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1 241 jshamlet
----------------------------------------------
2
Open8_assembler Documentation - Index
3
----------------------------------------------
4
 
5
1..... Introduction
6
2..... Assembler Directives
7
3..... Assembler Syntax
8
 3.1.. Case Sensitivity
9
 3.2.. Comments
10
 3.3.. Labels
11
 3.4.. Number Types
12
 3.5.. Strings
13
 3.6.. Mnemonics
14
4..... Error Messages
15
5..... Bugs
16
6..... Temporary Files
17
7..... Compiling
18
 7.1.. Compiling Object Files
19
 7.2.. Compiling Library Files
20
8..... Linking
21
9..... Arithmetics
22
10.... Open8_as Flags
23
11.... Good things to know about Open8_as
24
12.... Legal Note
25
 
26
 
27
----------------------------------------------
28
1.... Introduction
29
----------------------------------------------
30
 
31
This assembler was originally based on the WLA Assembler. The original
32
WLA assembler can be found at
33
 
34
http://www.iki.fi/~vhelin/wla.html
35
 
36
Please don't bother Ville Helin if Open8_as does something wrong. No doubt I've
37
introduced a bug or two when I modified it for Open8 uRISC code.
38
 
39
Note that the original assembler was targetted for other architectures, and
40
intended for use by game designers, so some of the samples aren't proper
41
Open8 uRISC code.
42
 
43
----------------------------------------------
44
2.... Assembler Directives
45
----------------------------------------------
46
 
47
Here are the supported directives (with examples) in Open8_as:
48
 
49
      .ASC "HELLO WORLD!"
50
      .ASCTABLE
51
      .ASCIITABLE
52
      .ASM
53
      .BR
54
      .BREAKPOINT
55
      .BYT 100, $30, %1000, "HELLO WORLD!"
56
      .DB 100, $30, %1000, "HELLO WORLD!"
57
      .DBCOS 0.2, 10, 3.2, 120, 1.3
58
      .DBRND 20, 0, 10
59
      .DBSIN 0.2, 10, 3.2, 120, 1.3
60
      .DEFINE IF $FF0F
61
      .DEF IF $FF0F
62
      .DS 256, $10
63
      .DSB 256, $10
64
      .DSTRUCT waterdrop INSTANCEOF water DATA "tingle", 40, 120
65
      .DSW 128, 20
66
      .DW 16000, 10, 255
67
      .DWCOS 0.2, 10, 3.2, 1024, 1.3
68
      .DWRND 20, 0, 10
69
      .DWSIN 0.2, 10, 3.2, 1024, 1.3
70
      .ELSE
71
      .EMPTYFILL $C9
72
      .ENDASM
73
      .ENDB
74
      .ENDE
75
      .ENDIF
76
      .ENDM
77
      .ENDME
78
      .ENDR
79
      .ENDRO
80
      .ENDS
81
      .ENDST
82
      .ENUM $C000
83
      .EQU IF $FF0F
84
      .FAIL
85
      .FCLOSE FP_DATABIN
86
      .FOPEN "data.bin" FP_DATABIN
87
      .FREAD FP_DATABIN DATA
88
      .FSIZE FP_DATABIN SIZE
89
      .IF DEBUG == 2
90
      .IFDEF IF
91
      .IFDEFM \2
92
      .IFEQ DEBUG 2
93
      .IFEXISTS "main.s"
94
      .IFGR DEBUG 2
95
      .IFGREQ DEBUG 1
96
      .IFLE DEBUG 2
97
      .IFLEEQ DEBUG 1
98
      .IFNDEF IF
99
      .IFNDEFM \2
100
      .IFNEQ DEBUG 2
101
      .INCBIN "sorority.bin"
102
      .INCDIR "/usr/programming/gb/include/"
103
      .INCLUDE "cgb_hardware.i"
104
      .INPUT NAME
105
      .MACRO TEST
106
      .ORG $150
107
      .OUTNAME "other.o"
108
      .PRINTT "Here we are...\n"
109
      .PRINTV DEC DEBUG+1
110
      .REDEFINE IF $F
111
      .REDEF IF $F
112
      .REPEAT 6
113
      .REPT 6
114
      .SEED 123
115
      .SECTION "Init" FORCE
116
      .SHIFT
117
      .STRUCT enemy_object
118
      .SYM SAUSAGE
119
      .SYMBOL SAUSAGE
120
      .UNDEFINE DEBUG
121
      .UNDEF DEBUG
122
      .WORD 16000, 10, 255
123
 
124
 
125
Descriptions:
126
 
127
----
128
.ASM
129
----
130
 
131
Tells Open8_as to start assembling. Use .ASM to continue the work which has been
132
disabled with .ENDASM. .ASM and .ENDASM can be used to mask away big blocks
133
of code. This is analogous to the ANSI C -comments (/*...*/), but .ASM and
134
.ENDASM can be nested, unlike the ANSI C -counterpart.
135
 
136
This is not a compulsory directive.
137
 
138
-------
139
.ENDASM
140
-------
141
 
142
Tells Open8_as to stop assembling. Use .ASM to continue the work.
143
 
144
This is not a compulsory directive.
145
 
146
----------------
147
.DBRND 20, 0, 10
148
----------------
149
 
150
Defines bytes, just like .DSB does, only this time they are filled with
151
(pseudo) random numbers. We use stdlib's rand() to generate the random
152
numbers. If you want to seed the random number generator, use .SEED.
153
 
154
The first parameter (20 in the example) defines the amount of numbers
155
we want to generate. The next two tell the range of the random numbers,
156
i.e. min and max.
157
 
158
Here's how it works:
159
 
160
.DBRND A, B, C
161
 
162
for (i = 0; i < A; i++)
163
  output_data((rand() % (C-B+1)) + B);
164
 
165
This is not a compulsory directive.
166
 
167
----------------
168
.DWRND 20, 0, 10
169
----------------
170
 
171
Analogous to .DBRND (but defines words).
172
 
173
This is not a compulsory directive.
174
 
175
-----------------------------
176
.DBCOS 0.2, 10, 3.2, 120, 1.3
177
-----------------------------
178
 
179
Defines bytes just like .DSB does, only this time they are filled with
180
cosine data. .DBCOS takes five arguments.
181
 
182
The first argument is the starting angle. Angle value ranges from 0 to
183
359.999..., but you can supply Open8_as with values that are out of the range -
184
Open8_as fixes them ok. The value can be integer or float.
185
 
186
The second one descibes the amount of additional angles. The example
187
will define 11 angles.
188
 
189
The third one is the adder value which is added to the angle value when
190
next angle is calculated. The value can be integer or float.
191
 
192
The fourth and fifth ones can be seen from the pseudo code below, which
193
also describes how .DBCOS works. The values can be integer or float.
194
 
195
Remember that cos (and sin) here returns values ranging from -1 to 1.
196
 
197
.DBCOS A, B, C, D, E
198
 
199
for (B++; B > 0; B--) {
200
  output_data((D * cos(A)) + E)
201
  A = keep_in_range(A + C)
202
}
203
 
