[systemd-devel] [PATCH v2 6/8] add GOP mode setting and splash drawing support

[Joonas Lahtinen]

Hi,

On 14.01.2014 16:13, Tom Gundersen wrote:
> On Tue, Jan 14, 2014 at 2:15 PM, Joonas Lahtinen
> <joonas.lahtinen at linux.intel.com> wrote:
>>> I've implemented very basic BMP support and commited it.
>>
>> The custom format was there for best possible speed to be achieved when
>> displaying the splash, as the original use case is extremely time critical.
>> I will look into the speed differences and see if there's still need to use
>> the custom format.
> In case it is still causing your trouble, the BMP parser can certainly
> be optimized a bit. In particular, if you target a specific format
> (e.g. without alpha support etc).

By our measurements, the original BGRX code only adds some 5 
milliseconds to the boot time compared to no logo at all, where the BMP 
code adds almost 70 milliseconds.

I think the most difference comes from the fact that in the BGRX file 
the pixel data is already in format suitable format for UEFI blit 
operations, and pixels are pushed to the blit operation as a big batch, 
just like they are loaded as one big batch. The BMP code invidually 
loops each pixel. Would the BGRX format be accepted aside the BMP 
format, for these speed reasons?

Regards, Joonas

> Cheers,
>
> Tom
>