1 <!doctype linuxdoc system>
4 <title>ld65 Users Guide
5 <author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
6 <date>02.12.2000, 02.10.2001
9 The ld65 linker combines object files into an executable file. ld65 is highly
10 configurable and uses configuration files for high flexibility.
13 <!-- Table of contents -->
16 <!-- Begin the document -->
20 The ld65 linker combines several object modules created by the ca65
21 assembler, producing an executable file. The object modules may be read
22 from a library created by the ar65 archiver (this is somewhat faster and
23 more convenient). The linker was designed to be as flexible as possible.
24 It complements the features that are built into the ca65 macroassembler:
28 <item> Accept any number of segments to form an executable module.
30 <item> Resolve arbitrary expressions stored in the object files.
32 <item> In case of errors, use the meta information stored in the object files
33 to produce helpful error messages. In case of undefined symbols,
34 expression range errors, or symbol type mismatches, ld65 is able to
35 tell you the exact location in the original assembler source, where
36 the symbol was referenced.
38 <item> Flexible output. The output of ld65 is highly configurable by a config
39 file. More common platforms are supported by builtin configurations
40 that may be activated by naming the target system. The output
41 generation was designed with different output formats in mind, so
42 adding other formats shouldn't be a great problem.
50 <sect1>Command line option overview<p>
52 The linker is called as follows:
55 ---------------------------------------------------------------------------
56 Usage: ld65 [options] module ...
58 -C name Use linker config file
59 -Ln name Create a VICE label file
60 -Lp Mark write protected segments as such (VICE)
61 -S addr Set the default start address
62 -V Print the linker version
64 -m name Create a map file
65 -o name Name the default output file
66 -t sys Set the target system
71 --config name Use linker config file
72 --help Help (this text)
73 --mapfile name Create a map file
74 --start-addr addr Set the default start address
75 --target sys Set the target system
76 --version Print the linker version
77 ---------------------------------------------------------------------------
81 <sect1>Command line options in detail<p>
83 Here is a description of all the command line options:
87 <tag><tt>-h, --help</tt></tag>
89 Print the short option summary shown above.
93 <tag><tt>-m name, --mapfile name</tt></tag>
95 This option (which needs an argument that will used as a filename for
96 the generated map file) will cause the linker to generate a map file.
97 The map file does contain a detailed overview over the modules used, the
98 sizes for the different segments, and a table containing exported
102 <label id="option-o">
103 <tag><tt>-o name</tt></tag>
105 The -o switch is used to give the name of the default output file.
106 Depending on your output configuration, this name may NOT be used as
107 name for the output file. However, for the builtin configurations, this
108 name is used for the output file name.
111 <label id="option-t">
112 <tag><tt>-t sys, --target sys</tt></tag>
114 The argument for the -t switch is the name of the target system. Since this
115 switch will activate a builtin configuration, it may not be used together
116 with the <tt><ref id="option-C" name="-C"></tt> option. The following target
117 systems are currently supported:
125 <item>cbm510 (CBM-II series with 40 column video)
126 <item>cbm610 (all CBM series-II computers with 80 column video)
127 <item>pet (all CBM PET systems except the 2001)
132 There are a few more targets defined but neither of them is actually
133 supported. See <ref id="builtin-configs" name="builtin configurations"> for
137 <label id="option-v">
138 <tag><tt>-v, --verbose</tt></tag>
140 Using the -v option, you may enable more output that may help you to
141 locate problems. If an undefined symbol is encountered, -v causes the
142 linker to print a detailed list of the references (that is, source file
143 and line) for this symbol.
146 <tag><tt>-vm</tt></tag>
148 Must be used in conjunction with <tt><ref id="option-m" name="-m"></tt>
149 (generate map file). Normally the map file will not include empty segments
150 and sections, or unreferenced symbols. Using this option, you can force the
151 linker to include all this information into the map file.
154 <label id="option-C">
155 <tag><tt>-C</tt></tag>
157 This gives the name of an output config file to use. See section 4 for more
158 information about config files. -C may not be used together with <tt><ref
159 id="option-t" name="-t"></tt>.
