i.MX ProcessorsのトピックRe: i.MX8M Plus PSPLASH Dual Display

i.MX8M Plus PSPLASH Dual Display

acremonini — Wed, 26 Feb 2025 09:02:11 GMT

Hello,

I'm having some trouble in setting PSplash in my application: I have both a LVDS display and a HDMI display connected to my board.

Main issue is that the LVDS display is rotated by 180°, so my psplash screen is upside down in one of the two display. I've seen that both displays are associated with the same frame buffer, so the image is just replicated on them. Even the resolution is the same, so the image takes a small part of the HDMI display.

How can I set a different behaviour on my displays?

Thanks,

Re: i.MX8M Plus PSPLASH Dual Display

joanxie — Thu, 27 Feb 2025 00:41:21 GMT

you can refer to the link as below

Weston clone mode on i.MX8MPlus - NXP Community

Re: i.MX8M Plus PSPLASH Dual Display

acremonini — Thu, 27 Feb 2025 10:27:54 GMT

@joanxie
Thanks,

if I understand correctly that is a guide about cloning the same Weston interface on multiple display.

But psplash doesn't use Weston, it outputs on the framebuffer /dev/fb0 that is mounted at startup (by drm?). This framebuffer is the same for both my lvds and hdmi display so rotation and resolution are not considered.
Is it possible to have two different framebuffer for hdmi and lvds?

Best regards,

Re: i.MX8M Plus PSPLASH Dual Display

joanxie — Mon, 03 Mar 2025 05:47:03 GMT

what bsp version do you use? as I known, only one frame buffer for psplash in the old bsp, you can refer to the patch as below

https://github.com/Renn22/psplash/commit/2913c24920a984331685eaa528f6b29c18e285c8#diff-6e9c80ea4001bf0f8870f2abc869a4ec4548faaf471e4f3bf33ef1d5eadc6163

Re: i.MX8M Plus PSPLASH Dual Display

acremonini — Mon, 03 Mar 2025 08:38:41 GMT

Thanks,

I'm using Psplash version provided with imx-linux-scarthgap Yocto (imx-6.6.23-2.0.0 xml).

I guess there will be modifications to be done on Psplash, and the patch you share could be useful, but there's a bigger problem:

there's just one frame buffer for both LVDS and HDMI (getting LVDS resolution). Even if I don't use psplash and i just put data with a dd on the frame buffer, the same pixel are shown both on HDMI and LVDS display.

If I understand correctly, it is imx-drm that creates the framebuffer and associates all displays with it. I just wonder if it is possible to associate LVDS and HDMI with different framebuffers.

Re: i.MX8M Plus PSPLASH Dual Display

joanxie — Fri, 07 Mar 2025 11:03:35 GMT

you can try two solution, the first one, you can refer to the patch I sent to you before, split the one frame buffer into two,it use cmd FBIO_WAITFORVSYNC to flip the two buffers, another one is refer to the weston, use new systemd service to replace the splash service, on theory, can use dual buffer to support your user case