Using VPDMA to show uboot lcd logo, but limited by time

Hi Harry,

The boot logo has limitation for 15 seconds max time.

See ti-ezsdk_dm814x-evm_5_05_02_00/docs/DM814x_EZ_Software_Developers_Guide.pdf

6.7 How to display a logo at boot

BR,
Pavel

Hi Pavel,

I'm very glad to receive your reply.

I know what you said, the time of logo dispaying is limited, and the max value is 15 seconds in the source code.

And I know I can modify the source time, and change the logo shown limited time. However, these are not what I want.

What I means is that I just want to remove the limit of time, and the logo can be shown always without a time limit not mater how long it is.

I found that in uboot a vpdma firmware was loaded, and I think it may be a limit in the vpdma firmware to make the screen refresh not continuous but with time limited. However, I don't have the vpdma firmware source code.

So, could you please give me a kind of hand? Maybe you can show me the way how ho change the vpdma firmware, or give me a new vpdma firmware modified on the time limit point.

Looking forward to your reply.

Thanks!

Harry,

Harry Lin1 said:

What I means is that I just want to remove the limit of time, and the logo can be shown always without a time limit not mater how l

We have to put time limit because we use temporary DMA list for displaying logo from uboot. When actual M3 driver comes up, it uses completely different layout for the DMA list, so we have to stop this temporary list.

There is an uboot parameter to specify boot logo time, we could display it as long as we want, but the main things, VENC will display back ground color from firmware loader init to FbDev start. This is right now unavoidable.

Regards,
Pavel

Hi Pavel,

As far as I know,  in the M3 vps source codes, there is a vpdma firmware loaded like in uboot. And I know that if we want to stop vpdma send, we can write (1 << 20) to VPDMA_LIST_ATTR register.

So, I think we can display the logo continuously, and we can control the uboot interact with M3 firmware.

But, how can I do to achieve it? Modify the vpdma firmware or some registers? Please tell me, thank you!

Harry,

Please refer to the below links, might be in help:

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/p/150496/733385.aspx#733385

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/t/209073.aspx

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/717/t/220648.aspx

Regards,
Pavel

Hi Pavel,

I am sorry I can't find the available information for what I want (because I can show the logo both on the lcd and hdmi out before, and to your reference is related to this).

I just need to know what should I do to support the logo display continuously without time limited in uboot.

And it's the lack of some description for vpdma registers and vpdma firmware source code.

Please help me to achieve it. Thanks you!

Harry,

Harry Lin1 said:

I just need to know what should I do to support the logo display continuously without time limited in uboot.

I think that the first link I have provided, is referencing the time limit in u-boot.

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/716/p/150496/733385.aspx#733385

(4) The time limitation is there as there is an issue to stop the list used to display the image before the loading of firmware. The 15 second limitation was there for the fast boot condition. This time limitation could be increased in the u-boot code by changing the macro for maximum time MAX_LOGO_TIME in the code, but make sure it stops before the firmware starts to load.

BR
Pavel

Hi Pavel,

I know I can change the MAX_LOGO_TIME to display logo as long as I want.

However, I wanna dispaly logo continuously without this limit. For example, if I can send just one frame to vpdma, and it will be shown over and over again, so the logo can be shown continuously, will this work?

In a word, I want the display logo continuously, but without time limit like MAX_LOGO_TIME setting.

Maybe we can refer to the practice of M3 to achieve it, can we?

Please give me some help!

Thanks!

Harry,

You'll have to change the VPDMA links to point to itself. But are you able to boot up properly, if you increase the duration. I believe M3 driver will not properly if you increase the duration till the application comes up.

Hi Renjith,

Thank you for your reply! Similar to your suggestion, I have already solved the problem.