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handle zero-pages ems allocation requests correctly (fixes VBDOS)

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@3381
This commit is contained in:
Sebastian Strohhäcker 2009-05-14 17:05:58 +00:00
parent db4387542f
commit a14636aea0
1 changed files with 27 additions and 13 deletions
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40
src/ints/ems.cpp
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@ -1,5 +1,5 @@
/*
* Copyright (C) 2002-2008 The DOSBox Team
* Copyright (C) 2002-2009 The DOSBox Team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -16,7 +16,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* $Id: ems.cpp,v 1.60 2008-11-27 18:57:45 c2woody Exp $ */
/* $Id: ems.cpp,v 1.61 2009-05-14 17:05:58 c2woody Exp $ */
#include <string.h>
#include <stdlib.h>
@ -79,16 +79,16 @@ public:
SetName("EMMXXXX0");
GEMMIS_seg=0;
}
bool Read(Bit8u * data,Bit16u * size) { return false;}
bool Write(Bit8u * data,Bit16u * size){
bool Read(Bit8u * /*data*/,Bit16u * /*size*/) { return false;}
bool Write(Bit8u * /*data*/,Bit16u * /*size*/){
LOG(LOG_IOCTL,LOG_NORMAL)("EMS:Write to device");
return false;
}
bool Seek(Bit32u * pos,Bit32u type){return false;}
bool Seek(Bit32u * /*pos*/,Bit32u /*type*/){return false;}
bool Close(){return false;}
Bit16u GetInformation(void){return 0xc080;}
bool ReadFromControlChannel(PhysPt bufptr,Bit16u size,Bit16u * retcode);
bool WriteToControlChannel(PhysPt bufptr,Bit16u size,Bit16u * retcode){return true;}
bool WriteToControlChannel(PhysPt /*bufptr*/,Bit16u /*size*/,Bit16u * /*retcode*/){return true;}
private:
Bit8u cache;
};
@ -126,7 +126,7 @@ bool device_EMM::ReadFromControlChannel(PhysPt bufptr,Bit16u size,Bit16u * retco
mem_writeb(GEMMIS_addr+0x0a+frnr,0x03); // frame type: EMS frame in 64k page
mem_writeb(GEMMIS_addr+0x0b+frnr,0xff); // owner: NONE
mem_writew(GEMMIS_addr+0x0c+frnr,0x7fff); // no logical page number
mem_writeb(GEMMIS_addr+0x0e + frnr,frct); // physical EMS page number
mem_writeb(GEMMIS_addr+0x0e+frnr,(Bit8u)(frct&0xff)); // physical EMS page number
mem_writeb(GEMMIS_addr+0x0f+frnr,0x00); // EMS frame
}
/* build non-EMS ROM frames (0xf000-0x10000) */
@ -224,8 +224,11 @@ static Bit8u EMM_AllocateMemory(Bit16u pages,Bit16u & dhandle,bool can_allocate_
while (emm_handles[handle].pages != NULL_HANDLE) {
if (++handle >= EMM_MAX_HANDLES) {return EMM_OUT_OF_HANDLES;}
}
MemHandle mem = MEM_AllocatePages(pages*4,false);
if (!mem) E_Exit("EMS:Memory allocation failure");
MemHandle mem = 0;
if (pages) {
mem = MEM_AllocatePages(pages*4,false);
if (!mem) E_Exit("EMS:Memory allocation failure");
}
emm_handles[handle].pages = pages;
emm_handles[handle].mem = mem;
/* Change handle only if there is no error. */
@ -251,8 +254,14 @@ static Bit8u EMM_AllocateSystemHandle(Bit16u pages) {
static Bit8u EMM_ReallocatePages(Bit16u handle,Bit16u & pages) {
/* Check for valid handle */
if (!ValidHandle(handle)) return EMM_INVALID_HANDLE;
/* Check for enough pages */
if (!MEM_ReAllocatePages(emm_handles[handle].mem,pages*4,false)) return EMM_OUT_OF_LOG;
if (emm_handles[handle].pages != 0) {
/* Check for enough pages */
if (!MEM_ReAllocatePages(emm_handles[handle].mem,pages*4,false)) return EMM_OUT_OF_LOG;
} else {
MemHandle mem = MEM_AllocatePages(pages*4,false);
if (!mem) E_Exit("EMS:Memory allocation failure during reallocation");
emm_handles[handle].mem = mem;
}
/* Update size */
emm_handles[handle].pages=pages;
return EMM_NO_ERROR;
@ -347,9 +356,14 @@ static Bit8u EMM_MapSegment(Bitu segment,Bit16u handle,Bit16u log_page) {
static Bit8u EMM_ReleaseMemory(Bit16u handle) {
/* Check for valid handle */
if (!ValidHandle(handle)) return EMM_INVALID_HANDLE;
// should check for saved_page_map flag here, returning an error if it's true
// as apps are required to restore the pagemap beforehand; to be checked
MEM_ReleasePages(emm_handles[handle].mem);
// if (emm_handles[handle].saved_page_map) return EMM_SAVEMAP_ERROR;
if (emm_handles[handle].pages != 0) {
MEM_ReleasePages(emm_handles[handle].mem);
}
/* Reset handle */
emm_handles[handle].mem=0;
if (handle==0) {
@ -1370,7 +1384,7 @@ public:
static EMS* test;
void EMS_ShutDown(Section* sec) {
void EMS_ShutDown(Section* /*sec*/) {
delete test;
}