204
This is not a compulsory directive.
205
 
206
-----------------------------
207
.DBSIN 0.2, 10, 3.2, 120, 1.3
208
-----------------------------
209
 
210
Analogous to .DBCOS, but does sin() instead of cos().
211
 
212
This is not a compulsory directive.
213
 
214
------------------------------
215
.DWCOS 0.2, 10, 3.2, 1024, 1.3
216
------------------------------
217
 
218
Analogous to .DBCOS (but defines words).
219
 
220
This is not a compulsory directive.
221
 
222
------------------------------
223
.DWSIN 0.2, 10, 3.2, 1024, 1.3
224
------------------------------
225
 
226
Analogous to .DBCOS (but defines words and does sin() instead of cos()).
227
 
228
This is not a compulsory directive.
229
 
230
--------------
231
.EMPTYFILL $C9
232
--------------
233
 
234
This byte is used in filling the unused areas of memory. EMPTYFILL
235
defaults to $00.
236
 
237
This is not a compulsory directive.
238
 
239
--------------------------------------
240
.INCDIR "/usr/programming/Open8/include/"
241
--------------------------------------
242
 
243
Changes the current include root directory. Use this to specify main
244
directory for the following .INCLUDE and .INCBIN directives.
245
If you want to change to the current working directory (Open8_as also defaults
246
to this), use
247
 
248
.INCDIR ""
249
 
250
This is not a compulsory directive.
251
 
252
-------------------------
253
.INCLUDE "cgb_hardware.i"
254
-------------------------
255
 
256
Includes the specified file to the source file. If the file's not found
257
in the .INCDIR directory, Open8_as tries to find it in the current working
258
directory.
259
 
260
This is not a compulsory directive.
261
 
262
----------------------
263
.INCBIN "sorority.bin"
264
----------------------
265
 
266
Includes the specified data file into the source file. .INCBIN caches
267
all files into memory, so you can .INCBIN any data file millions of
268
times, but it is loaded from hard drive only once.
269
 
270
You can optionally use SWAP after the file name, e.g.,
271
 
272
.INCBIN "kitten.bin" SWAP
273
 
274
.INCBIN data is divided into blocks of two bytes, and inside every block
275
the bytes are exchanged (like "SWAP r" does to nibbles). This requires that
276
the size of the file is even.
277
 
278
You can also force Open8_as to skip n bytes from the beginning of the file
279
by writing for example:
280
 
281
.INCBIN "kitten.bin" SKIP 4
282
 
283
Four bytes are skipped from the beginning of kitten.bin and the rest
284
is incbinned.
285
 
286
It is also possible to incbin only n bytes from a file:
287
 
288
.INCBIN "kitten.bin" READ 10
289
 
290
Will read ten bytes from the beginning of kitten.bin.
291
 
292
You can also force Open8_as to create a definition holding the size
293
of the file:
294
 
295
.INCBIN "kitten.bin" FSIZE size_of_kitten
296
 
297
And you can combine all these four commands:
298
 
299
.INCBIN "kitten.bin" SKIP 10 READ 8 SWAP FSIZE size_of_kitten
300
 
301
This example shows how to incbin eight bytes (swapped) after skipping
302
10 bytes from the beginning of file "kitten.bin", and how to get the
303
size of the file into a definition label "size_of_kitten". Note that the
304
order of the extra commands is important.
305
 
306
If the file's not found in the .INCDIR directory, Open8_as tries to find it
307
in the current working directory.
308
 
309
This is not a compulsory directive.
310
 
311
-----------
312
.INPUT NAME
313
-----------
314
 
315
.INPUT is much like any Basic-language input: .INPUT asks the user
316
for a value or string. After .INPUT is the variable name used to store
317
the data.
318
 
319
.INPUT works like .REDEFINE, but the user gets to type in the data.
320
 
321
Here are few examples how to use input:
322
 
323
.PRINTT "The name of the TFT pic? "
324
.INPUT NAME
325
.NAME NAME
326
 
327
...
328
 
329
.PRINTT "Give the .DB amount.\n"
330
.INPUT S
331
.PRINTT "Give .DB data one at a time.\n"
332
.REPEAT S
333
  .INPUT B
334
  .DB B
335
.ENDR
336
 
337
...
338
 
339
This is not a compulsory directive.
340
 
341
-----
342
.FAIL
343
-----
344
 
345
Terminates the compiling process.
346
 
347
This is not a compulsory directive.
348
 
349
------------------
350
.FCLOSE FP_DATABIN
351
------------------
352
 
353
Closes the filehandle FP_DATABIN.
354
 
355
This is not a compulsory directive.
356
 
357
----------------------------
358
.FOPEN "data.bin" FP_DATABIN
359
----------------------------
360
 
361
Opens the file "data.bin" for reading and associates the filehandle with
362
name "FP_DATABIN".
363
 
364
This is not a compulsory directive.
365
 
366
----------------------
367
.FREAD FP_DATABIN DATA
368
----------------------
369
 
370
Reads one byte from "FP_DATABIN" and creates a definition called "DATA"
371
to hold it. "DATA" is an ordinary definition label, so you can .UNDEFINE it.
372
 
373
Here's an example on how to use .FREAD:
374
 
375
.fopen "data.bin" fp
376
.fsize fp t
377
.repeat t
378
.fread fp d
379
.db d+26
380
.endr
381
.undefine t, d
382
 
383
This is not a compulsory directive.
384
 
385
----------------------
386
.FSIZE FP_DATABIN SIZE
387
----------------------
388
 
389
Creates a definition called "SIZE", which holds the size of the file
390
associated with the filehandle "FP_DATABIN". "SIZE" is an ordinary
391
definition label, so you can .UNDEFINE it.
392
 
393
This is not a compulsory directive.
394
 
395
-----------
396
.MACRO TEST
397
-----------
398
 
399
Begins a macro called 'TEST'.
400
 
401
You can use '\@' inside a macro to e.g., separate a label from the other
402
macro 'TEST' occurrences. '\@' is replaced with an integer number
403
indicating the amount of times the macro has been called previously so
404
it is unique to every macro call. '\@' can also be used inside strings
405
inside a macro or just as a plain value. Look at the following examples
406
for more information.
407
 
408
Also, if you want to use macro arguments in e.g., calculation, you can
409
type '\X' where X is the number of the argument. Another way to refer
410
to the arguments is to use their names given in the definition of the
411
macro (see the examples for this).
412
 
413
Remember to use .ENDM to finish the macro definition. Note that you
414
cannot use .INCLUDE inside a macro. Note that Open8_as' macros are in fact
415
more like procedures than real macros, because Open8_as doesn't substitute
416
macro calls with macro data. Instead Open8_as jumps to the macro when it
417
encounters a macro call at compile time.
418
 
419
You can call macros from inside a macro. Note that the preprocessor
420
does not expand the macros. Open8_as traverses through the code according to
421
the macro calls, so macros really define a very simple programming
422
language.
423
 
