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wine/dlls/winedos/himem.c
Jonathan Ernst 360a3f9142 Update the address of the Free Software Foundation.
2006-05-23 14:11:13 +02:00

294 lines
8.9 KiB
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/*
* DOS upper memory management.
*
* Copyright 2002 Jukka Heinonen
*
* 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 "dosexe.h"
#include "wine/debug.h"
WINE_DEFAULT_DEBUG_CHANNEL(dosmem);
/*
* Wine DOS memory layout above 640k:
*
* a0000 - affff : VGA graphics (vga.c)
* b0000 - bffff : Monochrome text (unused)
* b8000 - bffff : VGA text (vga.c)
* c0000 - cffff : EMS frame (int67.c)
* d0000 - effff : Free memory for UMBs (himem.c)
* f0000 - fffff : BIOS stuff (msdos/dosmem.c)
* 100000 -10ffff : High memory area (unused)
*/
/*
* Table of real mode segments and protected mode selectors
* for code stubs and other miscellaneous storage.
*/
struct DPMI_segments *DOSVM_dpmi_segments = NULL;
/*
* First and last address available for upper memory blocks.
*/
#define DOSVM_UMB_BOTTOM 0xd0000
#define DOSVM_UMB_TOP 0xeffff
/*
* First free address for upper memory blocks.
*/
static DWORD DOSVM_umb_free = DOSVM_UMB_BOTTOM;
/***********************************************************************
* DOSVM_AllocUMB
*
* Allocate upper memory block (UMB) from upper memory.
* Returned pointer is aligned to 16-byte (paragraph) boundary.
*
* This routine is only for allocating static storage for
* Wine internal uses. Allocated memory can be accessed from
* real mode, memory is taken from area already mapped and reserved
* by Wine and the allocation has very little memory and speed
* overhead. Use of this routine also preserves precious DOS
* conventional memory.
*/
LPVOID DOSVM_AllocUMB( DWORD size )
{
LPVOID ptr = (LPVOID)DOSVM_umb_free;
size = ((size + 15) >> 4) << 4;
if(DOSVM_umb_free + size - 1 > DOSVM_UMB_TOP) {
ERR("Out of upper memory area.\n");
return 0;
}
DOSVM_umb_free += size;
return ptr;
}
/**********************************************************************
* alloc_selector
*
* Allocate a selector corresponding to a real mode address.
* size must be < 64k.
*/
static WORD alloc_selector( void *base, DWORD size, unsigned char flags )
{
WORD sel = wine_ldt_alloc_entries( 1 );
if (sel)
{
LDT_ENTRY entry;
wine_ldt_set_base( &entry, base );
wine_ldt_set_limit( &entry, size - 1 );
wine_ldt_set_flags( &entry, flags );
wine_ldt_set_entry( sel, &entry );
}
return sel;
}
/***********************************************************************
* DOSVM_AllocCodeUMB
*
* Allocate upper memory block for storing code stubs.
* Initializes real mode segment and 16-bit protected mode selector
* for the allocated code block.
*
* FIXME: should allocate a single PM selector for the whole UMB range.
*/
LPVOID DOSVM_AllocCodeUMB( DWORD size, WORD *segment, WORD *selector )
{
LPVOID ptr = DOSVM_AllocUMB( size );
if (segment)
*segment = (DWORD)ptr >> 4;
if (selector)
*selector = alloc_selector( ptr, size, WINE_LDT_FLAGS_CODE );
return ptr;
}
/***********************************************************************
* DOSVM_AllocDataUMB
*
* Allocate upper memory block for storing data.
* Initializes real mode segment and 16-bit protected mode selector
* for the allocated data block.
*/
LPVOID DOSVM_AllocDataUMB( DWORD size, WORD *segment, WORD *selector )
{
LPVOID ptr = DOSVM_AllocUMB( size );
if (segment)
*segment = (DWORD)ptr >> 4;
if (selector)
*selector = alloc_selector( ptr, size, WINE_LDT_FLAGS_DATA );
return ptr;
}
/***********************************************************************
* DOSVM_InitSegments
*
* Initializes DOSVM_dpmi_segments. Allocates required memory and
* sets up segments and selectors for accessing the memory.
