Sweden-Number/msdos/dosmem.c

761 lines
23 KiB
C

/*
* DOS memory emulation
*
* Copyright 1995 Alexandre Julliard
* Copyright 1996 Marcus Meissner
*/
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include "winbase.h"
#include "wine/winbase16.h"
#include "global.h"
#include "ldt.h"
#include "miscemu.h"
#include "vga.h"
#include "module.h"
#include "task.h"
#include "debugtools.h"
DECLARE_DEBUG_CHANNEL(dosmem)
DECLARE_DEBUG_CHANNEL(selector)
HANDLE16 DOSMEM_BiosDataSeg; /* BIOS data segment at 0x40:0 */
HANDLE16 DOSMEM_BiosSysSeg; /* BIOS ROM segment at 0xf000:0 */
static char *DOSMEM_dosmem;
DWORD DOSMEM_CollateTable;
DWORD DOSMEM_ErrorCall;
DWORD DOSMEM_ErrorBuffer;
/* use 2 low bits of 'size' for the housekeeping */
#define DM_BLOCK_DEBUG 0xABE00000
#define DM_BLOCK_TERMINAL 0x00000001
#define DM_BLOCK_FREE 0x00000002
#define DM_BLOCK_MASK 0x001FFFFC
/*
#define __DOSMEM_DEBUG__
*/
typedef struct {
unsigned size;
} dosmem_entry;
typedef struct {
unsigned blocks;
unsigned free;
} dosmem_info;
#define NEXT_BLOCK(block) \
(dosmem_entry*)(((char*)(block)) + \
sizeof(dosmem_entry) + ((block)->size & DM_BLOCK_MASK))
#define VM_STUB(x) (0x90CF00CD|(x<<8)) /* INT x; IRET; NOP */
#define VM_STUB_SEGMENT 0xf000 /* BIOS segment */
/***********************************************************************
* DOSMEM_MemoryBase
*
* Gets the DOS memory base.
*/
char *DOSMEM_MemoryBase(HMODULE16 hModule)
{
TDB *pTask = hModule ? NULL : (TDB *)GlobalLock16( GetCurrentTask() );
NE_MODULE *pModule = (hModule || pTask) ? NE_GetPtr( hModule ? hModule : pTask->hModule ) : NULL;
GlobalUnlock16( GetCurrentTask() );
if (pModule && pModule->dos_image)
return pModule->dos_image;
else
return DOSMEM_dosmem;
}
/***********************************************************************
* DOSMEM_MemoryTop
*
* Gets the DOS memory top.
*/
static char *DOSMEM_MemoryTop(HMODULE16 hModule)
{
return DOSMEM_MemoryBase(hModule)+0x9FFFC; /* 640K */
}
/***********************************************************************
* DOSMEM_InfoBlock
*
* Gets the DOS memory info block.
*/
static dosmem_info *DOSMEM_InfoBlock(HMODULE16 hModule)
{
return (dosmem_info*)(DOSMEM_MemoryBase(hModule)+0x10000); /* 64K */
}
/***********************************************************************
* DOSMEM_RootBlock
*
* Gets the DOS memory root block.
*/
static dosmem_entry *DOSMEM_RootBlock(HMODULE16 hModule)
{
/* first block has to be paragraph-aligned */
return (dosmem_entry*)(((char*)DOSMEM_InfoBlock(hModule)) +
((((sizeof(dosmem_info) + 0xf) & ~0xf) - sizeof(dosmem_entry))));
}
/***********************************************************************
* DOSMEM_FillIsrTable
*
* Fill the interrupt table with fake BIOS calls to BIOSSEG (0xf000).
*
* NOTES:
* Linux normally only traps INTs performed from or destined to BIOSSEG
* for us to handle, if the int_revectored table is empty. Filling the
* interrupt table with calls to INT stubs in BIOSSEG allows DOS programs
* to hook interrupts, as well as use their familiar retf tricks to call
* them, AND let Wine handle any unhooked interrupts transparently.
