Re: Using VESA BIOS in Framebuffer driver
From: Cheshire Cat Fish <hidden>
Date: 2003-05-14 21:37:58
-- A precariously balanced mixture of myopic optimism and rampant paranoia.
I am developing a framebuffer driver for my PLC 69030 video card. I have gone through the Source code of the Sample framebuffer driver and i have some clarifications needed. Please clarify my doubts.
I am in the process of doing exactly this for a custom board. So this will be like the blind leading the blind I suspect, but for what it is worth, here is what I know...
1.How does the Frame buffer driver Switches graphics modes, i mean how does it initializes the graphics system say in 640*480*256 mode and switch to say 800*600*24 mode. Does it depend on VESA BIOS calls to do this ?
I think this is up to you how you want to do this. In mine, I do it by directly programming the hardware (no BIOS calls whatsoever). Basically, you are told to set a mode - how you do that is up to you.
2.How does the framebuffer driver achieve paging ? Say my display memoy is 4mb and i want divide it into 4 pages then how will i do this ?
I'm not sure what you mean by paging. Video memory isn't typically paged. Is not all 4MB available at once? Noel. _________________________________________________________________ The new MSN 8: advanced junk mail protection and 2 months FREE* http://join.msn.com/?page=features/junkmail ------------------------------------------------------- Enterprise Linux Forum Conference & Expo, June 4-6, 2003, Santa Clara The only event dedicated to issues related to Linux enterprise solutions www.enterpriselinuxforum.com