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:
124 <item>c16 (works also for the c116 with memory up to 32K)
128 <item>cbm510 (CBM-II series with 40 column video)
129 <item>cbm610 (all CBM series-II computers with 80 column video)
130 <item>pet (all CBM PET systems except the 2001)
134 There are a few more targets defined but neither of them is actually
135 supported. See <ref id="builtin-configs" name="builtin configurations"> for
139 <label id="option-v">
140 <tag><tt>-v, --verbose</tt></tag>
142 Using the -v option, you may enable more output that may help you to
143 locate problems. If an undefined symbol is encountered, -v causes the
144 linker to print a detailed list of the references (that is, source file
145 and line) for this symbol.
148 <tag><tt>-vm</tt></tag>
150 Must be used in conjunction with <tt><ref id="option-m" name="-m"></tt>
151 (generate map file). Normally the map file will not include empty segments
152 and sections, or unreferenced symbols. Using this option, you can force the
153 linker to include all this information into the map file.
156 <label id="option-C">
157 <tag><tt>-C</tt></tag>
159 This gives the name of an output config file to use. See section 4 for more
160 information about config files. -C may not be used together with <tt><ref
161 id="option-t" name="-t"></tt>.
164 <tag><tt>-Ln</tt></tag>
166 This option allows you to create a file that contains all global labels and
167 may be loaded into VICE emulator using the <tt/ll/ (load label) command. You
168 may use this to debug your code with VICE. Note: Older versions had some
169 bugs in the label code. If you have problems, please get the latest VICE
173 <tag><tt>-Lp</tt></tag>
178 <label id="option-S">
179 <tag><tt>-S addr, --start-addr addr</tt></tag>
181 Using -S you may define the default starting address. If and how this
182 address is used depends on the config file in use. For the builtin
183 configurations, only the "none" system honors an explicit start address,
184 all other builtin config provide their own.
187 <tag><tt>-V, --version</tt></tag>
189 This option print the version number of the linker. If you send any
190 suggestions or bugfixes, please include this number.
194 If one of the modules is not found in the current directory, and the module
195 name does not have a path component, the value of the environment variable
196 <tt/CC65_LIB/ is prepended to the name, and the linker tries to open the
197 module with this new name.
201 <sect>Detailed workings<p>
203 The linker does several things when combining object modules:
205 First, the command line is parsed from left to right. For each object file
206 encountered (object files are recognized by a magic word in the header, so
207 the linker does not care about the name), imported and exported
208 identifiers are read from the file and inserted in a table. If a library
209 name is given (libraries are also recognized by a magic word, there are no
210 special naming conventions), all modules in the library are checked if an
211 export from this module would satisfy an import from other modules. All
212 modules where this is the case are marked. If duplicate identifiers are
213 found, the linker issues a warning.
215 This procedure (parsing and reading from left to right) does mean, that a
216 library may only satisfy references for object modules (given directly or from
217 a library) named <em/before/ that library. With the command line
220 ld65 crt0.o clib.lib test.o
223 the module test.o may not contain references to modules in the library
224 clib.lib. If this is the case, you have to change the order of the modules
228 ld65 crt0.o test.o clib.lib
231 Step two is, to read the configuration file, and assign start addresses
232 for the segments and define any linker symbols (see <ref id="config-files"
233 name="Configuration files">).
235 After that, the linker is ready to produce an output file. Before doing that,
236 it checks it's data for consistency. That is, it checks for unresolved
237 externals (if the output format is not relocatable) and for symbol type
238 mismatches (for example a zero page symbol is imported by a module as absolute
241 Step four is, to write the actual target files. In this step, the linker will
242 resolve any expressions contained in the segment data. Circular references are
243 also detected in this step (a symbol may have a circular reference that goes
244 unnoticed if the symbol is not used).
246 Step five is to output a map file with a detailed list of all modules,
247 segments and symbols encountered.