162 <tag><tt>-Ln</tt></tag>
164 This option allows you to create a file that contains all global labels and
165 may be loaded into VICE emulator using the <tt/ll/ (load label) command. You
166 may use this to debug your code with VICE. Note: Older versions had some
167 bugs in the label code. If you have problems, please get the latest VICE
171 <tag><tt>-Lp</tt></tag>
176 <label id="option-S">
177 <tag><tt>-S addr, --start-addr addr</tt></tag>
179 Using -S you may define the default starting address. If and how this
180 address is used depends on the config file in use. For the builtin
181 configurations, only the "none" system honors an explicit start address,
182 all other builtin config provide their own.
185 <tag><tt>-V, --version</tt></tag>
187 This option print the version number of the linker. If you send any
188 suggestions or bugfixes, please include this number.
192 If one of the modules is not found in the current directory, and the module
193 name does not have a path component, the value of the environment variable
194 <tt/CC65_LIB/ is prepended to the name, and the linker tries to open the
195 module with this new name.
199 <sect>Detailed workings<p>
201 The linker does several things when combining object modules:
203 First, the command line is parsed from left to right. For each object file
204 encountered (object files are recognized by a magic word in the header, so
205 the linker does not care about the name), imported and exported
206 identifiers are read from the file and inserted in a table. If a library
207 name is given (libraries are also recognized by a magic word, there are no
208 special naming conventions), all modules in the library are checked if an
209 export from this module would satisfy an import from other modules. All
210 modules where this is the case are marked. If duplicate identifiers are
211 found, the linker issues a warning.
213 This procedure (parsing and reading from left to right) does mean, that a
214 library may only satisfy references for object modules (given directly or from
215 a library) named <em/before/ that library. With the command line
218 ld65 crt0.o clib.lib test.o
221 the module test.o may not contain references to modules in the library
222 clib.lib. If this is the case, you have to change the order of the modules
226 ld65 crt0.o test.o clib.lib
229 Step two is, to read the configuration file, and assign start addresses
230 for the segments and define any linker symbols (see <ref id="config-files"
231 name="Configuration files">).
233 After that, the linker is ready to produce an output file. Before doing that,
234 it checks it's data for consistency. That is, it checks for unresolved
235 externals (if the output format is not relocatable) and for symbol type
236 mismatches (for example a zero page symbol is imported by a module as absolute
239 Step four is, to write the actual target files. In this step, the linker will
240 resolve any expressions contained in the segment data. Circular references are
241 also detected in this step (a symbol may have a circular reference that goes
242 unnoticed if the symbol is not used).
244 Step five is to output a map file with a detailed list of all modules,
245 segments and symbols encountered.
247 And, last step, if you give the <tt><ref id="option-v" name="-v"></tt> switch
248 twice, you get a dump of the segment data. However, this may be quite
249 unreadable if you're not a developer:-)
253 <sect>Configuration files<label id="config-files"><p>
255 Configuration files are used to describe the layout of the output file(s). Two
256 major topics are covered in a config file: The memory layout of the target
257 architecture, and the assignment of segments to memory areas. In addition,
258 several other attributes may be specified.
260 Case is ignored for keywords, that is, section or attribute names, but it is
261 <em/not/ ignored for names and strings.
265 <sect1>Memory areas<p>
267 Memory areas are specified in a <tt/MEMORY/ section. Lets have a look at an
268 example (this one describes the usable memory layout of the C64):
272 RAM1: start = $0800, size = $9800;
273 ROM1: start = $A000, size = $2000;
274 RAM2: start = $C000, size = $1000;
275 ROM2: start = $E000, size = $2000;
279 As you can see, there are two ram areas and two rom areas. The names
280 (before the colon) are arbitrary names that must start with a letter, with
281 the remaining characters being letters or digits. The names of the memory
282 areas are used when assigning segments. As mentioned above, case is
283 significant for these names.