424
Here are some examples:
425
 
426
.MACRO NOPMONSTER
427
       .REPT 32         ; it's just an example...
428
       NOP
429
       .ENDR
430
.ENDM
431
 
432
.MACRO LOAD_ABCD
433
       LD A, \1
434
       LD B, \2
435
       LD C, \3
436
       LD D, \4
437
       NOPMONSTER
438
       LD HL, 1<<\1
439
.INCBIN \5
440
.ENDM
441
 
442
.MACRO QUEEN
443
 
444
QUEEN\@:
445
        LD   A, \1
446
        LD   B, \1
447
        CALL QUEEN\@
448
 
449
        .DB  "\@", 0     ; will translate into a zero terminated string
450
                         ; holding the amount of macro QUEEN calls.
451
        .DB  "\\@", 0    ; will translate into a string containing
452
                         ; \@.
453
        .DB  \@          ; will translate into a number indicating
454
                         ; the amount of macro QUEEN calls.
455
 
456
.ENDM
457
 
458
.MACRO LOAD_ABCD_2 ARGS ONE, TWO, THREE, FOUR, FIVE
459
       LD A, ONE
460
       LD B, TWO
461
       LD C, THREE
462
       LD D, FOUR
463
       NOPMONSTER
464
       LD HL, 1< \2, etc.).
465
.SHIFT can thus only be used inside a .MACRO.
466
 
467
This is not a compulsory directive.
468
 
469
---------
470
.ORG $150
471
---------
472
 
473
Defines the starting address. The default starting address is $0
474
 
475
This is not a compulsory directive.
476
 
477
------------
478
.DS 256, $10
479
------------
480
 
481
.DS is an alias for .DSB.
482
 
483
This is not a compulsory directive.
484
 
485
-------------
486
.DSB 256, $10
487
-------------
488
 
489
Defines 256 bytes of $10.
490
 
491
This is not a compulsory directive.
492
 
493
----------------------------------------------------------
494
.DSTRUCT waterdrop INSTANCEOF water DATA "tingle", 40, 120
495
----------------------------------------------------------
496
 
497
Defines an instance of struct water, called waterdrop, and fills
498
it with the given data. Before calling .DSTRUCT we must have defined
499
the structure, and in this example it could be like:
500
 
501
.STRUCT water
502
name   ds 8
503
age    db
504
weight dw
505
.ENDST
506
 
507
Note that the keywords INSTANCEOF and DATA are optional, so
508
 
509
.DSTRUCT waterdrop, water, "tingle", 40, 120
510
 
511
also works. Also note that Open8_as fills the missing bytes with the data
512
defined with .EMPTYFILL, or $00 if no .EMPTYFILL has been issued.
513
 
514
In this example you would also get the following labels:
515
 
516
waterdrop
517
waterdrop.name
518
waterdrop.age
519
waterdrop.weight
520
 
521
This is not a compulsory directive.
522
 
523
------------
524
.DSW 128, 20
525
------------
526
 
527
Defines 128 words (two bytes) of 20.
528
 
529
This is not a compulsory directive.
530
 
531
-----------------------------------
532
.DB 100, $30, %1000, "HELLO WORLD!"
533
-----------------------------------
534
 
535
Defines bytes.
536
 
537
This is not a compulsory directive.
538
 
539
------------------------------------
540
.BYT 100, $30, %1000, "HELLO WORLD!"
541
------------------------------------
542
 
543
.BYT is an alias for .DB.
544
 
545
This is not a compulsory directive.
546
 
547
------------
548
.SYM SAUSAGE
549
------------
550
 
551
Open8_as treats symbols ("SAUSAGE" in this example) like labels, but they
552
only appear in the symbol files Open8_link outputs. Useful for finding out
553
the location where Open8_link puts data.
554
 
555
This is not a compulsory directive.
556
 
557
---------------
558
.SYMBOL SAUSAGE
559
---------------
560
 
561
.SYMBOL is an alias for .SYM.
562
 
563
This is not a compulsory directive.
564
 
565
---
566
.BR
567
---
568
 
569
Inserts a breakpoint that behaves like a .SYM without a name. Breakpoints
570
can only be seen in Open8_link's symbol file.
571
 
572
This is not a compulsory directive.
573
 
574
-----------
575
.BREAKPOINT
576
-----------
577
 
578
.BREAKPOINT is an alias for .BR.
579
 
580
This is not a compulsory directive.
581
 
582
-----------
583
.ASCIITABLE
584
-----------
585
 
586
.ASCIITABLE's only purpose is to provide character mapping for .ASC.
587
Take a look at the example:
588
 
589
.ASCIITABLE
590
MAP "A" TO "Z" = 0
591
MAP "!" = 90
592
.ENDA
593
 
594
Here we set such a mapping that character 'A' is equal to 0, 'B'
595
is equal to 1, 'C' is equal to 2, and so on, and '!' is equal to 90.
596
 
597
After you've given the .ASCIITABLE, use .ASC to define bytes using
598
this mapping (.ASC is an alias for .DB, but with .ASCIITABLE mapping).
599
For example, .ASC "AB!" would define bytes 0, 1 and 90.
600
 
601
Note that the following works as well:
602
 
603
.ASCIITABLE
604
MAP 'A' TO 'Z' = 0
605
MAP 65 = 90
606
.ENDA
607
 
608
Also note that the characters that are not given any mapping in
609
.ASCIITABLE map to themselves (i.e., 'A' maps to 'A', etc.).
610
 
611
This is not a compulsory directive.
612
 
613
---------
614
.ASCTABLE
615
---------
616
 
617
.ASCTABLE is an alias for .ASCIITABLE.
618
 
619
This is not a compulsory directive.
620
 
621
-------------------
622
.ASC "HELLO WORLD!"
623
-------------------
624
 
625
.ASC is an alias for .DB, but if you use .ASC it will remap
626
the characters using the mapping given via .ASCIITABLE.
627
 
628
This is not a compulsory directive.
629
 
630
------------------
631
.DW 16000, 10, 255
632
------------------
633
 
634
Defines words (two bytes each). .DW takes only numbers and
635
characters as input, not strings.
636
 
637
This is not a compulsory directive.
638
 
639
--------------------
640
.WORD 16000, 10, 255
641
--------------------
642
 
643
.WORD is an alias for .DW.
644
 
645
This is not a compulsory directive.
646
 
647
----------------
648
.DEFINE IF $FF0F
649
----------------
650
 
651
Assigns a number or a string to a definition label.
652
 
653
By default all defines are local to the file where they are
654
presented. If you want to make the definition visible to all the
655
files in the project, use .EXPORT.
656
 
657
Here are some examples:
658
 
659
.DEFINE X 1000
660
.DEFINE FILE "PD-03.TFT"
661
.DEFINE TXT1 "hello and welcome", 1, "to the Open8", 0
662
.DEFINE BYTES 1, 2, 3, 4, 5
663
.DEFINE COMPUTATION X+1
664
.DEFINE DEFAULTV
665
 
