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.