285 The syntax above is used in all sections of the config file. The name
286 (<tt/ROM1/ etc.) is said to be an identifier, the remaining tokens up to the
287 semicolon specify attributes for this identifier. You may use the equal sign
288 to assign values to attributes, and you may use a comma to separate
289 attributes, you may also leave both out. But you <em/must/ use a semicolon to
290 mark the end of the attributes for one identifier. The section above may also
291 have looked like this:
294 # Start of memory section
312 There are of course more attributes for a memory section than just start and
313 size. Start and size are mandatory attributes, that means, each memory area
314 defined <em/must/ have these attributes given (the linker will check that). I
315 will cover other attributes later. As you may have noticed, I've used a
316 comment in the example above. Comments start with a hash mark (`#'), the
317 remainder of the line is ignored if this character is found.
322 Let's assume you have written a program for your trusty old C64, and you would
323 like to run it. For testing purposes, it should run in the <tt/RAM/ area. So
324 we will start to assign segments to memory sections in the <tt/SEGMENTS/
329 CODE: load = RAM1, type = ro;
330 RODATA: load = RAM1, type = ro;
331 DATA: load = RAM1, type = rw;
332 BSS: load = RAM1, type = bss, define = yes;
336 What we are doing here is telling the linker, that all segments go into the
337 <tt/RAM1/ memory area in the order specified in the <tt/SEGMENTS/ section. So
338 the linker will first write the <tt/CODE/ segment, then the <tt/RODATA/
339 segment, then the <tt/DATA/ segment - but it will not write the <tt/BSS/
340 segment. Why? Enter the segment type: For each segment specified, you may also
341 specify a segment attribute. There are five possible segment attributes:
345 wprot same as ro but will be marked as write protected in
346 the VICE label file if -Lp is given
348 bss means that this is an uninitialized segment
349 zp a zeropage segment
352 So, because we specified that the segment with the name BSS is of type bss,
353 the linker knows that this is uninitialized data, and will not write it to an
354 output file. This is an important point: For the assembler, the <tt/BSS/
355 segment has no special meaning. You specify, which segments have the bss
356 attribute when linking. This approach is much more flexible than having one
357 fixed bss segment, and is a result of the design decision to supporting an
358 arbitrary segment count.
360 If you specify "<tt/type = bss/" for a segment, the linker will make sure that
361 this segment does only contain uninitialized data (that is, zeroes), and issue
362 a warning if this is not the case.
364 For a <tt/bss/ type segment to be useful, it must be cleared somehow by your
365 program (this happens usually in the startup code - for example the startup
366 code for cc65 generated programs takes care about that). But how does your
367 code know, where the segment starts, and how big it is? The linker is able to
368 give that information, but you must request it. This is, what we're doing with
369 the "<tt/define = yes/" attribute in the <tt/BSS/ definitions. For each
370 segment, where this attribute is true, the linker will export three symbols.
373 __NAME_LOAD__ This is set to the address where the
375 __NAME_RUN__ This is set to the run address of the
376 segment. We will cover run addresses
378 __NAME_SIZE__ This is set to the segment size.
381 Replace <tt/NAME/ by the name of the segment, in the example above, this would
382 be <tt/BSS/. These symbols may be accessed by your code.
384 Now, as we've configured the linker to write the first three segments and
385 create symbols for the last one, there's only one question left: Where does
386 the linker put the data? It would be very convenient to have the data in a
389 <sect1>Output files<p>
391 We don't have any files specified above, and indeed, this is not needed in a
392 simple configuration like the one above. There is an additional attribute
393 "file" that may be specified for a memory area, that gives a file name to
394 write the area data into. If there is no file name given, the linker will
395 assign the default file name. This is "a.out" or the one given with the
396 <tt><ref id="option-o" name="-o"></tt> option on the command line. Since the
397 default behaviour is ok for our purposes, I did not use the attribute in the
398 example above. Let's have a look at it now.
