FAT driver, IMGMOUNT: Add code to allow directing all FAT driver acce…

…ss through INT 13h so that if any program depends on hooking INT 13h to intercept I/O, it will work

include/bios_disk.h

@@ -594,7 +594,9 @@ class imageDiskINT13Drive : public imageDisk {
 	virtual ~imageDiskINT13Drive();
 
 	uint8_t bios_disk = 0;
+	bool enable_int13 = false;
 	imageDisk* subdisk = NULL;
+	bool busy = false;
 };
 
 #endif

src/cpu/callback.cpp

@@ -691,6 +691,11 @@ Bitu CALLBACK_SetupExtra(Bitu callback, Bitu type, PhysPt physAddress, bool use_
 		phys_writeb(physAddress+0x01,(uint8_t)0xCF);		//An IRET Instruction
 		phys_writew(physAddress+0x02,(uint16_t)0x0ECD);		// int 0e
 		phys_writeb(physAddress+0x04,(uint8_t)0xCF);		//An IRET Instruction
+		// for the image disk support to call
+		phys_writew(physAddress+0x05,(uint16_t)0x13CD);		// int 13
+		phys_writeb(physAddress+0x07,0xFE);
+		phys_writeb(physAddress+0x08,0x38);
+		phys_writew(physAddress+0x09,(uint16_t)call_idle);
 		return (use_cb?9:5);
 	case CB_VESA_WAIT:
 		if (use_cb) E_Exit("VESA wait must not implement a callback handler!");

src/dos/dos_programs.cpp

@@ -6114,10 +6114,10 @@ class IMGMOUNT : public Program {
 				if ((*i) == "int13") {
 					char buf[32];
 
-					if (drive >= 2)
-						sprintf(buf,"=%u",drive+0x80-2);
+					if (drive >= 'C')
+						sprintf(buf,"=%u",drive+0x80-'C');
 					else
-						sprintf(buf,"=%u",drive);
+						sprintf(buf,"=%u",drive-'A');
 
 					(*i) += buf;
 				}
@@ -6344,6 +6344,13 @@ class IMGMOUNT : public Program {
 						}
 					}
 				}
+
+				/* now that the image is attached to INT 13h the INT 13 image can use it now */
+				if (image->class_id == imageDisk::ID_INT13) {
+					imageDiskINT13Drive *x = (imageDiskINT13Drive*)image;
+					x->enable_int13 = true;
+					LOG_MSG("INT 13 image enabling calling");
+				}
 			}
 			return true;
 		}

src/dos/drive_fat.cpp

@@ -2495,6 +2495,8 @@ bool fatDrive::FileCreate(DOS_File **file, const char *name, uint16_t attributes
 
 	if (unformatted) return false;
 
+	checkDiskChange();
+
     if (readonly) {
 		DOS_SetError(DOSERR_WRITE_PROTECTED);
         return false;
@@ -2598,6 +2600,8 @@ bool fatDrive::FileCreate(DOS_File **file, const char *name, uint16_t attributes
 bool fatDrive::FileExists(const char *name) {
 	if (unformatted) return false;
 
+	checkDiskChange();
+
     direntry fileEntry = {};
 	uint32_t dummy1, dummy2;
 	uint16_t save_errorcode = dos.errorcode;
@@ -2609,6 +2613,8 @@ bool fatDrive::FileExists(const char *name) {
 bool fatDrive::FileOpen(DOS_File **file, const char *name, uint32_t flags) {
 	if (unformatted) return false;
 
+	checkDiskChange();
+
     direntry fileEntry = {};
 	uint32_t dirClust, subEntry;
 
@@ -2639,6 +2645,8 @@ bool fatDrive::FileStat(const char * /*name*/, FileStat_Block *const /*stat_bloc
 bool fatDrive::FileUnlink(const char * name) {
 	if (unformatted) return false;
 
+	checkDiskChange();
+
     if (readonly) {
 		DOS_SetError(DOSERR_WRITE_PROTECTED);
         return false;
@@ -2688,6 +2696,8 @@ bool fatDrive::FileUnlink(const char * name) {
 bool fatDrive::FindFirst(const char *_dir, DOS_DTA &dta,bool fcb_findfirst) {
 	if (unformatted) return false;
 
