1/*- 2 * Copyright (c) 1998 Jonathan Lemon 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD$ 27 */ 28 29#include <machine/asmacros.h> /* miscellaneous asm macros */ 30#include <machine/trap.h> 31 32#include "assym.s" 33 34#define SCR_NEWPTD PCB_ESI /* readability macros */ 35#define SCR_VMFRAME PCB_EBP /* see vm86.c for explanation */ 36#define SCR_STACK PCB_ESP 37#define SCR_PGTABLE PCB_EBX 38#define SCR_ARGFRAME PCB_EIP 39#define SCR_TSS0 PCB_VM86 40#define SCR_TSS1 (PCB_VM86+4) 41 42 .data 43 ALIGN_DATA 44 45 .globl vm86pcb 46 47vm86pcb: .long 0 48 49 .text 50 51/* 52 * vm86_bioscall(struct trapframe_vm86 *vm86) 53 */ 54ENTRY(vm86_bioscall) 55 movl vm86pcb,%edx /* scratch data area */ 56 movl 4(%esp),%eax 57 movl %eax,SCR_ARGFRAME(%edx) /* save argument pointer */ 58 pushl %ebx 59 pushl %ebp 60 pushl %esi 61 pushl %edi 62 pushl %gs 63 64 movl PCPU(CURTHREAD),%ecx 65 cmpl %ecx,PCPU(FPCURTHREAD) /* do we need to save fp? */ 66 jne 1f 67 pushl %edx 68 movl TD_PCB(%ecx),%ecx 69 pushl PCB_SAVEFPU(%ecx) 70 call npxsave 71 addl $4,%esp 72 popl %edx /* recover our pcb */ 731: 74 movl SCR_VMFRAME(%edx),%ebx /* target frame location */ 75 movl %ebx,%edi /* destination */ 76 movl SCR_ARGFRAME(%edx),%esi /* source (set on entry) */ 77 movl $VM86_FRAMESIZE/4,%ecx /* sizeof(struct vm86frame)/4 */ 78 cld 79 rep 80 movsl /* copy frame to new stack */ 81 82 movl PCPU(CURPCB),%eax 83 pushl %eax /* save curpcb */ 84 movl %edx,PCPU(CURPCB) /* set curpcb to vm86pcb */ 85 86 movl PCPU(TSS_GDT),%ebx /* entry in GDT */ 87 movl 0(%ebx),%eax 88 movl %eax,SCR_TSS0(%edx) /* save first word */ 89 movl 4(%ebx),%eax 90 andl $~0x200, %eax /* flip 386BSY -> 386TSS */ 91 movl %eax,SCR_TSS1(%edx) /* save second word */ 92 93 movl PCB_EXT(%edx),%edi /* vm86 tssd entry */ 94 movl 0(%edi),%eax 95 movl %eax,0(%ebx) 96 movl 4(%edi),%eax 97 movl %eax,4(%ebx) 98 movl $GPROC0_SEL*8,%esi /* GSEL(entry, SEL_KPL) */ 99 ltr %si 100 101 movl %cr3,%eax 102 pushl %eax /* save address space */ 103 movl IdlePTD,%ecx 104 movl %ecx,%ebx 105 addl $KERNBASE,%ebx /* va of Idle PTD */ 106 movl 0(%ebx),%eax 107 pushl %eax /* old ptde != 0 when booting */ 108 pushl %ebx /* keep for reuse */ 109 110 movl %esp,SCR_STACK(%edx) /* save current stack location */ 111 112 movl SCR_NEWPTD(%edx),%eax /* mapping for vm86 page table */ 113 movl %eax,0(%ebx) /* ... install as PTD entry 0 */ 114 115#if defined(PAE) || defined(PAE_TABLES) 116 movl IdlePDPT,%ecx 117#endif 118 movl %ecx,%cr3 /* new page tables */ 119 movl SCR_VMFRAME(%edx),%esp /* switch to new stack */ 120 121 pushl %esp 122 call vm86_prepcall /* finish setup */ 123 add $4, %esp 124 125 /* 126 * Return via doreti 127 */ 128 MEXITCOUNT 129 jmp doreti 130 131 132/* 133 * vm86_biosret(struct trapframe_vm86 *vm86) 134 */ 135ENTRY(vm86_biosret) 136 movl vm86pcb,%edx /* data area */ 137 138 movl 4(%esp),%esi /* source */ 139 movl SCR_ARGFRAME(%edx),%edi /* destination */ 140 movl $VM86_FRAMESIZE/4,%ecx /* size */ 141 cld 142 rep 143 movsl /* copy frame to original frame */ 144 145 movl SCR_STACK(%edx),%esp /* back to old stack */ 146 popl %ebx /* saved va of Idle PTD */ 147 popl %eax 148 movl %eax,0(%ebx) /* restore old pte */ 149 popl %eax 150 movl %eax,%cr3 /* install old page table */ 151 152 movl PCPU(TSS_GDT),%ebx /* entry in GDT */ 153 movl SCR_TSS0(%edx),%eax 154 movl %eax,0(%ebx) /* restore first word */ 155 movl SCR_TSS1(%edx),%eax 156 movl %eax,4(%ebx) /* restore second word */ 157 movl $GPROC0_SEL*8,%esi /* GSEL(entry, SEL_KPL) */ 158 ltr %si 159 160 popl PCPU(CURPCB) /* restore curpcb/curproc */ 161 movl SCR_ARGFRAME(%edx),%edx /* original stack frame */ 162 movl TF_TRAPNO(%edx),%eax /* return (trapno) */ 163 164 popl %gs 165 popl %edi 166 popl %esi 167 popl %ebp 168 popl %ebx 169 ret /* back to our normal program */ 170