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Linux on LiteX-VexRiscv
BSD 2-Clause "Simplified" License
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Problems with HDMI display on Linux #368

Open mmx-114514 opened 1 year ago

mmx-114514 commented 1 year ago

How to display via HDMI on linux system please? Is it by mounting the hdmi peripheral via liitex and then selecting the HDMI display related compilation options on buildroot, I tried to do this but it doesn't show up.

Dolu1990 commented 1 year ago

Do you have it in the DTS ?

mmx-114514 commented 1 year ago

It doesn't seem to be there. I selected hdmi via litex and I was able to see its constraints on the pins in .cst, but I can't find any configuration for hdmi in dts. Do I have to write my own documentation for this?

Dolu1990 commented 1 year ago

ahhh curious, and is the HDMI displaying some random static noise when you boot ? Thing is for Digilent nexys video for example, if i remember well, the framebuffer was included in the dts by default

mmx-114514 commented 1 year ago

Sorry, there is no output when HDMI is activated. I'm using Sipeed_tang_20k and the output dts file has nothing related to hdmi and hdmi has no output. I double-checked make.py in linux-on-litex-vexriscv to make sure that video_terminal was added, and re-executed make.py, and the .dts file still had no hdmi related configuration after compilation.

Dolu1990 commented 1 year ago

Ahhh, i don't know much about that side of things. no hdmi output mean no hdmi signal at all ?

mmx-114514 commented 1 year ago

Yes. I forgot to add the framebuffer xD. so far I solved the problem now I have the output of the linux terminal info. Thanks buddy.

code11killer commented 1 year ago

Yes. I forgot to add the framebuffer xD. so far I solved the problem now I have the output of the linux terminal info. Thanks buddy.

hello，I want to ask how to solve the problem. I meet the problem ，too

mmx-114514 commented 1 year ago

code11killer Add framebuffer to make.py

code11killer commented 1 year ago

code11killer Add framebuffer to make.py

I add it to make.py. but I don't know how to output the video in my screen. beacuse I can't use the xrandr. Is there any other way? please

code11killer commented 1 year ago

code11killer Add framebuffer to make.py

and after I add it，I also can't see the video in DTS. If it's convenient, can you add a contact information to talk about it?

mmx-114514 commented 1 year ago

Ahhh, i don't know much about that side of things. no hdmi output mean no hdmi signal at all ?

Hello, I am experiencing a new problem, after introducing frame buffer output HDMI, the cpu performance is severely degraded, I have enabled --with-coherent-dma but the effect is not improved, I don't know how coherent-dma works here.

mmx-114514 commented 1 year ago

Ahhh, i don't know much about that side of things. no hdmi output mean no hdmi signal at all ?

By the way, I currently implemented a terminal output text via HDMI on the display, and I would like to be able to display images, after adding the fbv related libraries in buildroot, cat /dev/urandom > /dev/fb0 can output garbled code normally with uart and HDMI, but I can't display the images with fbv (image), the error Displayed as: ?25lopen /dev/fb0: No such file or directory. and I can't find anything about framebuffer in DTS. I would like to know what I can do to make linux access the framebuffer for image display.