;; ======================================================================== ;; ;; Emu-Link Support Macros: File I/O ;; ;; ;; ;; The File I/O API provides a traditional C-style file I/O API to the ;; ;; Intellivision. jzIntv sandboxes the file I/O to a single directory ;; ;; specified on jzIntv's command line. ;; ;; ;; ;; Filenames can be no longer than 31 characters, and are limited to ;; ;; alphanumerics, "-", "_" and ".". The filenames may not start with ;; ;; a ".", either. ;; ;; ;; ;; The file I/O API allows up to 8 files to be open simultaneously, as ;; ;; long as jzIntv's host OS also permits. ;; ;; ;; ;; On platforms that distinguish between binary and text files, jzIntv ;; ;; attempts to open files in binary mode. ;; ;; ;; ;; API SUMMARY ;; ;; ;; ;; ELFI_OPEN Opens a file, returning a file descriptor ;; ;; ELFI_CLOSE Closes a file descriptor ;; ;; ELFI_READ Reads bytes from a file ;; ;; ELFI_READ16 Reads words (big-endian format) from a file ;; ;; ELFI_WRITE Writes bytes to a file ;; ;; ELFI_WRITE16 Writes words (big-endian format) to a file ;; ;; ELFI_LSEEK Seeks within a file, returning new file offset ;; ;; ELFI_UNLINK Unlinks (removes) a file. ;; ;; ELFI_RENAME Renames a file. ;; ;; ;; ;; See below for details on the API. The API macros attempt to take ;; ;; their arguments either in registers or as constants. One exception: ;; ;; APIs that take a file descriptor require you to *always* pass it in ;; ;; register R2. For APIs that take filenames, give a pointer to the ;; ;; ASCIIZ string, not the string itself. ;; ;; ;; ;; The API documentation below comes directly from jzIntv. If you ;; ;; choose to pass in some arguments as registers, you must match the ;; ;; indicated register assignments. See special note at LSEEK. ;; ;; ;; ;; ======================================================================== ;; IF (DEFINED _EMU_LINK_MAC) = 0 ERR "You must include emu_link.mac before el_fileio.mac" ENDI IF ((DEFINED _EL_FILEIO_MAC) = 0) AND ((DEFINED _EMU_LINK_MAC) <> 0) _EL_FILEIO_MAC QEQU 1 ;; ======================================================================== ;; ;; Flags for ELFI_OPEN ;; ;; ======================================================================== ;; O_RDONLY QEQU (1 SHL 0) ; Open for read-only access O_WRONLY QEQU (2 SHL 0) ; Open for write-only access O_RDWR QEQU (3 SHL 0) ; Open for read-write access O_APPEND QEQU (1 SHL 2) ; Open for append O_CREAT QEQU (1 SHL 3) ; Allow creating a new file O_EXCL QEQU (1 SHL 4) ; Fail if file already exists O_TRUNC QEQU (1 SHL 5) ; Truncate existing file ;; ======================================================================== ;; ;; Flags for ELFI_LSEEK ;; ;; ======================================================================== ;; SEEK_SET QEQU 0 ; Seek relative to start of file SEEK_CUR QEQU 1 ; Seek relative to current position SEEK_END QEQU 2 ; Seek relative to end of file ;; ======================================================================== ;; ;; Emu-Link API numbers for all the ELFI_xxx APIs. ;; ;; ======================================================================== ;; ELFI_API PROC @@open QEQU 10 @@close QEQU 11 @@read QEQU 12 @@read16 QEQU 13 @@write QEQU 14 @@write16 QEQU 15 @@lseek QEQU 16 @@unlink QEQU 17 @@rename QEQU 18 ENDP ;; ======================================================================== ;; ;; Utility macros ;; ;; ======================================================================== ;; MACRO _elfi_arg arg, reg IF _el_isreg(%arg%) = 0 MVII #%arg%, R%reg% ELSE IF EL_CPU_REGS.%arg% <> %reg% ERR "ELFI: %arg% used where R%reg% required" ENDI ENDI ENDM MACRO _elfi_arg32 arg, regl, regh IF _el_isreg(%arg%) = 0 MVII #%arg% AND $FFFF, R%regl% MVII #%arg% SHR 16, R%regh% ELSE IF EL_CPU_REGS.%arg% <> %regl% ERR "ELFI: %arg% used where R%regl% required" ENDI ENDI ENDM ;* ======================================================================== *; ;* ELFI_OPEN Open a new file on behalf of the Intellivision. *; ;* *; ;* INPUTS: *; ;* R2 Pointer to ASCIIZ filename. *; ;* R3 Flags. Flags must come from the table above, ORed together. *; ;* *; ;* OUTPUTS: *; ;* C Clear on success, set on failure *; ;* R0 errno on failure *; ;* R2 File descriptor on success *; ;* *; ;* ======================================================================== *; MACRO ELFI_OPEN fname, flags _elfi_arg %fname%, 2 _elfi_arg %flags%, 3 EL_CALL_SC ELFI_API.open ENDM ;* ======================================================================== *; ;* ELFI_CLOSE Close the requested file. *; ;* *; ;* INPUTS: *; ;* R2 File descriptor *; ;* *; ;* OUTPUTS: *; ;* C Clear on success, set on failure *; ;* R0 errno on failure *; ;* ======================================================================== *; MACRO ELFI_CLOSE EL_CALL_SC ELFI_API.close ENDM ;* ======================================================================== *; ;* ELFI_READ Read from the file into a buffer as bytes. *; ;* ELFI_READ16 Read from the file into a buffer as big endian words. *; ;* *; ;* The READ API reads in bytes, populating the lower 8 bits of the *; ;* specified locations. The READ16 API reads in words in big-endian, *; ;* populating all 16 bits of the specified locations, if said locations *; ;* are in 16-bit RAM. *; ;* *; ;* The buffer gets written to memory in the same manner as if the CPU *; ;* wrote it, with all the same restrictions therein (ie. you can't *; ;* overwrite ROM or violate STIC access windows). The writes take zero *; ;* time, however. *; ;* *; ;* INPUTS: *; ;* R2 File descriptor *; ;* R3 Pointer to buffer *; ;* R4 Number of bytes (READ) or words (READ16) to read. *; ;* *; ;* OUTPUTS: *; ;* C Clear on success, set on failure *; ;* R0 errno on failure *; ;* R1 Number of bytes/words read *; ;* @R3 Data read *; ;* *; ;* ======================================================================== *; MACRO ELFI_READ buf, len _elfi_arg %buf%, 3 _elfi_arg %len%, 4 EL_CALL_SC ELFI_API.read ENDM MACRO ELFI_READ16 buf, len _elfi_arg %buf%, 3 _elfi_arg %len%, 4 EL_CALL_SC ELFI_API.read16 ENDM ;* ======================================================================== *; ;* ELFI_WRITE, ELFI_WRITE16 *; ;* *; ;* The WRITE API writes out bytes, taking them from the lower 8 bits of *; ;* the specified locations. The WRITE16 API writes out words in big- *; ;* endian, writing out the full 16-bit value read from the specified *; ;* locations. *; ;* *; ;* The buffer gets read from memory in the same manner as if the CPU *; ;* read it, with all the same restrictions therein (ie. you can't *; ;* violate STIC access windows). The reads take zero time, however. *; ;* *; ;* INPUTS: *; ;* R2 File descriptor *; ;* R3 Pointer to buffer *; ;* R4 Number of bytes (WRITE) or words (WRITE16) to write *; ;* *; ;* OUTPUTS *; ;* C Clear on success, set on failure *; ;* R0 errno on failure *; ;* R1 Number of bytes/words written *; ;* *; ;* ======================================================================== *; MACRO ELFI_WRITE buf, len _elfi_arg %buf%, 3 _elfi_arg %len%, 4 EL_CALL_SC ELFI_API.write ENDM MACRO ELFI_WRITE16 buf, len _elfi_arg %buf%, 3 _elfi_arg %len%, 4 EL_CALL_SC ELFI_API.write16 ENDM ;* ======================================================================== *; ;* ELFI_LSEEK *; ;* *; ;* Changes the offset within the file, and returns the new offset. *; ;* Offsets are 32 bits, signed. *; ;* *; ;* INPUTS: *; ;* R2 File descriptor *; ;* R3 Lower 16 bits of signed offset *; ;* R4 Upper 16 bits of signed offset *; ;* R5 "Whence": 0 == SEEK_SET, 1 == SEEK_CUR, 2 == SEEK_END *; ;* *; ;* OUTPUTS: *; ;* C Clear on success, set on failure *; ;* R0 errno on failure *; ;* R1 Lower 16 bits of new file offset *; ;* R2 Upper 16 bits of new file offset *; ;* *; ;* NOTE: When passing in the file offset in registers R4:R3, specify *; ;* the argument to the macro as simply "R3". This will tell the macro *; ;* that the offset is in the register pair R4:R3. *; ;* *; ;* ======================================================================== *; MACRO ELFI_LSEEK ofs, whence _elfi_arg32 %ofs%, 3, 4 _elfi_arg %whence%, 5 EL_CALL_SC ELFI_API.lseek ENDM ;* ======================================================================== *; ;* ELFI_UNLINK *; ;* *; ;* Tries to unlink (ie. remove) a file from the file system. No check is *; ;* made to determine if the file is currently open. Behavior is defined *; ;* by jzIntv's host OS. *; ;* *; ;* INPUTS: *; ;* R2 Pointer to ASCIIZ file name *; ;* *; ;* OUTPUTS: *; ;* C Clear on success, set on failure *; ;* R0 errno on failure *; ;* ======================================================================== *; MACRO ELFI_UNLINK fname _elfi_arg %fname%, 2 EL_CALL_SC ELFI_API.unlink ENDM ;* ======================================================================== *; ;* ELFI_RENAME *; ;* *; ;* Tries to rename a file in the file system. No check is made to *; ;* determine if the file is currently open. Behavior is defined by *; ;* jzIntv's host OS. *; ;* *; ;* INPUTS: *; ;* R2 Pointer to ASCIIZ file name for old name *; ;* R3 Pointer to ASCIIZ file name for new name *; ;* *; ;* OUTPUTS: *; ;* C Clear on success, set on failure *; ;* R0 errno on failure *; ;* ======================================================================== *; MACRO ELFI_RENAME old, new _elfi_arg %old%, 2 _elfi_arg %new%, 3 EL_CALL_SC ELFI_API.rename ENDM ENDI