*/
static void DOSMEM_FillIsrTable(HMODULE16 hModule)
{
SEGPTR *isr = (SEGPTR*)DOSMEM_MemoryBase(hModule);
DWORD *stub = (DWORD*)((char*)isr + (VM_STUB_SEGMENT << 4));
int x;
for (x=0; x<256; x++) isr[x]=PTR_SEG_OFF_TO_SEGPTR(VM_STUB_SEGMENT,x*4);
for (x=0; x<256; x++) stub[x]=VM_STUB(x);
}
/***********************************************************************
* DOSMEM_InitDPMI
*
* Allocate the global DPMI RMCB wrapper.
*/
static void DOSMEM_InitDPMI(void)
{
extern UINT16 DPMI_wrap_seg;
static char wrap_code[]={
0xCD,0x31, /* int $0x31 */
0xCB /* lret */
};
LPSTR wrapper = (LPSTR)DOSMEM_GetBlock(0, sizeof(wrap_code), &DPMI_wrap_seg);
memcpy(wrapper, wrap_code, sizeof(wrap_code));
}
BIOSDATA * DOSMEM_BiosData()
{
return (BIOSDATA *)(DOSMEM_MemoryBase(0)+0x400);
}
BYTE * DOSMEM_BiosSys()
{
return DOSMEM_MemoryBase(0)+0xf0000;
}
struct _DOS_LISTOFLISTS * DOSMEM_LOL()
{
return (struct _DOS_LISTOFLISTS *)DOSMEM_MapRealToLinear
(PTR_SEG_OFF_TO_SEGPTR(HIWORD(DOS_LOLSeg),0));
}
/***********************************************************************
* DOSMEM_FillBiosSegments
*
* Fill the BIOS data segment with dummy values.
*/
static void DOSMEM_FillBiosSegments(void)
{
BYTE *pBiosSys = (BYTE *)GlobalLock16( DOSMEM_BiosSysSeg );
BYTE *pBiosROMTable = pBiosSys+0xe6f5;
BIOSDATA *pBiosData = (BIOSDATA *)GlobalLock16( DOSMEM_BiosDataSeg );
/* bogus 0xe0xx addresses !! Adapt int 0x10/0x1b if change needed */
BYTE *pVideoStaticFuncTable = pBiosSys+0xe000;
BYTE *pVideoStateInfo = pBiosSys+0xe010;
BYTE *p;
int i;
/* Clear all unused values */
memset( pBiosData, 0, sizeof(*pBiosData) );
/* FIXME: should check the number of configured drives and ports */
pBiosData->Com1Addr = 0x3f8;
pBiosData->Com2Addr = 0x2f8;
pBiosData->Lpt1Addr = 0x378;
pBiosData->Lpt2Addr = 0x278;
pBiosData->InstalledHardware = 0x5463;
pBiosData->MemSize = 640;
pBiosData->NextKbdCharPtr = 0x1e;
pBiosData->FirstKbdCharPtr = 0x1e;
pBiosData->VideoMode = 3;
pBiosData->VideoColumns = 80;
pBiosData->VideoPageSize = 80 * 25 * 2;
pBiosData->VideoPageStartAddr = 0xb800;
pBiosData->VideoCtrlAddr = 0x3d4;
pBiosData->Ticks = INT1A_GetTicksSinceMidnight();
pBiosData->NbHardDisks = 2;
pBiosData->KbdBufferStart = 0x1e;
pBiosData->KbdBufferEnd = 0x3e;
pBiosData->RowsOnScreenMinus1 = 23;
pBiosData->BytesPerChar = 0x10;
pBiosData->ModeOptions = 0x64;
pBiosData->FeatureBitsSwitches = 0xf9;
pBiosData->VGASettings = 0x51;
pBiosData->DisplayCombination = 0x08;
pBiosData->DiskDataRate = 0;
/* fill ROM configuration table (values from Award) */
*(WORD *)(pBiosROMTable)= 0x08; /* number of bytes following */
*(pBiosROMTable+0x2) = 0xfc; /* model */
*(pBiosROMTable+0x3) = 0x01; /* submodel */
