From: Michael K. <kau...@so...> - 2002-12-15 15:05:29
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On Saturday 14 December 2002 23:29, you wrote: > On Fri, 2002-12-13 at 23:33, Michael Kaufmann wrote: > > Hello, > > > > i would like to use a mono LCD with a framebuffer driver. > > > > I've modified existing drivers, and after a lot of work i now have a > > clear picture on my display. Unfortunately, the complete picture is > > mirrored. The Bootlogo is top/right instead of top/left and the ascii > > output starts from right to left. > > > > Where is the right place to modify this behaviour? > > I'm also looking for a possibility to rotate the picture. > > Because my videocontroller can emulate 15 grayscales, i'm useing 4bpp= =2E > > > > It would be very nice, if someone can guide me in the right direction= =2E > > Are you using fbcon-cfb4.c to draw the characters? Is the whole displa= y > mirrored, including individual characters? If you run an fb-based app > (like fbtest for instance), is the display also mirrored? Yes, i'm using fbon-cfb4.c. The console is on my display, i see the boot= logo=20 and the kernel messages in the display mirrored. I never used fbtest. By = the=20 way, where can i find fbtest? But i already startet nanox/microwindows on= top=20 of the fb, and the picture is also mirrored. =20 > If it's the whole display, maybe your hardware supports mirroring (some > hardware with video overlay need this to support YUV formats that are > either vertically or horizontally mirrored). Maybe it has something > like that. Otherwise, it will be difficult to correct this without > rewriting practically everything. No, i don't think so. It is a simple video controller. Nevertheless, i ha= ve=20 just looked in the datasheet, and do not found such a feature.=20 I don't think that this is a bug or something like this in the framebuffe= r.=20 Because everthing works like i exect it, but i have to mirror the picture= =2E I have also measured with a scope all signals to the display, and the=20 generated output looks like i expect it. The datastream starts with the f= irst=20 pixel (in the picture top/left) and continues with the second pixel (on t= he=20 right of the first pixel) and so on. But my display is mapping this datastream from the right to the left. Please take a look on the attached picture, i think it explains the behav= iour. I can reproduce it without Linux with a simple monitor programm At the moment i have two explanations: 1) I have a display witch must be accessed unusual, and the LINUX FB does= n't support this kind of access (not yet). 2) There is a hardware problem with the signals to the display (changed=20 signals like frame-pulse, and line-pulse, or something like this. I don't think that it is a hardware problem, but i will check the connect= ion=20 again. Is there really no way in the framebuffer to mirror and/or rotate = the=20 picture data? When i have to fix it in software, what kind of code do i have to rewrite= ?=20 And, thank's for your reply! =20 Bye Michael |