initial commit

1 files changed, 117 insertions, 0 deletions

diff --git a/xex.h b/xex.h
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index 0000000..2300481
--- /dev/null
+++ b/xex.h
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+#ifndef XEX_H
+#define XEX_H
+
+/* A xex_segment represents one segment of a XEX file. */
+typedef struct {
+	unsigned short start_addr;
+	unsigned short end_addr;
+	unsigned char *object;
+	int len;
+	unsigned char has_ff_header;
+} xex_segment;
+
+/* object points to an array containing ONLY the data bytes, not the
+	header bytes! Use xex_get_object() to reconstitute the full
+	segment with headers.
+
+	(Note that I'm using the word "object" in the sense of "object code",
+	not in its OOP sense)
+ */
+
+#define XEX_RUNAD 0x2e0
+#define XEX_INITAD 0x2e2
+
+#define XEX_LSB(x) (x & 0xff)
+#define XEX_MSB(x) ((x >> 8) & 0xff)
+#define XEX_ADDR(x, y) ((unsigned char)x | ((unsigned char)y << 8))
+
+/* All int functions return true for success or false for failure.
+	On failure, the variable xex_errno will be set to one of the
+	XERR_* constants. Caller may use xex_strerror(xex_errno) to
+	get a human-readable error message (or xex_perror()).
+
+	Note that XERR_NONE == 0, so you can use the construct:
+	if(xex_errno) {
+		// handle error here
+	}
+ */
+
+#define XERR_NONE      0
+#define XERR_SYSCALL   1
+#define XERR_REVERSED  2
+#define XERR_TRUNCATED 3
+#define XERR_NULLDATA  4
+#define XERR_MAXERR    5
+
+extern int xex_errno;
+extern int xex_verbose;
+
+/* Initialize a xex_segment from the data pointed to by segment, which must
+	not be null. segment must be a complete segment, including start/end
+	addresses and possible $FFFF header. seg->object will point within the
+	data, so don't free() it until you're done with seg! */
+int xex_new_seg(xex_segment *seg, unsigned char *segment);
+
+/* Set up seg as an init address segment. object must have room for at
+	least 2 characters. A copy of the object pointer is stored in
+	seg->object, so don't free(object) until you're done with seg. */
+int xex_init_seg(xex_segment *seg, unsigned char *object, unsigned short addr);
+
+/* Set up seg as an run address segment. object must have room for at
+	least 2 characters. A copy of the object pointer is stored in seg->object,
+	so don't free(object) until you're done with seg.*/
+int xex_run_seg(xex_segment *seg, unsigned char *object, unsigned short addr);
+
+/* Since this library does NOT allocate any memory, reading a segment must
+	be done in two pieces. xex_fread_seg_header() reads the 4- or 6-byte
+	header and sets seg->len to the size of the segment. xex_fread_seg_data()
+	then reads this number of bytes from the file, into seg->object.
+
+	Example usage:
+
+	xex_segment seg;
+
+	xex_fread_seg_header(&seg, my_file);
+	seg.object = malloc(seg->len);
+	xex_fread_seg_data(&seg, my_file);
+
+	// ...later, the caller must free(seg.object) when done with it.
+
+	xex_fread_seg_header() returns 0 on EOF, with xex_errno set to
+	XERR_NONE. It also returns 0 on failure, but xex_errno will be
+	something other than XERR_NONE.
+*/
+int xex_fread_seg_header(xex_segment *seg, FILE *file);
+int xex_fread_seg_data(xex_segment *seg, FILE *file);
+
+/* If you're dealing with xex files sequentially, and want to use a
+	static buffer instead of malloc(), you can use xex_fread_seg() instead.
+	seg->object should point to a buffer large enough to hold any segment's
+	object code (64K, to be on the safe side), or you WILL get segfaults. */
+int xex_fread_seg(xex_segment *seg, FILE *file);
+
+/* xex_fwrite_seg() writes a segment to a file, which must be opened
+	for output. */
+int xex_fwrite_seg(xex_segment *seg, FILE *file);
+
+/* Extract the object code from a segment. data must have room for len+6
+	bytes (or len+4 if has_ff_header is false). data will be the raw
+	segment data, suitable for writing to a XEX file. */
+int xex_get_object(xex_segment *seg, unsigned char *data);
+
+/* Sanity check a segment. Make sure start_addr is less than end_addr,
+	that it doesn't wrap around the 6502 address space, and so on.
+	Returns true if segment is OK. */
+int xex_check_seg(xex_segment *seg);
+
+/* Get human-readable error message. If xex_errno is XSYSCALL, the system's
+	strerror() is called. */
+char *xex_strerror(int err);
+
+/* Shortcut for xex_strerror(), like system's perror() */
+void xex_perror(char *msg);
+
+/* Debugging aid */
+void xex_print_seg_info(xex_segment *seg);
+
+#endif /* XEX_H */