*(pBiosROMTable+0x4) = 0x00; /* BIOS revision */
*(pBiosROMTable+0x5) = 0x74; /* feature byte 1 */
*(pBiosROMTable+0x6) = 0x00; /* feature byte 2 */
*(pBiosROMTable+0x7) = 0x00; /* feature byte 3 */
*(pBiosROMTable+0x8) = 0x00; /* feature byte 4 */
*(pBiosROMTable+0x9) = 0x00; /* feature byte 5 */
p = pVideoStaticFuncTable;
for (i=0; i < 7; i++)
*(p+i) = 0xff; /* modes supported 1 to 7 */
*(p+0x7) = 7; /* scan lines supported */
*(p+0x8) = 0; /* tot nr of char blocks in text mode */
*(p+0x9) = 0; /* max nr of active char blocks in text */
*(WORD *)(p+0xa) = 0x8ff; /* misc support flags */
*(WORD *)(p+0xc) = 0; /* reserved */
*(p+0xe) = 0x3f; /* save pointer function flags */
*(p+0xf) = 0; /* reserved */
p = pVideoStateInfo;
*(DWORD *)p = 0xf000e000; /* address of pVideoStaticFuncTable, FIXME: always real mode ? */
*(p+0x04) = /* current video mode, needs updates ! */
pBiosData->VideoMode;
*(WORD *)(p+0x05) = /* number of columns, needs updates ! */
pBiosData->VideoColumns;
*(WORD *)(p+0x07) = 0; /* length of regen (???) buffer in bytes */
*(WORD *)(p+0x09) = 0; /* starting address of regen (?) buffer */
*(WORD *)(p+0x0b) = 0; /* cursorpos page 0 */
*(WORD *)(p+0x0d) = 0; /* cursorpos page 1 */
*(WORD *)(p+0x0f) = 0; /* page 2 */
*(WORD *)(p+0x11) = 0; /* page 3 */
*(WORD *)(p+0x13) = 0; /* page 4 */
*(WORD *)(p+0x15) = 0; /* page 5 */
*(WORD *)(p+0x17) = 0; /* page 6 */
*(WORD *)(p+0x19) = 0; /* page 7 */
*(WORD *)(p+0x1b) = 0x0a0b; /* cursor size (start/end line) */
*(p+0x1d) = 0; /* active display page */
*(WORD *)(p+0x1e) = 0x3da; /* CRTC port address */
*(p+0x20) = 0x0; /* current setting of port 0x3x8 */
*(p+0x21) = 0x0; /* current setting of port 0x3x9 */
*(p+0x22) = 23; /* number of rows - 1 */
*(WORD *)(p+0x23) = 0x10; /* bytes/character */
*(p+0x25) = /* comb. of active display */
pBiosData->DisplayCombination;
*(p+0x26) = 0; /* DCC (???) of alternate display */
*(WORD *)(p+0x27) = 16; /* number of colors in current mode */
*(p+0x29) = 1; /* number of pages in current mode */
*(p+0x2a) = 3; /* number of scan lines active */
/* (0,1,2,3) = (200,350,400,480) */
*(p+0x2b) = 0; /* primary character block (?) */
*(p+0x2c) = 0; /* secondary character block (?) */
*(p+0x2d) = /* miscellaneous flags */
(pBiosData->VGASettings & 0x0f)
| ((pBiosData->ModeOptions & 1) << 4); /* cursor emulation */
*(p+0x2e) = 0; /* non-VGA mode support */
*(WORD *)(p+0x2f) = 0; /* reserved */
*(p+0x31) = /* video memory available */
(pBiosData->ModeOptions & 0x60 >> 5);
*(p+0x32) = 0; /* save pointer state flags */
*(p+0x33) = 4; /* display info and status */
/* BIOS date string */
strcpy((char *)pBiosSys+0xfff5, "13/01/99");
/* BIOS ID */
*(pBiosSys+0xfffe) = 0xfc;
}
