1 <!doctype linuxdoc system>
4 <title>ld65 Users Guide
5 <author>Ullrich von Bassewitz, <htmlurl url="mailto:uz@cc65.org" name="uz@cc65.org">
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 ...
59 -m name Create a map file
60 -o name Name the default output file
61 -t sys Set the target system
64 -C name Use linker config file
65 -Ln name Create a VICE label file
66 -Lp Mark write protected segments as such (VICE)
67 -S addr Set the default start address
68 -V Print the linker version
71 --help Help (this text)
72 --mapfile name Create a map file
73 --target sys Set the target system
74 --version Print the linker version
75 ---------------------------------------------------------------------------
79 <sect1>Command line options in detail<p>
81 Here is a description of all the command line options:
85 <tag><tt>-h, --help</tt></tag>
87 Print the short option summary shown above.
91 <tag><tt>-m name, --mapfile name</tt></tag>
93 This option (which needs an argument that will used as a filename for
94 the generated map file) will cause the linker to generate a map file.
95 The map file does contain a detailed overview over the modules used, the
96 sizes for the different segments, and a table containing exported
100 <label id="option-o">
101 <tag><tt>-o name</tt></tag>
103 The -o switch is used to give the name of the default output file.
104 Depending on your output configuration, this name may NOT be used as
105 name for the output file. However, for the builtin configurations, this
106 name is used for the output file name.
109 <label id="option-t">
110 <tag><tt>-t sys, --target sys</tt></tag>
112 The argument for the -t switch is the name of the target system. Since this
113 switch will activate a builtin configuration, it may not be used together
114 with the <tt><ref id="option-C" name="-C"></tt> option. The following target
115 systems are currently supported:
123 <item>cbm610 (all CBM series-II computers with 80 column video)
124 <item>pet (all CBM PET systems except the 2001)
129 There are a few more targets defined but neither of them is actually
130 supported. See <ref id="builtin-configs" name="builtin configurations"> for
134 <label id="option-v">
135 <tag><tt>-v, --verbose</tt></tag>
137 Using the -v option, you may enable more output that may help you to
138 locate problems. If an undefined symbol is encountered, -v causes the
139 linker to print a detailed list of the references (that is, source file
140 and line) for this symbol.
143 <tag><tt>-vm</tt></tag>
145 Must be used in conjunction with <tt><ref id="option-m" name="-m"></tt>
146 (generate map file). Normally the map file will not include empty segments
147 and sections, or unreferenced symbols. Using this option, you can force the
148 linker to include all this information into the map file.
151 <label id="option-C">
152 <tag><tt>-C</tt></tag>
154 This gives the name of an output config file to use. See section 4 for more
155 information about config files. -C may not be used together with <tt><ref
156 id="option-t" name="-t"></tt>.
159 <tag><tt>-Ln</tt></tag>
161 This option allows you to create a file that contains all global labels and
162 may be loaded into VICE emulator using the <tt/ll/ (load label) command. You
163 may use this to debug your code with VICE. Note: Older versions had some
164 bugs in the label code. If you have problems, please get the latest VICE
168 <tag><tt>-Lp</tt></tag>
173 <label id="option-S">
174 <tag><tt>-S addr, --start-addr addr</tt></tag>
176 Using -S you may define the default starting address. If and how this
177 address is used depends on the config file in use. For the builtin
178 configurations, only the "none" system honors an explicit start address,
179 all other builtin config provide their own.
182 <tag><tt>-V, --version</tt></tag>
184 This option print the version number of the linker. If you send any
185 suggestions or bugfixes, please include this number.
189 If one of the modules is not found in the current directory, and the module
190 name does not have a path component, the value of the environment variable
191 <tt/CC65_LIB/ is prepended to the name, and the linker tries to open the
192 module with this new name.
