On Fri, Mar 04, 2005 at 09:28:31PM +0530, Mukund JB. wrote: > > The kernel does not use an X server. The X server has nothing to do > > with the frame buffer drivers, except that X could use the frame > buffer > > as its display. You could also use gtk-fb or Qt-fb to display a GUI. > > Yes, X server uses the framebuffer driver supplied buffer. I just weanne > to know, is there another way that a GUI application can work without > using Framebuufer driver & probably through some other display driver. Check out svgalib, a library which directly accesses the video chip. Note: it is very well possible that you leave the video card in an unusable state with svgalib... > I just have this in mind because; assume that I have an i810 chipset > grph card. The Xserver also provides a driver (i810_drv.o) for that > which is not framebuffer driver. > Probably, this is what is in use on my system just because I have no > access to /dev/fb0 & on accessing it says NO such device. The X server directly accesses the video chip. If there is no framebuffer device, it switches to the first free virtual console (usually /dev/tty7, as the first six virtual consoles have a login prompt) and programs the video hardware to go to the correct graphics mode. If there is a framebuffer device, the X server can either be told (through the configuration file) to use it and no graphics reprogramming is needed, or it can still do the switch to the correct graphics mode itself. In all cases, the X server watches the key presses, and if you press Ctrl-Alt-F1, it will reprogram the video chip to the previous state (if necessary) and switch to virtual console 1. > Also, how could the Xserver dynamically change the interfaces like > sometimes accessing /dev/fb0 or /dev/xxx? It doesn't do it dynamically, you have to tell it in the configuration file. > Is the i810_drv.o a monolithic driver? No, otherwise it would have been linked into the XFree86 server binary. > > > If I want to write/modify the driver to rotate the screen by 90 > degrees, > > > at which level/files I need to do the modifications in the above > shown > > > files. > > > > No need for that, X already supports that through the RANDR extention. > > It was developed to allow on-the-fly rotating of screen contents on > > hand-held devices, but it can be used on desktops as well. > > > > > Is it available in XFree86 version 4.3.0 release? Yes, it has been available for two years or so. Run "xdpyinfo" and look at the extensions. > Can u please forward > me a document or links of that kind that could narrate me how I use > Xserver to rotate the screen. http://keithp.com/~keithp/talks/randr/ Erik -- Erik Mouw J.A.K.Mouw@xxxxxxxxxxxxxx mouw@xxxxxxxxxxxx
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