/***********************************************************************
* DOSMEM_InitCollateTable
*
* Initialises the collate table (character sorting, language dependent)
*/
static void DOSMEM_InitCollateTable()
{
DWORD x;
unsigned char *tbl;
int i;
x = GlobalDOSAlloc16(258);
DOSMEM_CollateTable = MAKELONG(0,(x>>16));
tbl = DOSMEM_MapRealToLinear(DOSMEM_CollateTable);
*(WORD*)tbl = 0x100;
tbl += 2;
for ( i = 0; i < 0x100; i++) *tbl++ = i;
}
/***********************************************************************
* DOSMEM_InitErrorTable
*
* Initialises the error tables (DOS 5+)
*/
static void DOSMEM_InitErrorTable()
{
DWORD x;
char *call;
/* We will use a snippet of real mode code that calls */
/* a WINE-only interrupt to handle moving the requested */
/* message into the buffer... */
/* FIXME - There is still something wrong... */
/* FIXME - Find hex values for opcodes...
(On call, AX contains message number
DI contains 'offset' (??)
Resturn, ES:DI points to counted string )
PUSH BX
MOV BX, AX
MOV AX, (arbitrary subfunction number)
INT (WINE-only interrupt)
POP BX
RET
*/
const int code = 4;
const int buffer = 80;
const int SIZE_TO_ALLOCATE = code + buffer;
/* FIXME - Complete rewrite of the table system to save */
/* precious DOS space. Now, we return the 0001:???? as */
/* DOS 4+ (??, it seems to be the case in MS 7.10) treats that */
/* as a special case and programs will use the alternate */
/* interface (a farcall returned with INT 24 (AX = 0x122e, DL = */
/* 0x08) which lets us have a smaller memory footprint anyway. */
x = GlobalDOSAlloc16(SIZE_TO_ALLOCATE);
DOSMEM_ErrorCall = MAKELONG(0,(x>>16));
DOSMEM_ErrorBuffer = DOSMEM_ErrorCall + code;
call = DOSMEM_MapRealToLinear(DOSMEM_ErrorCall);
memset(call, 0, SIZE_TO_ALLOCATE);
/* Fixme - Copy assembly into buffer here */
}
/***********************************************************************
* DOSMEM_InitMemory
*
* Initialises the DOS memory structures.
*/
static void DOSMEM_InitMemory(HMODULE16 hModule)
{
/* Low 64Kb are reserved for DOS/BIOS so the useable area starts at
* 1000:0000 and ends at 9FFF:FFEF. */
dosmem_info* info_block = DOSMEM_InfoBlock(hModule);
dosmem_entry* root_block = DOSMEM_RootBlock(hModule);
dosmem_entry* dm;
root_block->size = DOSMEM_MemoryTop(hModule) - (((char*)root_block) + sizeof(dosmem_entry));
info_block->blocks = 0;
info_block->free = root_block->size;
dm = NEXT_BLOCK(root_block);
dm->size = DM_BLOCK_TERMINAL;
root_block->size |= DM_BLOCK_FREE
#ifdef __DOSMEM_DEBUG__
| DM_BLOCK_DEBUG;
#endif
;
}
/***********************************************************************
* DOSMEM_MovePointers
*
* Relocates any pointers into DOS memory to a new address space.