196 <sect>Detailed workings<p>
198 The linker does several things when combining object modules:
200 First, the command line is parsed from left to right. For each object file
201 encountered (object files are recognized by a magic word in the header, so
202 the linker does not care about the name), imported and exported
203 identifiers are read from the file and inserted in a table. If a library
204 name is given (libraries are also recognized by a magic word, there are no
205 special naming conventions), all modules in the library are checked if an
206 export from this module would satisfy an import from other modules. All
207 modules where this is the case are marked. If duplicate identifiers are
208 found, the linker issues a warning.
210 This procedure (parsing and reading from left to right) does mean, that a
211 library may only satisfy references for object modules (given directly or from
212 a library) named <em/before/ that library. With the command line
215 ld65 crt0.o clib.lib test.o
218 the module test.o may not contain references to modules in the library
219 clib.lib. If this is the case, you have to change the order of the modules
223 ld65 crt0.o test.o clib.lib
226 Step two is, to read the configuration file, and assign start addresses
227 for the segments and define any linker symbols (see <ref id="config-files"
228 name="Configuration files">).
230 After that, the linker is ready to produce an output file. Before doing that,
231 it checks it's data for consistency. That is, it checks for unresolved
232 externals (if the output format is not relocatable) and for symbol type
233 mismatches (for example a zero page symbol is imported by a module as absolute
236 Step four is, to write the actual target files. In this step, the linker will
237 resolve any expressions contained in the segment data. Circular references are
238 also detected in this step (a symbol may have a circular reference that goes
239 unnoticed if the symbol is not used).
241 Step five is to output a map file with a detailed list of all modules,
242 segments and symbols encountered.
244 And, last step, if you give the <tt><ref id="option-v" name="-v"></tt> switch
245 twice, you get a dump of the segment data. However, this may be quite
246 unreadable if you're not a developer:-)
250 <sect>Configuration files<label id="config-files"><p>
252 Configuration files are used to describe the layout of the output file(s). Two
253 major topics are covered in a config file: The memory layout of the target
254 architecture, and the assignment of segments to memory areas. In addition,
255 several other attributes may be specified.
257 Case is ignored for keywords, that is, section or attribute names, but it is
258 <em/not/ ignored for names and strings.
262 <sect1>Memory areas<p>
264 Memory areas are specified in a <tt/MEMORY/ section. Lets have a look at an
265 example (this one describes the usable memory layout of the C64):
269 RAM1: start = $0800, size = $9800;
270 ROM1: start = $A000, size = $2000;
271 RAM2: start = $C000, size = $1000;
272 ROM2: start = $E000, size = $2000;
276 As you can see, there are two ram areas and two rom areas. The names
277 (before the colon) are arbitrary names that must start with a letter, with
278 the remaining characters being letters or digits. The names of the memory
279 areas are used when assigning segments. As mentioned above, case is
280 significant for these names.
282 The syntax above is used in all sections of the config file. The name
283 (<tt/ROM1/ etc.) is said to be an identifier, the remaining tokens up to the
284 semicolon specify attributes for this identifier. You may use the equal sign
285 to assign values to attributes, and you may use a comma to separate
286 attributes, you may also leave both out. But you <em/must/ use a semicolon to
287 mark the end of the attributes for one identifier. The section above may also
288 have looked like this:
291 # Start of memory section
309 There are of course more attributes for a memory section than just start and
310 size. Start and size are mandatory attributes, that means, each memory area
311 defined <em/must/ have these attributes given (the linker will check that). I
312 will cover other attributes later. As you may have noticed, I've used a
313 comment in the example above. Comments start with a hash mark (`#'), the
314 remainder of the line is ignored if this character is found.
