[PATCH 0/9] Enable splash screen

[Nikhil M Jain]

Hi Simon,

On 16/03/23 10:10, Nikhil M Jain wrote:
> Hi Simon,
> 
> On 15/03/23 19:38, Simon Glass wrote:
>> Hi Nikhil,
>>
>> On Wed, 15 Mar 2023 at 00:07, Nikhil M Jain <n-jain1 at ti.com> wrote:
>>>
>>> Hi Simon,
>>>
>>> On 15/03/23 03:38, Simon Glass wrote:
>>>> Hi Nikhil,
>>>>
>>>> On Mon, 13 Mar 2023 at 04:15, Nikhil M Jain <n-jain1 at ti.com> wrote:
>>>>>
>>>>> To enable splash screen at SPL stage move video driver and splash 
>>>>> screen
>>>>> framework at SPL, which will bring up image on display very quickly 
>>>>> and
>>>>> thus have early display support in SPL.
>>>>>
>>>>> Nikhil M Jain (9):
>>>>>     drivers: video: Kconfig: Necessary configs for video at SPL
>>>>>     drivers: video: tidss: Kconfig: Configs to enable TIDSS at SPL
>>>>>     cmd: Kconfig: Add necessary configs for splash screen at SPL
>>>>>     drivers: video: Makefile: Compile video driver files at SPL
>>>>>     drivers: video: tidss: Makefile: Add condition to compile TIDSS 
>>>>> at SPL
>>>>>     cmd: Makefile: Add rules to build bmp.c and read.c at SPL
>>>>>     common: splash: Enable splash_display at SPL stage
>>>>>     drivers: video: video-uclass: Disable u-boot logo at SPL
>>>>>     board: ti: am62x: evm: OSPI support for splash screen
>>>>>
>>>>>    board/ti/am62x/evm.c         |  6 ++++++
>>>>>    cmd/Kconfig                  | 17 +++++++++++++++++
>>>>>    cmd/Makefile                 |  2 ++
>>>>>    common/splash.c              |  2 +-
>>>>>    drivers/video/Kconfig        | 32 ++++++++++++++++++++++++++++----
>>>>>    drivers/video/Makefile       |  6 ++++++
>>>>>    drivers/video/tidss/Kconfig  |  6 ++++++
>>>>>    drivers/video/tidss/Makefile |  1 +
>>>>>    drivers/video/video-uclass.c |  2 +-
>>>>>    include/splash.h             |  2 +-
>>>>>    10 files changed, 69 insertions(+), 7 deletions(-)
>>>>
>>>> I'm not necessarily arguing against this, but what is the need for
>>>> this? How many milliseconds earlier does the image appear with this
>>>> patch? What is the bottleneck? We should be able to get to U-Boot
>>>> proper very quickly.
>>>>
>>> There is a significant difference in time, by adding support in SPL
>>> splash screen comes up by approx 650ms and at u-boot proper it comes at
>>> 2.6s, measured from first print in console as seen on AM62x. Also we
>>> plan to skip u-boot proper and load kernel directly.
>>
>> Yes that really is terrible. It should be under a second for U-Boot 
>> proper!
>>
>> Have you tried using bootstage to report the numbers?
>>
> No I haven't used the bootstage, I will use it to get the numbers.
>
Boot stage logs
link: https://gist.github.com/NikMJain/beb60fe42b1e89829cdd5b8713284330


>> Have you tried using tracing to figure out what is wrong? Is it just
>> slow storage?
>>
> U-boot proper comes up in one sec but the splash display is called 
> through stdio_add_devices which is late in the board_init_r sequence 
> defined in board_r.c.
>  >> Regards,
>> Simon
> 
> Thanks

On AM62x we have multi-stage boot first R5 SPL comes up then A53 SPL and 
u-boot proper, due to which splash screen at u-boot proper takes over 2 
sec. On AM62x we have an aggressive requirement for an early splash 
screen. Hence we are moving splash screen support to SPL., which will 
bring splash screen time to approx 600 ms.

We also want to support falcon boot mode from A53 SPL, we have customers 
who don't want u-boot proper in production boot flow and still require 
splash screen, the only way to support it is to add  splash screen at SPL.

u-boot logs with splash screen timings, measurement through 
timer_get_boot_us at u-boot proper and SPL.
link: https://gist.github.com/NikMJain/3be0b6c92092678b6aec8e5fdbc46a98

Thanks,
Nikhil