*/
static void DOSMEM_MovePointers(LPVOID dest, LPVOID src, DWORD size)
{
unsigned long delta = dest-src;
unsigned cnt;
ldt_entry ent;
/* relocate base addresses of any selectors pointing into memory */
for (cnt=FIRST_LDT_ENTRY_TO_ALLOC; cnt<LDT_SIZE; cnt++) {
LDT_GetEntry(cnt, &ent);
if ((ent.base >= (unsigned long)src) && \
(ent.base < ((unsigned long)src + size))) {
ent.base += delta;
LDT_SetEntry(cnt, &ent);
}
}
}
/***********************************************************************
* DOSMEM_Init
*
* Create the dos memory segments, and store them into the KERNEL
* exported values.
*/
BOOL DOSMEM_Init(HMODULE16 hModule)
{
if (!hModule)
{
/* Allocate 1 MB dosmemory
* - it is mostly wasted but we can use some of it to
* store internal translation tables, etc...
*/
DOSMEM_dosmem = VirtualAlloc( NULL, 0x100000, MEM_COMMIT,
PAGE_EXECUTE_READWRITE );
if (!DOSMEM_dosmem)
{
WARN_(dosmem)("Could not allocate DOS memory.\n" );
return FALSE;
}
DOSMEM_BiosDataSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_dosmem+0x400,
0x100, 0, FALSE, FALSE, FALSE, NULL );
DOSMEM_BiosSysSeg = GLOBAL_CreateBlock(GMEM_FIXED,DOSMEM_dosmem+0xf0000,
0x10000, 0, FALSE, FALSE, FALSE, NULL );
DOSMEM_FillIsrTable(0);
DOSMEM_FillBiosSegments();
DOSMEM_InitMemory(0);
DOSMEM_InitCollateTable();
DOSMEM_InitErrorTable();
DOSMEM_InitDPMI();
DOSDEV_InstallDOSDevices();
}
else
{
#if 0
DOSMEM_FillIsrTable(hModule);
DOSMEM_InitMemory(hModule);
#else
LPVOID base = DOSMEM_MemoryBase(hModule);
/* bootstrap the new V86 task with a copy of the "system" memory */
memcpy(base, DOSMEM_dosmem, 0x100000);
/* then move existing selectors to it */
DOSMEM_MovePointers(base, DOSMEM_dosmem, 0x100000);
#endif
}
return TRUE;
}
/***********************************************************************
* DOSMEM_Tick
*
* Increment the BIOS tick counter. Called by timer signal handler.
*/
void DOSMEM_Tick( WORD timer )
{
BIOSDATA *pBiosData = DOSMEM_BiosData();
if (pBiosData) pBiosData->Ticks++;
}
/***********************************************************************
* DOSMEM_GetBlock
*
* Carve a chunk of the DOS memory block (without selector).
*/
LPVOID DOSMEM_GetBlock(HMODULE16 hModule, UINT size, UINT16* pseg)
{
UINT blocksize;
char *block = NULL;
dosmem_info *info_block = DOSMEM_InfoBlock(hModule);
dosmem_entry *dm;
#ifdef __DOSMEM_DEBUG_
dosmem_entry *prev = NULL;
#endif
if( size > info_block->free ) return NULL;
dm = DOSMEM_RootBlock(hModule);
while (dm && dm->size != DM_BLOCK_TERMINAL)
{
#ifdef __DOSMEM_DEBUG__
if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
{
WARN_(dosmem)("MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
return NULL;
}
prev = dm;
#endif
if( dm->size & DM_BLOCK_FREE )
{
dosmem_entry *next = NEXT_BLOCK(dm);
while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
{
dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
next = NEXT_BLOCK(dm);
}
blocksize = dm->size & DM_BLOCK_MASK;
if( blocksize >= size )
{
block = ((char*)dm) + sizeof(dosmem_entry);
