projects / thirdparty / man-pages.git / blame
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|---|---|---|
| fea681da MK |
1 | .\" Copyright 1993 Rickard E. Faith (faith@cs.unc.edu) |
| 2 | .\" Copyright 1997 Andries E. Brouwer (aeb@cwi.nl) | |
| 3 | .\" | |
| 5fbde956 | 4 | .\" SPDX-License-Identifier: Linux-man-pages-copyleft |
| fea681da | 5 | .\" |
| 1d767b55 | 6 | .TH VM86 2 2021-03-22 "Linux" "Linux Programmer's Manual" |
| fea681da MK |
7 | .SH NAME |
| 8 | vm86old, vm86 \- enter virtual 8086 mode | |
| 013cbe85 AC |
9 | .SH LIBRARY |
| 10 | Standard C library | |
| 8fc3b2cf | 11 | .RI ( libc ", " \-lc ) |
| fea681da | 12 | .SH SYNOPSIS |
| 511bb71b | 13 | .nf |
| fea681da | 14 | .B #include <sys/vm86.h> |
| 68e4db0a | 15 | .PP |
| fea681da | 16 | .BI "int vm86old(struct vm86_struct *" info ); |
| fea681da | 17 | .BI "int vm86(unsigned long " fn ", struct vm86plus_struct *" v86 ); |
| 511bb71b | 18 | .fi |
| fea681da MK |
19 | .SH DESCRIPTION |
| 20 | The system call | |
| e511ffb6 | 21 | .BR vm86 () |
| c13182ef | 22 | was introduced in Linux 0.97p2. |
| 11b520ed | 23 | In Linux 2.1.15 and 2.0.28, it was renamed to |
| e511ffb6 | 24 | .BR vm86old (), |
| fea681da | 25 | and a new |
| e511ffb6 | 26 | .BR vm86 () |
| c13182ef | 27 | was introduced. |
| c9942389 MK |
28 | The definition of |
| 29 | .IR "struct vm86_struct" | |
| 30 | was changed | |
| fea681da | 31 | in 1.1.8 and 1.1.9. |
| dd3568a1 | 32 | .PP |
| fea681da | 33 | These calls cause the process to enter VM86 mode (virtual-8086 in Intel |
| c13182ef | 34 | literature), and are used by |
| fea681da MK |
35 | .BR dosemu . |
| 36 | .PP | |
| 37 | VM86 mode is an emulation of real mode within a protected mode task. | |
| 47297adb | 38 | .SH RETURN VALUE |
| c13182ef MK |
39 | On success, zero is returned. |
| 40 | On error, \-1 is returned, and | |
| fea681da | 41 | .I errno |
| f6a4078b | 42 | is set to indicate the error. |
| fea681da MK |
43 | .SH ERRORS |
| 44 | .TP | |
| 45 | .B EFAULT | |
| 46 | This return value is specific to i386 and indicates a problem with getting | |
| 7fac88a9 | 47 | user-space data. |
| fea681da MK |
48 | .TP |
| 49 | .B ENOSYS | |
| 50 | This return value indicates the call is not implemented on the present | |
| 51 | architecture. | |
| 52 | .TP | |
| 53 | .B EPERM | |
| c13182ef MK |
54 | Saved kernel stack exists. |
| 55 | (This is a kernel sanity check; the saved | |
| 33a0ccb2 | 56 | stack should exist only within vm86 mode itself.) |
| 47297adb | 57 | .SH CONFORMING TO |
| 6dd57cb4 PW |
58 | This call is specific to Linux on 32-bit Intel processors, |
| 59 | and should not be used in programs intended to be portable. |