int21.c

freedos32的源代码

				r->x.dx = 0; /* Revision 0, no flags... */
				RMREGS_CLEAR_CARRY;
				return;
			}
			r->h.al = 0xFF; /* Invalid subfunction */
			RMREGS_SET_CARRY;
			return;
		/* DOS 2+ - Get free disk space (DL=drive number, 0=default, 1=A, etc.) */
		case 0x36:
		{
			fd32_getfsfree_t fsfree;
			char drive[4] = " :\\";
			drive[0] = fd32_get_default_drive();
			if (r->h.dl) drive[0] = r->h.dl + 'A' - 1;
			fsfree.Size = sizeof(fd32_getfsfree_t);
			res = fd32_get_fsfree(drive, &fsfree);
			LOG_PRINTF(("INT 21h - Get free disk space for \"%s\", returns %08x\n", drive, res));
			LOG_PRINTF(("          Got: %lu secperclus, %lu availclus, %lu bytspersec, %lu totclus\n",
			            fsfree.SecPerClus, fsfree.AvailClus, fsfree.BytesPerSec, fsfree.TotalClus));
			if (res < 0)
			{
				r->x.ax = 0xFFFF; /* Unusual way to report error condition */
				return;
			}
			r->x.ax = fsfree.SecPerClus;  /* AX = Sectors per cluster     */
			r->x.bx = fsfree.AvailClus;   /* BX = Number of free clusters */
			r->x.cx = fsfree.BytesPerSec; /* CX = Bytes per sector        */
			r->x.dx = fsfree.TotalClus;   /* DX = Total clusters on drive */
			return;
		}
		/* DOS 2+ - "MKDIR" - Create subdirectory (DS:DX->ASCIZ directory name) */
		case 0x39:
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			LOG_PRINTF(("INT 21h - Make directory \"%s\"\n", fn));
			if (res >= 0) res = fd32_mkdir(fn);
			break;
		/* DOS 2+ - "RMDIR" - Remove subdirectory (DS:DX->ASCIZ directory name) */
		case 0x3A:
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			LOG_PRINTF(("INT 21h - Remove directory \"%s\"\n", fn));
			if (res >= 0) res = fd32_rmdir(fn);
			break;
		/* DOS 2+ - "CHDIR" - Set current directory (DS:DX->ASCIZ directory name) */
		case 0x3B:
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			LOG_PRINTF(("INT 21h - Change directory to \"%s\"\n", fn));
			if (res >= 0) res = fd32_chdir(fn);
			break;
		/* DOS 2+ - "CREAT" - Create or truncate file (DS:DX->ASCIZ file name,
		 * CX=attributes, volume label and directory not allowed).
		 */
		case 0x3C:
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			LOG_PRINTF(("INT 21h - Creat \"%s\" with attr %04x\n", fn, r->x.cx));
			if (res < 0) break;
			res = fd32_open(fn, O_RDWR | O_CREAT | O_TRUNC, r->x.cx, 0, NULL);
			res2dos(res, r);
			if (res >= 0) r->x.ax = (WORD) res; /* The new handle */
			break;
		/* DOS 2+ - "OPEN" - Open existing file (DS:DX->ASCIZ file name,
		 * AL=opening mode, CL=search attributes for server call).
		 */
		case 0x3D:
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			LOG_PRINTF(("INT 21h - Open \"%s\" with mode %02x\n", fn, r->h.al));
			if (res < 0) break;
			res = fd32_open(fn, r->h.al, FD32_ANONE, 0, NULL);
			res2dos(res, r);
			if (res >= 0) r->x.ax = (WORD) res; /* The new handle */
			break;
		/* DOS 2+ - "CLOSE" - Close file (BX=file handle) */
		case 0x3E:
			LOG_PRINTF(("INT 21h - Close handle %04x\n", r->x.bx));
			res = fd32_close(r->x.bx);
			break; /* Recent DOSes preserve AH, we are OK with this */
		/* DOS 2+ - "READ" - Read from file or device (BX=file handle,
		 * CX=bytes to read, DS:DX->transfer buffer).