249 And, last step, if you give the <tt><ref id="option-v" name="-v"></tt> switch
250 twice, you get a dump of the segment data. However, this may be quite
251 unreadable if you're not a developer:-)
255 <sect>Configuration files<label id="config-files"><p>
257 Configuration files are used to describe the layout of the output file(s). Two
258 major topics are covered in a config file: The memory layout of the target
259 architecture, and the assignment of segments to memory areas. In addition,
260 several other attributes may be specified.
262 Case is ignored for keywords, that is, section or attribute names, but it is
263 <em/not/ ignored for names and strings.
267 <sect1>Memory areas<p>
269 Memory areas are specified in a <tt/MEMORY/ section. Lets have a look at an
270 example (this one describes the usable memory layout of the C64):
274 RAM1: start = $0800, size = $9800;
275 ROM1: start = $A000, size = $2000;
276 RAM2: start = $C000, size = $1000;
277 ROM2: start = $E000, size = $2000;
281 As you can see, there are two ram areas and two rom areas. The names
282 (before the colon) are arbitrary names that must start with a letter, with
283 the remaining characters being letters or digits. The names of the memory
284 areas are used when assigning segments. As mentioned above, case is
285 significant for these names.
287 The syntax above is used in all sections of the config file. The name
288 (<tt/ROM1/ etc.) is said to be an identifier, the remaining tokens up to the
289 semicolon specify attributes for this identifier. You may use the equal sign
290 to assign values to attributes, and you may use a comma to separate
291 attributes, you may also leave both out. But you <em/must/ use a semicolon to
292 mark the end of the attributes for one identifier. The section above may also
293 have looked like this:
296 # Start of memory section
314 There are of course more attributes for a memory section than just start and
315 size. Start and size are mandatory attributes, that means, each memory area
316 defined <em/must/ have these attributes given (the linker will check that). I
317 will cover other attributes later. As you may have noticed, I've used a
318 comment in the example above. Comments start with a hash mark (`#'), the
319 remainder of the line is ignored if this character is found.
324 Let's assume you have written a program for your trusty old C64, and you would
325 like to run it. For testing purposes, it should run in the <tt/RAM/ area. So
326 we will start to assign segments to memory sections in the <tt/SEGMENTS/
331 CODE: load = RAM1, type = ro;
332 RODATA: load = RAM1, type = ro;
333 DATA: load = RAM1, type = rw;
334 BSS: load = RAM1, type = bss, define = yes;
338 What we are doing here is telling the linker, that all segments go into the
339 <tt/RAM1/ memory area in the order specified in the <tt/SEGMENTS/ section. So
340 the linker will first write the <tt/CODE/ segment, then the <tt/RODATA/
341 segment, then the <tt/DATA/ segment - but it will not write the <tt/BSS/
342 segment. Why? Enter the segment type: For each segment specified, you may also
343 specify a segment attribute. There are five possible segment attributes:
347 wprot same as ro but will be marked as write protected in
348 the VICE label file if -Lp is given
350 bss means that this is an uninitialized segment
351 zp a zeropage segment
354 So, because we specified that the segment with the name BSS is of type bss,
355 the linker knows that this is uninitialized data, and will not write it to an
356 output file. This is an important point: For the assembler, the <tt/BSS/
357 segment has no special meaning. You specify, which segments have the bss
358 attribute when linking. This approach is much more flexible than having one
359 fixed bss segment, and is a result of the design decision to supporting an
360 arbitrary segment count.
362 If you specify "<tt/type = bss/" for a segment, the linker will make sure that
363 this segment does only contain uninitialized data (that is, zeroes), and issue
364 a warning if this is not the case.
366 For a <tt/bss/ type segment to be useful, it must be cleared somehow by your
367 program (this happens usually in the startup code - for example the startup
368 code for cc65 generated programs takes care about that). But how does your
369 code know, where the segment starts, and how big it is? The linker is able to
370 give that information, but you must request it. This is, what we're doing with
371 the "<tt/define = yes/" attribute in the <tt/BSS/ definitions. For each
372 segment, where this attribute is true, the linker will export three symbols.
