| /* |
| * 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( (PVOID)&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) |
| { |
| DWORD addr = except->ExceptionRecord->ExceptionInformation[1]; |
| if (addr >= (ULONG_PTR)DOSMEM_dosmem + DOSMEM_protect && |
| addr < (ULONG_PTR)DOSMEM_dosmem + DOSMEM_SIZE) |
| { |
| if (load_winedos()) return EXCEPTION_CONTINUE_EXECUTION; |
| } |
| } |
| return EXCEPTION_CONTINUE_SEARCH; |
| } |
| |
| /********************************************************************** |
| * setup_dos_mem |
| * |
| * Setup the first megabyte for DOS memory access |
| */ |
| static char* setup_dos_mem(void) |
| { |
| int sys_offset = 0; |
| int page_size = getpagesize(); |
| void *addr = NULL; |
| |
| if (wine_mmap_is_in_reserved_area( NULL, DOSMEM_SIZE ) != 1) |
| { |
| addr = wine_anon_mmap( (void *)page_size, DOSMEM_SIZE-page_size, |
| PROT_READ | PROT_WRITE, 0 ); |
| if (addr == (void *)page_size) addr = NULL; /* we got what we wanted */ |
| else munmap( addr, DOSMEM_SIZE - page_size ); |
| } |
| |
| if (!addr) |
| { |
| /* now reserve from address 0 */ |
| wine_anon_mmap( NULL, DOSMEM_SIZE, PROT_NONE, MAP_FIXED ); |
| |
| /* inform the memory manager that there is a mapping here, but don't commit yet */ |
| VirtualAlloc( NULL, DOSMEM_SIZE, MEM_RESERVE | MEM_SYSTEM, PAGE_NOACCESS ); |
| sys_offset = 0xf0000; |
| DOSMEM_protect = DOSMEM_64KB; |
| } |
| else |
| { |
| ERR("Cannot use first megabyte for DOS address space, please report\n" ); |
| /* allocate the DOS area somewhere else */ |
| addr = VirtualAlloc( NULL, DOSMEM_SIZE, MEM_RESERVE, PAGE_NOACCESS ); |
| if (!addr) |
| { |
| ERR( "Cannot allocate DOS memory\n" ); |
| ExitProcess(1); |
| } |
| } |
| DOSMEM_dosmem = addr; |
| RtlAddVectoredExceptionHandler(FALSE, dosmem_handler); |
| return (char*)addr + sys_offset; |
| } |
| |
| |
| /*********************************************************************** |
| * DOSMEM_Init |
| * |
| * Create the dos memory segments, and store them into the KERNEL |
| * exported values. |
| */ |
| BOOL DOSMEM_Init(void) |
| { |
| char* sysmem = setup_dos_mem(); |
| |
| 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; |
| } |