400 The "file" attribute (the keyword may also be written as "FILE" if you like
401 that better) takes a string enclosed in double quotes (`"') that specifies the
402 file, where the data is written. You may specifiy the same file several times,
403 in that case the data for all memory areas having this file name is written
404 into this file, in the order of the memory areas defined in the <tt/MEMORY/
405 section. Let's specify some file names in the <tt/MEMORY/ section used above:
409 RAM1: start = $0800, size = $9800, file = %O;
410 ROM1: start = $A000, size = $2000, file = "rom1.bin";
411 RAM2: start = $C000, size = $1000, file = %O;
412 ROM2: start = $E000, size = $2000, file = "rom2.bin";
416 The <tt/%O/ used here is a way to specify the default behaviour explicitly:
417 <tt/%O/ is replaced by a string (including the quotes) that contains the
418 default output name, that is, "a.out" or the name specified with the <tt><ref
419 id="option-o" name="-o"></tt> option on the command line. Into this file, the
420 linker will first write any segments that go into <tt/RAM1/, and will append
421 then the segments for <tt/RAM2/, because the memory areas are given in this
422 order. So, for the RAM areas, nothing has really changed.
424 We've not used the ROM areas, but we will do that below, so we give the file
425 names here. Segments that go into <tt/ROM1/ will be written to a file named
426 "rom1.bin", and segments that go into <tt/ROM2/ will be written to a file
427 named "rom2.bin". The name given on the command line is ignored in both cases.
430 <sect1>LOAD and RUN addresses (ROMable code)<p>
432 Let us look now at a more complex example. Say, you've successfully tested
433 your new "Super Operating System" (SOS for short) for the C64, and you
434 will now go and replace the ROMs by your own code. When doing that, you
435 face a new problem: If the code runs in RAM, we need not to care about
436 read/write data. But now, if the code is in ROM, we must care about it.
437 Remember the default segments (you may of course specify your own):
441 RODATA read only data
443 BSS uninitialized data, read/write
446 Since <tt/BSS/ is not initialized, we must not care about it now, but what
447 about <tt/DATA/? <tt/DATA/ contains initialized data, that is, data that was
448 explicitly assigned a value. And your program will rely on these values on
449 startup. Since there's no other way to remember the contents of the data
450 segment, than storing it into one of the ROMs, we have to put it there. But
451 unfortunately, ROM is not writeable, so we have to copy it into RAM before
452 running the actual code.
454 The linker cannot help you copying the data from ROM into RAM (this must be
455 done by the startup code of your program), but it has some features that will
456 help you in this process.
458 First, you may not only specify a "<tt/load/" attribute for a segment, but
459 also a "<tt/run/" attribute. The "<tt/load/" attribute is mandatory, and, if
460 you don't specify a "<tt/run/" attribute, the linker assumes that load area
461 and run area are the same. We will use this feature for our data area:
465 CODE: load = ROM1, type = ro;
466 RODATA: load = ROM2, type = ro;
467 DATA: load = ROM2, run = RAM2, type = rw, define = yes;
468 BSS: load = RAM2, type = bss, define = yes;
472 Let's have a closer look at this <tt/SEGMENTS/ section. We specify that the
473 <tt/CODE/ segment goes into <tt/ROM1/ (the one at $A000). The readonly data
474 goes into <tt/ROM2/. Read/write data will be loaded into <tt/ROM2/ but is run
475 in <tt/RAM2/. That means that all references to labels in the <tt/DATA/
476 segment are relocated to be in <tt/RAM2/, but the segment is written to
477 <tt/ROM2/. All your startup code has to do is, to copy the data from it's
478 location in <tt/ROM2/ to the final location in <tt/RAM2/.
480 So, how do you know, where the data is located? This is the second point,
481 where you get help from the linker. Remember the "<tt/define/" attribute?
482 Since we have set this attribute to true, the linker will define three
483 external symbols for the data segment that may be accessed from your code:
486 __DATA_LOAD__ This is set to the address where the segment
487 is loaded, in this case, it is an address in
489 __DATA_RUN__ This is set to the run address of the segment,
490 in this case, it is an address in RAM2.
491 __DATA_SIZE__ This is set to the segment size.
494 So, what your startup code must do, is to copy <tt/__DATA_SIZE__/ bytes from
495 <tt/__DATA_LOAD__/ to <tt/__DATA_RUN__/ before any other routines are called.
496 All references to labels in the <tt/DATA/ segment are relocated to <tt/RAM2/
497 by the linker, so things will work properly.
