zasm emul: add dumpSymbolTable debug routine

Very helpful...

tools/emul/zasm/glue.asm

@@ -5,6 +5,7 @@
 .equ STDIN_SEEK		0x01
 .equ FS_DATA_PORT	0x02
 .equ FS_SEEK_PORT	0x03
+.equ STDERR_PORT	0x04
 
 jp	init	; 3 bytes
 ; *** JUMP TABLE ***
@@ -53,6 +54,7 @@ init:
 	; signal the emulator we're done
 	halt
 
+; *** I/O ***
 emulGetC:
 	in	a, (STDIO_PORT)
 	or	a		; cp 0

tools/emul/zasm/user.asm

@@ -16,7 +16,51 @@ fsSeek		.equ    0x2a
 fsTell		.equ    0x2d
 
 .equ	FS_HANDLE_SIZE	8
+.equ	STDERR_PORT	0x04
 .equ	USER_CODE	0x4800
 .equ	RAMSTART	0x5800
 .org	USER_CODE
+
+	call	zasmMain
+	;call	dumpSymTable
+	ret
+
 #include "main.asm"
+
+; *** Debug ***
+debugPrint:
+	push	af
+	push	hl
+.loop:
+	ld	a, (hl)
+	or	a
+	jr	z, .end
+	out	(STDERR_PORT), a
+	inc	hl
+	jr	.loop
+.end:
+	ld	a, 0x0a
+	out	(STDERR_PORT), a
+	pop	hl
+	pop	af
+	ret
+
+dumpSymTable:
+	ld	hl, SYM_NAMES
+	ld	de, SYM_VALUES
+.loop:
+	call	debugPrint
+	ld	a, (de)
+	out	(12), a
+	inc	de
+	ld	a, (de)
+	out	(12), a
+	inc	de
+	xor	a
+	call	findchar
+	inc	hl
+	ld	a, (hl)
+	or	a
+	ret	z
+	jr	.loop
+

tools/emul/zasm/zasm.c

@@ -31,6 +31,7 @@
 #define STDIN_SEEK_PORT 0x01
 #define FS_DATA_PORT 0x02
 #define FS_SEEK_PORT 0x03
+#define STDERR_PORT 0x04
 
 // Other consts
 #define STDIN_BUFSIZE 0x8000
@@ -128,6 +129,8 @@ static void io_write(int unused, uint16_t addr, uint8_t val)
             fsdev_ptr = (val << 8) & 0xff00;
             fsdev_middle_of_seek_tell = 1;
         }
+    } else if (addr == STDERR_PORT) {
+        fputc(val, stderr);
     } else {
         fprintf(stderr, "Out of bounds I/O write: %d / %d\n", addr, val);
     }