if( blocksize - size > 0x20 )
{
/* split dm so that the next one stays
* paragraph-aligned (and dm loses free bit) */
dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
sizeof(dosmem_entry));
next = (dosmem_entry*)(((char*)dm) +
sizeof(dosmem_entry) + dm->size);
next->size = (blocksize - (dm->size +
sizeof(dosmem_entry))) | DM_BLOCK_FREE
#ifdef __DOSMEM_DEBUG__
| DM_BLOCK_DEBUG
#endif
;
} else dm->size &= DM_BLOCK_MASK;
info_block->blocks++;
info_block->free -= dm->size;
if( pseg ) *pseg = (block - DOSMEM_MemoryBase(hModule)) >> 4;
#ifdef __DOSMEM_DEBUG__
dm->size |= DM_BLOCK_DEBUG;
#endif
break;
}
dm = next;
}
else dm = NEXT_BLOCK(dm);
}
return (LPVOID)block;
}
/***********************************************************************
* DOSMEM_FreeBlock
*/
BOOL DOSMEM_FreeBlock(HMODULE16 hModule, void* ptr)
{
dosmem_info *info_block = DOSMEM_InfoBlock(hModule);
if( ptr >= (void*)(((char*)DOSMEM_RootBlock(hModule)) + sizeof(dosmem_entry)) &&
ptr < (void*)DOSMEM_MemoryTop(hModule) && !((((char*)ptr)
- DOSMEM_MemoryBase(hModule)) & 0xf) )
{
dosmem_entry *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
#ifdef __DOSMEM_DEBUG__
&& ((dm->size & DM_BLOCK_DEBUG) == DM_BLOCK_DEBUG )
#endif
)
{
info_block->blocks--;
info_block->free += dm->size;
dm->size |= DM_BLOCK_FREE;
return TRUE;
}
}
return FALSE;
}
/***********************************************************************
* DOSMEM_ResizeBlock
*/
LPVOID DOSMEM_ResizeBlock(HMODULE16 hModule, void* ptr, UINT size, UINT16* pseg)
{
char *block = NULL;
dosmem_info *info_block = DOSMEM_InfoBlock(hModule);
if( ptr >= (void*)(((char*)DOSMEM_RootBlock(hModule)) + sizeof(dosmem_entry)) &&
ptr < (void*)DOSMEM_MemoryTop(hModule) && !((((char*)ptr)
- DOSMEM_MemoryBase(hModule)) & 0xf) )
{
dosmem_entry *dm = (dosmem_entry*)(((char*)ptr) - sizeof(dosmem_entry));
if( pseg ) *pseg = ((char*)ptr - DOSMEM_MemoryBase(hModule)) >> 4;
if( !(dm->size & (DM_BLOCK_FREE | DM_BLOCK_TERMINAL))
)
{
dosmem_entry *next = NEXT_BLOCK(dm);
UINT blocksize, orgsize = dm->size & DM_BLOCK_MASK;
while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
{
dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
next = NEXT_BLOCK(dm);
}
blocksize = dm->size & DM_BLOCK_MASK;
if (blocksize >= size)
{
block = ((char*)dm) + sizeof(dosmem_entry);
if( blocksize - size > 0x20 )
{
/* split dm so that the next one stays
* paragraph-aligned (and next gains free bit) */
dm->size = (((size + 0xf + sizeof(dosmem_entry)) & ~0xf) -
sizeof(dosmem_entry));
next = (dosmem_entry*)(((char*)dm) +
sizeof(dosmem_entry) + dm->size);
next->size = (blocksize - (dm->size +
sizeof(dosmem_entry))) | DM_BLOCK_FREE
;
} else dm->size &= DM_BLOCK_MASK;
info_block->free += orgsize - dm->size;
} else {
/* the collapse didn't help, try getting a new block */
block = DOSMEM_GetBlock(hModule, size, pseg);
if (block) {
/* we got one, copy the old data there (we do need to, right?) */
memcpy(block, ((char*)dm) + sizeof(dosmem_entry),
(size<orgsize) ? size : orgsize);