375 __NAME_LOAD__ This is set to the address where the
377 __NAME_RUN__ This is set to the run address of the
378 segment. We will cover run addresses
380 __NAME_SIZE__ This is set to the segment size.
383 Replace <tt/NAME/ by the name of the segment, in the example above, this would
384 be <tt/BSS/. These symbols may be accessed by your code.
386 Now, as we've configured the linker to write the first three segments and
387 create symbols for the last one, there's only one question left: Where does
388 the linker put the data? It would be very convenient to have the data in a
391 <sect1>Output files<p>
393 We don't have any files specified above, and indeed, this is not needed in a
394 simple configuration like the one above. There is an additional attribute
395 "file" that may be specified for a memory area, that gives a file name to
396 write the area data into. If there is no file name given, the linker will
397 assign the default file name. This is "a.out" or the one given with the
398 <tt><ref id="option-o" name="-o"></tt> option on the command line. Since the
399 default behaviour is ok for our purposes, I did not use the attribute in the
400 example above. Let's have a look at it now.
402 The "file" attribute (the keyword may also be written as "FILE" if you like
403 that better) takes a string enclosed in double quotes (`"') that specifies the
404 file, where the data is written. You may specifiy the same file several times,
405 in that case the data for all memory areas having this file name is written
406 into this file, in the order of the memory areas defined in the <tt/MEMORY/
407 section. Let's specify some file names in the <tt/MEMORY/ section used above:
411 RAM1: start = $0800, size = $9800, file = %O;
412 ROM1: start = $A000, size = $2000, file = "rom1.bin";
413 RAM2: start = $C000, size = $1000, file = %O;
414 ROM2: start = $E000, size = $2000, file = "rom2.bin";
418 The <tt/%O/ used here is a way to specify the default behaviour explicitly:
419 <tt/%O/ is replaced by a string (including the quotes) that contains the
420 default output name, that is, "a.out" or the name specified with the <tt><ref
421 id="option-o" name="-o"></tt> option on the command line. Into this file, the
422 linker will first write any segments that go into <tt/RAM1/, and will append
423 then the segments for <tt/RAM2/, because the memory areas are given in this
424 order. So, for the RAM areas, nothing has really changed.
426 We've not used the ROM areas, but we will do that below, so we give the file
427 names here. Segments that go into <tt/ROM1/ will be written to a file named
428 "rom1.bin", and segments that go into <tt/ROM2/ will be written to a file
429 named "rom2.bin". The name given on the command line is ignored in both cases.
432 <sect1>LOAD and RUN addresses (ROMable code)<p>
434 Let us look now at a more complex example. Say, you've successfully tested
435 your new "Super Operating System" (SOS for short) for the C64, and you
436 will now go and replace the ROMs by your own code. When doing that, you
437 face a new problem: If the code runs in RAM, we need not to care about
438 read/write data. But now, if the code is in ROM, we must care about it.
439 Remember the default segments (you may of course specify your own):
443 RODATA read only data
445 BSS uninitialized data, read/write
448 Since <tt/BSS/ is not initialized, we must not care about it now, but what
449 about <tt/DATA/? <tt/DATA/ contains initialized data, that is, data that was
450 explicitly assigned a value. And your program will rely on these values on
451 startup. Since there's no other way to remember the contents of the data
452 segment, than storing it into one of the ROMs, we have to put it there. But
453 unfortunately, ROM is not writeable, so we have to copy it into RAM before
454 running the actual code.
456 The linker cannot help you copying the data from ROM into RAM (this must be
457 done by the startup code of your program), but it has some features that will
458 help you in this process.