*/
void DOSVM_InitSegments( void )
{
LPSTR ptr;
int i;
static const char wrap_code[]={
0xCD,0x31, /* int $0x31 */
0xCB /* lret */
};
static const char enter_xms[]=
{
/* XMS hookable entry point */
0xEB,0x03, /* jmp entry */
0x90,0x90,0x90, /* nop;nop;nop */
/* entry: */
/* real entry point */
/* for simplicity, we'll just use the same hook as DPMI below */
0xCD,0x31, /* int $0x31 */
0xCB /* lret */
};
static const char enter_pm[]=
{
0x50, /* pushw %ax */
0x52, /* pushw %dx */
0x55, /* pushw %bp */
0x89,0xE5, /* movw %sp,%bp */
/* get return CS */
0x8B,0x56,0x08, /* movw 8(%bp),%dx */
/* just call int 31 here to get into protected mode... */
/* it'll check whether it was called from dpmi_seg... */
0xCD,0x31, /* int $0x31 */
/* we are now in the context of a 16-bit relay call */
/* need to fixup our stack;
* 16-bit relay return address will be lost,
* but we won't worry quite yet
*/
0x8E,0xD0, /* movw %ax,%ss */
0x66,0x0F,0xB7,0xE5, /* movzwl %bp,%esp */
/* set return CS */
0x89,0x56,0x08, /* movw %dx,8(%bp) */
0x5D, /* popw %bp */
0x5A, /* popw %dx */
0x58, /* popw %ax */
0xfb, /* sti, enable and check virtual interrupts */
0xCB /* lret */
};
static const char relay[]=
{
0xca, 0x04, 0x00, /* 16-bit far return and pop 4 bytes (relay void* arg) */
0xcd, 0x31, /* int 31 */
0xfb, 0x66, 0xcb /* sti and 32-bit far return */
};
/*
* Allocate pointer array.
*/
DOSVM_dpmi_segments = DOSVM_AllocUMB( sizeof(struct DPMI_segments) );
/*
* RM / offset 0: Exit from real mode.
* RM / offset 2: Points to lret opcode.
*/
ptr = DOSVM_AllocCodeUMB( sizeof(wrap_code),
&DOSVM_dpmi_segments->wrap_seg, 0 );
memcpy( ptr, wrap_code, sizeof(wrap_code) );
/*
* RM / offset 0: XMS driver entry.
*/
ptr = DOSVM_AllocCodeUMB( sizeof(enter_xms),
&DOSVM_dpmi_segments->xms_seg, 0 );
memcpy( ptr, enter_xms, sizeof(enter_xms) );
/*
* RM / offset 0: Switch to DPMI.
* PM / offset 8: DPMI raw mode switch.
*/
ptr = DOSVM_AllocCodeUMB( sizeof(enter_pm),
&DOSVM_dpmi_segments->dpmi_seg,
&DOSVM_dpmi_segments->dpmi_sel );
memcpy( ptr, enter_pm, sizeof(enter_pm) );
/*
* PM / offset N*6: Interrupt N in DPMI32.
*/
ptr = DOSVM_AllocCodeUMB( 6 * 256,
0, &DOSVM_dpmi_segments->int48_sel );
for(i=0; i<256; i++) {
/*
* Each 32-bit interrupt handler is 6 bytes:
* 0xCD,<i> = int <i> (nested 16-bit interrupt)
* 0x66,0xCA,0x04,0x00 = ret 4 (32-bit far return and pop 4 bytes / eflags)
*/
ptr[i * 6 + 0] = 0xCD;
ptr[i * 6 + 1] = i;
ptr[i * 6 + 2] = 0x66;
ptr[i * 6 + 3] = 0xCA;
ptr[i * 6 + 4] = 0x04;
ptr[i * 6 + 5] = 0x00;
}
/*
* PM / offset N*5: Interrupt N in 16-bit protected mode.
*/
ptr = DOSVM_AllocCodeUMB( 5 * 256,
0, &DOSVM_dpmi_segments->int16_sel );
for(i=0; i<256; i++) {
/*
* Each 16-bit interrupt handler is 5 bytes:
* 0xCD,<i> = int <i> (interrupt)
* 0xCA,0x02,0x00 = ret 2 (16-bit far return and pop 2 bytes / eflags)
*/
ptr[i * 5 + 0] = 0xCD;
ptr[i * 5 + 1] = i;
ptr[i * 5 + 2] = 0xCA;
ptr[i * 5 + 3] = 0x02;
ptr[i * 5 + 4] = 0x00;
}
/*
* PM / offset 0: Stub where __wine_call_from_16_regs returns.
* PM / offset 3: Stub which swaps back to 32-bit application code/stack.
* PM / offset 5: Stub which enables interrupts
*/
ptr = DOSVM_AllocCodeUMB( sizeof(relay),
0, &DOSVM_dpmi_segments->relay_code_sel);
memcpy( ptr, relay, sizeof(relay) );
/*
* Space for 16-bit stack used by relay code.
*/
ptr = DOSVM_AllocDataUMB( DOSVM_RELAY_DATA_SIZE,
0, &DOSVM_dpmi_segments->relay_data_sel);
memset( ptr, 0, DOSVM_RELAY_DATA_SIZE );
}
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