't base their accessment on any real, measured timings, or
>   otherwise they would start optimizing completely different areas of
>   the code.

Maybe they are looking at all areas (including the different ones) of 
possible optimizations. And this thread is only one topic (note 1).

Best regards

Dirk

note 1: I agree that the different topics will give more improvement. 
E.g. [1]. Looking at that thread, unfortunately there is less discussion 
than here while it will give more improvement :(

[1] http://lists.denx.de/pipermail/u-boot/2012-February/117270.html