460 First, you may not only specify a "<tt/load/" attribute for a segment, but
461 also a "<tt/run/" attribute. The "<tt/load/" attribute is mandatory, and, if
462 you don't specify a "<tt/run/" attribute, the linker assumes that load area
463 and run area are the same. We will use this feature for our data area:
467 CODE: load = ROM1, type = ro;
468 RODATA: load = ROM2, type = ro;
469 DATA: load = ROM2, run = RAM2, type = rw, define = yes;
470 BSS: load = RAM2, type = bss, define = yes;
474 Let's have a closer look at this <tt/SEGMENTS/ section. We specify that the
475 <tt/CODE/ segment goes into <tt/ROM1/ (the one at $A000). The readonly data
476 goes into <tt/ROM2/. Read/write data will be loaded into <tt/ROM2/ but is run
477 in <tt/RAM2/. That means that all references to labels in the <tt/DATA/
478 segment are relocated to be in <tt/RAM2/, but the segment is written to
479 <tt/ROM2/. All your startup code has to do is, to copy the data from it's
480 location in <tt/ROM2/ to the final location in <tt/RAM2/.
482 So, how do you know, where the data is located? This is the second point,
483 where you get help from the linker. Remember the "<tt/define/" attribute?
484 Since we have set this attribute to true, the linker will define three
485 external symbols for the data segment that may be accessed from your code:
488 __DATA_LOAD__ This is set to the address where the segment
489 is loaded, in this case, it is an address in
491 __DATA_RUN__ This is set to the run address of the segment,
492 in this case, it is an address in RAM2.
493 __DATA_SIZE__ This is set to the segment size.
496 So, what your startup code must do, is to copy <tt/__DATA_SIZE__/ bytes from
497 <tt/__DATA_LOAD__/ to <tt/__DATA_RUN__/ before any other routines are called.
498 All references to labels in the <tt/DATA/ segment are relocated to <tt/RAM2/
499 by the linker, so things will work properly.
502 <sect1>Other MEMORY area attributes<p>
504 There are some other attributes not covered above. Before starting the
505 reference section, I will discuss the remaining things here.
507 You may request symbols definitions also for memory areas. This may be
508 useful for things like a software stack, or an i/o area.
512 STACK: start = $C000, size = $1000, define = yes;
516 This will define three external symbols that may be used in your code:
519 __STACK_START__ This is set to the start of the memory
520 area, $C000 in this example.
521 __STACK_SIZE__ The size of the area, here $1000.
522 __STACK_LAST__ This is NOT the same as START+SIZE.
523 Instead, it it defined as the first
524 address that is not used by data. If we
525 don't define any segments for this area,
526 the value will be the same as START.
529 A memory section may also have a type. Valid types are
532 ro for readonly memory
533 rw for read/write memory.
536 The linker will assure, that no segment marked as read/write or bss is put
537 into a memory area that is marked as readonly.
539 Unused memory in a memory area may be filled. Use the "<tt/fill = yes/"
540 attribute to request this. The default value to fill unused space is zero. If
541 you don't like this, you may specify a byte value that is used to fill these
542 areas with the "<tt/fillval/" attribute. This value is also used to fill unfilled
543 areas generated by the assemblers <tt/.ALIGN/ and <tt/.RES/ directives.
546 <sect1>Other SEGMENT attributes<p>
548 Segments may be aligned to some memory boundary. Specify "<tt/align = num/" to
549 request this feature. Num must be a power of two. To align all segments on a
554 CODE: load = ROM1, type = ro, align = $100;
555 RODATA: load = ROM2, type = ro, align = $100;
556 DATA: load = ROM2, run = RAM2, type = rw, define = yes,
558 BSS: load = RAM2, type = bss, define = yes, align = $100;
562 If an alignment is requested, the linker will add enough space to the output
563 file, so that the new segment starts at an address that is divideable by the
564 given number without a remainder. All addresses are adjusted accordingly. To
565 fill the unused space, bytes of zero are used, or, if the memory area has a
566 "<tt/fillval/" attribute, that value. Alignment is always needed, if you have
567 the used the <tt/.ALIGN/ command in the assembler. The alignment of a segment
568 must be equal or greater than the alignment used in the <tt/.ALIGN/ command.
