[PATCH 00/16] Refactor the architecture parts of mt7628

Stefan Roese
2020-01-10T13:13:21Z

Hi Weijie,

On 10.01.20 11:48, Weijie Gao wrote:

<snip>

>>>> Did you compare the boot speed with using SPL + main U-Boot vs U-Boot
>>>> only?
>>>
>>> As far as I tested the difference of boot time should be less than 1s.
>>
>> 1 second is quite a lot of time. I prefer to stay with the non compressed
>> boot configuration then. Testing shows that the new SPL based version
>> also boots pretty fast, when the main U-Boot proper is not compressed.
>>
>>>>
>>>> In the current combined image the non-compressed U-Boot proper is
>>>> included. Why did you not include the LZMA compressed image per default?
>>>> Is the decompression too slow?
>>>
>>> I just kept these two boards untouched. I can switch them to compressed
>>> mode if you have no concern.
>>
>> I did not test yet. If its really a difference in time of 1 second (or
>> similar), then let stay with uncompressed for these board please.
>>
>> Thanks,
>> Stefan
>
>
> I did a precise measurement, and this is the result:
>
> type | spl load/decompression time | boot to shell (total time)
> spl + lzma | 75ms | 563ms
> spl + none | 139ms | 627ms
> non-spl | N/A | 626ms

Great. Thanks for doing these tests and reporting here.

> Actually spl+lzma is the fastest. I think this is because it has the
> smallest binary size.

Makes sense. SPI NOR load time savage is bigger than the added
decompression time.

> It's OK to switch all of them to compressed mode.

Yes, please do so. This might be a nice boot time increase for other
boards as well. I'll do some tests on i.MX6 soon. :)

Thanks,
Stefan