vm86old, vm86 — enter virtual 8086 mode
#include <sys/vm86.h>
int
vm86old( |
struct vm86_struct * | info) ; |
int
vm86( |
unsigned long | fn, |
struct vm86plus_struct * | v86) ; |
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
(virtual-8086 in Intel literature), and are used by
dosemu
.
VM86 mode is an emulation of real mode within a protected mode task.
On success, zero is returned. On error, −1 is
returned, and errno
is set
appropriately.
This return value is specific to i386 and indicates a problem with getting userspace data.
This return value indicates the call is not implemented on the present architecture.
Saved kernel stack exists. (This is a kernel sanity check; the saved stack should only exist within vm86 mode itself.)
This call is specific to Linux on Intel processors, and should not be used in programs intended to be portable.
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