569 The linker will check that, and issue a warning, if the alignment of a segment
570 is lower than the alignment requested in a <tt/.ALIGN/ command of one of the
571 modules making up this segment.
573 For a given segment you may also specify a fixed offset into a memory area or
574 a fixed start address. Use this if you want the code to run at a specific
575 address (a prominent case is the interrupt vector table which must go at
576 address $FFFA). Only one of <tt/ALIGN/ or <tt/OFFSET/ or <tt/START/ may be
577 specified. If the directive creates empty space, it will be filled with zero,
578 of with the value specified with the "<tt/fillval/" attribute if one is given.
579 The linker will warn you if it is not possible to put the code at the
580 specified offset (this may happen if other segments in this area are too
581 large). Here's an example:
585 VECTORS: load = ROM2, type = ro, start = $FFFA;
589 or (for the segment definitions from above)
593 VECTORS: load = ROM2, type = ro, offset = $1FFA;
597 File names may be empty, data from segments assigned to a memory area with
598 an empty file name is discarded. This is useful, if the a memory area has
599 segments assigned that are empty (for example because they are of type
600 bss). In that case, the linker will create an empty output file. This may
601 be suppressed by assigning an empty file name to that memory area.
603 The symbol <tt/%S/ may be used to access the default start address (that is,
604 $200 or the value given on the command line with the <tt><ref id="option-S"
605 name="-S"></tt> option).
609 <sect1>The FILES section<p>
611 The <tt/FILES/ section is used to support other formats than straight binary
612 (which is the default, so binary output files do not need an explicit entry
613 in the <tt/FILES/ section).
615 The <tt/FILES/ section lists output files and as only attribute the format of
616 each output file. Assigning binary format to the default output file would
625 The only other available output format is the o65 format specified by Andre
626 Fachat. It is defined like this:
634 The necessary o65 attributes are defined in a special section labeled
639 <sect1>The FORMAT section<p>
641 The <tt/FORMAT/ section is used to describe file formats. The default (binary)
642 format has currently no attributes, so, while it may be listed in this
643 section, the attribute list is empty. The second supported format, o65, has
644 several attributes that may be defined here.
648 o65: os = lunix, version = 0, type = small,
649 import = LUNIXKERNEL,
660 In addition to the <tt/MEMORY/ and <tt/SEGMENTS/ sections described above, the
661 linker has features that may be enabled by an additional section labeled
662 <tt/FEATURES/. Currently, one such feature is available: <tt/CONDES/ is used
663 to tell the linker to emit module constructor/destructor tables.
667 CONDES: segment = RODATA,
669 label = __CONSTRUCTOR_TABLE__,
670 count = __CONSTRUCTOR_COUNT__;
674 The <tt/CONDES/ feature has several attributes:
678 <tag><tt>segment</tt></tag>
680 This attribute tells the linker into which segment the table should be
681 placed. If the segment does not exist, it is created.
684 <tag><tt>type</tt></tag>
686 Describes the type of the routines to place in the table. Type may be
687 one of the predefined types <tt/constructor/ or <tt/destructor/, or a
688 numeric value between 0 and 6.
691 <tag><tt>label</tt></tag>
693 This specifies the label to use for the table. The label points to the
694 start of the table in memory and may be used from within user written
698 <tag><tt>count</tt></tag>
700 This is an optional attribute. If specified, an additional symbol is
701 defined by the linker using the given name. The value of this symbol
702 is the number of entries (<em/not/ bytes) in the table. While this
703 attribute is optional, it is often useful to define it.
706 <tag><tt>order</tt></tag>
708 Optional attribute that takes one of the keywords <tt/increasing/ or
709 <tt/decreasing/ as an argument. Specifies the sorting order of the entries
710 within the table. The default is <tt/increasing/, which means that the
711 entries are sorted with increasing priority (the first entry has the lowest
712 priority). You may change this behaviour by specifying <tt/decreasing/ as
713 the argument, the order of entries is reversed in this case.