319 Let's assume you have written a program for your trusty old C64, and you would
320 like to run it. For testing purposes, it should run in the <tt/RAM/ area. So
321 we will start to assign segments to memory sections in the <tt/SEGMENTS/
326 CODE: load = RAM1, type = ro;
327 RODATA: load = RAM1, type = ro;
328 DATA: load = RAM1, type = rw;
329 BSS: load = RAM1, type = bss, define = yes;
333 What we are doing here is telling the linker, that all segments go into the
334 <tt/RAM1/ memory area in the order specified in the <tt/SEGMENTS/ section. So
335 the linker will first write the <tt/CODE/ segment, then the <tt/RODATA/
336 segment, then the <tt/DATA/ segment - but it will not write the <tt/BSS/
337 segment. Why? Enter the segment type: For each segment specified, you may also
338 specify a segment attribute. There are five possible segment attributes:
342 wprot same as ro but will be marked as write protected in
343 the VICE label file if -Lp is given
345 bss means that this is an uninitialized segment
346 empty will not go in any output file
347 zp a zeropage segment
350 So, because we specified that the segment with the name BSS is of type bss,
351 the linker knows that this is uninitialized data, and will not write it to an
352 output file. This is an important point: For the assembler, the <tt/BSS/
353 segment has no special meaning. You specify, which segments have the bss
354 attribute when linking. This approach is much more flexible than having one
355 fixed bss segment, and is a result of the design decision to supporting an
356 arbitrary segment count.
358 If you specify "<tt/type = bss/" for a segment, the linker will make sure that
359 this segment does only contain uninitialized data (that is, zeroes), and issue
360 a warning if this is not the case.
362 For a <tt/bss/ type segment to be useful, it must be cleared somehow by your
363 program (this happens usually in the startup code - for example the startup
364 code for cc65 generated programs takes care about that). But how does your
365 code know, where the segment starts, and how big it is? The linker is able to
366 give that information, but you must request it. This is, what we're doing with
367 the "<tt/define = yes/" attribute in the <tt/BSS/ definitions. For each
368 segment, where this attribute is true, the linker will export three symbols.
371 __NAME_LOAD__ This is set to the address where the
373 __NAME_RUN__ This is set to the run address of the
374 segment. We will cover run addresses
376 __NAME_SIZE__ This is set to the segment size.
379 Replace <tt/NAME/ by the name of the segment, in the example above, this would
380 be <tt/BSS/. These symbols may be accessed by your code.
382 Now, as we've configured the linker to write the first three segments and
383 create symbols for the last one, there's only one question left: Where does
384 the linker put the data? It would be very convenient to have the data in a
387 <sect1>Output files<p>
389 We don't have any files specified above, and indeed, this is not needed in a
390 simple configuration like the one above. There is an additional attribute
391 "file" that may be specified for a memory area, that gives a file name to
392 write the area data into. If there is no file name given, the linker will
393 assign the default file name. This is "a.out" or the one given with the
394 <tt><ref id="option-o" name="-o"></tt> option on the command line. Since the
395 default behaviour is ok for our purposes, I did not use the attribute in the
396 example above. Let's have a look at it now.
398 The "file" attribute (the keyword may also be written as "FILE" if you like
399 that better) takes a string enclosed in double quotes (`"') that specifies the
400 file, where the data is written. You may specifiy the same file several times,
401 in that case the data for all memory areas having this file name is written
402 into this file, in the order of the memory areas defined in the <tt/MEMORY/
403 section. Let's specify some file names in the <tt/MEMORY/ section used above:
407 RAM1: start = $0800, size = $9800, file = %O;
408 ROM1: start = $A000, size = $2000, file = "rom1.bin";
409 RAM2: start = $C000, size = $1000, file = %O;
410 ROM2: start = $E000, size = $2000, file = "rom2.bin";
414 The <tt/%O/ used here is a way to specify the default behaviour explicitly:
415 <tt/%O/ is replaced by a string (including the quotes) that contains the
416 default output name, that is, "a.out" or the name specified with the <tt><ref
417 id="option-o" name="-o"></tt> option on the command line. Into this file, the
418 linker will first write any segments that go into <tt/RAM1/, and will append
419 then the segments for <tt/RAM2/, because the memory areas are given in this
420 order. So, for the RAM areas, nothing has really changed.
