reactos/msvc6/ntoskrnl/ke_i386_v86m_sup.c

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/*
* ReactOS kernel
* Copyright (C) 2000 David Welch <welch@cwcom.net>
*
* Moved to MSVC-compatible inline assembler by Mike Nordell, 2003-12-25
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* FILE: ntoskrnl/ke/i386/vm86_sup.S
* PURPOSE: V86 mode support
* PROGRAMMER: David Welch (welch@cwcom.net)
* UPDATE HISTORY:
* Created 09/10/00
*/
/* INCLUDES ******************************************************************/
#pragma hdrstop
#include <ddk/ntddk.h>
#include <ddk/status.h>
#include <internal/i386/segment.h>
#include <internal/i386/fpu.h>
#include <internal/ps.h>
#include <ddk/defines.h>
#include <internal/v86m.h>
#include <ntos/tss.h>
#include <internal/trap.h>
#include <internal/ps.h>
#include <roscfg.h>
#include <internal/ntoskrnl.h>
#include <internal/i386/segment.h>
#include <internal/ps.h>
// Taken from ntoskrnl/include/internal/v86m.h, since that one must be fixed
// a bit before it could be used from here.
#define KV86M_REGISTERS_EBP (0x0)
#define KV86M_REGISTERS_EDI (0x4)
#define KV86M_REGISTERS_ESI (0x8)
#define KV86M_REGISTERS_EDX (0xC)
#define KV86M_REGISTERS_ECX (0x10)
#define KV86M_REGISTERS_EBX (0x14)
#define KV86M_REGISTERS_EAX (0x18)
#define KV86M_REGISTERS_DS (0x1C)
#define KV86M_REGISTERS_ES (0x20)
#define KV86M_REGISTERS_FS (0x24)
#define KV86M_REGISTERS_GS (0x28)
#define KV86M_REGISTERS_EIP (0x2C)
#define KV86M_REGISTERS_CS (0x30)
#define KV86M_REGISTERS_EFLAGS (0x34)
#define KV86M_REGISTERS_ESP (0x38)
#define KV86M_REGISTERS_SS (0x3C)
void KiV86Complete();
/*
* Starts in v86 mode with the registers set to the
* specified values.
*/
__declspec(naked)
VOID Ki386RetToV86Mode(KV86M_REGISTERS* InRegs,
KV86M_REGISTERS* OutRegs)
{
__asm
{
/*
* Setup a stack frame
*/
push ebp
mov ebp, esp
pushad /* Save registers */
mov ebx, InRegs
/*
* Save ebp
*/
push ebp
/*
* Save a pointer to IN_REGS which the v86m exception handler will
* use to handle exceptions
*/
push ebx
/*
* Since we are going to fiddle with the stack pointer this must be
* a critical section for this processor
*/
/*
* Save the old initial stack
*/
mov esi, fs:KPCR_CURRENT_THREAD
mov edi, KTHREAD_INITIAL_STACK[esi]
push edi
/*
* We also need to set the stack in the kthread structure
*/
mov KTHREAD_INITIAL_STACK[esi], esp
/*
* The stack used for handling exceptions from v86 mode in this thread
* will be the current stack adjusted so we don't overwrite the
* existing stack frames
*/
mov esi, fs:KPCR_TSS
mov KTSS_ESP0[esi], esp
/*
* Create the stack frame for an iret to v86 mode
*/
push KV86M_REGISTERS_GS[ebx]
push KV86M_REGISTERS_FS[ebx]
push KV86M_REGISTERS_DS[ebx]
push KV86M_REGISTERS_ES[ebx]
push KV86M_REGISTERS_SS[ebx]
push KV86M_REGISTERS_ESP[ebx]
push KV86M_REGISTERS_EFLAGS[ebx]
push KV86M_REGISTERS_CS[ebx]
push KV86M_REGISTERS_EIP[ebx]
/*
* Setup the CPU registers
*/
mov eax, KV86M_REGISTERS_EAX[ebx]
mov ecx, KV86M_REGISTERS_ECX[ebx]
mov edx, KV86M_REGISTERS_EDX[ebx]
mov esi, KV86M_REGISTERS_ESI[ebx]
mov edi, KV86M_REGISTERS_EDI[ebx]
mov ebp, KV86M_REGISTERS_EBP[ebx]
mov ebx, KV86M_REGISTERS_EBX[ebx]
/*
* Go to v86 mode
*/
iretd
/*
* Handle the completion of a vm86 routine. We are called from
* an exception handler with the registers at the point of the
* exception on the stack.
*/
jmp KiV86Complete // TMN: Function-splitting
}
}
__declspec(naked)
void KiV86Complete()
{
__asm
{
/* Restore the original ebp */
mov ebp, TF_ORIG_EBP[esp]
/* Get a pointer to the OUT_REGS structure */
mov ebx, 12[ebp] // OutRegs
/* Skip debug information and unsaved registers */
add esp, 0x30
/* Ignore 32-bit segment registers */
add esp, 12
/* Save the vm86 registers into the OUT_REGS structure */
pop dword ptr KV86M_REGISTERS_EDX[ebx]
pop dword ptr KV86M_REGISTERS_ECX[ebx]
pop dword ptr KV86M_REGISTERS_EAX[ebx]
/* Restore the old previous mode */
pop eax
mov ss:KTHREAD_PREVIOUS_MODE[esi], al
/* Restore the old exception handler list */
pop eax
mov fs:KPCR_EXCEPTION_LIST, eax
/* Ignore the 32-bit fs register */
add esp, 4
pop dword ptr KV86M_REGISTERS_EDI[ebx]
pop dword ptr KV86M_REGISTERS_ESI[ebx]
pop dword ptr KV86M_REGISTERS_EBX[ebx]
pop dword ptr KV86M_REGISTERS_EBP[ebx]
/* Ignore error code */
add esp, 4
pop dword ptr KV86M_REGISTERS_EIP[ebx]
pop dword ptr KV86M_REGISTERS_CS[ebx]
pop dword ptr KV86M_REGISTERS_EFLAGS[ebx]
pop dword ptr KV86M_REGISTERS_ESP[ebx]
pop dword ptr KV86M_REGISTERS_SS[ebx]
pop dword ptr KV86M_REGISTERS_ES[ebx]
pop dword ptr KV86M_REGISTERS_DS[ebx]
pop dword ptr KV86M_REGISTERS_FS[ebx]
pop dword ptr KV86M_REGISTERS_GS[ebx]
/*
* We are going to fiddle with the stack so this must be a critical
* section for this process
*/
cli
/*
* Restore the initial stack
*/
pop eax
mov esi, fs:KPCR_TSS
mov KTSS_ESP0[esi], eax
/*
* We also need to set the stack in the kthread structure
*/
mov esi, fs:KPCR_CURRENT_THREAD
mov edi, KTHREAD_INITIAL_STACK[esi]
mov KTHREAD_INITIAL_STACK[esi], eax
/* Exit the critical section */
sti
/* Ignore IN_REGS pointer */
add esp, 4
/* Ignore ebp restored above */
add esp, 4
/* Return to caller */
popad
mov esp, ebp
pop ebp
ret
} // end of __asm block
}