+	checkDiskChange();
+
     direntry dummyClust = {};
 
     // volume label searches always affect root directory, no matter the current directory, at least with FCBs
@@ -3050,6 +3060,8 @@ bool fatDrive::FindNext(DOS_DTA &dta) {
 bool fatDrive::SetFileAttr(const char *name, uint16_t attr) {
 	if (unformatted) return false;
 
+	checkDiskChange();
+
     if (readonly) {
 		DOS_SetError(DOSERR_WRITE_PROTECTED);
         return false;
@@ -3354,6 +3366,8 @@ void fatDrive::zeroOutCluster(uint32_t clustNumber) {
 bool fatDrive::MakeDir(const char *dir) {
 	if (unformatted) return false;
 
+	checkDiskChange();
+
 	const char *lfn = NULL;
 
     if (readonly) {
@@ -3459,6 +3473,8 @@ bool fatDrive::MakeDir(const char *dir) {
 bool fatDrive::RemoveDir(const char *dir) {
 	if (unformatted) return false;
 
+	checkDiskChange();
+
 	if (readonly) {
 		DOS_SetError(DOSERR_WRITE_PROTECTED);
 		return false;
@@ -3530,6 +3546,8 @@ bool fatDrive::RemoveDir(const char *dir) {
 bool fatDrive::Rename(const char * oldname, const char * newname) {
 	if (unformatted) return false;
 
+	checkDiskChange();
+
 	const char *lfn = NULL;
 
     if (readonly) {
@@ -3646,3 +3664,58 @@ void fatDrive::clusterChainMemory::clear(void) {
 	current_cluster_index = 0;
 }
 
+void fatDrive::checkDiskChange(void) {
+	bool chg = false;
+
+	if (loadedDisk->detectDiskChange() && !BPB.is_fat32()) {
+		LOG_MSG("FAT: disk change\n");
+
+		FAT_BootSector bootbuffer = {};
+		loadedDisk->Read_AbsoluteSector(0+partSectOff,&bootbuffer);
+
+		void* var = &bootbuffer.bpb.v.BPB_BytsPerSec;
+		bootbuffer.bpb.v.BPB_BytsPerSec = var_read((uint16_t*)var);
+		var = &bootbuffer.bpb.v.BPB_RsvdSecCnt;
+		bootbuffer.bpb.v.BPB_RsvdSecCnt = var_read((uint16_t*)var);
+		var = &bootbuffer.bpb.v.BPB_RootEntCnt;
+		bootbuffer.bpb.v.BPB_RootEntCnt = var_read((uint16_t*)var);
+		var = &bootbuffer.bpb.v.BPB_TotSec16;
+		bootbuffer.bpb.v.BPB_TotSec16 = var_read((uint16_t*)var);
+		var = &bootbuffer.bpb.v.BPB_FATSz16;
+		bootbuffer.bpb.v.BPB_FATSz16 = var_read((uint16_t*)var);
+		var = &bootbuffer.bpb.v.BPB_SecPerTrk;
+		bootbuffer.bpb.v.BPB_SecPerTrk = var_read((uint16_t*)var);
+		var = &bootbuffer.bpb.v.BPB_NumHeads;
+		bootbuffer.bpb.v.BPB_NumHeads = var_read((uint16_t*)var);
+		var = &bootbuffer.bpb.v.BPB_HiddSec;
+		bootbuffer.bpb.v.BPB_HiddSec = var_read((uint32_t*)var);
+		var = &bootbuffer.bpb.v.BPB_TotSec32;
+		bootbuffer.bpb.v.BPB_TotSec32 = var_read((uint32_t*)var);
+		var = &bootbuffer.bpb.v.BPB_VolID;
+		bootbuffer.bpb.v.BPB_VolID = var_read((uint32_t*)var);
+
+		if (BPB.v.BPB_FATSz16 == 0) {
+			LOG_MSG("BPB_FATSz16 == 0 and not FAT32 BPB, not valid");
+			return;
+		}
+
+		uint32_t RootDirSectors;
+		uint32_t DataSectors;
+
+		RootDirSectors = ((BPB.v.BPB_RootEntCnt * 32u) + (BPB.v.BPB_BytsPerSec - 1u)) / BPB.v.BPB_BytsPerSec;
+
+		if (BPB.v.BPB_TotSec16 != 0)
+			DataSectors = (Bitu)BPB.v.BPB_TotSec16 - ((Bitu)BPB.v.BPB_RsvdSecCnt + ((Bitu)BPB.v.BPB_NumFATs * (Bitu)BPB.v.BPB_FATSz16) + (Bitu)RootDirSectors);
+		else
+			DataSectors = (Bitu)BPB.v.BPB_TotSec32 - ((Bitu)BPB.v.BPB_RsvdSecCnt + ((Bitu)BPB.v.BPB_NumFATs * (Bitu)BPB.v.BPB_FATSz16) + (Bitu)RootDirSectors);
+
+		CountOfClusters = DataSectors / BPB.v.BPB_SecPerClus;
+		firstDataSector = ((Bitu)BPB.v.BPB_RsvdSecCnt + ((Bitu)BPB.v.BPB_NumFATs * (Bitu)BPB.v.BPB_FATSz16) + (Bitu)RootDirSectors) + (Bitu)partSectOff;
+		firstRootDirSect = (Bitu)BPB.v.BPB_RsvdSecCnt + ((Bitu)BPB.v.BPB_NumFATs * (Bitu)BPB.v.BPB_FATSz16) + (Bitu)partSectOff;
+
+		LOG_MSG("NEW FAT: data=%llu root=%llu rootdirsect=%lu datasect=%lu",
+			(unsigned long long)firstDataSector,(unsigned long long)firstRootDirSect,
+			(unsigned long)RootDirSectors,(unsigned long)DataSectors);
+	}
+}
+

