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Added function 51, reallocate pages

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@240
This commit is contained in:
Sjoerd van der Berg 2002-08-29 11:13:56 +00:00
parent 48a3641de1
commit eb18047ff7
1 changed files with 56 additions and 0 deletions
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56
src/ints/ems.cpp
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@ -136,6 +136,59 @@ static Bit8u EMM_AllocateMemory(Bit16u pages,Bit16u & handle) {
return EMM_NO_ERROR;
}
static Bit8u EMM_ReallocatePages(Bit16u handle,Bit16u & pages) {
/* Check for valid handle */
if (handle>=EMM_MAX_HANDLES || emm_handles[handle].first_page==NULL_PAGE) return EMM_INVALID_HANDLE;
/* Check for enough pages */
if ((emm_handles[handle].pages+EMM_GetFreePages())<pages) return EMM_OUT_OF_LOG;
Bit16u page=emm_handles[handle].first_page;
Bit16u last=NULL_PAGE;
Bit16u page_count=emm_handles[handle].pages;
while (pages>0 && page_count>0) {
if (emm_pages[page].handle!=handle) E_Exit("EMM:Error illegal handle reference");
last=page;
page=emm_pages[page].next;
pages--;
page_count--;
}
/* Free the rest of the handles */
if (page_count && !pages) {
emm_handles[handle].pages-=page_count;
while (page_count>0) {
free(emm_pages[page].memory);
emm_pages[page].memory=0;
emm_pages[page].handle=NULL_HANDLE;
Bit16u next_page=emm_pages[page].next;
emm_pages[page].next=NULL_PAGE;
page=next_page;page_count--;
}
pages=emm_handles[handle].pages;
return EMM_NO_ERROR;
}
if (!page_count && pages) {
/* Allocate extra pages */
emm_handles[handle].pages+=pages;
page=0;
while (pages) {
if (emm_pages[page].handle==NULL_HANDLE) {
emm_pages[page].handle=handle;
emm_pages[page].memory=malloc(EMM_PAGE_SIZE);
if (!emm_pages[page].memory) E_Exit("EMM:Cannont allocate memory");
emm_pages[last].next=page;
last=page;
pages--;
} else {
if (++page>=EMM_MAX_PAGES) E_Exit("EMM:Ran out of pages");
}
}
pages=emm_handles[handle].pages;
return EMM_NO_ERROR;
}
/* Size exactly the same as the original size */
pages=emm_handles[handles].pages;
return EMM_NO_ERROR;
}
static Bit8u EMM_MapPage(Bitu phys_page,Bit16u handle,Bit16u log_page) {
/* Check for too high physical page */
if (phys_page>=EMM_MAX_PHYS) return EMM_ILL_PHYS;
@ -335,6 +388,9 @@ static Bitu INT67_Handler(void) {
break;
}
break;
case 0x51: /* Reallocate Pages */
reg_ah=EMM_ReallocatePages(reg_dx,reg_bx);
break;
case 0x53: // Set/Get Handlename
if (reg_al==0x00) { // Get Name not supported
LOG_ERROR("EMS:Get handle name not supported",reg_ah);