422 We've not used the ROM areas, but we will do that below, so we give the file
423 names here. Segments that go into <tt/ROM1/ will be written to a file named
424 "rom1.bin", and segments that go into <tt/ROM2/ will be written to a file
425 named "rom2.bin". The name given on the command line is ignored in both cases.
428 <sect1>LOAD and RUN addresses (ROMable code)<p>
430 Let us look now at a more complex example. Say, you've successfully tested
431 your new "Super Operating System" (SOS for short) for the C64, and you
432 will now go and replace the ROMs by your own code. When doing that, you
433 face a new problem: If the code runs in RAM, we need not to care about
434 read/write data. But now, if the code is in ROM, we must care about it.
435 Remember the default segments (you may of course specify your own):
439 RODATA read only data
441 BSS uninitialized data, read/write
444 Since <tt/BSS/ is not initialized, we must not care about it now, but what
445 about <tt/DATA/? <tt/DATA/ contains initialized data, that is, data that was
446 explicitly assigned a value. And your program will rely on these values on
447 startup. Since there's no other way to remember the contents of the data
448 segment, than storing it into one of the ROMs, we have to put it there. But
449 unfortunately, ROM is not writeable, so we have to copy it into RAM before
450 running the actual code.
452 The linker cannot help you copying the data from ROM into RAM (this must be
453 done by the startup code of your program), but it has some features that will
454 help you in this process.
456 First, you may not only specify a "<tt/load/" attribute for a segment, but
457 also a "<tt/run/" attribute. The "<tt/load/" attribute is mandatory, and, if
458 you don't specify a "<tt/run/" attribute, the linker assumes that load area
459 and run area are the same. We will use this feature for our data area:
463 CODE: load = ROM1, type = ro;
464 RODATA: load = ROM2, type = ro;
465 DATA: load = ROM2, run = RAM2, type = rw, define = yes;
466 BSS: load = RAM2, type = bss, define = yes;
470 Let's have a closer look at this <tt/SEGMENTS/ section. We specify that the
471 <tt/CODE/ segment goes into <tt/ROM1/ (the one at $A000). The readonly data
472 goes into <tt/ROM2/. Read/write data will be loaded into <tt/ROM2/ but is run
473 in <tt/RAM2/. That means that all references to labels in the <tt/DATA/
474 segment are relocated to be in <tt/RAM2/, but the segment is written to
475 <tt/ROM2/. All your startup code has to do is, to copy the data from it's
476 location in <tt/ROM2/ to the final location in <tt/RAM2/.
478 So, how do you know, where the data is located? This is the second point,
479 where you get help from the linker. Remember the "<tt/define/" attribute?
480 Since we have set this attribute to true, the linker will define three
481 external symbols for the data segment that may be accessed from your code:
484 __DATA_LOAD__ This is set to the address where the segment
485 is loaded, in this case, it is an address in
487 __DATA_RUN__ This is set to the run address of the segment,
488 in this case, it is an address in RAM2.
489 __DATA_SIZE__ This is set to the segment size.
492 So, what your startup code must do, is to copy <tt/__DATA_SIZE__/ bytes from
493 <tt/__DATA_LOAD__/ to <tt/__DATA_RUN__/ before any other routines are called.
494 All references to labels in the <tt/DATA/ segment are relocated to <tt/RAM2/
495 by the linker, so things will work properly.
498 <sect1>Other MEMORY area attributes<p>
500 There are some other attributes not covered above. Before starting the
501 reference section, I will discuss the remaining things here.
503 You may request symbols definitions also for memory areas. This may be
504 useful for things like a software stack, or an i/o area.
508 STACK: start = $C000, size = $1000, define = yes;
512 This will define three external symbols that may be used in your code:
515 __STACK_START__ This is set to the start of the memory
516 area, $C000 in this example.
517 __STACK_SIZE__ The size of the area, here $1000.
518 __STACK_LAST__ This is NOT the same as START+SIZE.
