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Diffstat (limited to 'board/MAI/bios_emulator/scitech/src/pm/dos/vflat.c')
| -rw-r--r-- | board/MAI/bios_emulator/scitech/src/pm/dos/vflat.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/board/MAI/bios_emulator/scitech/src/pm/dos/vflat.c b/board/MAI/bios_emulator/scitech/src/pm/dos/vflat.c new file mode 100644 index 0000000000..2e78e25a8b --- /dev/null +++ b/board/MAI/bios_emulator/scitech/src/pm/dos/vflat.c @@ -0,0 +1,251 @@ +/**************************************************************************** +* +* SciTech OS Portability Manager Library +* +* ======================================================================== +* +* The contents of this file are subject to the SciTech MGL Public +* License Version 1.0 (the "License"); you may not use this file +* except in compliance with the License. You may obtain a copy of +* the License at http://www.scitechsoft.com/mgl-license.txt +* +* Software distributed under the License is distributed on an +* "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or +* implied. See the License for the specific language governing +* rights and limitations under the License. +* +* The Original Code is Copyright (C) 1991-1998 SciTech Software, Inc. +* +* The Initial Developer of the Original Code is SciTech Software, Inc. +* All Rights Reserved. +* +* ======================================================================== +* +* Language: ANSI C +* Environment: 32-bit DOS +* +* Description: Main C module for the VFlat framebuffer routines. The page +* fault handler is always installed to handle up to a 4Mb +* framebuffer with a window size of 4Kb or 64Kb in size. +* +****************************************************************************/ + +#include "pmapi.h" +#include <stdlib.h> +#include <dos.h> + +/*-------------------------------------------------------------------------*/ +/* DOS4G/W, PMODE/W and CauseWay support. */ +/*-------------------------------------------------------------------------*/ + +#if defined(DOS4GW) + +#define VFLAT_START_ADDR 0xF0000000U +#define VFLAT_END_ADDR 0xF03FFFFFU +#define VFLAT_LIMIT (VFLAT_END_ADDR - VFLAT_START_ADDR) +#define PAGE_PRESENT 1 +#define PAGE_NOTPRESENT 0 +#define PAGE_READ 0 +#define PAGE_WRITE 2 + +PRIVATE ibool installed = false; +PRIVATE ibool haveDPMI = false; +PUBLIC ibool _ASMAPI VF_haveCauseWay = false; +PUBLIC uchar * _ASMAPI VF_zeroPtr = NULL; + +/* Low level assembler code */ + +int _ASMAPI InitPaging(void); +void _ASMAPI ClosePaging(void); +void _ASMAPI MapPhysical2Linear(ulong pAddr, ulong lAddr, int pages, int flags); +void _ASMAPI InstallFaultHandler(ulong baseAddr,int bankSize); +void _ASMAPI RemoveFaultHandler(void); +void _ASMAPI InstallBankFunc(int codeLen,void *bankFunc); + +void * _ASMAPI VF_malloc(uint size) +{ return PM_malloc(size); } + +void _ASMAPI VF_free(void *p) +{ PM_free(p); } + +PRIVATE ibool CheckDPMI(void) +/**************************************************************************** +* +* Function: CheckDPMI +* Returns: True if we are running under DPMI +* +****************************************************************************/ +{ + PMREGS regs; + + if (haveDPMI) + return true; + + /* Check if we are running under DPMI in which case we will not be + * able to install our page fault handlers. We can however use the + * DVA.386 or VFLATD.386 virtual device drivers if they are present. + */ + regs.x.ax = 0xFF00; + PM_int386(0x31,®s,®s); + if (!regs.x.cflag && (regs.e.edi & 8)) + return (haveDPMI = true); + return false; +} + +ibool PMAPI VF_available(void) +/**************************************************************************** +* +* Function: VF_available +* Returns: True if virtual buffer is available, false if not. +* +****************************************************************************/ +{ + if (!VF_zeroPtr) + VF_zeroPtr = PM_mapPhysicalAddr(0,0xFFFFFFFF,true); + if (CheckDPMI()) + return false; + + /* Standard DOS4GW, PMODE/W and Causeway */ + if (InitPaging() == -1) + return false; + ClosePaging(); + return true; +} + +void * PMAPI