500 <sect1>Other MEMORY area attributes<p>
502 There are some other attributes not covered above. Before starting the
503 reference section, I will discuss the remaining things here.
505 You may request symbols definitions also for memory areas. This may be
506 useful for things like a software stack, or an i/o area.
510 STACK: start = $C000, size = $1000, define = yes;
514 This will define three external symbols that may be used in your code:
517 __STACK_START__ This is set to the start of the memory
518 area, $C000 in this example.
519 __STACK_SIZE__ The size of the area, here $1000.
520 __STACK_LAST__ This is NOT the same as START+SIZE.
521 Instead, it it defined as the first
522 address that is not used by data. If we
523 don't define any segments for this area,
524 the value will be the same as START.
527 A memory section may also have a type. Valid types are
530 ro for readonly memory
531 rw for read/write memory.
534 The linker will assure, that no segment marked as read/write or bss is put
535 into a memory area that is marked as readonly.
537 Unused memory in a memory area may be filled. Use the "<tt/fill = yes/"
538 attribute to request this. The default value to fill unused space is zero. If
539 you don't like this, you may specify a byte value that is used to fill these
540 areas with the "<tt/fillval/" attribute. This value is also used to fill unfilled
541 areas generated by the assemblers <tt/.ALIGN/ and <tt/.RES/ directives.
544 <sect1>Other SEGMENT attributes<p>
546 Segments may be aligned to some memory boundary. Specify "<tt/align = num/" to
547 request this feature. Num must be a power of two. To align all segments on a
552 CODE: load = ROM1, type = ro, align = $100;
553 RODATA: load = ROM2, type = ro, align = $100;
554 DATA: load = ROM2, run = RAM2, type = rw, define = yes,
556 BSS: load = RAM2, type = bss, define = yes, align = $100;
560 If an alignment is requested, the linker will add enough space to the output
561 file, so that the new segment starts at an address that is divideable by the
562 given number without a remainder. All addresses are adjusted accordingly. To
563 fill the unused space, bytes of zero are used, or, if the memory area has a
564 "<tt/fillval/" attribute, that value. Alignment is always needed, if you have
565 the used the <tt/.ALIGN/ command in the assembler. The alignment of a segment
566 must be equal or greater than the alignment used in the <tt/.ALIGN/ command.
567 The linker will check that, and issue a warning, if the alignment of a segment
568 is lower than the alignment requested in a <tt/.ALIGN/ command of one of the
569 modules making up this segment.
571 For a given segment you may also specify a fixed offset into a memory area or
572 a fixed start address. Use this if you want the code to run at a specific
573 address (a prominent case is the interrupt vector table which must go at
574 address $FFFA). Only one of <tt/ALIGN/ or <tt/OFFSET/ or <tt/START/ may be
575 specified. If the directive creates empty space, it will be filled with zero,
576 of with the value specified with the "<tt/fillval/" attribute if one is given.
577 The linker will warn you if it is not possible to put the code at the
578 specified offset (this may happen if other segments in this area are too
579 large). Here's an example:
583 VECTORS: load = ROM2, type = ro, start = $FFFA;
587 or (for the segment definitions from above)
591 VECTORS: load = ROM2, type = ro, offset = $1FFA;
595 File names may be empty, data from segments assigned to a memory area with
596 an empty file name is discarded. This is useful, if the a memory area has
597 segments assigned that are empty (for example because they are of type
598 bss). In that case, the linker will create an empty output file. This may
599 be suppressed by assigning an empty file name to that memory area.
601 The symbol <tt/%S/ may be used to access the default start address (that is,
602 $200 or the value given on the command line with the <tt><ref id="option-S"
603 name="-S"></tt> option).
607 <sect1>The FILES section<p>
609 The <tt/FILES/ section is used to support other formats than straight binary
610 (which is the default, so binary output files do not need an explicit entry
611 in the <tt/FILES/ section).
613 The <tt/FILES/ section lists output files and as only attribute the format of
614 each output file. Assigning binary format to the default output file would
623 The only other available output format is the o65 format specified by Andre
624 Fachat. It is defined like this:
632 The necessary o65 attributes are defined in a special section labeled
637 <sect1>The FORMAT section<p>
639 The <tt/FORMAT/ section is used to describe file formats. The default (binary)
640 format has currently no attributes, so, while it may be listed in this
641 section, the attribute list is empty. The second supported format, o65, has
642 several attributes that may be defined here.
