[U-Boot] [PATCH 0/4] Accurate boot time measurement

[Graeme Russ]

Hi Simon,

>
> Hi Detlev and Wolfgang,
>
> Thanks for your comments. I understand a little bit of healthy inertia
> and do appreciate the constraints.
>
> I believe I have covered this ground very thoroughly and would like
> advice please on what to do next. The options I can see are:
>
> - change the code to use a fallback when a microsecond timer is not available
> - integrate with boot progress
> - something else? drop it?

I suggest you create a V2 of this patch series, integrating the logging
into show_boot_progress() - Have a crawl through the existing code and see
if you can safely use a bit in the progress number (preferably a fixed
bit number across all platforms, or one defined in the config file if
this is not possible) to indicate if that progress mark should be logged

One day we can perhaps standardise how the parameter to show_boot_progress
is treated so the same value is consistent across the entire U-Boot code.

Don't worry too much about the 'pre-relocation' case for the time being.
You will have to check the relocated flag stored in global data so no
attempt to log is made before relocation. If there is enough support for
pre-relocation logging, there can always be a V3 patch :)

Make sure that the new feature has zero impact if the configuration option
is not enabled (CONFIG_LOG_BOOT_PROGRESS for example). Try not to make it
too ugly by littering code with #ifdef - If the bulk can be put into a
file which can be selectively included in the Makefile that would be good.
show_boot_progress() will naturally have some #ifdef's in it

Make sure you clearly comment in each patch that it is V2 and the changes
made from V1 and that you run it all through checkpatch.pl (from the Linux
kernel source)

Regards,

Graeme