On 08.02.2012 00:36, Wolfgang Denk wrote:
Dear Graeme Russ,
In message CALButCKfG+guStJP+M5E=NSr34VPhzgbREbxQuXD6028sw6x6A@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