4 * Copyright 1995 Alexandre Julliard
5 * Copyright 1996 Marcus Meissner
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include "wine/port.h"
29 #include <sys/types.h>
30 #ifdef HAVE_SYS_MMAN_H
31 # include <sys/mman.h>
38 #include "wine/winbase16.h"
40 #include "kernel_private.h"
42 #include "wine/debug.h"
44 WINE_DEFAULT_DEBUG_CHANNEL(dosmem
);
45 WINE_DECLARE_DEBUG_CHANNEL(selector
);
47 WORD DOSMEM_0000H
; /* segment at 0:0 */
48 WORD DOSMEM_BiosDataSeg
; /* BIOS data segment at 0x40:0 */
49 WORD DOSMEM_BiosSysSeg
; /* BIOS ROM segment at 0xf000:0 */
51 /* DOS memory highest address (including HMA) */
52 #define DOSMEM_SIZE 0x110000
53 #define DOSMEM_64KB 0x10000
55 /* when looking at DOS and real mode memory, we activate in three different
56 * modes, depending the situation.
57 * 1/ By default (protected mode), the first MB of memory (actually 0x110000,
58 * when you also look at the HMA part) is always reserved, whatever you do.
59 * We allocated some PM selectors to this memory, even if this area is not
60 * committed at startup
61 * 2/ if a program tries to use the memory through the selectors, we actually
62 * commit this memory, made of: BIOS segment, but also some system
63 * information, usually low in memory that we map for the circumstance also
64 * in the BIOS segment, so that we keep the low memory protected (for NULL
65 * pointer deref catching for example). In this case, we're still in PM
66 * mode, accessing part of the "physical" real mode memory. In fact, we don't
67 * map all the first meg, we keep 64k uncommitted to still catch NULL
68 * pointers dereference
69 * 3/ if the process enters the real mode, then we (also) commit the full first
70 * MB of memory (and also initialize the DOS structures in it).
73 /* DOS memory base (linear in process address space) */
74 static char *DOSMEM_dosmem
;
75 /* number of bytes protected from _dosmem. 0 when DOS memory is initialized,
76 * 64k otherwise to trap NULL pointers deref */
77 static DWORD DOSMEM_protect
;
79 static LONG WINAPI
dosmem_handler(EXCEPTION_POINTERS
* except
);
81 struct winedos_exports winedos
;
83 BOOL
load_winedos(void)
85 static HANDLE hRunOnce
/* = 0 */;
86 static HMODULE hWineDos
/* = 0 */;
88 /* FIXME: this isn't 100% thread safe, as we won't catch access to 1MB while
89 * loading winedos (and may return uninitialized valued)
91 if (hWineDos
) goto done
;
94 HANDLE hEvent
= CreateEventW( NULL
, TRUE
, FALSE
, NULL
);
95 if (InterlockedCompareExchangePointer( (PVOID
)&hRunOnce
, hEvent
, 0 ) == 0)
99 /* ok, we're the winning thread */
100 if (!VirtualProtect( DOSMEM_dosmem
+ DOSMEM_protect
,
101 DOSMEM_SIZE
- DOSMEM_protect
,
102 PAGE_EXECUTE_READWRITE
, NULL
) ||
103 !(hModule
= LoadLibraryA( "winedos.dll" )))
105 ERR("Could not load winedos.dll, DOS subsystem unavailable\n");
106 hModule
= (HMODULE
)1; /* not to try to load it again */
110 #define GET_ADDR(func) winedos.func = (void *)GetProcAddress( hModule, #func );
111 GET_ADDR(AllocDosBlock
);
112 GET_ADDR(FreeDosBlock
);
113 GET_ADDR(ResizeDosBlock
);
116 GET_ADDR(EmulateInterruptPM
);
117 GET_ADDR(CallBuiltinHandler
);
121 RtlRemoveVectoredExceptionHandler( dosmem_handler
);
123 SetEvent( hRunOnce
);
126 /* someone beat us here... */
127 CloseHandle( hEvent
);
130 /* and wait for the winner to have finished */