src/dos/drives.h

@@ -521,6 +521,8 @@ class fatDrive : public DOS_Drive {
 	virtual uint32_t GetFirstClusterOffset(void);
 	virtual uint32_t GetHighestClusterNumber(void);
 
+	void checkDiskChange(void);
+
 	unsigned char bios_disk = 0;
 	bool unformatted = false;
 };

src/ints/bios.cpp

@@ -9352,6 +9352,8 @@ void BuildACPITable(void) {
 	rsdt_tw.finish();
 }
 
+extern unsigned int INT13Xfer;
+
 class BIOS:public Module_base{
 private:
     static Bitu cb_bios_post__func(void) {
@@ -9370,6 +9372,7 @@ class BIOS:public Module_base{
 	INT13_ElTorito_NoEmuDriveNumber = 0;
 	INT13_ElTorito_NoEmuCDROMDrive = 0;
 	INT13_ElTorito_IDEInterface = -1;
+	INT13Xfer = 0;
 
 	ACPI_mem_enable(false);
 	ACPI_REGION_SIZE = 0;

src/ints/bios_disk.cpp

@@ -30,6 +30,7 @@
 #include "../dos/drives.h"
 #include "mapper.h"
 #include "ide.h"
+#include "cpu.h"
 
 #if defined(_MSC_VER)
 # pragma warning(disable:4244) /* const fmath::local::uint64_t to double possible loss of data */
@@ -3739,11 +3740,95 @@ imageDiskEmptyDrive::~imageDiskEmptyDrive() {
 
