Name
vm86old, vm86 - enter virtual 8086 modeLibrary
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.)