I can't speak to that what you're doing is actually correct, however because you make three separate asm calls, it is possible that the compiler is doing something strange in between. You should use: asm volatile ( "movb $0x00, %ah\n" "movb $0x13, %al\n" "int $0x10\n" ); Also note that you are destroying the current value in the ax register without telling the compiler. Check out http://www.linuxassembly.org/ for more information about inline assembly. On Fri, 27 Sep 2002, Tom Bradley wrote: > I am trying to do a simple vga(320x200x256) driver but am having troubles > switching the video mode. I am using: > asm volatile("movb $0x00, %ah;"); > asm volatile("movb $0x13, %al;"); > asm volatile("int $0x10;"); > which several websites and books are saying is all that is needed to > switch modes. However this locks up my machine. What am I doing wrong? > > > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > -- John Tyner jtyner@cs.ucr.edu -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
