The STM32L4R9 Discovery kit it comes with a small round (390x390) DSI based display. I am trying to setup a standard rectangular DSI based display. All the example projects for STM32L4R9xx use a round display using GFXMMU look-up table ...

[slime]

Since I don't have a round display, I don't need this lookup table to convert the bit locations, but there is no obvious way to not use it. How do you bypass this GFXMMU look-up table method and just send the raw image array to the DSI path? I am using this project for testing:

https://github.com/STMicroelectronics/STM32CubeL4/tree/master/Projects/32L4R9IDISCOVERY/Examples/DSI/DSI_CmdMode_SingleBuffer

[MM..1]

As first you need check how mode your DSI display support. Some rect displays dont support command mode . Video mode is supported on all and is good point to start, and too is better MCU offload .

[slime]

The screen supports command mode. Sending an image works, its just being modified (has a circle boarder).

[Tignac]

as you don't have a round display you probably don't need to go through GFXMMU.

You should define your layer address directly to be the physical frame buffer

#define LAYER_ADDRESS (uint32_t) PhysFrameBuffer

And update the LayerCfg.ImageWidth to the effective size of your display (when you are using the GFXMMU the ImageWidth must be set to 1024)

[slime]

Thank you. Your suggestion worked.

• #define LAYER_ADDRESS (uint32_t) PhysFrameBuffer
• Increasing the PhysFrameBuffer size as needed for the display size
• Removing the usage of 1024 in LTDC config, and in the CopyInVirtualBuffer()
• Dma2dHandle.Init.Mode  = DMA2D_M2M;

The only thing that isn't correct yet is the colors are off; red is cyan, blue is yellow, and green is pink.