2 # Copyright (c) 1998 Robert Nordier
5 # Redistribution and use in source and binary forms are freely
6 # permitted provided that the above copyright notice and this
7 # paragraph and the following disclaimer are duplicated in all
10 # This software is provided "AS IS" and without any express or
11 # implied warranties, including, without limitation, the implied
12 # warranties of merchantability and fitness for a particular
16 # $FreeBSD: src/sys/boot/i386/btx/lib/btxv86.s,v 1.3 1999/08/28 00:40:08 peter Exp $
17 # $DragonFly: src/sys/boot/pc32/btx/lib/btxv86.S,v 1.2 2003/06/17 04:28:18 dillon Exp $
28 # Fields in V86 interface structure.
30 .set V86_CTL,0x0 # Control flags
31 .set V86_ADDR,0x4 # Int number/address
32 .set V86_ES,0x8 # V86 ES
33 .set V86_DS,0xc # V86 DS
34 .set V86_FS,0x10 # V86 FS
35 .set V86_GS,0x14 # V86 GS
36 .set V86_EAX,0x18 # V86 EAX
37 .set V86_ECX,0x1c # V86 ECX
38 .set V86_EDX,0x20 # V86 EDX
39 .set V86_EBX,0x24 # V86 EBX
40 .set V86_EFL,0x28 # V86 eflags
41 .set V86_EBP,0x2c # V86 EBP
42 .set V86_ESI,0x30 # V86 ESI
43 .set V86_EDI,0x34 # V86 EDI
47 .set INT_V86,0x31 # Interrupt number
48 .set SIZ_V86,0x38 # Size of V86 structure
50 # V86 interface function.
52 __v86int: popl __v86ret # Save return address
53 pushl $__v86 # Push pointer
54 call __v86_swap # Load V86 registers
56 call __v86_swap # Load user registers
57 addl $0x4,%esp # Discard pointer
58 pushl __v86ret # Restore return address
61 # Swap V86 and user registers.
63 __v86_swap: xchgl %ebp,0x4(%esp,1) # Swap pointer, EBP
64 xchgl %eax,V86_EAX(%ebp) # Swap EAX
65 xchgl %ecx,V86_ECX(%ebp) # Swap ECX
66 xchgl %edx,V86_EDX(%ebp) # Swap EDX
67 xchgl %ebx,V86_EBX(%ebp) # Swap EBX
71 xchgl %eax,V86_EFL(%ebp) # Swap
74 movl 0x8(%esp,1),%eax # Load EBP
75 xchgl %eax,V86_EBP(%ebp) # Swap
76 movl %eax,0x8(%esp,1) # Save EBP
78 xchgl %esi,V86_ESI(%ebp) # Swap ESI
79 xchgl %edi,V86_EDI(%ebp) # Swap EDI
80 xchgl %ebp,0x4(%esp,1) # Swap pointer, EBP
83 # V86 interface structure.