Strange behavior Bios driver + VESA

[bigorenski]

Hello, Im dropping to real mode to use some bios calls on my system. Everything works fine, except that when I try to write in Vesa addr it doesnt work. Mode change and all other things are working just fine.
Vesa function 0x4f01(get mode info) return AX=00 (success)

Does anyone knows whats wrong? Thanks

(sorry for my english)

[dansmahajan]

Hello, Im dropping to real mode to use some bios calls on my system

dropping to real mode ??? how ???
as it sounds to me is you are dropping from pmode to rmode, again how ??
as far as i know only way in x86 processors is virtual 8086 mode

so please elaborate what you mean by dropping to real mode

[Jezze]

@dansmahajan: Dropping to real mode is very much possible without using virtual 8086 mode.

[dansmahajan]

@dansmahajan: Dropping to real mode is very much possible without using virtual 8086 mode.

Thanx Jezze i found a article regarding this on wiki.But i think it is(switching to rmode) useful only if you want to execute a particular instruction
whereas if we want to emulate a 16bit program and also use a 32 bit program vm86 is a better option (feel free to criticize this) and i guess this is how 16bit emulators work in 32bit os

[b.zaar]

Have you tried Pm86? =)

[Combuster]

Everything works fine, except that when I try to write in Vesa addr it doesnt work

Which address are you writing to? How did you get it?