wine/dlls/kernel32/dosmem.c
2009-03-11 13:03:31 +01:00

237 lines
7.7 KiB
C

/*
* DOS memory emulation
*
* Copyright 1995 Alexandre Julliard
* Copyright 1996 Marcus Meissner
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include "config.h"
#include "wine/port.h"
#include <signal.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#ifdef HAVE_SYS_MMAN_H
# include <sys/mman.h>
#endif
#include "windef.h"
#include "winbase.h"
#include "excpt.h"
#include "winternl.h"
#include "wine/winbase16.h"
#include "kernel_private.h"
#include "toolhelp.h"
#include "wine/debug.h"
WINE_DEFAULT_DEBUG_CHANNEL(dosmem);
WINE_DECLARE_DEBUG_CHANNEL(selector);
WORD DOSMEM_0000H; /* segment at 0:0 */
WORD DOSMEM_BiosDataSeg; /* BIOS data segment at 0x40:0 */
WORD DOSMEM_BiosSysSeg; /* BIOS ROM segment at 0xf000:0 */
/* DOS memory highest address (including HMA) */
#define DOSMEM_SIZE 0x110000
#define DOSMEM_64KB 0x10000
/* when looking at DOS and real mode memory, we activate in three different
* modes, depending the situation.
* 1/ By default (protected mode), the first MB of memory (actually 0x110000,
* when you also look at the HMA part) is always reserved, whatever you do.
* We allocated some PM selectors to this memory, even if this area is not
* committed at startup
* 2/ if a program tries to use the memory through the selectors, we actually
* commit this memory, made of: BIOS segment, but also some system
* information, usually low in memory that we map for the circumstance also
* in the BIOS segment, so that we keep the low memory protected (for NULL
* pointer deref catching for example). In this case, we're still in PM
* mode, accessing part of the "physical" real mode memory. In fact, we don't
* map all the first meg, we keep 64k uncommitted to still catch NULL
* pointers dereference
* 3/ if the process enters the real mode, then we (also) commit the full first
* MB of memory (and also initialize the DOS structures in it).
*/
/* DOS memory base (linear in process address space) */
static char *DOSMEM_dosmem;
/* number of bytes protected from _dosmem. 0 when DOS memory is initialized,
* 64k otherwise to trap NULL pointers deref */
static DWORD DOSMEM_protect;
static LONG WINAPI dosmem_handler(EXCEPTION_POINTERS* except);
struct winedos_exports winedos;
BOOL load_winedos(void)
{
static HANDLE hRunOnce /* = 0 */;
static HMODULE hWineDos /* = 0 */;
/* FIXME: this isn't 100% thread safe, as we won't catch access to 1MB while
* loading winedos (and may return uninitialized valued)
*/
if (hWineDos) goto done;
if (hRunOnce == 0)
{
HANDLE hEvent = CreateEventW( NULL, TRUE, FALSE, NULL );
if (InterlockedCompareExchangePointer( &hRunOnce, hEvent, 0 ) == 0)
{
HMODULE hModule;
/* ok, we're the winning thread */
if (!VirtualProtect( DOSMEM_dosmem + DOSMEM_protect,
DOSMEM_SIZE - DOSMEM_protect,
PAGE_READWRITE, NULL ) ||
!(hModule = LoadLibraryA( "winedos.dll" )))
{
ERR("Could not load winedos.dll, DOS subsystem unavailable\n");
hModule = (HMODULE)1; /* not to try to load it again */
}
else
{
#define GET_ADDR(func) winedos.func = (void *)GetProcAddress( hModule, #func );