646 o65: os = lunix, version = 0, type = small,
647 import = LUNIXKERNEL,
658 In addition to the <tt/MEMORY/ and <tt/SEGMENTS/ sections described above, the
659 linker has features that may be enabled by an additional section labeled
660 <tt/FEATURES/. Currently, one such feature is available: <tt/CONDES/ is used
661 to tell the linker to emit module constructor/destructor tables.
665 CONDES: segment = RODATA,
667 label = __CONSTRUCTOR_TABLE__,
668 count = __CONSTRUCTOR_COUNT__;
672 The <tt/CONDES/ feature has several attributes:
676 <tag><tt>segment</tt></tag>
678 This attribute tells the linker into which segment the table should be
679 placed. If the segment does not exist, it is created.
682 <tag><tt>type</tt></tag>
684 Describes the type of the routines to place in the table. Type may be
685 one of the predefined types <tt/constructor/ or <tt/destructor/, or a
686 numeric value between 0 and 6.
689 <tag><tt>label</tt></tag>
691 This specifies the label to use for the table. The label points to the
692 start of the table in memory and may be used from within user written
696 <tag><tt>count</tt></tag>
698 This is an optional attribute. If specified, an additional symbol is
699 defined by the linker using the given name. The value of this symbol
700 is the number of entries (<em/not/ bytes) in the table. While this
701 attribute is optional, it is often useful to define it.
704 <tag><tt>order</tt></tag>
706 Optional attribute that takes one of the keywords <tt/increasing/ or
707 <tt/decreasing/ as an argument. Specifies the sorting order of the entries
708 within the table. The default is <tt/increasing/, which means that the
709 entries are sorted with increasing priority (the first entry has the lowest
710 priority). You may change this behaviour by specifying <tt/decreasing/ as
711 the argument, the order of entries is reversed in this case.
713 Please note that the order of entries with equal priority is undefined.
717 Without specifying the <tt/CONDES/ feature, the linker will not create any
718 tables, even if there are <tt/condes/ entries in the object files.
720 For more information see the <tt/.CONDES/ command in the <htmlurl
721 url="ca65.html" name="ca65 manual">.
725 <sect1>Builtin configurations<label id="builtin-configs"><p>
727 Here is a list of the builin configurations for the different target
731 <tag><tt>none</tt></tag>
734 RAM: start = %S, size = $10000, file = %O;
737 CODE: load = RAM, type = rw;
738 RODATA: load = RAM, type = rw;
739 DATA: load = RAM, type = rw;
740 BSS: load = RAM, type = bss, define = yes;
743 CONDES: segment = RODATA,
745 label = __CONSTRUCTOR_TABLE__,
746 count = __CONSTRUCTOR_COUNT__;
747 CONDES: segment = RODATA,
749 label = __DESTRUCTOR_TABLE__,
750 count = __DESTRUCTOR_COUNT__;
753 __STACKSIZE__ = $800; # 2K stack
757 <tag><tt>atari</tt></tag>
760 ZP: start = $82, size = $7E, type = rw;
761 HEADER: start = $0000, size = $6, file = %O;
762 RAM: start = $1F00, size = $9D1F, file = %O; # $9D1F: matches upper bound $BC1F
765 EXEHDR: load = HEADER, type = wprot;
766 CODE: load = RAM, type = wprot, define = yes;
767 RODATA: load = RAM, type = wprot;
768 DATA: load = RAM, type = rw;
769 BSS: load = RAM, type = bss, define = yes;
770 ZEROPAGE: load = ZP, type = zp;
