1 <!doctype linuxdoc system>
5 <title>cc65 Compiler Intro
7 <url url="mailto:uz@cc65.org" name="Ullrich von Bassewitz">,<newline>
8 <url url="mailto:cbmnut@hushmail.com" name="CbmNut">,<newline>
9 <url url="mailto:greg.king5@verizon.net" name="Greg King">
13 How to use the cc65 C language system -- an introduction.
16 <!-- Table of contents -->
19 <!-- Begin the document -->
23 This is a short intro of how to use the compiler and the bin-utils. It contains
24 a step-by-step example of how to build a complete application from one C and
25 one assembly modules. This file does <em/not/ contain a complete reference for
26 the tools used in the process. There are separate files describing those tools,
27 in detail (see <url url="index.html">).
29 I do assume that you have downloaded and installed the compiler and
30 target-specific files. Windows users should use the friendly .exe installer
31 (named cc65-2.13.0-1.exe for version 2.13.0 of the package - adjust the
32 version number if necessary). It does not only install the target files, but
33 will also set up necessary environment variables for you.
35 If you're going for the .ZIP archives, please note that there is one file for
36 the host platform (Windows, DOS or OS/2), one file for each target platform
37 (C64 or whatever) and a separate file containing the docs (which include the
38 file you're currently reading). So for most uses, you will need at least 3
39 files and unpack all three into one directory. In case of the .ZIP archives,
40 you will also need to set the environment variables <tt/CC65_INC/,
41 <tt/LD65_LIB/ and <tt/LD65_CFG/ as described below.
43 <em/Note:/ There is a much simpler way to compile this example, by using the
44 <bf/cl65/ compile-and-link utility. However, it makes sense to understand how
45 the separate steps work. How to do the example with the <bf/cl65/ utility is
46 described <ref id="using-cl65" name="later">.
49 <sect1>Before we start<p>
51 You will find a copy of the sample modules, used in the next section, in the
52 "<tt>cc65/samples/tutorial</tt>" directory. If you encounter problems with
53 missing include files and/or libraries, please check the environment variables
54 <tt/CC65_INC/, <tt/LD65_LIB/ and <tt/LD65_CFG/. They should point to the
55 <tt/include/, <tt/lib/ and <tt/cfg/ subdirectories of the directory, where you
59 <sect1>The sample modules<p>
61 To explain the development flow, I will use the following example modules:
68 extern const char text[]; /* In text.s */
72 printf ("%s\n", text);
80 _text: .asciiz "Hello world!"
84 <sect1>Translation phases<p>
86 We assume that the target file should be named "hello", and the target system
96 +---------+ +---------+ +---------+
97 | hello.s | | text.s | | crt0.o |
98 +---------+ +---------+ +---------+
102 +---------+ +---------+ +---------+
103 | hello.o | | text.o | | c64.lib |
104 +---------+ +---------+ +---------+
108 +----------------------->ld65<
113 <tt/crt0.o/ (the startup code) and <tt/c64.lib/ (the C64 version of the runtime
114 and C library) are provided in binary form in the cc65 package. Actually, the
115 startup code is contained in the library, so you won't need to care about it.
119 <sect>The compiler<p>
121 The compiler translates one C source into one assembly source, for each
122 invocation. It does <em/not/ create object files directly, and it is <em/not/
123 able to translate more than one file per run.
125 In the example above, we would use the following command line, to translate
126 <tt/hello.c/ into <tt/hello.s/:
129 cc65 -O -t c64 hello.c
132 The <tt/-O/ switch tells the compiler to do an additional optimizer run, which
133 is usually a good idea, since it makes the code smaller. If you don't care
134 about the size, but want to have slightly faster code, use <tt/-Oi/ to inline
135 some runtime functions.
137 The <tt/-t/ switch is followed by the target system name.
139 If the compiler does not complain about errors in our "hello world" program, we
140 will have a file named "<tt/hello.s/", in our directory, that contains the
141 assembly source for the <bf/hello/ module.
143 For more information about the compiler, see <url url="cc65.html">.
147 <sect>The assembler<p>
149 The assembler translates one assembly source into an object file, for each
150 invocation. The assembler is <em/not/ able to translate more than one source
153 Let's translate the "hello.s" and "text.s" files from our example:
160 The <tt/-t/ switch is needed when translating the <tt/text.s/ file, so the
161 text is converted from the input character-set (usually ISO-8859-1) into the
162 target character-set (PETSCII, in this example) by the assembler. The
163 compiler-generated file <tt/hello.s/ does not contain any character constants,
164 so specification of a target is not necessary (it wouldn't do any harm,
167 If the assembler does not complain, we should now have two object files (named
168 <tt/hello.o/ and <tt/text.o/) in the current directory.