666
All definitions with multiple values are marked as data strings,
667
and .DB is about the only place where you can later on use them.
668
 
669
.DEFINE BYTES 1, 2, 3, 4, 5
670
.DB 0, BYTES, 6
671
 
672
is the same as
673
 
674
.DB 0, 1, 2, 3, 4, 5, 6
675
 
676
If you omit the definition value (in our example "DEFAULTV"), Open8_as
677
will default to 0.
678
 
679
Note that you must do your definition before you use it, otherwise
680
Open8_as will use the final value of the definition. Here's an example
681
of this:
682
 
683
.DEFINE AAA 10
684
.DB AAA            ; will be 10.
685
.REDEFINE AAA 11
686
 
687
but
688
 
689
.DB AAA            ; will be 11.
690
.DEFINE AAA 10
691
.REDEFINE AAA 11
692
 
693
You can also create definitions on the command line. Here's an
694
example of this:
695
 
696
Open8_as AS -vl -DMOON -DNAME=john -DPRICE=100 -DADDRESS=$100 math.s
697
 
698
MOON's value will be 0, NAME is a string definition with value "john",
699
PRICE's value will be 100, and ADDRESS's value will be $100.
700
 
701
Note that
702
 
703
.DEFINE AAA = 10   ; the same as ".DEFINE AAA 10".
704
 
705
works as well.
706
 
707
This is not a compulsory directive.
708
 
709
-------------
710
.DEF IF $FF0F
711
-------------
712
 
713
.DEF is an alias for .DEFINE.
714
 
715
This is not a compulsory directive.
716
 
717
-------------
718
.EQU IF $FF0F
719
-------------
720
 
721
.EQU is an alias for .DEFINE.
722
 
723
This is not a compulsory directive.
724
 
725
----------------
726
.REDEFINE IF $0F
727
----------------
728
 
729
Assigns a new value or a string to an old definition. If the
730
definition doesn't exist, .REDEFINE performs .DEFINE's work.
731
 
732
When used with .REPT REDEFINE helps creating tables:
733
 
734
.DEFINE CNT 0
735
 
736
.REPT 256
737
.DB CNT
738
.REDEFINE CNT CNT+1
739
.ENDR
740
 
741
This is not a compulsory directive.
742
 
743
-------------
744
.REDEF IF $0F
745
-------------
746
 
747
.REDEF is an alias for .REDEFINE.
748
 
749
This is not a compulsory directive.
750
 
751
--------------
752
.IF DEBUG == 2
753
--------------
754
 
755
If the condition is fulfilled the following piece of code is
756
acknowledged until .ENDIF/.ELSE occurs in the text, otherwise
757
it is skipped. Operands must be immediate values or strings.
758
 
759
The following operators are supported:
760
<  - less than
761
<= - less or equal to
762
>  - greater than
763
>= - greater or equal to
764
== - equals to
765
!= - doesn't equal to
766
 
767
All IF (yes, including .IFDEF, .IFNDEF, etc) directives can be
768
nested.
769
 
770
This is not a compulsory directive.
771
 
772
---------
773
.IFDEF IF
774
---------
775
 
776
If "IF" is defined, then the following piece of code is acknowledged
777
until .ENDIF/.ELSE occurs in the text, otherwise it is skipped.
778
 
779
This is not a compulsory directive.
780
 
781
------------------
782
.IFEXISTS "main.s"
783
------------------
784
 
785
If "main.s" file can be found, then the following piece of code is
786
acknowledged until .ENDIF/.LESE occurs in the text, otherwise it is
787
skipped.
788
 
789
By writing the following few lines you can include a file if it exists
790
without breaking the compiling loop if it doesn't exist.
791
 
792
.IFEXISTS FILE
793
.INCLUDE FILE
794
.ENDIF
795
 
796
This is not a compulsory directive.
797
 
798
---------------
799
.UNDEFINE DEBUG
800
---------------
801
 
802
Removes the supplied definition label from system. If there is no
803
such label as given no error is displayed as the result would be the
804
same.
805
 
806
You can undefine as many definitions as you wish with one .UNDEFINE:
807
 
808
.UNDEFINE NUMBER, NAME, ADDRESS, COUNTRY
809
.UNDEFINE NAME, AGE
810
 
811
This is not a compulsory directive.
812
 
813
------------
814
.UNDEF DEBUG
815
------------
816
 
817
.UNDEF is an alias for .UNDEFINE.
818
 
819
This is not a compulsory directive.
820
 
821
----------
822
.IFNDEF IF
823
----------
824
 
825
If "IF" is not defined, then the following piece of code is acknowledged
826
until .ENDIF/.ELSE occurs in the text, otherwise it is skipped.
827
 
828
This is not a compulsory directive.
829
 
830
----------
831
.IFDEFM \2
832
----------
833
 
834
If the specified argument is defined (argument number two, in the example),
835
then the following piece of code is acknowledged until .ENDIF/.ELSE occurs
836
in the macro, otherwise it is skipped.
837
 
838
This is not a compulsory directive. .IFDEFM works only inside a macro.
839
 
840
-----------
841
.IFNDEFM \2
842
-----------
843
 
844
If the specified argument is not defined, then the following piece of
845
code is acknowledged until .ENDIF/.ELSE occurs in the macro, otherwise
846
it is skipped.
847
 
848
This is not a compulsory directive. .IFNDEFM works only inside a macro.
849
 
850
-------------
851
.IFEQ DEBUG 2
852
-------------
853
 
854
If the value of DEBUG equals to 2, then the following piece of code is
855
acknowledged until .ENDIF/.ELSE occurs in the text, otherwise it is skipped.
856
Both arguments can be computations, defines or immediate values.
857
 
858
This is not a compulsory directive.
859
 
860
--------------
861
.IFNEQ DEBUG 2
862
--------------
863
 
864
If the value of DEBUG doesn't equal to 2, then the following piece of
865
code is acknowledged until .ENDIF/.ELSE occurs in the text, otherwise it is
866
skipped. Both arguments can be computations, defines or immediate
867
values.
868
 
869
This is not a compulsory directive.
870
 
871
-------------
872
.IFLE DEBUG 2
873
-------------
874
 
875
If the value of DEBUG is less than 2, then the following piece of code is
876
acknowledged until .ENDIF/.ELSE occurs in the text, otherwise it is skipped.
877
Both arguments can be computations, defines or immediate values.
878
 
879
This is not a compulsory directive.
880
 
881
---------------
882
.IFLEEQ DEBUG 2
883
---------------
884
 
885
If the value of DEBUG is less or equal to 2, then the following piece of code is
886
acknowledged until .ENDIF/.ELSE occurs in the text, otherwise it is skipped.
887
Both arguments can be computations, defines or immediate values.
888
 