715 Please note that the order of entries with equal priority is undefined.
719 Without specifying the <tt/CONDES/ feature, the linker will not create any
720 tables, even if there are <tt/condes/ entries in the object files.
722 For more information see the <tt/.CONDES/ command in the <htmlurl
723 url="ca65.html" name="ca65 manual">.
727 <sect1>Builtin configurations<label id="builtin-configs"><p>
729 Here is a list of the builin configurations for the different target
733 <tag><tt>none</tt></tag>
736 RAM: start = %S, size = $10000, file = %O;
739 CODE: load = RAM, type = rw;
740 RODATA: load = RAM, type = rw;
741 DATA: load = RAM, type = rw;
742 BSS: load = RAM, type = bss, define = yes;
745 CONDES: segment = RODATA,
747 label = __CONSTRUCTOR_TABLE__,
748 count = __CONSTRUCTOR_COUNT__;
749 CONDES: segment = RODATA,
751 label = __DESTRUCTOR_TABLE__,
752 count = __DESTRUCTOR_COUNT__;
755 __STACKSIZE__ = $800; # 2K stack
759 <tag><tt>atari</tt></tag>
762 ZP: start = $82, size = $7E, type = rw;
763 HEADER: start = $0000, size = $6, file = %O;
764 RAM: start = $1F00, size = $9D1F, file = %O; # $9D1F: matches upper bound $BC1F
767 EXEHDR: load = HEADER, type = wprot;
768 CODE: load = RAM, type = wprot, define = yes;
769 RODATA: load = RAM, type = wprot;
770 DATA: load = RAM, type = rw;
771 BSS: load = RAM, type = bss, define = yes;
772 ZEROPAGE: load = ZP, type = zp;
773 AUTOSTRT: load = RAM, type = wprot;
776 CONDES: segment = RODATA,
778 label = __CONSTRUCTOR_TABLE__,
779 count = __CONSTRUCTOR_COUNT__;
780 CONDES: segment = RODATA,
782 label = __DESTRUCTOR_TABLE__,
783 count = __DESTRUCTOR_COUNT__;
786 __STACKSIZE__ = $800; # 2K stack
790 <tag><tt>atmos</tt></tag>
793 ZP: start = $02, size = $1A, type = rw, define = yes;
794 RAM: start = $0600, size = $9200, define = yes, file = %O;
797 CODE: load = RAM, type = wprot;
798 RODATA: load = RAM, type = wprot;
799 DATA: load = RAM, type = rw;
800 BSS: load = RAM, type = bss, define = yes;
801 ZEROPAGE: load = ZP, type = zp;
804 CONDES: segment = RODATA,
806 label = __CONSTRUCTOR_TABLE__,
807 count = __CONSTRUCTOR_COUNT__;
808 CONDES: segment = RODATA,
810 label = __DESTRUCTOR_TABLE__,
811 count = __DESTRUCTOR_COUNT__;
814 __STACKSIZE__ = $800; # 2K stack
818 <tag><tt>c16</tt></tag>
821 ZP: start = $02, size = $1A, type = rw;
822 RAM: start = $0fff, size = $7001, file = %O;
825 CODE: load = RAM, type = wprot;
826 RODATA: load = RAM, type = wprot;
827 DATA: load = RAM, type = rw;
828 BSS: load = RAM, type = bss, define = yes;
829 ZEROPAGE: load = ZP, type = zp;
832 CONDES: segment = RODATA,
834 label = __CONSTRUCTOR_TABLE__,
835 count = __CONSTRUCTOR_COUNT__;
836 CONDES: segment = RODATA,
838 label = __DESTRUCTOR_TABLE__,
839 count = __DESTRUCTOR_COUNT__;
842 __STACKSIZE__ = $800; # 2K stack
846 <tag><tt>c64</tt></tag>
849 ZP: start = $02, size = $1A, type = rw;
850 RAM: start = $7FF, size = $c801, define = yes, file = %O;
853 CODE: load = RAM, type = wprot;
854 RODATA: load = RAM, type = wprot;
855 DATA: load = RAM, type = rw;