		 */
		case 0x3F:
			res = fd32_read(r->x.bx, (void *) FAR2ADDR(r->x.ds, r->x.dx), r->x.cx);
			//LOG_PRINTF(("INT 21h - Read (AH=3Fh) from handle %04x (%d bytes). Res=%08xh\n", r->x.bx, r->x.cx, res));
			if (res < 0) break;
			#if 0 /* FIXME: Can this be removed now? */
			/* This is a quick'n'dirty hack to return \n after \r from stdin.  */
			/* It works only if console input is on handle 0 and if the number */
			/* of bytes to read is greater than the first carriage return.     */
			/* TODO: Make this \r\n stuff functional according to the console. */
			if (r->x.bx == 0)
			{
				BYTE *buf = (BYTE *) FAR2ADDR(r->x.ds, r->x.dx);
				if (res < r->x.cx) buf[res++] = '\n';
			}
			#endif
			RMREGS_CLEAR_CARRY;
			r->x.ax = (WORD) res; /* bytes read */
			return;
		/* DOS 2+ - "WRITE" - Write to file or device (BX=file handle,
		 * CX=bytes to write, DS:DX->transfer buffer).
		 */
		case 0x40:
			res = fd32_write(r->x.bx, (/*const*/ void *) FAR2ADDR(r->x.ds, r->x.dx), r->x.cx);
			//LOG_PRINTF(("INT 21h - Write (AH=40h) to handle %04x (%d bytes). Res=%08xh\n", r->x.bx, r->x.cx, res));
			res2dos(res, r);
			if (res >= 0) r->x.ax = (WORD) res; /* bytes written */
			return;
		/* DOS 2+ - "UNLINK" - Delete file (DS:DX->ASCIZ file name,
		 * CL=search attributes for server call).
		 */
		case 0x41:
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			LOG_PRINTF(("INT 21h - Delete file \"%s\"\n", fn));
			if (res >= 0) res = fd32_unlink(fn, FD32_FAALL | FD32_FRNONE);
			break;
		/* DOS 2+ - "LSEEK" - Set current file position (BX=file handle,
		 * CX:DX=offset, AL=origin).
		 * FIXME: Replace with off_t
		 */
		case 0x42:
			res = fd32_lseek(r->x.bx, ((long long) r->x.cx << 8) + (long long) r->x.dx, r->h.al, &res64);
			res2dos(res, r);
			if (res >= 0)
			{
				r->x.ax = (WORD) res64;
				r->x.dx = (WORD) (res64 >> 16);
			}
			return;
		/* DOS 2+ - Get/set file attributes */
		case 0x43:
			dos_get_and_set_attributes(r);
			return;
		/* IOCTL functions
		 * TODO: They should be done... one day
		 */
		case 0x44:
			res = fd32_get_dev_info(r->x.bx);
			if (res < 0)
			{
				r->x.ax = DOS_EBADF;
				RMREGS_SET_CARRY;
			}
			else
			{
				r->x.ax = res;
				r->x.dx = r->x.ax;
				RMREGS_CLEAR_CARRY;
			}
			return;
		/* DOS 2+ - "DUP" - Duplicate file handle (BX=file handle) */
		case 0x45:
			/* BX file handle */
			res = fd32_dup(r->x.bx);
			res2dos(res, r);
			if (res >= 0) r->x.ax = (WORD) res; /* new handle */
			return;
		/* DOS 2+ - "DUP2", "FORCEDUP" - Force duplicate file handle
		 * (BX=file handle, CX=new handle).
		 */
		case 0x46:
			res = fd32_forcedup(r->x.bx, r->x.cx);
			break;
		/* DOS 2+ - "CWD" - Get current directory (DL=drive number, 0=default
		 * 1=A, etc., DS:DI->64 bytes buffer for ASCIZ path name).