519 Instead, it it defined as the first
520 address that is not used by data. If we
521 don't define any segments for this area,
522 the value will be the same as START.
525 A memory section may also have a type. Valid types are
528 ro for readonly memory
529 rw for read/write memory.
532 The linker will assure, that no segment marked as read/write or bss is put
533 into a memory area that is marked as readonly.
535 Unused memory in a memory area may be filled. Use the "<tt/fill = yes/"
536 attribute to request this. The default value to fill unused space is zero. If
537 you don't like this, you may specify a byte value that is used to fill these
538 areas with the "<tt/fillval/" attribute. This value is also used to fill unfilled
539 areas generated by the assemblers <tt/.ALIGN/ and <tt/.RES/ directives.
542 <sect1>Other SEGMENT attributes<p>
544 Segments may be aligned to some memory boundary. Specify "<tt/align = num/" to
545 request this feature. Num must be a power of two. To align all segments on a
550 CODE: load = ROM1, type = ro, align = $100;
551 RODATA: load = ROM2, type = ro, align = $100;
552 DATA: load = ROM2, run = RAM2, type = rw, define = yes,
554 BSS: load = RAM2, type = bss, define = yes, align = $100;
558 If an alignment is requested, the linker will add enough space to the output
559 file, so that the new segment starts at an address that is divideable by the
560 given number without a remainder. All addresses are adjusted accordingly. To
561 fill the unused space, bytes of zero are used, or, if the memory area has a
562 "<tt/fillval/" attribute, that value. Alignment is always needed, if you have
563 the used the <tt/.ALIGN/ command in the assembler. The alignment of a segment
564 must be equal or greater than the alignment used in the <tt/.ALIGN/ command.
565 The linker will check that, and issue a warning, if the alignment of a segment
566 is lower than the alignment requested in a <tt/.ALIGN/ command of one of the
567 modules making up this segment.
569 For a given segment you may also specify a fixed offset into a memory area or
570 a fixed start address. Use this if you want the code to run at a specific
571 address (a prominent case is the interrupt vector table which must go at
572 address $FFFA). Only one of <tt/ALIGN/ or <tt/OFFSET/ or <tt/START/ may be
573 specified. If the directive creates empty space, it will be filled with zero,
574 of with the value specified with the "<tt/fillval/" attribute if one is given.
575 The linker will warn you if it is not possible to put the code at the
576 specified offset (this may happen if other segments in this area are too
577 large). Here's an example:
581 VECTORS: load = ROM2, type = ro, start = $FFFA;
585 or (for the segment definitions from above)
589 VECTORS: load = ROM2, type = ro, offset = $1FFA;
593 File names may be empty, data from segments assigned to a memory area with
594 an empty file name is discarded. This is useful, if the a memory area has
595 segments assigned that are empty (for example because they are of type
596 bss). In that case, the linker will create an empty output file. This may
597 be suppressed by assigning an empty file name to that memory area.
599 The symbol <tt/%S/ may be used to access the default start address (that is,
600 $200 or the value given on the command line with the <tt><ref id="option-S"
601 name="-S"></tt> option).
607 In addition to the <tt/MEMORY/ and <tt/SEGMENTS/ sections described above, the
608 linker has features that may be enabled by an additional section labeled
609 <tt/FEATURES/. Currently, one such feature is available: <tt/CONDES/ is used
610 to tell the linker to emit module constructor/destructor tables.
614 CONDES: segment = RODATA,
616 label = __CONSTRUCTOR_TABLE__,
617 count = __CONSTRUCTOR_COUNT__;
621 The <tt/CONDES/ feature has several attributes:
625 <tag><tt>segment</tt></tag>
627 This attribute tells the linker into which segment the table should be
628 placed. If the segment does not exist, it is created.
631 <tag><tt>type</tt></tag>
633 Describes the type of the routines to place in the table. Type may be
634 one of the predefined types <tt/constructor/ or <tt/destructor/, or a
635 numeric value between 0 and 6.
