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Posted: Sun Mar 16, 2008 12:59 pm
by xyzzy
Philip wrote:i found out the linear video buffer address is usually at
f000 0000h
writing to memory from this address can put pixel on the screen
so actually in protected mode it's easier to use vesa
Uhh, you have to switch mode first? Which is easier to do in real mode/V8086 mode.
Also, where did you find that? Most of my boxes have different addresses.
Posted: Sun Mar 16, 2008 5:49 pm
by Combuster
First machine I tested put the LFB at 0xEE000000. The second at 0xFD000000. Both had AGP ATI Rage card. My V2100 board appeared at 0xF2000000, and IIRC bochs had it by default at 0xE000000
That's nothing at 0xF0000000
Posted: Mon Mar 17, 2008 2:22 am
by zaleschiemilgabriel
I think those addresses are initialized by the BIOS to whatever it feels best (when it initializes PCI devices and ACPI tables). There are also some BIOS that let you customize resource usage, including memory space.