vm86bios.s revision 37889
134840Sjlemon/*- 234840Sjlemon * Copyright (c) 1998 Jonathan Lemon 334840Sjlemon * All rights reserved. 434840Sjlemon * 534840Sjlemon * Redistribution and use in source and binary forms, with or without 634840Sjlemon * modification, are permitted provided that the following conditions 734840Sjlemon * are met: 834840Sjlemon * 1. Redistributions of source code must retain the above copyright 934840Sjlemon * notice, this list of conditions and the following disclaimer. 1034840Sjlemon * 2. Redistributions in binary form must reproduce the above copyright 1134840Sjlemon * notice, this list of conditions and the following disclaimer in the 1234840Sjlemon * documentation and/or other materials provided with the distribution. 1334840Sjlemon * 1434840Sjlemon * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1534840Sjlemon * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1634840Sjlemon * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1734840Sjlemon * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1834840Sjlemon * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1934840Sjlemon * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2034840Sjlemon * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2134840Sjlemon * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2234840Sjlemon * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2334840Sjlemon * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2434840Sjlemon * SUCH DAMAGE. 2534840Sjlemon * 2637889Sjlemon * $Id: vm86bios.s,v 1.2 1998/03/24 16:51:36 jlemon Exp $ 2734840Sjlemon */ 2834840Sjlemon 2934840Sjlemon#include "opt_vm86.h" 3034840Sjlemon 3134840Sjlemon#include <machine/asmacros.h> /* miscellaneous asm macros */ 3234840Sjlemon#include <machine/trap.h> 3334840Sjlemon 3434840Sjlemon#include "assym.s" 3534840Sjlemon 3637889Sjlemon#define SCR_NEWPTD PCB_ESI /* readability macros */ 3737889Sjlemon#define SCR_VMFRAME PCB_EBP /* see vm86.c for explanation */ 3837889Sjlemon#define SCR_STACK PCB_ESP 3937889Sjlemon#define SCR_PGTABLE PCB_EBX 4037889Sjlemon#define SCR_ARGFRAME PCB_EIP 4137889Sjlemon#define SCR_TSS0 PCB_FS 4237889Sjlemon#define SCR_TSS1 PCB_GS 4337889Sjlemon 4434840Sjlemon .data 4534840Sjlemon ALIGN_DATA 4634840Sjlemon 4734840Sjlemon .globl _in_vm86call, _vm86pcb 4834840Sjlemon 4934840Sjlemon_in_vm86call: .long 0 5034840Sjlemon_vm86pcb: .long 0 5134840Sjlemon 5234840Sjlemon .text 5334840Sjlemon 5434840Sjlemon/* 5534840Sjlemon * vm86_bioscall(struct trapframe_vm86 *vm86) 5634840Sjlemon */ 5734840SjlemonENTRY(vm86_bioscall) 5837889Sjlemon movl _vm86pcb,%edx /* scratch data area */ 5934840Sjlemon movl 4(%esp),%eax 6037889Sjlemon movl %eax,SCR_ARGFRAME(%edx) /* save argument pointer */ 6134840Sjlemon pushl %ebx 6234840Sjlemon pushl %ebp 6334840Sjlemon pushl %esi 6434840Sjlemon pushl %edi 6534840Sjlemon pushl %fs 6634840Sjlemon pushl %gs 