170 For more information about the assembler, see <url url="ca65.html">.
176 The linker combines several object and library files into one output file.
177 <bf/ld65/ is very configurable, but fortunately has built-in configurations,
178 so we don't need to mess with configuration files, here.
180 The compiler uses small functions to do things that cannot be done inline
181 without a big impact on code size. Those runtime functions, together with the
182 C library, are in an object-file archive named after the system, in this case,
183 "<tt/c64.lib/". We have to specify that file on the command line, so that the
184 linker can resolve those functions.
186 Let's link our files to get the final executable:
189 ld65 -o hello -t c64 hello.o text.o c64.lib
192 The argument after <tt/-o/ specifies the name of the output file, the argument
193 after <tt/-t/ gives the target system. The following arguments are object
194 files or libraries. Since the target library resolves imports in <tt/hello.o/
195 and <tt/text.o/, it must be specified <em/after/ those files.
197 After a successful linker run, we have a file named "<tt/hello/", ready for
200 For more information about the linker, see <url url="ld65.html">.
204 <sect>The easy way (using the cl65 utility)<label id="using-cl65"><p>
206 The <bf/cl65/ utility is able to do all of the steps described above, in just
207 one command line, and it has defaults for some options that are very
208 well-suited for our example.
210 To compile both files into one executable, enter:
213 cl65 -O hello.c text.s
216 The <bf/cl65/ utility knows how to translate C files into object files (it will
217 call the compiler, and then the assembler). It does know also how to create
218 object files from assembly files (it will call only the assembler, for that).
219 It knows how to build an executable (it will pass all object files to the
220 linker). And finally, it has the C64 as a default target, and will supply the
221 correct startup file and runtime library names to the linker, so you don't
222 have to care about that.
224 The one-liner above should give you a C64 executable named "<tt/hello/" in the
227 For more information about the compile & link utility, see <url
232 <sect>Running The Executable<p>
234 <em/Note: this section is incomplete!/
236 Depending on the target, cc65 chooses several methods of making a program
237 available for execution. Here, we list sample emulators and instructions for
238 running the program. Unless noted, similar instructions would also apply to a
239 real machine. One word of advice: we suggest you clear the screen at the
240 start, and wait for a keypress at the end of your program, as each target
241 varies in its start and exit conditions.
248 url="http://applewin.berlios.de/">:
250 Emulates Apple ][/enhanced Apple //e computers, with
251 sound, video, joysticks, serial port, and disk images. Includes monitor. Only
252 for Windows. The package comes with a DOS 3.3 disk (called "master.dsk") image;
253 however, you will need <bf/AppleCommander 1.3.5/ or later (available at <url
254 url="http://applecommander.sourceforge.net/">).
256 Compile the tutorial with
259 cl65 -O -t apple2 hello.c text.s
261 for the Apple ][, or:
263 cl65 -O -t apple2enh hello.c text.s
265 for the enhanced Apple //e.
267 Then, put the file onto an Apple disk image, for use with an emulator. Copy
268 the <tt/master.dsk/ which comes with <bf/AppleWin/, and rename it to
269 <tt/cc65.dsk/, then use <bf/AppleCommander/:
272 java -jar ac.jar -cc65 cc65.dsk test B < hello
275 Note that a convention in the Apple world is that "hello" is the file which is
276 run automatically upon booting a DOS disk, sort of like the "autoexec.bat" of
277 the MSDOS/Windows world. We've avoided that in the example, however. Also,
278 the <tt/B/ parameter must be in caps., and "test" is the name of the program as
279 it will appear on the Apple disk.
281 Start the emulator, click on the <bf/Disk 1/ icon, and point to <bf/cc65.dsk/;
282 then, click the big Apple logo, to boot the system. Then, type this on the
289 You will see "Hello, World!" appear on the same line. Thanks to
290 <url url="mailto:ol.sc@web.de" name="Oliver Schmidt"> for his help
291 in completing this section.
296 <sect2>Atari800Win PLus<p>
298 url="http://www.atari.org.pl/PLus/index_us.htm">:
300 Emulates Atari 400/800/65XE/130XE/800XL/1200XL/5200, with stereo sound, disk
301 images, scanline-exact NTSC/PAL video, joysticks, mouse, cartridges, and RAM
302 expansions. Includes monitor. Unfortunately, only for Windows. You will need
303 the emulator, "atarixl.rom" or "atariosb.rom"/"ataribas.rom", and "dos25.xfd"
304 files (not supplied).
