vm86 (2)





NAME

       vm86old, vm86 - enter virtual 8086 mode


SYNOPSIS

       #include <sys/vm86.h>

       int vm86old(struct vm86_struct *info);

       int vm86(unsigned long fn, struct vm86plus_struct *v86);


DESCRIPTION

       The  system  call  vm86 was introduced in Linux 0.97p2. In Linux 2.1.15
       and 2.0.28 it was renamed to vm86old, and a new  vm86  was  introduced.
       The  definition of `struct vm86_struct' was changed in 1.1.8 and 1.1.9.

       These calls cause the process to enter  VM86  mode,  and  are  used  by
       dosemu.


RETURN VALUE

       On  success,  zero is returned.  On error, -1 is returned, and errno is
       set appropriately.


ERRORS

       (for vm86old)

       EPERM  Saved kernel stack exists. (This is a kernel sanity  check;  the
              saved stack should only exist within vm86 mode itself.)


CONFORMING TO

       This  call  is specific to Linux on Intel processors, and should not be
       used in programs intended to be portable.

Linux 2.1.15                      1997-07-17                           vm86(2)