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Reorganized DOS memory remapping slightly, so that the real-mode 

interrupt table can exist even when low DOS memory isn't mapped,
and is copied down along with the BIOS area whenever it is mapped.
Added DOSMEM_SystemBase() which returns a pointer to the virtual
real-mode interrupt table and BIOS data segment.
Allowed DOSMEM_Init(TRUE) to be called more than once.
This commit is contained in:
Ove Kaaven 2000-11-13 04:11:57 +00:00 committed by Alexandre Julliard
parent 27939f00fd
commit b27ee9b89d
2 changed files with 41 additions and 18 deletions
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1
include/miscemu.h
View File

@ -143,6 +143,7 @@ extern BOOL DOSMEM_Init(BOOL);
extern void DOSMEM_Tick(WORD timer);
extern WORD DOSMEM_AllocSelector(WORD);
extern char * DOSMEM_MemoryBase(void);
extern char * DOSMEM_SystemBase(void);
extern LPVOID DOSMEM_GetBlock(UINT size, WORD* p);
extern BOOL DOSMEM_FreeBlock(void* ptr);
extern LPVOID DOSMEM_ResizeBlock(void* ptr, UINT size, WORD* p);

58
msdos/dosmem.c
View File

@ -64,8 +64,11 @@ typedef struct {
/* DOS memory base */
static char *DOSMEM_dosmem;
/* bios area; normally at offset 0x400, but can be moved to trap NULL pointers */
static void *DOSMEM_biosdata;
/* DOS system base (for interrupt vector table and BIOS data area)
* ...should in theory (i.e. Windows) be equal to DOSMEM_dosmem (NULL),
* but is normally set to 0xf0000 in Wine to allow trapping of NULL pointers,
* and only relocated to NULL when absolutely necessary */
static char *DOSMEM_sysmem;
/* various real-mode code stubs */
WORD DOSMEM_wrap_seg;
@ -73,6 +76,16 @@ WORD DOSMEM_xms_seg;
WORD DOSMEM_dpmi_seg;
WORD DOSMEM_dpmi_sel;
/***********************************************************************
* DOSMEM_SystemBase
*
* Gets the virtual DOS memory base (interrupt table).
*/
char *DOSMEM_SystemBase(void)
{
return DOSMEM_sysmem;
}
/***********************************************************************
* DOSMEM_MemoryBase
*
@ -129,11 +142,17 @@ static dosmem_entry *DOSMEM_RootBlock(void)
*/
static void DOSMEM_FillIsrTable(void)
{
SEGPTR *isr = (SEGPTR*)DOSMEM_dosmem;
DWORD *stub = (DWORD*)((char*)isr + (VM_STUB_SEGMENT << 4));
SEGPTR *isr = (SEGPTR*)DOSMEM_sysmem;
int x;
for (x=0; x<256; x++) isr[x]=PTR_SEG_OFF_TO_SEGPTR(VM_STUB_SEGMENT,x*4);
}
static void DOSMEM_MakeIsrStubs(void)
{
DWORD *stub = (DWORD*)(DOSMEM_dosmem + (VM_STUB_SEGMENT << 4));
int x;
for (x=0; x<256; x++) stub[x]=VM_STUB(x);
}
@ -198,7 +217,7 @@ static void DOSMEM_InitDPMI(void)
BIOSDATA * DOSMEM_BiosData()
{
return (BIOSDATA *)DOSMEM_biosdata;
return (BIOSDATA *)(DOSMEM_sysmem + 0x400);
}
BYTE * DOSMEM_BiosSys()
@ -429,7 +448,7 @@ static void DOSMEM_InitMemory(void)
*/
static void setup_dos_mem( int dos_init )
{
int bios_offset = 0x400;
int sys_offset = 0;
int page_size = VIRTUAL_GetPageSize();
void *addr = VIRTUAL_mmap( -1, (void *)page_size, 0x110000-page_size, 0,
PROT_READ | PROT_WRITE | PROT_EXEC, 0 );
@ -451,8 +470,8 @@ static void setup_dos_mem( int dos_init )
if (!dos_init)
{
VirtualProtect( addr, 0x10000, PAGE_NOACCESS, NULL );
/* move the BIOS data from 0x400 to 0xf0400 */
bios_offset += 0xf0000;
/* move the BIOS and ISR area from 0x00000 to 0xf0000 */
sys_offset += 0xf0000;
}
}
else
@ -468,7 +487,7 @@ static void setup_dos_mem( int dos_init )
}
}
DOSMEM_dosmem = addr;
DOSMEM_biosdata = (char *)addr + bios_offset;
DOSMEM_sysmem = (char*)addr + sys_offset;
}
@ -480,19 +499,20 @@ static void setup_dos_mem( int dos_init )
*/
BOOL DOSMEM_Init(BOOL dos_init)
{
static int already_done;
static int already_done, already_mapped;
if (!already_done)
{
setup_dos_mem( dos_init );
DOSMEM_0000H = GLOBAL_CreateBlock( GMEM_FIXED, DOSMEM_biosdata - 0x400,
DOSMEM_0000H = GLOBAL_CreateBlock( GMEM_FIXED, DOSMEM_sysmem,
0x10000, 0, FALSE, FALSE, FALSE );
DOSMEM_BiosDataSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_biosdata,
DOSMEM_BiosDataSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_sysmem + 0x400,
0x100, 0, FALSE, FALSE, FALSE );
DOSMEM_BiosSysSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_dosmem+0xf0000,
0x10000, 0, FALSE, FALSE, FALSE );
DOSMEM_FillBiosSegments();
DOSMEM_FillIsrTable();
DOSMEM_InitMemory();
DOSMEM_InitCollateTable();
DOSMEM_InitErrorTable();
@ -500,7 +520,7 @@ BOOL DOSMEM_Init(BOOL dos_init)
DOSDEV_InstallDOSDevices();
already_done = 1;
}
else if (dos_init)
else if (dos_init && !already_mapped)
{
if (DOSMEM_dosmem)
{
@ -510,14 +530,16 @@ BOOL DOSMEM_Init(BOOL dos_init)
MESSAGE( "Warning: unprotecting the first 64KB of memory to allow real-mode calls.\n"
" NULL pointer accesses will no longer be caught.\n" );
VirtualProtect( NULL, 0x10000, PAGE_EXECUTE_READWRITE, NULL );
/* copy the BIOS area down to 0x400 */
memcpy( DOSMEM_dosmem + 0x400, DOSMEM_biosdata, 0x100 );
DOSMEM_biosdata = DOSMEM_dosmem + 0x400;
/* copy the BIOS and ISR area down */
memcpy( DOSMEM_dosmem, DOSMEM_sysmem, 0x400 + 0x100 );
DOSMEM_sysmem = DOSMEM_dosmem;
SetSelectorBase( DOSMEM_0000H, 0 );
SetSelectorBase( DOSMEM_BiosDataSeg, 0x400 );
/* we may now need the actual interrupt stubs, and since we've just moved the
* interrupt vector table away, we can fill the area with stubs instead... */
DOSMEM_MakeIsrStubs();
already_mapped = 1;
}
/* interrupt table is at addr 0, so only do this when setting up DOS mode */
if (dos_init) DOSMEM_FillIsrTable();
return TRUE;
}