889
This is not a compulsory directive.
890
 
891
-------------
892
.IFGR DEBUG 2
893
-------------
894
 
895
If the value of DEBUG is greater than 2, then the following piece of code is
896
acknowledged until .ENDIF/.ELSE occurs in the text, otherwise it is skipped.
897
Both arguments can be computations, defines or immediate values.
898
 
899
This is not a compulsory directive.
900
 
901
---------------
902
.IFGREQ DEBUG 2
903
---------------
904
 
905
If the value of DEBUG is greater or equal to 2, then the following piece of code is
906
acknowledged until .ENDIF/.ELSE occurs in the text, otherwise it is skipped.
907
Both arguments can be computations, defines or immediate values.
908
 
909
This is not a compulsory directive.
910
 
911
-----
912
.ELSE
913
-----
914
 
915
If the previous .IFxxx failed then the following text until
916
.ENDIF is acknowledged.
917
 
918
This is not a compulsory directive.
919
 
920
------
921
.ENDIF
922
------
923
 
924
This terminates any .IFxxx directive.
925
 
926
This is not a compulsory directive, but if you use any .IFxxx then
927
you need also to apply this.
928
 
929
---------
930
.REPEAT 6
931
---------
932
 
933
Repeats the text enclosed between ".REPEAT x" and ".ENDR" x times (6 in
934
this example). You can use .REPEATs inside .REPEATs. 'x' must be >= 0.
935
 
936
This is not a compulsory directive.
937
 
938
-------
939
.REPT 6
940
-------
941
 
942
.REPT is an alias for .REPEAT.
943
 
944
This is not a compulsory directive.
945
 
946
-----
947
.ENDR
948
-----
949
 
950
Ends the repetition.
951
 
952
This is not a compulsory directive, but when .REPEAT is used this one is
953
required to terminate it.
954
 
955
-----------
956
.ENUM $C000
957
-----------
958
 
959
Starts enumeration from $C000. Very useful for defining variables.
960
 
961
To start a descending enumeration, put "DESC" after the starting
962
address. Open8_as defaults to "ASC" (ascending enumeration).
963
 
964
You can also add "EXPORT" after these if you want to export all
965
the generated definitions automatically.
966
 
967
Here's an example of .ENUM:
968
 
969
...
970
.STRUCT mon                ; check out the documentation on
971
name ds 2                  ; .STRUCT
972
age  db
973
.ENDST
974
 
975
.ENUM $A000
976
_scroll_x DB               ; db  - define byte (byt and byte work also)
977
_scroll_y DB
978
player_x: DW               ; dw  - define word (word works also)
979
player_y: DW
980
map_01:   DS  16           ; ds  - define size (bytes)
981
map_02    DSB 16           ; dsb - define size (bytes)
982
map_03    DSW  8           ; dsw - define size (words)
983
monster   INSTANCEOF mon 3 ; three instances of structure mon
984
dragon    INSTANCEOF mon   ; one mon
985
.ENDE
986
...
987
 
988
Previous example transforms into following definitions:
989
 
990
.DEFINE _scroll_x      $A000
991
.DEFINE _scroll_y      $A001
992
.DEFINE player_x       $A002
993
.DEFINE player_y       $A004
994
.DEFINE map_01         $A006
995
.DEFINE map_02         $A016
996
.DEFINE map_03         $A026
997
.DEFINE monster        $A036
998
.DEFINE monster.name   $A036
999
.DEFINE monster.age    $A038
1000
.DEFINE monster.1      $A036
1001
.DEFINE monster.1.name $A036
1002
.DEFINE monster.1.age  $A038
1003
.DEFINE monster.2      $A039
1004
.DEFINE monster.2.name $A039
1005
.DEFINE monster.2.age  $A03B
1006
.DEFINE monster.3      $A03C
1007
.DEFINE monster.3.name $A03C
1008
.DEFINE monster.3.age  $A03E
1009
.DEFINE dragon         $A03F
1010
.DEFINE dragon.name    $A03F
1011
.DEFINE dragon.age     $A041
1012
 
1013
DB, DW, DS, DSB, DSW and INSTANCEOF can also be in lowercase. You
1014
can also use a dotted version of the symbols, but it doesn't advance
1015
the memory address. Here's an exmple:
1016
 
1017
.ENUM $C000 DESC EXPORT
1018
bigapple_h db
1019
bigapple_l db
1020
bigapple:  .dw
1021
.ENDE
1022
 
1023
And this is what is generated:
1024
 
1025
.DEFINE bigapple_h $BFFF
1026
.DEFINE bigapple_l $BFFE
1027
.DEFINE bigapple   $BFFE
1028
.EXPORT bigapple, bigapple_l, bigapple_h
1029
 
1030
This way you can generate a 16bit variable address along with pointers
1031
to its parts.
1032
 
1033
If you want more flexible variable positioning, take a look at
1034
.RAMSECTIONs.
1035
 
1036
This is not a compulsory directive.
1037
 
1038
-----
1039
.ENDE
1040
-----
1041
 
1042
Ends the enumeration.
1043
 
1044
This is not a compulsory directive, but when .ENUM is used this one is
1045
required to terminate it.
1046
 
1047
--------------------
1048
.STRUCT enemy_object
1049
--------------------
1050
 
1051
Begins the definition of a structure. These structures can be placed
1052
inside RAMSECTIONs and ENUMs. Here's an example:
1053
 
1054
.STRUCT enemy_object
1055
id    dw               ; the insides of a .STRUCT are 1:1 like in .ENUM
1056
x     db               ; except that no structs inside structs are
1057
y     db               ; allowed.
1058
data  ds  10
1059
info  dsb 16
1060
stats dsw  4
1061
.ENDST
1062
 
1063
This also creates a definition "_sizeof_[struct name]", in our example
1064
this would be "_sizeof_enemy_object", and the value of this definition
1065
is the size of the object, in bytes (2+1+1+10+16+4*2 = 38 in the example).
1066
 
1067
You'll get the following definitions as well:
1068
 
1069
enemy_object.id    (== 0)
1070
enemy_object.x     (== 2)
1071
enemy_object.y     (== 3)
1072
enemy_object.data  (== 4)
1073
enemy_object.info  (== 14)
1074
enemy_object.stats (== 30)
1075
 
1076
After defining a .STRUCT you can create an instance of it in a .RAMSECTION /
1077
.ENUM by typing
1078
 
1079
 INSTANCEOF  [optional, the number of structures]
1080
 
1081
Here's an example:
1082
 
1083
.RAMSECTION "enemies" BANK 4 SLOT 4
1084
enemies   INSTANCEOF enemy_object 4
1085
enemyman  INSTANCEOF enemy_object
1086
enemyboss INSTANCEOF enemy_object
1087
.ENDS
1088
 
1089
This will create labels like "enemies", "enemies.id", "enemies.x", "enemies.y"
1090
and so on. Label "enemies" is followed by four "enemy_object" structures,
1091
and only the first one is labeled. After there four come "enemyman" and
1092
"enemyboss" instances.
1093
 
1094
Take a look at the documentation on .RAMSECTION & .ENUM, they have more
1095
examples of how you can use .STRUCTs.
1096
 