		 */
		case 0x47:
		{
			char  drive[2] = "A";
			char *c;
			char *dest = (char *) FAR2ADDR(r->x.ds, r->x.si);
			LOG_PRINTF(("INT 21h - Get current dir of drive %02x\n", r->h.dl));
			drive[0] = fd32_get_default_drive();
			if (r->h.dl) drive[0] = r->h.dl + 'A' - 1;
			res = fd32_getcwd(drive, fn);
			if (res < 0) break;
			LOG_PRINTF(("After getcwd:\"%s\"\n", fn));
			/* Convert all component to 8.3 */
			res = fd32_sfn_truename(fn, fn);
			if (res < 0) break;
			LOG_PRINTF(("After sfn_truename:\"%s\"\n", fn));
			/* Skip drive specification and initial backslash as required from DOS */
			for (c = fn; *c != '\\'; c++);
			strcpy(dest, c + 1);
			LOG_PRINTF(("Returned CWD:\"%s\"\n", dest));
			r->x.ax = 0x0100; /* Undocumented success return value */
			RMREGS_CLEAR_CARRY;
			/* TODO: Convert from UTF-8 to OEM */
			return;
		}
		/* DOS 2+ - "EXEC" - Load and/or Execute program */
		case 0x4B:
		{
			ExecParams *pb;
			char *args, *p, c[128];
			int cnt, i;
			pb = (ExecParams *) FAR2ADDR(r->x.es, r->x.bx);
			/* Only AH = 0x00 - Load and Execute - is currently supported */
			if (r->h.al != 0)
			{
				r->h.al = 0xFF; /* Invalid subfunction */
				RMREGS_SET_CARRY;
				return;
			}
			p = (char *) FAR2ADDR(pb->arg_seg, pb->arg_offs);
			cnt = *p++;
			if (cnt == 0) {
				args = NULL;
			} else {
				for (i = 0; i < cnt; i++) {
				c[i] = *p++;
				}
				c[i] = 0;
				args = c;
			}
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			LOG_PRINTF(("INT 21h - Load and Execute \"%s\"\n", fn));
			if (res >= 0) res = dos_exec(fn, pb->Env, args, pb->Fcb1, pb->Fcb2, &dos_return_code);
			break;
		}
		/* DOS 2+ - Get return code */
		case 0x4D:
			RMREGS_CLEAR_CARRY;
			r->h.ah = 0; /* Only normal termination, for now... */
			r->h.al = dos_return_code;
			dos_return_code = 0; /* DOS clears it after reading it */
			return;
		/* DOS 2+ - "FINDFIRST" - Find first matching file (DS:DX->ASCIZ file spec,
		 * CX=allowable attributes (archive and read only ignored),
		 * AL=special flag for append (ignored).
		 */
		case 0x4E:
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			LOG_PRINTF(("INT 21h - Findfirst \"%s\" with attr %04x\n", fn, r->x.cx));
			if (res < 0) break;
			res = fd32_dos_findfirst(fn, r->x.cx, current_psp->dta);
			LOG_PRINTF(("a\n"));
			res2dos(res, r);
			LOG_PRINTF(("b\n"));
			if (res == -ENOENT) r->x.ax = DOS_ENOMOREF;
			LOG_PRINTF(("c\n"));
			return;
		/* DOS 2+ - "FINDNEXT" - Find next matching file */
		case 0x4F:
			LOG_PRINTF(("INT 21h - Findnext\n"));
			res = fd32_dos_findnext(current_psp->dta);
			res2dos(res, r);
			if (res == -ENOENT) r->x.ax = DOS_ENOMOREF;
			return;
		/* DOS 2+ - "RENAME" - Rename or move file (DS:DX->old name,
		 * ES:DI->new name, CL=attributes for server call).
		 */
		case 0x56:
		{
			char newfn[FD32_LFNPMAX];
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			if (res < 0) break;
			res = fix_path(newfn, (const char *) FAR2ADDR(r->x.es, r->x.di), sizeof(newfn));
			if (res < 0) break;
			LOG_PRINTF(("INT 21h - Renaming \"%s\" to \"%s\"\n", fn, newfn));
			res = fd32_rename(fn, newfn);
			break;
		}
		/* DOS 2+ - Get/set file's time stamps */
		case 0x57:
			get_and_set_time_stamps(r);
			return;
		/* DOS 3.0+ - Create new file (DS:DX->ASCIZ file name, CX=attributes) */
		case 0x5B:
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			LOG_PRINTF(("INT 21h - Creating new file (AH=5Bh) \"%s\" with attr %04x\n", fn, r->x.cx));
			if (res < 0) break;
			res = fd32_open(fn, O_RDWR | O_CREAT | O_EXCL, r->x.cx, 0, NULL);
			res2dos(res, r);
			if (res >= 0) r->x.ax = (WORD) res; /* The new handle */
			return;
		/* DOS 3.0+ - Get current PSP address */
		case 0x62:
			LOG_PRINTF(("INT 21h - Get current PSP address\n"));
			r->x.bx = (DWORD) current_psp >> 4;
			return;
		/* DOS 3.3+ - "FFLUSH" - Commit file
		 * and DOS 4.0+ Undocumented - Commit file (BX=file handle).
