From 983c3370ea0ed75cf6d8245b90ba251048580562 Mon Sep 17 00:00:00 2001 From: Gregory Nutt Date: Fri, 18 Oct 2013 10:11:20 -0600 Subject: [PATCH] SAMA5 LCD: Move framebuffers to center of free memory region. That creates a guard band around the framebuffers that gives a little protection from any bad writes into the framebuffer --- configs/sama5d3x-ek/README.txt | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+) diff --git a/configs/sama5d3x-ek/README.txt b/configs/sama5d3x-ek/README.txt index 40522bed1d..6f3fe4a96d 100644 --- a/configs/sama5d3x-ek/README.txt +++ b/configs/sama5d3x-ek/README.txt @@ -2270,6 +2270,40 @@ Configurations $ cd ~/nuttx-git/nuttx $ make + STATUS: + 2013-10-18. This example kind of works, but there are still far too + many outstanding issues: + + a) It runs of the SAMA5D31 and SAMA5D34, but not on the SAMA5D33. This + board is from a different manufacturer and there may be some SDRAM- + related issues? + b) There appears to be an SDRAM noise issue on the SAMA5D31 and SAMA5D34. + I suspect that the SDRAM setup is non-optimal. The symptom is that + writing into frame buffer (in SDRAM) occasionally corrupts the DMA + descriptors (also in SDRAM) When the bad DMA descriptors are + fetched, the channel shuts down and the display goes black. This + problem could also be cause by a bad write outside of the framebuffer, + but was not the case in the few examples that I studied. + c) There are some occasional start up issues. It appears that the LCDC + is programed incorrectly and groups of pixels in the images are + reversed (producing an odd serrated look to the images). + d) I think that there may be more issues if GRAPHICS and INPUT debug is + off. I have not tested with DEBUG off. + e) The biggest problem is the touchscreen accuracy. The touchscreen + seems stable during calibration, but the first thing that this + example requires is a touch in the far, far, upper left corner of + the display. In that region, I cannot get reliable touch measurements + and so I cannot get past the opening display. + f) The NxWM example was designed tiny displays. On this large 800x480 + display, the icons are too tiny to be usable. I have created a large + 320x320 logo for the opening screen and added image scaling to expand + the images in the taskbar. The expanded images are not great. If I + ever get past the opening screen, the same problems will exist in the + application toolbar and in the start winow. These icons are not yet + scaled. + + Bottom line: Not ready for prime time. + ostest: This configuration directory, performs a simple OS test using