uGFX on STM32F746-Discovery + ChibiOS skipping every other line

[rvense]

Hello. Thank you very much for this great project!

I copied the STM32F746 example that comes with ChibiOS (LED blinker) and made the changes to the makefile described on the wiki.

I added some code to main.c that initializes a console and prints some text to it. This works when run from an example that uses raw32 instead of ChibiOS.

With ChibiOS, however, it looks like every other vertical line is skipped. The text is recognisable as text, but not readable. I added a yellow bar to the bottom, but it comes out as alternative yellow and black lines.

I have enabed CONTROL to rotate the display 180 degrees. This worked in raw32. Using Chibi, if I disable them, I get the errors in the attached file about PIXELFORMAT macros not being defined for the STM32 display driver, but in a way that would only show up if CONTROL is not enabled. The output is still garbled in the same way. I think this might be related - and the output looks like it could be data written incorrectly.

gfxconf.h

make.err

Makefile

Edited November 12, 2017 by rvense

[rvense]

Hm: setting LTDC_USE_DMA2D to FALSE in drivers/gdisp/STM32LTDC/gdisp_lld_config.h fixes the issue. Affirms the suspicion that it's the wrong size of data being written somehow?

Edited November 12, 2017 by rvense

[inmarket]

Make sure you are using the latest repository version or at least v2.8 of uGFX.

There were significant fixes to do with dma and the cpu cache between v2.7 and v2.8

[rvense]

Thank you so much, that fixed the issue. I can echo text over USB serial now and have it show up on the screen. Very cool.

The Makefile example for the STM32F746 board  that's linked from the site includes uGFX 2.5, and that's what I was using.

Edited November 12, 2017 by rvense