131 WaitForSingleObject( hRunOnce
, INFINITE
);
133 return (hWineDos
!= (HMODULE
)1);
136 /******************************************************************
139 * Handler to catch access to our 1MB address space reserved for real memory
141 static LONG WINAPI
dosmem_handler(EXCEPTION_POINTERS
* except
)
143 if (except
->ExceptionRecord
->ExceptionCode
== EXCEPTION_ACCESS_VIOLATION
)
145 DWORD addr
= except
->ExceptionRecord
->ExceptionInformation
[1];
146 if (addr
>= (ULONG_PTR
)DOSMEM_dosmem
+ DOSMEM_protect
&&
147 addr
< (ULONG_PTR
)DOSMEM_dosmem
+ DOSMEM_SIZE
)
149 if (load_winedos()) return EXCEPTION_CONTINUE_EXECUTION
;
152 return EXCEPTION_CONTINUE_SEARCH
;
155 /**********************************************************************
158 * Setup the first megabyte for DOS memory access
160 static char* setup_dos_mem(void)
163 int page_size
= getpagesize();
166 if (wine_mmap_is_in_reserved_area( NULL
, DOSMEM_SIZE
) != 1)
168 addr
= wine_anon_mmap( (void *)page_size
, DOSMEM_SIZE
-page_size
,
169 PROT_READ
| PROT_WRITE
| PROT_EXEC
, 0 );
170 if (addr
== (void *)page_size
) addr
= NULL
; /* we got what we wanted */
171 else munmap( addr
, DOSMEM_SIZE
- page_size
);
176 /* now reserve from address 0 */
177 wine_anon_mmap( NULL
, DOSMEM_SIZE
, 0, MAP_FIXED
);
179 /* inform the memory manager that there is a mapping here, but don't commit yet */
180 VirtualAlloc( NULL
, DOSMEM_SIZE
, MEM_RESERVE
| MEM_SYSTEM
, PAGE_NOACCESS
);
181 sys_offset
= 0xf0000;
182 DOSMEM_protect
= DOSMEM_64KB
;
186 ERR("Cannot use first megabyte for DOS address space, please report\n" );
187 /* allocate the DOS area somewhere else */
188 addr
= VirtualAlloc( NULL
, DOSMEM_SIZE
, MEM_RESERVE
, PAGE_NOACCESS
);
191 ERR( "Cannot allocate DOS memory\n" );
195 DOSMEM_dosmem
= addr
;
196 RtlAddVectoredExceptionHandler(FALSE
, dosmem_handler
);
197 return (char*)addr
+ sys_offset
;
201 /***********************************************************************
204 * Create the dos memory segments, and store them into the KERNEL
207 BOOL
DOSMEM_Init(void)
209 char* sysmem
= setup_dos_mem();
211 DOSMEM_0000H
= GLOBAL_CreateBlock( GMEM_FIXED
, sysmem
,
212 DOSMEM_64KB
, 0, WINE_LDT_FLAGS_DATA
);
213 DOSMEM_BiosDataSeg
= GLOBAL_CreateBlock( GMEM_FIXED
, sysmem
+ 0x400,
214 0x100, 0, WINE_LDT_FLAGS_DATA
);
215 DOSMEM_BiosSysSeg
= GLOBAL_CreateBlock( GMEM_FIXED
, DOSMEM_dosmem
+ 0xf0000,
216 DOSMEM_64KB
, 0, WINE_LDT_FLAGS_DATA
);
221 /***********************************************************************
222 * DOSMEM_MapLinearToDos
224 * Linear address to the DOS address space.
226 UINT
DOSMEM_MapLinearToDos(LPVOID ptr
)
228 if (((char*)ptr
>= DOSMEM_dosmem
) &&
229 ((char*)ptr
< DOSMEM_dosmem
+ DOSMEM_SIZE
))
230 return (char *)ptr
- DOSMEM_dosmem
;
235 /***********************************************************************
236 * DOSMEM_MapDosToLinear
238 * DOS linear address to the linear address space.
240 LPVOID
DOSMEM_MapDosToLinear(UINT ptr
)
242 if (ptr
< DOSMEM_SIZE
) return DOSMEM_dosmem
+ ptr
;
247 /***********************************************************************
248 * DOSMEM_MapRealToLinear
250 * Real mode DOS address into a linear pointer
252 LPVOID
DOSMEM_MapRealToLinear(DWORD x
)
256 lin
= DOSMEM_dosmem
+ HIWORD(x
) * 16 + LOWORD(x
);
257 TRACE_(selector
)("(0x%08lx) returns %p.\n", x
, lin
);