856 BSS: load = RAM, type = bss, define = yes;
857 ZEROPAGE: load = ZP, type = zp;
860 CONDES: segment = RODATA,
862 label = __CONSTRUCTOR_TABLE__,
863 count = __CONSTRUCTOR_COUNT__;
864 CONDES: segment = RODATA,
866 label = __DESTRUCTOR_TABLE__,
867 count = __DESTRUCTOR_COUNT__;
870 __STACKSIZE__ = $800; # 2K stack
874 <tag><tt>c128</tt></tag>
877 ZP: start = $02, size = $1A, type = rw;
878 RAM: start = $1bff, size = $a401, define = yes, file = %O;
881 CODE: load = RAM, type = wprot;
882 RODATA: load = RAM, type = wprot;
883 DATA: load = RAM, type = rw;
884 BSS: load = RAM, type = bss, define = yes;
885 ZEROPAGE: load = ZP, type = zp;
888 CONDES: segment = RODATA,
890 label = __CONSTRUCTOR_TABLE__,
891 count = __CONSTRUCTOR_COUNT__;
892 CONDES: segment = RODATA,
894 label = __DESTRUCTOR_TABLE__,
895 count = __DESTRUCTOR_COUNT__;
896 CONDES: segment = RODATA,
898 label = __IRQFUNC_TABLE__,
899 count = __IRQFUNC_COUNT__;
902 __STACKSIZE__ = $800; # 2K stack
906 <tag><tt>plus4</tt></tag>
909 ZP: start = $02, size = $1A, type = rw;
910 RAM: start = $0fff, size = $7001, file = %O;
913 CODE: load = RAM, type = wprot;
914 RODATA: load = RAM, type = wprot;
915 DATA: load = RAM, type = rw;
916 BSS: load = RAM, type = bss, define = yes;
917 ZEROPAGE: load = ZP, type = zp;
920 CONDES: segment = RODATA,
922 label = __CONSTRUCTOR_TABLE__,
923 count = __CONSTRUCTOR_COUNT__;
924 CONDES: segment = RODATA,
926 label = __DESTRUCTOR_TABLE__,
927 count = __DESTRUCTOR_COUNT__;
930 __STACKSIZE__ = $800; # 2K stack
934 <tag><tt>cbm510</tt></tag>
937 ZP: start = $02, size = $1A, type = rw;
938 RAM: start = $0001, size = $F3FF, file = %O;
939 VIDRAM: start = $F400, size = $0400, define = yes, file = "";
942 CODE: load = RAM, type = wprot;
943 RODATA: load = RAM, type = wprot;
944 DATA: load = RAM, type = rw;
945 BSS: load = RAM, type = bss, define = yes;
946 ZEROPAGE: load = ZP, type = zp;
949 CONDES: segment = RODATA,
951 label = __CONSTRUCTOR_TABLE__,
952 count = __CONSTRUCTOR_COUNT__;
953 CONDES: segment = RODATA,
955 label = __DESTRUCTOR_TABLE__,
956 count = __DESTRUCTOR_COUNT__;
957 CONDES: segment = RODATA,
959 label = __IRQFUNC_TABLE__,
960 count = __IRQFUNC_COUNT__;
963 __STACKSIZE__ = $781; # ~2K stack
967 <tag><tt>cbm610</tt></tag>
970 ZP: start = $02, size = $1A, type = rw;
971 RAM: start = $0001, size = $FFF0, file = %O;
974 CODE: load = RAM, type = wprot;
975 RODATA: load = RAM, type = wprot;
976 DATA: load = RAM, type = rw;
977 BSS: load = RAM, type = bss, define = yes;
978 ZEROPAGE: load = ZP, type = zp;
981 CONDES: segment = RODATA,
983 label = __CONSTRUCTOR_TABLE__,
984 count = __CONSTRUCTOR_COUNT__;
985 CONDES: segment = RODATA,
987 label = __DESTRUCTOR_TABLE__,
988 count = __DESTRUCTOR_COUNT__;
991 __STACKSIZE__ = $800; # 2K stack
995 <tag><tt>pet</tt></tag>
998 ZP: start = $02, size = $1A, type = rw;
999 RAM: start = $03FF, size = $7BFF, file = %O;
1002 CODE: load = RAM, type = wprot;
1003 RODATA: load = RAM, type = wprot;
1004 DATA: load = RAM, type = rw;
