[U-Boot] [PATCH 0/7] Bootgraph.pl instrumentation support for UBoot

[Simon Glass]

Hi Mike,

On Wed, Aug 31, 2011 at 3:47 PM, Mike Frysinger <vapier at gentoo.org> wrote:
> On Wednesday, August 31, 2011 18:20:54 Andrew Murray wrote:
>> This patchset introduces the CONFIG_BOOT_TRACE option which provides
>> support for boot time instrumentation.
>>
>> When enabled printf output is prefixed with timing information (similar to
>> the kernel's CONFIG_PRINTK_TIME option) and additional output is generated
>> which instruments functions and commands called (much like the kernel's
>> initcall_debug functionality).
>>
>> The kernel's bootgraph.pl script has been ported to render UBoots
>> instrumented ouptut into a pretty SVG graph. An example of this can be
>> found here: http://goo.gl/dX8aR - which shows the boot time of a Beagle
>> board.
>>
>> The patch currently provides support for instrumentation of UBoot commands
>> (e.g. U_BOOT_CMD) for all platforms but only when the HUSH shell is not in
>> use. Initialisation instrumentation is only limited to the
>> arch/arm/lib/board.c file at present but can very easily be extended to
>> other relevant files.
>
> i feel like we've had similar ideas tossed around semi-recently.  am i just
> misremembering ?
> -mike
>

Yes, for example:

http://patchwork.ozlabs.org/patch/95513/

It got caught up with a big discussion about whether we want a
microsecond timer. There is now one in Tegra, but not in the generic
timer API. There was also a request to unify this with the
boot_progress stuff (i.e. it turned into a big cleanup).

I haven't got back to it yet, but could probably do something next week.

I also have patches to pass the timings to the kernel and have it
report them to user space through a device. Planning to send an RFC to
the LKML about that probably next week as well. Could be fun.

Regards,
Simon