framebuffer questions

Jens Nixdorf schrubte am Dienstag, 19. August 2003 11:28:

Some corrections: The board _has_ VGA, but the display ist connected through the data-bus of the processor, so i cannot use VGA.

regards, Jens

I don't think that you're going to be able to plug the LCD into the VGA. Most smaller displays like that aren't setup for that

Assuming that you can't, you're going to have to write a driver.

You can

However, I have no idea how well Linux will function with a non-VGA size screen.

Alex Pavloff schrubte am Mittwoch, 20. August 2003 17:44:

You're right, the lcd will be connected to a cpu-port.

To write a driver is also my idea. So i looked into the kernel-sources to get some understanding how the framebuffer works. But there are some things i didn't found out yet:

1. The framebuffer represents mostly the memory of a vga-card, but i need also the write-routines, because i have to change the port to write to. Where is this set in the kernel? Or should i put my own write-routines directly into the framebuffer (fbmem.c)?
2. Normally there are several fb-drivers in the source. When they are compiled as modules, the kernel looks at the hardware, is reading some stuff and with this stuff it can determine which card is connected. My lcd is deaf and mutely, because the lack of own "intelligence", so it would not answer. How can i say the kernel, that it has to use _my_ framebuffer-driver?

Screen sizes shouldnt be a problem, because the customers product will be a handheld-like device, which has only predefined applications on it (which also have to be written yet).

regards, Jens

There are various kernel command line options that will work.

For these questions that I can't answer properly , I would really recommend asking the folks on the linux fb list...