 /////
 
+unsigned int INT13Xfer = 0;
+size_t INT13XferSize = 4096;
+
+static void imageDiskCallINT13(void) {
+	unsigned int rv = CALLBACK_RealPointer(call_int13);
+	Bitu oldIF=GETFLAG(IF);
+	SETFLAGBIT(IF,true);
+	uint16_t oldcs=SegValue(cs);
+	uint32_t oldeip=reg_eip;
+	SegSet16(cs,rv>>16);
+	reg_eip=(rv&0xFFFF)+4+5;
+	DOSBOX_RunMachine();
+	reg_eip=oldeip;
+	SegSet16(cs,oldcs);
+	SETFLAGBIT(IF,oldIF);
+}
+
 uint8_t imageDiskINT13Drive::Read_Sector(uint32_t head,uint32_t cylinder,uint32_t sector,void * data,unsigned int req_sector_size) {
-	return subdisk->Read_Sector(head,cylinder,sector,data,req_sector_size);
+	if (!enable_int13 || busy) return subdisk->Read_Sector(head,cylinder,sector,data,req_sector_size);
+
+	uint8_t ret = 0x05;
+	unsigned int retry = 3;
+
+	if (req_sector_size == 0) req_sector_size = sector_size;
+
+//	LOG_MSG("INT13 read C/H/S %u/%u/%u busy=%u",cylinder,head,sector,busy);
+
+	if (!busy && sector_size == req_sector_size && sector_size <= INT13XferSize) {
+		busy = true;
+
+		if (INT13Xfer == 0) INT13Xfer = DOS_GetMemory(INT13XferSize/16u,"INT 13 transfer buffer");
+
+		unsigned int s_eax = reg_eax;
+		unsigned int s_ebx = reg_ebx;
+		unsigned int s_ecx = reg_ecx;
+		unsigned int s_edx = reg_edx;
+		unsigned int s_es  = SegValue(es);
+		unsigned int s_fl  = reg_flags;
+
+again:
+		reg_eax = 0x200/*read command*/ | 1/*count*/;
+		reg_ebx = 0;
+		reg_ch = cylinder;
+		reg_cl = sector;
+		reg_dh = head;
+		reg_dl = bios_disk;
+		CPU_SetSegGeneral(es,INT13Xfer);
+
+		imageDiskCallINT13();
+
+		if (reg_flags & FLAG_CF) {
+			ret = reg_ah;
+			if (ret == 0) ret = 0x05;
+
+			if (ret == 6/*disk change*/) {
+				diskChangeFlag = true;
+				if (--retry > 0) goto again;
+			}
+		}
+		else {
+			MEM_BlockRead32(INT13Xfer<<4,data,sector_size);
+			data = (void*)((char*)data + sector_size);
+			if ((++sector) >= (sectors + 1)) {
+				assert(sector == (sectors + 1));
+				sector = 1;
+				if ((++head) >= heads) {
+					assert(head == heads);
+					head = 0;
+					cylinder++;
+				}
+			}
+		}
+
+		reg_eax = s_eax;
+		reg_ebx = s_ebx;
+		reg_ecx = s_ecx;
+		reg_edx = s_edx;
+		reg_flags = s_fl;
+		CPU_SetSegGeneral(es,s_es);
+
+		busy = false;
+	}
+
+	return ret;
 }
 
 uint8_t imageDiskINT13Drive::Write_Sector(uint32_t head,uint32_t cylinder,uint32_t sector,const void * data,unsigned int req_sector_size) {
+	if (INT13Xfer == 0) INT13Xfer = DOS_GetMemory(INT13XferSize/16u,"INT 13 transfer buffer");
+
 	return subdisk->Write_Sector(head,cylinder,sector,data,req_sector_size);
 }
 
@@ -3804,7 +3889,38 @@ uint32_t imageDiskINT13Drive::getSectSize(void) {
 }
 
 bool imageDiskINT13Drive::detectDiskChange(void) {
-	return subdisk->detectDiskChange();
+	if (enable_int13 && !busy) {
+		busy = true;
+
+		unsigned int s_eax = reg_eax;
+		unsigned int s_ebx = reg_ebx;
+		unsigned int s_ecx = reg_ecx;
+		unsigned int s_edx = reg_edx;
+		unsigned int s_fl  = reg_flags;
+
+		reg_eax = 0x1600/*disk change detect*/;
+		reg_dl = bios_disk;
+		CPU_SetSegGeneral(es,INT13Xfer);
+
+		imageDiskCallINT13();
+
+		if (reg_flags & FLAG_CF) {
+			if (reg_ah == 0x06) {
+				LOG_MSG("INT13 image disk change flag\n");
+				diskChangeFlag = true;
+			}
+		}
+
+		reg_eax = s_eax;
+		reg_ebx = s_ebx;
+		reg_ecx = s_ecx;
+		reg_edx = s_edx;
+		reg_flags = s_fl;
+
+		busy = false;
+	}
+
+	return imageDisk::detectDiskChange();
 }
 
 imageDiskINT13Drive::imageDiskINT13Drive(imageDisk *sdisk) : imageDisk(ID_INT13) {