InitDPMI(ulong baseAddr,int bankSize,int codeLen,void *bankFunc) +/**************************************************************************** +* +* Function: InitDOS4GW +* Parameters: baseAddr - Base address of framebuffer bank window +* bankSize - Physical size of banks in Kb (4 or 64) +* codeLen - Length of 32 bit bank switch function +* bankFunc - Pointer to protected mode bank function +* Returns: Near pointer to virtual framebuffer, or NULL on failure. +* +* Description: Installs the virtual linear framebuffer handling for +* DPMI environments. This requires the DVA.386 or VFLATD.386 +* virtual device drivers to be installed and functioning. +* +****************************************************************************/ +{ + (void)baseAddr; + (void)bankSize; + (void)codeLen; + (void)bankFunc; + return NULL; +} + +void * PMAPI InitDOS4GW(ulong baseAddr,int bankSize,int codeLen,void *bankFunc) +/**************************************************************************** +* +* Function: InitDOS4GW +* Parameters: baseAddr - Base address of framebuffer bank window +* bankSize - Physical size of banks in Kb (4 or 64) +* codeLen - Length of 32 bit bank switch function +* bankFunc - Pointer to protected mode bank function +* Returns: Near pointer to virtual framebuffer, or NULL on failure. +* +* Description: Installs the virtual linear framebuffer handling for +* the DOS4GW extender. +* +****************************************************************************/ +{ + int i; + + if (InitPaging() == -1) + return NULL; /* Cannot do hardware paging! */ + + /* Map 4MB of video memory into linear address space (read/write) */ + if (bankSize == 64) { + for (i = 0; i < 64; i++) { + MapPhysical2Linear(baseAddr,VFLAT_START_ADDR+(i<<16),16, + PAGE_WRITE | PAGE_NOTPRESENT); + } + } + else { + for (i = 0; i < 1024; i++) { + MapPhysical2Linear(baseAddr,VFLAT_START_ADDR+(i<<12),1, + PAGE_WRITE | PAGE_NOTPRESENT); + } + } + + /* Install our page fault handler and banks switch function */ + InstallFaultHandler(baseAddr,bankSize); + InstallBankFunc(codeLen,bankFunc); + installed = true; + return (void*)VFLAT_START_ADDR; +} + +void * PMAPI VF_init(ulong baseAddr,int bankSize,int codeLen,void *bankFunc) +/**************************************************************************** +* +* Function: VF_init +* Parameters: baseAddr - Base address of framebuffer bank window +* bankSize - Physical size of banks in Kb (4 or 64) +* codeLen - Length of 32 bit bank switch function +* bankFunc - Pointer to protected mode bank function +* Returns: Near pointer to virtual framebuffer, or NULL on failure. +* +* Description: Installs the virtual linear framebuffer handling. +* +****************************************************************************/ +{ + if (installed) + return (void*)VFLAT_START_ADDR; + if (codeLen > 100) + return NULL; /* Bank function is too large! */ + if (!VF_zeroPtr) + VF_zeroPtr = PM_mapPhysicalAddr(0,0xFFFFFFFF,true); + if (CheckDPMI()) + return InitDPMI(baseAddr,bankSize,codeLen,bankFunc); + return InitDOS4GW(baseAddr,bankSize,codeLen,bankFunc); +} + +void PMAPI VF_exit(void) +/**************************************************************************** +* +* Function: VF_exit +* +* Description: Closes down the virtual framebuffer services and +* restores the previous page fault handler. +* +****************************************************************************/ +{ + if (installed) { + if (haveDPMI) { + /* DPMI support */ + } + else { + /* Standard DOS4GW and PMODE/W support */ + RemoveFaultHandler(); + ClosePaging(); + } + installed = false; + } +} + +/*-------------------------------------------------------------------------*/ +/* Support mapped out for other compilers. */ +/*-------------------------------------------------------------------------*/ + +#else + +ibool PMAPI VF_available(void) +{ + return false; +} + +void * PMAPI VF_init(ulong baseAddr,int bankSize,int codeLen,void *bankFunc) +{ + (void)baseAddr; + (void)bankSize; + (void)codeLen; + (void)bankFunc; + return NULL; +} + +void PMAPI VF_exit(void) +{ +} + +#endif |
