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Some kind of pagefault implementation

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@1446
This commit is contained in:
Sjoerd van der Berg 2003-11-18 22:20:10 +00:00
parent e23e7206e5
commit f854f9a58c
1 changed files with 86 additions and 4 deletions
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90
src/cpu/paging.cpp
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@ -24,6 +24,9 @@
#include "mem.h"
#include "paging.h"
#include "regs.h"
#include "lazyflags.h"
#include "cpu.h"
#include "debug.h"
#define LINK_TOTAL (64*1024)
@ -67,9 +70,64 @@ HostPt PageHandler::GetHostPt(Bitu phys_page) {
}
Bits Full_DeCode(void);
struct PF_Entry {
Bitu cs;
Bitu eip;
Bitu page_addr;
};
#define PF_QUEUESIZE 16
struct {
Bitu used;
PF_Entry entries[PF_QUEUESIZE];
} pf_queue;
static Bits PageFaultCore(void) {
CPU_CycleLeft+=CPU_Cycles;
CPU_Cycles=1;
Bitu ret=Full_DeCode();
CPU_CycleLeft+=CPU_Cycles;
if (ret<0) E_Exit("Got a dosbox close machine in pagefault core?");
if (ret)
return ret;
if (!pf_queue.used) E_Exit("PF Core without PF");
PF_Entry * entry=&pf_queue.entries[pf_queue.used-1];
X86PageEntry pentry;
pentry.load=MEM_PhysReadD(entry->page_addr);
if (pentry.block.p && entry->cs == SegValue(cs) && entry->eip==reg_eip)
return -1;
return 0;
}
Bitu DEBUG_EnableDebugger(void);
void PAGING_PageFault(PhysPt lin_addr,Bitu page_addr,Bitu type) {
/* Save the state of the cpu cores */
LOG_MSG("PageFault at %X type %d queue %d",lin_addr,type,pf_queue.used);
LazyFlags old_lflags;
memcpy(&old_lflags,&lflags,sizeof(LazyFlags));
CPU_Decoder * old_cpudecoder;
old_cpudecoder=cpudecoder;
cpudecoder=&PageFaultCore;
paging.cr2=lin_addr;
PF_Entry * entry=&pf_queue.entries[pf_queue.used++];
entry->cs=SegValue(cs);
entry->eip=reg_eip;
entry->page_addr=page_addr;
//Caused by a write by default?
CPU_Exception(14,0x2 | ((cpu.cpl>0) ? 0x1 : 0));
DEBUG_EnableDebugger();
DOSBOX_RunMachine();
pf_queue.used--;
memcpy(&lflags,&old_lflags,sizeof(LazyFlags));
cpudecoder=old_cpudecoder;
}
class InitPageHandler : public PageHandler {
public:
InitPageHandler() {flags=0;}
InitPageHandler() {flags=PFLAG_ILLEGAL;}
void AddPageLink(Bitu lin_page, Bitu phys_page) {
assert(0);
}
@ -97,11 +155,34 @@ public:
InitPage(addr);
mem_writed(addr,val);
}
void InitPage(Bitu addr) {
Bitu lin_page=addr >> 12;
void InitPage(Bitu lin_addr) {
Bitu lin_page=lin_addr >> 12;
Bitu phys_page;
if (paging.enabled) {
E_Exit("No paging support");
Bitu d_index=lin_page >> 10;
Bitu t_index=lin_page & 0x3ff;
Bitu table_addr=(paging.base.page<<12)+d_index*4;
X86PageEntry table;
table.load=MEM_PhysReadD(table_addr);
if (!table.block.p) {
LOG(LOG_PAGING,LOG_ERROR)("NP Table");
PAGING_PageFault(lin_addr,table_addr,0);
table.load=MEM_PhysReadD(table_addr);
if (!table.block.p)
E_Exit("Pagefault didn't correct table");
}
X86PageEntry entry;
Bitu entry_addr=(table.block.base << 12)+t_index*4;
entry.load=MEM_PhysReadD(entry_addr);
if (!entry.block.p) {
LOG(LOG_PAGING,LOG_ERROR)("NP Page");
PAGING_PageFault(lin_addr,entry_addr,0);
entry.load=MEM_PhysReadD(entry_addr);
if (!entry.block.p)
E_Exit("Pagefault didn't correct page");
}
phys_page=entry.block.base;
LOG_MSG("Linked page lin page %X to phys page %X",lin_page,phys_page);
} else {
if (lin_page<LINK_START) phys_page=mapfirstmb[lin_page];
else phys_page=lin_page;
@ -213,5 +294,6 @@ void PAGING_Init(Section * sec) {
for (i=0;i<LINK_START;i++) {
mapfirstmb[i]=i;
}
pf_queue.used=0;
}