306 Compile the tutorial with
309 cl65 -O -t atari hello.c text.s
312 Start the emulator, choose <bf/File>Autoboot image/ or <bf/File>Load
313 executable/, and point to the "<bf/hello/" executable. It is customary to
314 rename executables of that type to "<bf/hello.xex/". The file has a 7-byte
315 header meant to be loaded directly from Atari DOS 2/2.5 or compatibles.
317 On a real Atari, you would need a disk drive, and Atari DOS 2.5 or compatible.
318 Turn on the computer, type
324 at the BASIC prompt, then choose <bf/N. CREATE MEM.SAV/,
325 then choose <bf/L. BINARY LOAD/, and enter <tt/HELLO/.
327 The emulation, also, supports that method. Look at <bf/Atari>Settings/, and
328 check <bf/Enable H: Patch for Hard Disk Devices/, then <bf/Atari>Hard
329 disks/, and set the path of <bf/H1:/ to your executables directory, then use
330 "<bf/H0:HELLO.XEX/" in the above procedure (after pressing <tt/L/), to access
331 your harddrive directly.
333 <em/Note:/ There is no delay after the program exits, as you are returned
334 to the DOS menu. Your C program should wait for a keypress if you want to see
342 url="http://code.google.com/p/oriculator/">:
344 Emulates Oric-1 and Atmos computers, with sound, disk images,
345 scanline-exact NTSC/PAL video, and movie export. Includes a monitor.
346 Fortunately, for all SDL platforms. You will need just the emulator; all
349 Compile the tutorial with
352 cl65 -O -t atmos hello.c text.s -o hello.tap
355 Start the emulator, choose <bf/F1/ and <bf/Insert tape.../, and point to
356 the "<bf/hello.tap/" executable. After it has finished loading, type
362 On a real Atmos, you would need a tape drive.
363 Turn on the computer, type
369 at the BASIC prompt. After it has finished loading, type
375 The emulation, also, supports that method.
382 url="http://vice-emu.sourceforge.net/">:
384 Emulates Commodore 64/128/VIC-20/PET/CBM II/Plus 4 computers. Supports
385 printers, serial port and adapters, stereo sound, disk drives and images, RAM expansions,
386 cartridges, ethernet connection, cycle-exact NTSC/PAL video, mice, graphics tablet,
387 lightpens, and joysticks. Includes monitor. Runs on MSDOS/PCDOS, Win9x/ME/NT/2000/XP, OS2,
388 BeOS x86, Acorn RISC OS, and most Unixes.
390 Compile the tutorial with
392 cl65 -O -t <sys> hello.c text.s
394 Substitute the name of a Commodore computer for that <tt/<sys>/:
406 Start the desired version of the emulator (CBM610 programs run on
407 the CBM II [<tt/xcbm2/] emulator).
409 In the Windows versions of VICE, choose <bf>File>Autoboot disk/tape
410 image...</bf>, choose your executable, and click <bf/OK/.
412 In the Unix versions, hold down the mouse's first button. Move the pointer to
413 <bf>Smart-attach disk/tape...</bf>, and release the button. Choose your
414 executable, and click <bf/Autostart/.
416 The file has a 14-byte header which corresponds to a PRG-format BASIC program,
417 consisting of a single line, similar to this:
423 On a real Commodore with attached disk drive, you would type:
435 on PET/CBM II/C128/C16/Plus 4; then, type
441 On a Commodore 128, you can combine those two commands:
446 The output will appear on a separate line, and you will be returned to a BASIC
451 Available at <it/Click Here Software's/ <url
452 url="http://cbmfiles.com/geos/index.html" name="GEOS download section">:
454 <it><bf/G/raphics <bf/E/nvironment <bf/O/perating <bf/S/ystem.</it>
455 It provides a WIMP GUI (Windows, Icons, and Mouse-Pointer Graphical User
456 Interface) for Commodore's computer models <bf/64/ and <bf/128/. It can be
457 controlled by many different types of input devices:
463 <item>graphics drawing tablets
467 The tutorial files are different for GEOS. You will find them "next door," in
468 "<tt>cc65/samples/geos</tt>"; they are called "<tt/hello1.c/" and
469 "<tt/hello1res.grc/".
471 Compile the tutorial with
473 cl65 -t geos-cbm -O -o hello1 hello1res.grc hello1.c
475 Copy the resulting file "<tt/hello1/" onto a (GEOS-format) disk.
477 Boot the GEOS master disk/image.
480 When you want to run GEOS in an emulator, you must adjust that emulator so that
481 it does a "true drive" emulation. Each emulator has its own way of turning that
486 VICE even has different ways that depend on which operating system is running
489 <item>In Windows, you must click on <bf/Options/ (in an always visible menu).