1005 BSS: load = RAM, type = bss, define = yes;
1006 ZEROPAGE: load = ZP, type = zp;
1009 CONDES: segment = RODATA,
1011 label = __CONSTRUCTOR_TABLE__,
1012 count = __CONSTRUCTOR_COUNT__;
1013 CONDES: segment = RODATA,
1015 label = __DESTRUCTOR_TABLE__,
1016 count = __DESTRUCTOR_COUNT__;
1019 __STACKSIZE__ = $800; # 2K stack
1023 <tag><tt>apple2</tt></tag>
1026 ZP: start = $00, size = $1A, type = rw;
1027 RAM: start = $800, size = $8E00, file = %O;
1030 CODE: load = RAM, type = ro;
1031 RODATA: load = RAM, type = ro;
1032 DATA: load = RAM, type = rw;
1033 BSS: load = RAM, type = bss, define = yes;
1034 ZEROPAGE: load = ZP, type = zp;
1037 CONDES: segment = RODATA,
1039 label = __CONSTRUCTOR_TABLE__,
1040 count = __CONSTRUCTOR_COUNT__;
1041 CONDES: segment = RODATA,
1043 label = __DESTRUCTOR_TABLE__,
1044 count = __DESTRUCTOR_COUNT__;
1047 __STACKSIZE__ = $800; # 2K stack
1051 <tag><tt>geos</tt></tag>
1054 HEADER: start = $204, size = 508, file = %O;
1055 RAM: start = $400, size = $5C00, file = %O;
1058 HEADER: load = HEADER, type = ro;
1059 CODE: load = RAM, type = ro;
1060 RODATA: load = RAM, type = ro;
1061 DATA: load = RAM, type = rw;
1062 BSS: load = RAM, type = bss, define = yes;
1065 CONDES: segment = RODATA,
1067 label = __CONSTRUCTOR_TABLE__,
1068 count = __CONSTRUCTOR_COUNT__;
1069 CONDES: segment = RODATA,
1071 label = __DESTRUCTOR_TABLE__,
1072 count = __DESTRUCTOR_COUNT__;
1075 __STACKSIZE__ = $800; # 2K stack
1081 The "<tt/start/" attribute for the <tt/RAM/ memory area of the CBM systems is
1082 two less than the actual start of the basic RAM to account for the two bytes
1083 load address that is needed on disk and supplied by the startup code.
1087 <sect>Bugs/Feedback<p>
1089 If you have problems using the linker, if you find any bugs, or if you're
1090 doing something interesting with it, I would be glad to hear from you. Feel
1091 free to contact me by email (<htmlurl url="mailto:uz@cc65.org"
1092 name="uz@cc65.org">).
1098 ld65 (and all cc65 binutils) are (C) Copyright 1998-2001 Ullrich von
1099 Bassewitz. For usage of the binaries and/or sources the following
1100 conditions do apply:
1102 This software is provided 'as-is', without any expressed or implied
1103 warranty. In no event will the authors be held liable for any damages
1104 arising from the use of this software.
1106 Permission is granted to anyone to use this software for any purpose,
1107 including commercial applications, and to alter it and redistribute it
1108 freely, subject to the following restrictions:
1111 <item> The origin of this software must not be misrepresented; you must not
1112 claim that you wrote the original software. If you use this software
1113 in a product, an acknowledgment in the product documentation would be
1114 appreciated but is not required.
1115 <item> Altered source versions must be plainly marked as such, and must not
1116 be misrepresented as being the original software.
1117 <item> This notice may not be removed or altered from any source