[PATCH 1/2] Boottime: A tool for automatic measurement of kernel/bootloader boot time

Simon Glass sjg at chromium.org
Thu Nov 29 15:35:16 EST 2012


Hi,

On Tue, Nov 20, 2012 at 8:16 AM, Lee Jones <lee.jones at linaro.org> wrote:
>> > > +/* for automatic boot timing testcases */
>> > > +#define ATAG_BOOTTIME  0x41000403
>> > Where can I refer this ATAG usage? can you point out the reference URL
>> > or patches?
>>
>> I assumed this would be in Mainline u-boot, but apparently not.
>> On closer inspection of the internal ST-Ericsson u-boot, this
>> functionality appears to be provided by patches which currently
>> exist as delta. So in essence, the bootloader you use will have
>> to be patched in a similar way for you to retrieve information
>> surrounding bootloader boot times.
>>
>> And there was me thinking it was magic. ;)
>
> Okay, so I'm going through the motions of upstreaming this magic
> now. Please see the link below for reference:
>
> http://marc.info/?l=u-boot&m=135342273317337&w=2

Given that U-Boot has bootstage, would it make sense to upstream that
to the kernel? Some RFC patches were sent before this went into U-Boot
to sound out the interest.

http://lwn.net/Articles/460432/

Regards,
Simon

>
> --
> Lee Jones
> Linaro ST-Ericsson Landing Team Lead
> Linaro.org │ Open source software for ARM SoCs
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