490 Then, you must click on <bf/True drive emulation/.
491 <item>In Unix, you must <em/hold down/ the second button on your mouse. Move
492 the pointer down to <bf/Drive settings/. Then, move the pointer over to
493 <bf/Enable true drive emulation/. (If there is a check-mark in front of
494 those words, that feature already is turned on -- then, move the pointer
495 off of that menu.) Release the mouse button.
499 Find the <bf/CONVERT/ program on the boot disk [tap the 6-key; then, you
500 should see its icon in the fourth position on the <bf/deskTop/'s directory
501 notePad]. Move GEOS's pointer over to <bf/CONVERT/'s icon; double-click
502 it to run that program. Click on the <bf/Disk/ icon; put the disk with
503 "<tt/hello1/" into the drive; and, click the <bf/OK/ icon. Use the little
504 icons under the list of file-names to move through that list until you find
505 "<tt/hello1/". Click on it; and then, click on the <bf/Convrt/ icon.
506 <bf/CONVERT/ will ask you to confirm that you choose the correct file; click
507 <bf/YES/ if you did (or, click <bf/NO/ if you made a mistake). After the
508 program has converted "<tt/hello1/" from a CBM file into a GEOS file, it will
509 announce what it did -- click on <bf/OK/. <bf/CONVERT/ will show the file list
510 again. This time, click on <bf/Quit/.
512 (You might need to put the boot disk back into the drive, in order to reload
513 <bf/deskTop/. Then, you must swap back to the disk with the tutorial program
514 on it, and click on its disk icon [on the right side of the screen].)
516 Now, you must find <bf/hello1/. Click on the lower left-hand corner of the
517 directory notePad. Look at the eight file-positions on each page until you see
518 <bf/hello1/. Double-click on its icon.
520 The output is shown in a GEOS dialog box; click <bf/OK/ when you have finished
523 <sect1>Ohio Scientific Challenger 1P<p>
524 Available at <url url="http://www.pcjs.org/docs/c1pjs/" name="C1Pjs">:
526 Emulates the Ohio Scientific Challenger 1P computer in different configurations.
527 The 32 kb RAM machine that must be used with the default compiler settings is
528 <url url="http://www.pcjs.org/devices/c1p/machine/32kb/" name="here">.
530 In addition to cc65 the srec_cat program from the
531 <url url="http://srecord.sourceforge.net/" name="SRecord">
532 tool collection must be installed. Some Linux distributions also provide the
533 srecord package directly as an installable package.
535 The osic1p runtime library returns to the boot prompt when the
536 main() program exits. Therefore the C file in the tutorial must be slightly
537 modified in order to see the results on the screen. Otherwise the program
538 would print the text string and then jump to the boot prompt, making it
539 impossible to see the results of running the tutorial program.
541 In addition to that the osic1p target does not yet have support for stdio
542 functions. Only the functions from the conio library are available.
544 Therefore modify the hello.c source file as follows:
550 extern const char text[]; /* In text.s */
555 cprintf ("%s\r\nPress <RETURN>\r\n", text);
561 Compile the tutorial with
564 cl65 -O -t osic1p hello.c text.s
567 Convert the executable file into a text file that can be loaded via
568 the Ohio Scientific 65V PROM monitor at start address 0x200:
571 srec_cat hello -binary -offset 0x200 -o hello.c1p -Ohio_Scientific -execution-start-address=0x200
574 Open the URL <url url="http://www.pcjs.org/devices/c1p/machine/32kb/" name="http://www.pcjs.org/devices/c1p/machine/32kb/">
575 and wait until the emulator has been loaded. Click on the "BREAK"
576 button to display the boot prompt, then press the "M" key to enter the
577 65V PROM monitor. Click the "Choose File" button and select the file "hello.c1p"
578 that was created as the output of the above invocation of the "srec_cat"
579 command. Press the "Load" button. You should see the following text on the
587 After hitting the RETURN key you should see the boot prompt again.
589 The program can also be uploaded over the serial port to a real Challenger 1P
590 computer with 32 kB RAM. See the <url url="osi.html" name="Ohio Scientifc-specific documentation"> for instructions how to
591 compile for other RAM sizes.
593 <sect1>Contributions wanted<p>
595 We need your help! Recommended emulators and instructions for other targets
596 are missing. We suggest that you choose emulators with good compatibility.
597 Also, being able to run all computers in the target series is good for
598 target compatibility testing. A machine-language monitor is almost essential
599 for debugging, but a native debugger could be used, as well.
601 Finally, emulators which run on Unix or Windows would help to reach a wider