6734840Sjlemon 6834840Sjlemon#ifdef SMP 6934840Sjlemon pushl %edx 7034840Sjlemon ALIGN_LOCK /* Get global lock */ 7134840Sjlemon popl %edx 7234840Sjlemon#endif 7334840Sjlemon movl _curproc,%ecx 7434840Sjlemon pushl %ecx /* save _curproc value */ 7534840Sjlemon testl %ecx,%ecx 7634840Sjlemon je 1f /* no process to save */ 7734840Sjlemon 7834840Sjlemon#if NNPX > 0 7934840Sjlemon cmpl %ecx,_npxproc /* do we need to save fp? */ 8034840Sjlemon jne 1f 8134840Sjlemon movl P_ADDR(%ecx),%ecx 8234840Sjlemon addl $PCB_SAVEFPU,%ecx 8334840Sjlemon pushl %edx 8434840Sjlemon call _npxsave 8534840Sjlemon popl %edx /* recover our pcb */ 8634840Sjlemon#endif 8734840Sjlemon 8834840Sjlemon1: 8937889Sjlemon movl SCR_VMFRAME(%edx),%ebx /* target frame location */ 9034840Sjlemon movl %ebx,%edi /* destination */ 9137889Sjlemon movl SCR_ARGFRAME(%edx),%esi /* source (set on entry) */ 9234840Sjlemon movl $21,%ecx /* sizeof(struct vm86frame)/4 */ 9334840Sjlemon cld 9434840Sjlemon rep 9534840Sjlemon movsl /* copy frame to new stack */ 9634840Sjlemon 9734840Sjlemon movl TF_TRAPNO(%ebx),%ebx 9834840Sjlemon cmpl $256,%ebx 9934840Sjlemon jb 1f /* no page frame to map */ 10034840Sjlemon 10134840Sjlemon andl $~PAGE_MASK,%ebx 10234840Sjlemon#if 0 10334840Sjlemon orl $PG_V|PG_RW|PG_U,%ebx /* XXX assembler error?? */ 10434840Sjlemon#endif 10534840Sjlemon orl $0x7,%ebx 10637889Sjlemon movl SCR_PGTABLE(%edx),%eax /* va of vm86 page table */ 10734840Sjlemon movl %ebx,4(%eax) /* set vm86 PTE entry 1 */ 10834840Sjlemon1: 10934840Sjlemon movl _curpcb,%eax 11034840Sjlemon pushl %eax /* save curpcb */ 11134840Sjlemon movl %edx,_curpcb /* set curpcb to vm86pcb */ 11234840Sjlemon movl $0,_curproc /* erase curproc */ 11334840Sjlemon 11434840Sjlemon movl _my_tr,%esi 11534840Sjlemon leal _gdt(,%esi,8),%ebx /* entry in GDT */ 11634840Sjlemon movl 0(%ebx),%eax 11737889Sjlemon movl %eax,SCR_TSS0(%edx) /* save first word */ 11834840Sjlemon movl 4(%ebx),%eax 11934840Sjlemon andl $~0x200, %eax /* flip 386BSY -> 386TSS */ 12037889Sjlemon movl %eax,SCR_TSS1(%edx) /* save second word */ 12134840Sjlemon 12234840Sjlemon movl PCB_EXT(%edx),%edi /* vm86 tssd entry */ 12334840Sjlemon movl 0(%edi),%eax 12434840Sjlemon movl %eax,0(%ebx) 12534840Sjlemon movl 4(%edi),%eax 12634840Sjlemon movl %eax,4(%ebx) 12734840Sjlemon shll $3,%esi /* GSEL(entry, SEL_KPL) */ 12834840Sjlemon ltr %si 12934840Sjlemon 13034840Sjlemon movl %cr3,%eax 13134840Sjlemon pushl %eax /* save address space */ 13234840Sjlemon#ifdef SMP 13334840Sjlemon movl _my_idlePTD,%ecx 13434840Sjlemon#else 13534840Sjlemon movl _IdlePTD,%ecx 13634840Sjlemon#endif 13734840Sjlemon movl %ecx,%ebx 13834840Sjlemon addl $KERNBASE,%ebx /* va of Idle PTD */ 13934840Sjlemon movl 0(%ebx),%eax 14034840Sjlemon pushl %eax /* old ptde != 0 when booting */ 14134840Sjlemon pushl %ebx /* keep for reuse */ 14234840Sjlemon 14337889Sjlemon movl %esp,SCR_STACK(%edx) /* save