1097
A WORD OF WARNING: Don't use labels b, B, w and W inside a struct as e.g.,
1098
Open8_as sees enemy.b as a byte sized reference to enemy. All other labels should
1099
be safe.
1100
 
1101
lda enemy1.b  ; load a byte from zeropage address enemy1 or from the address
1102
              ; of enemy1.b??? i can't tell you, and Open8_as can't tell you...
1103
 
1104
This is not a compulsory directive.
1105
 
1106
------
1107
.ENDST
1108
------
1109
 
1110
Ends the structure definition.
1111
 
1112
This is not a compulsory directive, but when .STRUCT is used this one is
1113
required to terminate it.
1114
 
1115
---------
1116
.SEED 123
1117
---------
1118
 
1119
Seeds the random number generator.
1120
 
1121
This is not a compulsory directive. The random number generator is
1122
initially seeded with the output of time(), which is, according to
1123
the manual, "the time since the Epoch (00:00:00 UTC, January 1, 1970),
1124
measured in seconds". So if you don't .SEED the random number generator
1125
yourself with a constant value, .DBRND and .DWRND give you different
1126
values every time you run Open8_as.
1127
 
1128
---------------------
1129
.SECTION "Init" FORCE
1130
---------------------
1131
 
1132
Section is a continuous area of data which is placed into the output
1133
file according to the section type and .ORG directive
1134
values.
1135
 
1136
The example begins a section called "Init". Before a section can be
1137
declared, .ORG must be used unless Open8_as is in library file
1138
output mode. Library file's sections must all be FREE ones. .BANK tells
1139
the bank number where this section will be later relocated into. .ORG
1140
tells the offset for the relocation from the beginning of .BANK.
1141
 
1142
You can supply the preferred section size (bytes) inside the section
1143
name string. Here's an example:
1144
 
1145
.SECTION "Init_100" FREE
1146
 
1147
will create a section ("Init") with size of 100 bytes, unless the actual
1148
data overflows from the section, in which case the section size is
1149
enlarged to contain all the data. Note that the syntax for explicit
1150
section size defining is: "NAME_X", where "NAME" is the name of the
1151
section and "X" is the size (decimal or hexadecimal value).
1152
 
1153
You can also give the size of the section the following way:
1154
 
1155
.SECTION "Init" SIZE 100 FREE
1156
 
1157
It's possible to force Open8_link to align the FREE, SEMIFREE and SUPERFREE
1158
sections by giving the alignment as follows:
1159
 
1160
.SECTION "Init" SIZE 100 ALIGN 4 FREE
1161
 
1162
And if you want that Open8_as returns the ORG to what it was before issuing
1163
the section, put RETURNORG at the end of the parameter list:
1164
 
1165
.SECTION "Init" SIZE 100 ALIGN 4 FREE RETURNORG
1166
 
1167
By default Open8_as advances the ORG, so, for example, if your ORG was $0 before
1168
a section of 16 bytes, then the ORG will be 16 after the section.
1169
 
1170
Note also that if your section name begins with double underlines (e.g.,
1171
"__UNIQUE_SECTION!!!") the section will be unique in the sense that
1172
when Open8_link recieves files containing sections which share the same
1173
name, Open8_link will save only the first of them for further processing,
1174
all others are deleted from memory with corresponding labels, references
1175
and calculations.
1176
 
1177
If a section name begins with an exclamation mark ('!') it tells
1178
Open8_link to not to drop it, even if you use Open8_link's ability to discard
1179
all unreferenced sections and there are no references to the section.
1180
 
1181
FORCE after the name of the section tells Open8_as that the section _must_ be
1182
inserted so it starts at .ORG. FORCE can be replaced with FREE which
1183
means that the section can be inserted somewhere in the defined bank,
1184
where there is room. You can also use OVERWRITE to insert the section
1185
into the memory regardless of data collisions. Using OVERWRITE you can
1186
easily patch an existing ROM image just by .BACKGROUND'ing the ROM image and
1187
inserting OVERWRITE sections into it. SEMIFREE sections are also
1188
possible and they behave much like FREE sections. The only difference
1189
is that they are positioned somewhere in the bank starting from .ORG.
1190
SUPERFREE sections are also available, and they will be positioned into
1191
the first suitable place inside the first suitable bank (candidates
1192
for these suitable banks have the same size with the slot of the section,
1193
no other banks are considered). You can also leave away the type
1194
specifier as the default type for the section is FREE.
1195
 
1196
You can name the sections as you wish, but there is one special name.
1197
A section called "BANKHEADER" is placed in the front of the bank
1198
where it is defined. These sections contain data that is not in the
1199
memory map of the machine, so you can't refer to the data of a
1200
BANKHEADER section, but you can write references to outside. So no
1201
labels inside BANKHEADER sections. These special sections are useful
1202
when writing e.g., MSX programs. Note that library files don't take
1203
BANKHEADER sections.
1204
 
1205
Here's an example of a "BANKHEADER" section:
1206
 
1207
.BANK 0
1208
.ORG 0
1209
.SECTION "BANKHEADER"
1210
        .DW MAIN
1211
        .DW VBI
1212
.ENDS
1213
 
1214
.SECTION "Program"
1215
MAIN:    CALL   MONTY_ON_THE_RUN
1216
VBI:     PUSH   HL
1217
         ...
1218
         POP    HL
1219
         RETI
1220
.ENDS
1221
 
1222
Here's an example of an ordinary section:
1223
 
1224
.BANK 0
1225
.ORG $150
1226
.SECTION "Init" FREE
1227
        DI
1228
        LD  SP, $FFFE
1229
        SUB A
1230
        LD  ($FF00+R_IE), A
1231
.ENDS
1232
 
1233
This tells Open8_as that a FREE section called "Init" must be located somewhere
1234
in bank 0. If you replace FREE with SEMIFREE the section will be inserted
1235
somewhere in the bank 0, but not in the $0-$14F area. If you replace FREE
1236
with SUPERFREE the section will be inserted somewhere in the
1237
 
1238
Here's the order in which Open8_as writes the sections:
1239
1. FORCE
1240
2. SEMIFREE & FREE
1241
3. SUPERFREE
1242
4. OVERWRITE
1243
 
1244
Before the sections are inserted into the output file, they are sorted by
1245
size, so that the biggest section gets processed first and the smallest
1246
last.
1247
 
1248
You can also create a RAM section. For more information about them, please
1249
read the .RAMSECTION directive explanation.
1250
 
1251
This is not a compulsory directive.
1252
 
1253
--------------
1254
.EXPORT work_x
1255
--------------
1256
 
1257
Exports the definition "work_x" to outside world. Exported definitions are
1258
visible to all object files and libraries in the linking procedure. Note
1259
that you can only export value definitions, not string definitions.
1260
 