771 AUTOSTRT: load = RAM, type = wprot;
774 CONDES: segment = RODATA,
776 label = __CONSTRUCTOR_TABLE__,
777 count = __CONSTRUCTOR_COUNT__;
778 CONDES: segment = RODATA,
780 label = __DESTRUCTOR_TABLE__,
781 count = __DESTRUCTOR_COUNT__;
784 __STACKSIZE__ = $800; # 2K stack
788 <tag><tt>c64</tt></tag>
791 ZP: start = $02, size = $1A, type = rw;
792 RAM: start = $7FF, size = $c801, define = yes, file = %O;
795 CODE: load = RAM, type = wprot;
796 RODATA: load = RAM, type = wprot;
797 DATA: load = RAM, type = rw;
798 BSS: load = RAM, type = bss, define = yes;
799 ZEROPAGE: load = ZP, type = zp;
802 CONDES: segment = RODATA,
804 label = __CONSTRUCTOR_TABLE__,
805 count = __CONSTRUCTOR_COUNT__;
806 CONDES: segment = RODATA,
808 label = __DESTRUCTOR_TABLE__,
809 count = __DESTRUCTOR_COUNT__;
812 __STACKSIZE__ = $800; # 2K stack
816 <tag><tt>c128</tt></tag>
819 ZP: start = $02, size = $1A, type = rw;
820 RAM: start = $1bff, size = $a401, define = yes, file = %O;
823 CODE: load = RAM, type = wprot;
824 RODATA: load = RAM, type = wprot;
825 DATA: load = RAM, type = rw;
826 BSS: load = RAM, type = bss, define = yes;
827 ZEROPAGE: load = ZP, type = zp;
830 CONDES: segment = RODATA,
832 label = __CONSTRUCTOR_TABLE__,
833 count = __CONSTRUCTOR_COUNT__;
834 CONDES: segment = RODATA,
836 label = __DESTRUCTOR_TABLE__,
837 count = __DESTRUCTOR_COUNT__;
838 CONDES: segment = RODATA,
840 label = __IRQFUNC_TABLE__,
841 count = __IRQFUNC_COUNT__;
844 __STACKSIZE__ = $800; # 2K stack
848 <tag><tt>plus4</tt></tag>
851 ZP: start = $02, size = $1A, type = rw;
852 RAM: start = $0fff, size = $7001, file = %O;
855 CODE: load = RAM, type = wprot;
856 RODATA: load = RAM, type = wprot;
857 DATA: load = RAM, type = rw;
858 BSS: load = RAM, type = bss, define = yes;
859 ZEROPAGE: load = ZP, type = zp;
862 CONDES: segment = RODATA,
864 label = __CONSTRUCTOR_TABLE__,
865 count = __CONSTRUCTOR_COUNT__;
866 CONDES: segment = RODATA,
868 label = __DESTRUCTOR_TABLE__,
869 count = __DESTRUCTOR_COUNT__;
872 __STACKSIZE__ = $800; # 2K stack
876 <tag><tt>cbm510</tt></tag>
879 ZP: start = $02, size = $1A, type = rw;
880 RAM: start = $0001, size = $F3FF, file = %O;
881 VIDRAM: start = $F400, size = $0400, define = yes, file = "";
884 CODE: load = RAM, type = wprot;
885 RODATA: load = RAM, type = wprot;
886 DATA: load = RAM, type = rw;
887 BSS: load = RAM, type = bss, define = yes;
888 ZEROPAGE: load = ZP, type = zp;
891 CONDES: segment = RODATA,
893 label = __CONSTRUCTOR_TABLE__,
894 count = __CONSTRUCTOR_COUNT__;
895 CONDES: segment = RODATA,
897 label = __DESTRUCTOR_TABLE__,
898 count = __DESTRUCTOR_COUNT__;
899 CONDES: segment = RODATA,
901 label = __IRQFUNC_TABLE__,
902 count = __IRQFUNC_COUNT__;
905 __STACKSIZE__ = $781; # ~2K stack
909 <tag><tt>cbm610</tt></tag>
912 ZP: start = $02, size = $1A, type = rw;
913 RAM: start = $0001, size = $FFF0, file = %O;
916 CODE: load = RAM, type = wprot;
917 RODATA: load = RAM, type = wprot;
918 DATA: load = RAM, type = rw;
919 BSS: load = RAM, type = bss, define = yes;
920 ZEROPAGE: load = ZP, type = zp;
923 CONDES: segment = RODATA,
925 label = __CONSTRUCTOR_TABLE__,
926 count = __CONSTRUCTOR_COUNT__;
927 CONDES: segment = RODATA,
929 label = __DESTRUCTOR_TABLE__,
930 count = __DESTRUCTOR_COUNT__;
