vm86
Section: System Calls (2)
Updated: 2022-10-30
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NAME
vm86old, vm86 - enter virtual 8086 mode
LIBRARY
Standard C library
(libc, -lc)
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 (virtual-8086 in Intel
literature), and are used by
dosemu.
VM86 mode is an emulation of real mode within a protected mode task.
RETURN VALUE
On success, zero is returned.
On error, -1 is returned, and
errno
is set to indicate the error.
ERRORS
- EFAULT
-
This return value is specific to i386 and indicates a problem with getting
user-space data.
- ENOSYS
-
This return value indicates the call is not implemented on the present
architecture.
- EPERM
-
Saved kernel stack exists.
(This is a kernel sanity check; the saved
stack should exist only within vm86 mode itself.)
STANDARDS
This call is specific to Linux on 32-bit Intel processors,
and should not be used in programs intended to be portable.
Index
- NAME
-
- LIBRARY
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- STANDARDS
-
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Time: 01:45:11 GMT, March 29, 2024