1261
You can export as many definitions as you wish with one .EXPORT:
1262
 
1263
.EXPORT NUMBER, NAME, ADDRESS, COUNTRY
1264
.EXPORT NAME, AGE
1265
 
1266
This is not a compulsory directive.
1267
 
1268
--------------------------
1269
.PRINTT "Here we are...\n"
1270
--------------------------
1271
 
1272
Prints the given text into stdout. Good for debugging stuff. PRINTT takes
1273
only a string as argument, and the only supported formatting symbol is '\n'
1274
(line feed).
1275
 
1276
This is not a compulsory directive.
1277
 
1278
-------------------
1279
.PRINTV DEC DEBUG+1
1280
-------------------
1281
 
1282
Prints the value of the supplied definition or computation into stdout.
1283
Computation must be solvable at the time of printing (just like definitions
1284
values). PRINTV takes two parameters. The first describes the type of the
1285
print output. "DEC" means decimal, "HEX" means hexadecimal.
1286
 
1287
Use PRINTV with PRINTT as PRINTV doesn't print linefeeds, only the result.
1288
Here's an example:
1289
 
1290
.PRINTT "Value of \"DEBUG\" = $"
1291
.PRINTV HEX DEBUG
1292
.PRINTT "\n"
1293
 
1294
This is not a compulsory directive.
1295
 
1296
------------------
1297
.OUTNAME "other.o"
1298
------------------
1299
 
1300
Changes the name of the output file. Here's and example:
1301
 
1302
Open8_as -o test.s
1303
 
1304
would normally output "test.o", but if you had written
1305
 
1306
.OUTNAME "new.o"
1307
 
1308
somewhere in the code Open8_as would write the output to new.o instead.
1309
 
1310
This is not a compulsory directive.
1311
 
1312
 
1313
----------------------------------------------
1314
3.... Assembler Syntax
1315
----------------------------------------------
1316
 
1317
 
1318
3.1. Case Sensitivity
1319
 
1320
Open8_as is case sensitive, so be careful.
1321
 
1322
 
1323
3.2. Comments
1324
 
1325
Comments begin with ';' or '*' and end along with the line. ';' can be
1326
used anywhere, but '*' can be placed only at the beginning of a new line.
1327
 
1328
Open8_as also has ANSI-C -like commenting. This means you can start a
1329
multiline comment with "/*" and end it with "*/". Additionally, it has
1330
.ASM and .ENDASM directives. These function much like ANSI-C comments, but
1331
unlike the ANSI-C comments these can be nested.
1332
 
1333
 
1334
3.3. Labels
1335
 
1336
Labels are ordinary strings (which can also end to a ':'). Labels starting
1337
with "_" are considered to be local labels and do not show outside sections
1338
where they were defined, or outside object files, if they were not defined
1339
inside a section.
1340
 
1341
Here are few examples of different labels:
1342
 
1343
VBI_IRQ:
1344
VBI_IRQ2
1345
_VBI_LOOP:
1346
main:
1347
 
1348
3.4. Number Types
1349
 
1350
1000 - decimal
1351
$100 - hexadecimal
1352
100h - hexadecimal
1353
%100 - binary
1354
'x'  - character
1355
 
1356
Remember that if you use the suffix 'h' to give a hexadecimal value,
1357
and the value begins with an alphabet, you must place a zero in front of it
1358
so Open8_as knows it's not a label (e.g., "0ah" instead of "ah").
1359
 
1360
 
1361
3.5. Strings
1362
 
1363
Strings begin with and end to '"'. Note that no 0 is inserted to indicate
1364
the termination of the string like in e.g., ANSI C. You'll have to do it
1365
yourself. You can place quotation marks inside strings the way C
1366
preprocessors accept them.
1367
 
1368
Here are some examples of strings:
1369
 
1370
"Hello world!"
1371
"He said: \"Please, kiss me honey.\""
1372
 
1373
 
1374
----------------------------------------------
1375
4.... Error Messages
1376
----------------------------------------------
1377
 
1378
 
1379
There are quite a few of them in Open8_as, but most of them are not very
1380
informative. Coder beware.
1381
 
1382
 
1383
----------------------------------------------
1384
5.... Bugs
1385
----------------------------------------------
1386
 
1387
 
1388
Report bugs to jeremy.s.henry.ctr@mail.mil
1389
 
1390
 
1391
----------------------------------------------
1392
6.... Temporary Files
1393
----------------------------------------------
1394
 
1395
 
1396
Note that Open8 will generate two temporary files while it works. Both files
1397
are placed into the current working directory.
1398
 
1399
The filenames are ".wla%PID%a" and ".wla%PID%b" (%PID% is the process id).
1400
 
1401
When Open8 finishes its work these two files are deleted as they serve
1402
of no further use.
1403
 
1404
 
1405
----------------------------------------------
1406
7.... Compiling
1407
----------------------------------------------
1408
 
1409
 
1410
7.1. Compiling Object Files
1411
 
1412
To compile an object file use:
1413
 
1414
"Open8_as -[itvx]o [DEFINITIONS]  [OUTPUT FILE]"
1415
 
1416
These object files can be linked together (or with library files) later
1417
with "Open8_link".
1418
 
1419
Name object files so that they can be recognized as object files. Normal
1420
suffix is ".o" (Open8 default). This can also be changed with .OUTNAME.
1421
 
1422
With object files you can reduce the amount of compiling when editing
1423
small parts of the program. Note also the possibility of using local
1424
labels (starting with "_").
1425
 
1426
Note! When you compile objects, group 1 directives are saved for linking
1427
time, when they are all compared and if they differ, an error message is
1428
shown. It is advisable to use something like an include file to hold all
1429
the group 1 directives for that particular project and include it to every
1430
object file.
1431
 
1432
Here are some examples of definitions:
1433
 
1434
-DIEXIST
1435
-DDAY=10
1436
-DBASE=$10
1437
-DNAME=elvis
1438
 
1439
And here's an Open8 example creating definitions on the command line:
1440
 
1441
Open8_as -o -DDEBUG -DVERBOSE=5 -DNAME="math v1.0" math.s
1442
 
1443
DEBUG's value will be 0, VERBOSE's 5 and NAME is a string definition
1444
with value "math v1.0".
1445
 
1446
 
1447
7.2. Compiling Library Files
1448
 
1449
To compile a library file use:
1450
 
1451
"Open8_as -[itvx]l [DEFINITIONS]  [OUTPUT FILE]"
1452
 
1453
Name object files so that they can be recognized as library files. Normal
1454
suffix is ".lib" (Open8 default).
1455
 
1456
With library files you can reduce the amount of compiling. Library files
1457
are meant to hold general functions that can be used in different projects.
1458
Note also the possibility of using local labels (starting with "_").
1459
Library files consist only of FREE sections.
1460
 
1461
 
1462
----------------------------------------------
1463
8... Linking
1464
----------------------------------------------
1465
 
1466
 
1467
After you have produced one or more object files and perhaps some library
1468
files, you might want to link them together to produce a ROM image / program
1469
file. "Open8_link" is the program you use for that. Here's how you use it:
1470
 