current stack location */ 14434840Sjlemon 14537889Sjlemon movl SCR_NEWPTD(%edx),%eax /* mapping for vm86 page table */ 14634840Sjlemon movl %eax,0(%ebx) /* ... install as PTD entry 0 */ 14734840Sjlemon 14834840Sjlemon movl %ecx,%cr3 /* new page tables */ 14937889Sjlemon movl SCR_VMFRAME(%edx),%esp /* switch to new stack */ 15034840Sjlemon 15134840Sjlemon call _vm86_prepcall /* finish setup */ 15234840Sjlemon 15334840Sjlemon movl $1,_in_vm86call /* set flag for trap() */ 15434840Sjlemon 15534840Sjlemon /* 15634840Sjlemon * Return via _doreti 15734840Sjlemon */ 15834840Sjlemon#ifdef SMP 15934840Sjlemon ECPL_LOCK 16034840Sjlemon#ifdef CPL_AND_CML 16134840Sjlemon#error Not ready for CPL_AND_CML 16234840Sjlemon#endif 16334840Sjlemon pushl _cpl /* cpl to restore */ 16434840Sjlemon ECPL_UNLOCK 16534840Sjlemon#else 16634840Sjlemon pushl _cpl /* cpl to restore */ 16734840Sjlemon#endif 16834840Sjlemon subl $4,%esp /* dummy unit */ 16934840Sjlemon MPLOCKED incb _intr_nesting_level 17034840Sjlemon MEXITCOUNT 17134840Sjlemon jmp _doreti 17234840Sjlemon 17334840Sjlemon 17434840Sjlemon/* 17534840Sjlemon * vm86_biosret(struct trapframe_vm86 *vm86) 17634840Sjlemon */ 17734840SjlemonENTRY(vm86_biosret) 17834840Sjlemon movl _vm86pcb,%edx /* data area */ 17934840Sjlemon 18034840Sjlemon movl 4(%esp),%esi /* source */ 18137889Sjlemon movl SCR_ARGFRAME(%edx),%edi /* destination */ 18234840Sjlemon movl $21,%ecx /* size */ 18334840Sjlemon cld 18434840Sjlemon rep 18534840Sjlemon movsl /* copy frame to original frame */ 18634840Sjlemon 18737889Sjlemon movl SCR_STACK(%edx),%esp /* back to old stack */ 18834840Sjlemon popl %ebx /* saved va of Idle PTD */ 18934840Sjlemon popl %eax 19034840Sjlemon movl %eax,0(%ebx) /* restore old pte */ 19134840Sjlemon popl %eax 19234840Sjlemon movl %eax,%cr3 /* install old page table */ 19334840Sjlemon 19434840Sjlemon movl $0,_in_vm86call /* reset trapflag */ 19537889Sjlemon movl SCR_PGTABLE(%edx),%ebx /* va of vm86 page table */ 19634840Sjlemon movl $0,4(%ebx) /* ...clear entry 1 */ 19734840Sjlemon 19834840Sjlemon movl _my_tr,%esi 19934840Sjlemon leal _gdt(,%esi,8),%ebx /* entry in GDT */ 20037889Sjlemon movl SCR_TSS0(%edx),%eax 20134840Sjlemon movl %eax,0(%ebx) /* restore first word */ 20237889Sjlemon movl SCR_TSS1(%edx),%eax 20334840Sjlemon movl %eax,4(%ebx) /* restore second word */ 20434840Sjlemon shll $3,%esi /* GSEL(entry, SEL_KPL) */ 20534840Sjlemon ltr %si 20634840Sjlemon 20734840Sjlemon popl _curpcb /* restore curpcb/curproc */ 20834840Sjlemon popl _curproc 20937889Sjlemon movl SCR_ARGFRAME(%edx),%edx /* original stack frame */ 21034840Sjlemon movl TF_TRAPNO(%edx),%eax /* return (trapno) */ 21134840Sjlemon 21234840Sjlemon popl %gs 21334840Sjlemon popl %fs 21434840Sjlemon popl %edi 21534840Sjlemon popl %esi 21634840Sjlemon popl %ebp 21734840Sjlemon popl %ebx 21834840Sjlemon ret /* back to our normal program */ 219