GET_ADDR(AllocDosBlock);
GET_ADDR(FreeDosBlock);
GET_ADDR(ResizeDosBlock);
GET_ADDR(inport);
GET_ADDR(outport);
GET_ADDR(EmulateInterruptPM);
GET_ADDR(CallBuiltinHandler);
GET_ADDR(BiosTick);
#undef GET_ADDR
}
RtlRemoveVectoredExceptionHandler( dosmem_handler );
hWineDos = hModule;
SetEvent( hRunOnce );
goto done;
}
/* someone beat us here... */
CloseHandle( hEvent );
}
/* and wait for the winner to have finished */
WaitForSingleObject( hRunOnce, INFINITE );
done:
return (hWineDos != (HMODULE)1);
}
/******************************************************************
* dosmem_handler
*
* Handler to catch access to our 1MB address space reserved for real memory
*/
static LONG WINAPI dosmem_handler(EXCEPTION_POINTERS* except)
{
if (except->ExceptionRecord->ExceptionCode == EXCEPTION_ACCESS_VIOLATION)
{
char *addr = (char *)except->ExceptionRecord->ExceptionInformation[1];
if (addr >= DOSMEM_dosmem + DOSMEM_protect && addr < DOSMEM_dosmem + DOSMEM_SIZE)
{
if (load_winedos()) return EXCEPTION_CONTINUE_EXECUTION;
}
}
return EXCEPTION_CONTINUE_SEARCH;
}
/***********************************************************************
* DOSMEM_Init
*
* Create the dos memory segments, and store them into the KERNEL
* exported values.
*/
BOOL DOSMEM_Init(void)
{
char *sysmem;
void *addr = (void *)1;
SIZE_T size = DOSMEM_SIZE - 1;
if (NtAllocateVirtualMemory( GetCurrentProcess(), &addr, 0, &size,
MEM_RESERVE | MEM_COMMIT, PAGE_NOACCESS ))
{
ERR( "Cannot allocate DOS memory\n" );
ExitProcess(1);
}
if (addr <= (void *)DOSMEM_64KB)
{
DOSMEM_dosmem = 0;
DOSMEM_protect = DOSMEM_64KB;
sysmem = (char *)0xf0000; /* store sysmem in high addresses for now */
}
else
{
WARN( "First megabyte not available for DOS address space.\n" );
DOSMEM_dosmem = addr;
DOSMEM_protect = 0;
sysmem = DOSMEM_dosmem;
}
RtlAddVectoredExceptionHandler(FALSE, dosmem_handler);
DOSMEM_0000H = GLOBAL_CreateBlock( GMEM_FIXED, sysmem,
DOSMEM_64KB, 0, WINE_LDT_FLAGS_DATA );
DOSMEM_BiosDataSeg = GLOBAL_CreateBlock( GMEM_FIXED, sysmem + 0x400,
0x100, 0, WINE_LDT_FLAGS_DATA );
DOSMEM_BiosSysSeg = GLOBAL_CreateBlock( GMEM_FIXED, DOSMEM_dosmem + 0xf0000,
DOSMEM_64KB, 0, WINE_LDT_FLAGS_DATA );
return TRUE;
}
/***********************************************************************
* DOSMEM_MapLinearToDos
*
* Linear address to the DOS address space.
*/
UINT DOSMEM_MapLinearToDos(LPVOID ptr)
{
if (((char*)ptr >= DOSMEM_dosmem) &&
((char*)ptr < DOSMEM_dosmem + DOSMEM_SIZE))
return (char *)ptr - DOSMEM_dosmem;
return (UINT)ptr;
}
/***********************************************************************
* DOSMEM_MapDosToLinear
*
* DOS linear address to the linear address space.
*/
LPVOID DOSMEM_MapDosToLinear(UINT ptr)
{
if (ptr < DOSMEM_SIZE) return DOSMEM_dosmem + ptr;
return (LPVOID)ptr;
}
/***********************************************************************
* DOSMEM_MapRealToLinear
*
* Real mode DOS address into a linear pointer
*/
LPVOID DOSMEM_MapRealToLinear(DWORD x)
{
LPVOID lin;
lin = DOSMEM_dosmem + HIWORD(x) * 16 + LOWORD(x);
TRACE_(selector)("(0x%08x) returns %p.\n", x, lin );
return lin;
}