		 */
		case 0x68:
		case 0x6A:
			LOG_PRINTF(("INT 21h - fflush\n"));
			/* BX file handle */
			res = fd32_fflush(r->x.bx);
			break;
		/* DOS 5+ Undocumented - Null function */
		case 0x6B:
			LOG_PRINTF(("INT 21h - Null function. Hey, somebody calls it!\n"));
			r->h.al = 0;
			RMREGS_CLEAR_CARRY;
			return;
		/* DOS 4.0+ - Extended open/create file (AL=00h, BL=access and sharing mode,
		 * BH=flags, CX=attributes for creation, DL=action, DH=00h, DS:DI->ASCIZ file name).
		 */
		case 0x6C:
		{
			int action;
			res = parse_open_action(r->x.dx);
			if (res < 0) break;
			action = res;
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.si), sizeof(fn));
			if (res < 0) break;
			res = fd32_open(fn, action | (DWORD) r->x.bx, r->x.cx, 0, &action);
			LOG_PRINTF(("INT 21h - Extended open/create (AH=6Ch) \"%s\" res=%08xh\n", fn, res));
			res2dos(res, r);
			if (res >= 0)
			{
				r->x.ax = (WORD) res; /* The new handle */
				r->x.cx = (WORD) action; /* Action taken */
			}
			return;
		}
		/* Long File Name functions */
		case 0x71:
			if (use_lfn) lfn_functions(r);
			else
			{
				r->x.ax = 0x7100; /* Yet another convention */
				RMREGS_SET_CARRY;
			}
			return;
		/* Windows 95 beta - "FindClose" - Terminate directory search
		* _Guessing_ that BX is the directory handle.
		*/
		case 0x72:
			res = fd32_lfn_findclose(r->x.bx);
			break;
		/* Windows 95 FAT32 services.
		 * Only AH=03h "Get extended free space on drive" is currently supported.
		 */
		case 0x73:
		{
			ExtDiskFree *edf;
			fd32_getfsfree_t fsfree;
			LOG_PRINTF(("INT 21h - FAT32 service %02x issued\n", r->h.al));
			if (r->h.al != 0x03)
			{
				r->h.al = 0xFF; /* Unimplemented subfunction */
				RMREGS_SET_CARRY;
				return;
			}
			/* DS:DX->ASCIZ string for drive ("C:\" or "\\SERVER\Share")
			 * ES:DI->Buffer for extended free space structure (ExtFreSpace)
			 * CX=size of ES:DI buffer
			 */
			if (r->x.cx < sizeof(ExtDiskFree))
			{
				r->x.ax = DOS_EBUFSMALL;
				RMREGS_SET_CARRY;
				return;
			}
			edf = (ExtDiskFree *) FAR2ADDR(r->x.es, r->x.di);
			if (edf->Version != 0x0000)
			{
				r->x.ax = DOS_EINVAL;
				RMREGS_SET_CARRY;
				return;
			}
			fsfree.Size = sizeof(fd32_getfsfree_t);
			res = fix_path(fn, (const char *) FAR2ADDR(r->x.ds, r->x.dx), sizeof(fn));
			if (res < 0) break;
			res = fd32_get_fsfree(fn, &fsfree);
			if (res >= 0)
			{
				edf->Size = sizeof(ExtDiskFree);
				/* Currently we don't support volume compression */
				edf->SecPerClus  = fsfree.SecPerClus;
				edf->BytesPerSec = fsfree.BytesPerSec;
				edf->AvailClus   = fsfree.AvailClus;
				edf->TotalClus   = fsfree.TotalClus;
				edf->RealSecPerClus  = fsfree.SecPerClus;
				edf->RealBytesPerSec = fsfree.BytesPerSec;
				edf->RealAvailClus   = fsfree.AvailClus;
				edf->RealTotalClus   = fsfree.TotalClus;
			}
			break;
		}
		/* Unsupported or invalid functions */
		default:
			r->x.ax = DOS_ENOTSUP;
			RMREGS_SET_CARRY;
			return;
	}
	res2dos(res, r);
}