Re: [PATCH V7 0/2] firmware: Add support for boot_stats

[Souradeep Chowdhury <quic_schowdhu@quicinc.com>]

On 7/10/2023 8:50 PM, Brian Masney wrote:
> On Wed, Jul 05, 2023 at 11:02:30AM +0530, Souradeep Chowdhury wrote:
>> Qualcomm's proprietary Android boot-loaders capture boot time
>> stats, like the time when the bootloader started execution and at what
>> point the bootloader handed over control to the kernel etc. in the IMEM
>> region. This information is captured by the bootloader and populated on
>> the device tree properties "pre-abl-time" and "abl-time" which can be
>> be viewed from the user space like as follows:-
>>
>> /sys/firmware/devicetree/base/bootstats # cat abl_time
>> 17898
>>
>> As a part of this patch series added the bindings for boot-stats which
>> was suggested in the v6 of the series. The link for the same is as
>> follows:-
> 
> Should boot statistics be exposed to userspace through the qcom socinfo
> driver? I see that the socinfo v19 metadata has fields for the boot core
> and boot cluster [1], so boot timing wouldn't be out of place.

"Boot Cluster" and "boot core" are soc specific info which are fixed for 
a particular qcom soc recorded in smem region of memory. "Boot_stats" is
not a property of a soc as such, they are KPI measurements in the boot 
time path stored in the imem region. So I not sure if this is the right 
home for it.

> 
> Brian
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/soc/qcom/socinfo.c#n572
>