933 __STACKSIZE__ = $800; # 2K stack
937 <tag><tt>pet</tt></tag>
940 ZP: start = $02, size = $1A, type = rw;
941 RAM: start = $03FF, size = $7BFF, file = %O;
944 CODE: load = RAM, type = wprot;
945 RODATA: load = RAM, type = wprot;
946 DATA: load = RAM, type = rw;
947 BSS: load = RAM, type = bss, define = yes;
948 ZEROPAGE: load = ZP, type = zp;
951 CONDES: segment = RODATA,
953 label = __CONSTRUCTOR_TABLE__,
954 count = __CONSTRUCTOR_COUNT__;
955 CONDES: segment = RODATA,
957 label = __DESTRUCTOR_TABLE__,
958 count = __DESTRUCTOR_COUNT__;
961 __STACKSIZE__ = $800; # 2K stack
965 <tag><tt>apple2</tt></tag>
968 ZP: start = $00, size = $1A, type = rw;
969 RAM: start = $800, size = $8E00, file = %O;
972 CODE: load = RAM, type = ro;
973 RODATA: load = RAM, type = ro;
974 DATA: load = RAM, type = rw;
975 BSS: load = RAM, type = bss, define = yes;
976 ZEROPAGE: load = ZP, type = zp;
979 CONDES: segment = RODATA,
981 label = __CONSTRUCTOR_TABLE__,
982 count = __CONSTRUCTOR_COUNT__;
983 CONDES: segment = RODATA,
985 label = __DESTRUCTOR_TABLE__,
986 count = __DESTRUCTOR_COUNT__;
989 __STACKSIZE__ = $800; # 2K stack
993 <tag><tt>geos</tt></tag>
996 HEADER: start = $204, size = 508, file = %O;
997 RAM: start = $400, size = $5C00, file = %O;
1000 HEADER: load = HEADER, type = ro;
1001 CODE: load = RAM, type = ro;
1002 RODATA: load = RAM, type = ro;
1003 DATA: load = RAM, type = rw;
1004 BSS: load = RAM, type = bss, define = yes;
1007 CONDES: segment = RODATA,
1009 label = __CONSTRUCTOR_TABLE__,
1010 count = __CONSTRUCTOR_COUNT__;
1011 CONDES: segment = RODATA,
1013 label = __DESTRUCTOR_TABLE__,
1014 count = __DESTRUCTOR_COUNT__;
1017 __STACKSIZE__ = $800; # 2K stack
1023 The "<tt/start/" attribute for the <tt/RAM/ memory area of the CBM systems is
1024 two less than the actual start of the basic RAM to account for the two bytes
1025 load address that is needed on disk and supplied by the startup code.
1029 <sect>Bugs/Feedback<p>
1031 If you have problems using the linker, if you find any bugs, or if you're
1032 doing something interesting with it, I would be glad to hear from you. Feel
1033 free to contact me by email (<htmlurl url="mailto:uz@cc65.org"
1034 name="uz@cc65.org">).
1040 ld65 (and all cc65 binutils) are (C) Copyright 1998-2001 Ullrich von
1041 Bassewitz. For usage of the binaries and/or sources the following
1042 conditions do apply:
1044 This software is provided 'as-is', without any expressed or implied
1045 warranty. In no event will the authors be held liable for any damages
1046 arising from the use of this software.
1048 Permission is granted to anyone to use this software for any purpose,
1049 including commercial applications, and to alter it and redistribute it
1050 freely, subject to the following restrictions:
1053 <item> The origin of this software must not be misrepresented; you must not
1054 claim that you wrote the original software. If you use this software
1055 in a product, an acknowledgment in the product documentation would be
1056 appreciated but is not required.
1057 <item> Altered source versions must be plainly marked as such, and must not
1058 be misrepresented as being the original software.
1059 <item> This notice may not be removed or altered from any source