[Linaro] Displaying a image on frame buffer node /dev/fb0 from user space


#1

Hi,

I am using the Linaro release on DB820c board with HDMI monitor.

I am trying to display a image or just a single RGB color on the /dev/fb0 frame buffer node.

I am able to get the fixed and variable screen information by the FBIOGET_FSCREENINFO and FBIOGET_VSCREENINFO ioctl respectively, and then doing mmap() to dump data in the frame buffer. But I am not able to get anything on the HDMI display.

Then I found that, instead of mmap() call, we need to issue the MSMFB_ATOMIC_COMMIT ioctl from the user space, and the corresponding ioctl is handled at drivers/video/msm/mdss/mdss_fb.c -> mdss_fb_atomic_commit_ioctl().

So is there a sample application which I can refer to, so that I can populate the struct mdp_layer_commit and make the ioctl call from userspace ?

Thanks,
Sunny