1471
"Open8_link [-divsS]{b/r}  "
1472
 
1473
Choose 'b' for program file or 'r' for ROM image linking.
1474
 
1475
Link file is a text file that contains information about the files you want
1476
to link together. Here's the format:
1477
 
1478
1. You must define the group for the files. Put the name of the group
1479
inside brackets. Valid group definitions are
1480
 
1481
[objects]
1482
[libraries]
1483
[header]
1484
[footer]
1485
[definitions]
1486
 
1487
2. Start to list the file names.
1488
 
1489
[objects]
1490
main.o
1491
vbi.o
1492
level_01.o
1493
...
1494
 
1495
3. Give parameters to the library files:
1496
 
1497
[libraries]
1498
bank 0 slot 1 speed.lib
1499
bank 4 slot 2 map_data.lib
1500
...
1501
 
1502
Here you can also use "base" to define the 65816 CPU bank number
1503
(like .BASE works in Open8_as):
1504
 
1505
[libraries]
1506
bank 0 slot 1 base $80 speed.lib
1507
bank 4 slot 2 base $80 map_data.lib
1508
...
1509
 
1510
You must tell Open8_link the bank and the slot for the library files.
1511
 
1512
4. If you want to use header and/or footer in your project,
1513
you can type the following:
1514
 
1515
[header]
1516
header.dat
1517
[footer]
1518
footer.dat
1519
 
1520
5. If you want to make value definitions, here's your chance:
1521
 
1522
[definitions]
1523
debug 1
1524
max_str_len 128
1525
start $150
1526
...
1527
 
1528
If flag 'v' is used, Open8_link displays information about ROM file after a
1529
succesful linking.
1530
 
1531
If flag 'd' is used, Open8_link discards all unreferenced FREE and SEMIFREE
1532
sections. This way you can link big libraries to your project and Open8_link
1533
will choose only the used sections, so you won't be linking any dead code/data.
1534
 
1535
If flag 's' is used, a symbol information file is created.
1536
If flag 'S' is used, a symbol information file with breakpoints is created.
1537
 
1538
If flag 'i' is given, Open8_link will write list files. Note that you must
1539
compile the object and library files with -i flag as well. Otherwise Open8_link
1540
has no extra information it needs to build list files. Here is an example of
1541
a list file: Let's assume you've compiled a source file called "main.s" using
1542
the 'i' flag. After you've linked the result also with the 'i' flag Open8_link
1543
has created a list file called "main.lst". This file contains the source
1544
text and the result data the source compiled into. List files are good for
1545
debugging.
1546
 
1547
Make sure you don't create duplicate labels in different places in the
1548
memory map as they break the linking loop. Duplicate labels are allowed when
1549
they overlap each other in the destination machine's memory. Look at the
1550
following example:
1551
 
1552
...
1553
.BANK 0
1554
.ORG $150
1555
 
1556
        ...
1557
        LD      A, 1
1558
        CALL    LOAD_LEVEL
1559
        ...
1560
 
1561
LOAD_LEVEL:
1562
        LD      HL, $2000
1563
        LD      (HL), A
1564
        CALL    INIT_LEVEL
1565
        RET
1566
 
1567
.BANK 1
1568
.ORG 0
1569
 
1570
INIT_LEVEL:
1571
        ...
1572
        RET
1573
 
1574
.BANK 2
1575
.ORG $0
1576
 
1577
INIT_LEVEL:
1578
        ...
1579
        RET
1580
...
1581
 
1582
 
1583
Here duplicate INIT_LEVEL labels are accepted as they both point to the
1584
same memory address (in the program's point of view).
1585
 
1586
 
1587
----------------------------------------------
1588
9... Arithmetics
1589
----------------------------------------------
1590
 
1591
 
1592
Open8_as is able to solve really complex calculations like
1593
 
1594
-((HELLO / 2) | 3)
1595
skeletor_end-skeletor
1596
10/2.5
1597
 
1598
so you can write something like
1599
 
1600
LD HL, data_end-data
1601
LD A, (pointer + 1)
1602
CP (TEST + %100) & %10101010
1603
 
1604
Open8_link also has this ability so it can compute the pending calculations
1605
Open8_as wasn't able to solve.
1606
 
1607
The following operators are valid:
1608
 
1609
(, ), | (or), & (and), ^ (power), << (shift left), >> (shift right), +, -,
1610
# (modulo), ~ (xor), *, /, < (get the low byte) and > (get the high byte).
1611
 
1612
Note that you can do NOT using XOR:
1613
 
1614
VALUE_A ~ $FF   = 8bit NOT
1615
VALUE_B ~ $FFFF = 16bit NOT
1616
 
1617
Open8_as computes internally with real numbers so (5/2)*2 produces 5, not 4.
1618
 
1619
 
1620
 
1621
----------------------------------------------
1622
10... Open8_as Flags
1623
----------------------------------------------
1624
 
1625
 
1626
Here are short descriptions for the flags you can give to Open8_as:
1627
 
1628
You can supply Open8_as with some (or all or none) of the following option flags.
1629
 
1630
i - Add list file information. Adds extra information to the output so
1631
    Open8_link can produce list files.
1632
M - Open8 generates makefile rules describing the dependencies of the main
1633
    source file. Use only with flags 'o' and 'l'.
1634
q - Quiet mode. .PRINT* -directives output nothing.
1635
t - Test compile. Doesn't output any files.
1636
v - Verbose mode. Shows a lot of information about the compiling process.
1637
x - Extra compile time definitions. Open8_as does extra work by creating
1638
    few helpful definitions on the fly.
1639
 
1640
One (and only one) of the following command flags must be defined.
1641
 
1642
l - Output a library file.
1643
o - Output an object file.
1644
 
1645
Examples:
1646
 
1647
[seravy@localhost tbp]# Open8_as -voi testa.s
1648
[seravy@localhost tbp]# Open8_as -oM testa.s
1649
[seravy@localhost tbp]# Open8_as -l testb.s testb.lib
1650
 
1651
Note that the first example produces file named "testa.o".
1652
 
1653
 
1654
----------------------------------------------
1655
11... Good things to know about Open8_as
1656
----------------------------------------------
1657
 
1658
 
1659
- Is 64 bytes too little for a string (file names, labels, definition labels,
1660
  etc)? Check out "MAX_NAME_LENGTH" in defines.h.
1661
- Open8_as preprocessor doesn't expand macros and repetitions. Those are actually
1662
  traversed in the assembling phase.
1663
- Open8_as's source code is mainly a huge mess, but Open8_link is quite well
1664
  structured and written. So beware!
1665
- Do not write ".E" into your sources as Open8_as uses it internally to mark
1666
  the end of a file.
1667
 
1668
 
1669
----------------------------------------------
1670
12... Legal Note
1671
----------------------------------------------
1672
 
1673
Open8_as and Open8_link is licensed as GPL software, as are any helper programs.
1674
 
1675
Code in the examples section is licensed under the BSD license.
1676
 
1677
 

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