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.inc" 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 movl $npxsave,%eax 71 call *%eax 72 addl $4,%esp 73 popl %edx /* recover our pcb */ 741: 75 movl SCR_VMFRAME(%edx),%ebx /* target frame location */ 76 movl %ebx,%edi /* destination */ 77 movl SCR_ARGFRAME(%edx),%esi /* source (set on entry) */ 78 movl $VM86_FRAMESIZE/4,%ecx /* sizeof(struct vm86frame)/4 */ 79 cld 80 rep 81 movsl /* copy frame to new stack */ 82 83 movl PCPU(CURPCB),%eax 84 pushl %eax /* save curpcb */ 85 movl %edx,PCPU(CURPCB) /* set curpcb to vm86pcb */ 86 87 movl PCPU(TSS_GDT),%ebx /* entry in GDT */ 88 movl 0(%ebx),%eax 89 movl %eax,SCR_TSS0(%edx) /* save first word */ 90 movl 4(%ebx),%eax 91 andl $~0x200, %eax /* flip 386BSY -> 386TSS */ 92 movl %eax,SCR_TSS1(%edx) /* save second word */ 93 94 movl PCB_EXT(%edx),%edi /* vm86 tssd entry */ 95 movl 0(%edi),%eax 96 movl %eax,0(%ebx) 97 movl 4(%edi),%eax 98 movl %eax,4(%ebx) 99 movl $GPROC0_SEL*8,%esi /* GSEL(entry, SEL_KPL) */ 100 ltr %si 101 102 movl %cr3,%eax 103 pushl %eax /* save address space */ 104 cmpb $0,pae_mode 105 jne 2f 106 movl IdlePTD_nopae,%ecx /* va (and pa) of Idle PTD */ 107 jmp 3f 1082: movl IdlePTD_pae,%ecx 1093: movl %ecx,%ebx 110 movl 0(%ebx),%eax 111 pushl %eax /* old ptde != 0 when booting */ 112 pushl %ebx /* keep for reuse */ 113 114 movl %esp,SCR_STACK(%edx) /* save current stack location */ 115 116 movl SCR_NEWPTD(%edx),%eax /* mapping for vm86 page table */ 117 movl %eax,0(%ebx) /* ... install as PTD entry 0 */ 118 119 cmpb $0,pae_mode 120 je 4f 121 movl IdlePDPT,%ecx 1224: movl %ecx,%cr3 /* new page tables */ 123 movl SCR_VMFRAME(%edx),%esp /* switch to new stack */ 124 125 pushl %esp 126 movl $vm86_prepcall, %eax 127 call *%eax /* finish setup */ 128 add $4, %esp 129 130 /* 131 * Return via doreti 132 */ 133 jmp doreti 134 135 136/* 137 * vm86_biosret(struct trapframe_vm86 *vm86) 138 */ 139ENTRY(vm86_biosret) 140 movl vm86pcb,%edx /* data area */ 141 142 movl 4(%esp),%esi /* source */ 143 movl SCR_ARGFRAME(%edx),%edi /* destination */ 144 movl $VM86_FRAMESIZE/4,%ecx /* size */ 145 cld 146 rep 147 movsl /* copy frame to original frame */ 148 149 movl SCR_STACK(%edx),%esp /* back to old stack */ 150 popl %ebx /* saved va of Idle PTD */ 151 popl %eax 152 movl %eax,0(%ebx) /* restore old pte */ 153 popl %eax 154 movl %eax,%cr3 /* install old page table */ 155 156 movl PCPU(TSS_GDT),%ebx /* entry in GDT */ 157 movl SCR_TSS0(%edx),%eax 158 movl %eax,0(%ebx) /* restore first word */ 159 movl SCR_TSS1(%edx),%eax 160 movl %eax,4(%ebx) /* restore second word */ 161 movl $GPROC0_SEL*8,%esi /* GSEL(entry, SEL_KPL) */ 162 ltr %si 163 164 popl PCPU(CURPCB) /* restore curpcb/curproc */ 165 movl SCR_ARGFRAME(%edx),%edx /* original stack frame */ 166 movl TF_TRAPNO(%edx),%eax /* return (trapno) */ 167 168 popl %gs 169 popl %edi 170 popl %esi 171 popl %ebp 172 popl %ebx 173 ret /* back to our normal program */ 174