/* * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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; } /*********************************************************************** * 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. */ LPVOID DOSVM_AllocCodeUMB( DWORD size, WORD *segment, WORD *selector ) { LPVOID ptr = DOSVM_AllocUMB( size ); if (segment) *segment = (DWORD)ptr >> 4; if (selector) *selector = SELECTOR_AllocBlock( 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 = SELECTOR_AllocBlock( 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 */ 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, = int (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, = int (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 ); }