/* free old block */
info_block->blocks--;
info_block->free += dm->size;
dm->size |= DM_BLOCK_FREE;
} else {
/* and Bill Gates said 640K should be enough for everyone... */
/* need to split original and collapsed blocks apart again,
* and free the collapsed blocks again, before exiting */
if( blocksize - orgsize > 0x20 )
{
/* split dm so that the next one stays
* paragraph-aligned (and next gains free bit) */
dm->size = (((orgsize + 0xf + sizeof(dosmem_entry)) & ~0xf) -
sizeof(dosmem_entry));
next = (dosmem_entry*)(((char*)dm) +
sizeof(dosmem_entry) + dm->size);
next->size = (blocksize - (dm->size +
sizeof(dosmem_entry))) | DM_BLOCK_FREE
;
} else dm->size &= DM_BLOCK_MASK;
}
}
}
}
return (LPVOID)block;
}
/***********************************************************************
* DOSMEM_Available
*/
UINT DOSMEM_Available(HMODULE16 hModule)
{
UINT blocksize, available = 0;
dosmem_entry *dm;
dm = DOSMEM_RootBlock(hModule);
while (dm && dm->size != DM_BLOCK_TERMINAL)
{
#ifdef __DOSMEM_DEBUG__
if( (dm->size & DM_BLOCK_DEBUG) != DM_BLOCK_DEBUG )
{
WARN_(dosmem)("MCB overrun! [prev = 0x%08x]\n", 4 + (UINT)prev);
return NULL;
}
prev = dm;
#endif
if( dm->size & DM_BLOCK_FREE )
{
dosmem_entry *next = NEXT_BLOCK(dm);
while( next->size & DM_BLOCK_FREE ) /* collapse free blocks */
{
dm->size += sizeof(dosmem_entry) + (next->size & DM_BLOCK_MASK);
next->size = (DM_BLOCK_FREE | DM_BLOCK_TERMINAL);
next = NEXT_BLOCK(dm);
}
blocksize = dm->size & DM_BLOCK_MASK;
if ( blocksize > available ) available = blocksize;
dm = next;
}
else dm = NEXT_BLOCK(dm);
}
return available;
}
/***********************************************************************
* DOSMEM_MapLinearToDos
*
* Linear address to the DOS address space.
*/
UINT DOSMEM_MapLinearToDos(LPVOID ptr)
{
if (((char*)ptr >= DOSMEM_MemoryBase(0)) &&
((char*)ptr < DOSMEM_MemoryBase(0) + 0x100000))
return (UINT)ptr - (UINT)DOSMEM_MemoryBase(0);
return (UINT)ptr;
}
/***********************************************************************
* DOSMEM_MapDosToLinear
*
* DOS linear address to the linear address space.
*/
LPVOID DOSMEM_MapDosToLinear(UINT ptr)
{
if (ptr < 0x100000) return (LPVOID)(ptr + (UINT)DOSMEM_MemoryBase(0));
return (LPVOID)ptr;
}
/***********************************************************************
* DOSMEM_MapRealToLinear
*
* Real mode DOS address into a linear pointer
*/
LPVOID DOSMEM_MapRealToLinear(DWORD x)
{
LPVOID lin;
lin=DOSMEM_MemoryBase(0)+(x&0xffff)+(((x&0xffff0000)>>16)*16);
TRACE_(selector)("(0x%08lx) returns 0x%p.\n",
x,lin );
return lin;
}
/***********************************************************************
* DOSMEM_AllocSelector
*
* Allocates a protected mode selector for a realmode segment.
*/
WORD DOSMEM_AllocSelector(WORD realsel)
{
HMODULE16 hModule = GetModuleHandle16("KERNEL");
WORD sel;
sel=GLOBAL_CreateBlock(
GMEM_FIXED,DOSMEM_dosmem+realsel*16,0x10000,
hModule,FALSE,FALSE,FALSE,NULL
);
TRACE_(selector)("(0x%04x) returns 0x%04x.\n",
realsel,sel
);
return sel;
}