638 <tag><tt>label</tt></tag>
640 This specifies the label to use for the table. The label points to the
641 start of the table in memory and may be used from within user written
645 <tag><tt>count</tt></tag>
647 This is an optional attribute. If specified, an additional symbol is
648 defined by the linker using the given name. The value of this symbol
649 is the number of entries (<em/not/ bytes) in the table. While this
650 attribute is optional, it is often useful to define it.
653 <tag><tt>order</tt></tag>
655 Optional attribute that takes one of the keywords <tt/increasing/ or
656 <tt/decreasing/ as an argument. Specifies the sorting order of the entries
657 within the table. The default is <tt/increasing/, which means that the
658 entries are sorted with increasing priority (the first entry has the lowest
659 priority). You may change this behaviour by specifying <tt/decreasing/ as
660 the argument, the order of entries is reversed in this case.
662 Please note that the order of entries with equal priority is undefined.
666 Without specifying the <tt/CONDES/ feature, the linker will not create any
667 tables, even if there are <tt/condes/ entries in the object files.
669 For more information see the <tt/.CONDES/ command in the <htmlurl
670 url="ca65.html" name="ca65 manual">.
674 <sect1>Builtin configurations<label id="builtin-configs"><p>
676 Here is a list of the builin configurations for the different target
680 <tag><tt>none</tt></tag>
683 RAM: start = %S, size = $10000, file = %O;
686 CODE: load = RAM, type = rw;
687 RODATA: load = RAM, type = rw;
688 DATA: load = RAM, type = rw;
689 BSS: load = RAM, type = bss, define = yes;
692 CONDES: segment = RODATA,
694 label = __CONSTRUCTOR_TABLE__,
695 count = __CONSTRUCTOR_COUNT__;
696 CONDES: segment = RODATA,
698 label = __DESTRUCTOR_TABLE__,
699 count = __DESTRUCTOR_COUNT__;
703 <tag><tt>atari</tt></tag>
706 ZP: start = $82, size = $7E, type = rw;
707 HEADER: start = $0000, size = $6, file = %O;
708 RAM: start = $1F00, size = $9D1F, file = %O;
711 EXEHDR: load = HEADER, type = wprot;
712 CODE: load = RAM, type = wprot, define = yes;
713 RODATA: load = RAM, type = wprot;
714 DATA: load = RAM, type = rw;
715 BSS: load = RAM, type = bss, define = yes;
716 ZEROPAGE: load = ZP, type = zp;
717 AUTOSTRT: load = RAM, type = wprot;
720 CONDES: segment = RODATA,
722 label = __CONSTRUCTOR_TABLE__,
723 count = __CONSTRUCTOR_COUNT__;
724 CONDES: segment = RODATA,
726 label = __DESTRUCTOR_TABLE__,
727 count = __DESTRUCTOR_COUNT__;
731 <tag><tt>c64</tt></tag>
734 ZP: start = $02, size = $1A, type = rw;
735 RAM: start = $7FF, size = $c801, file = %O;
738 CODE: load = RAM, type = wprot;
739 RODATA: load = RAM, type = wprot;
740 DATA: load = RAM, type = rw;
741 BSS: load = RAM, type = bss, define = yes;
742 ZEROPAGE: load = ZP, type = zp;
745 CONDES: segment = RODATA,
747 label = __CONSTRUCTOR_TABLE__,
748 count = __CONSTRUCTOR_COUNT__;
749 CONDES: segment = RODATA,
751 label = __DESTRUCTOR_TABLE__,
752 count = __DESTRUCTOR_COUNT__;
758 <tag><tt>c128</tt></tag>
761 ZP: start = $02, size = $1A, type = rw;
762 RAM: start = $1bff, size = $a401, file = %O;
765 CODE: load = RAM, type = wprot;
766 RODATA: load = RAM, type = wprot;
767 DATA: load = RAM, type = rw;
768 BSS: load = RAM, type = bss, define = yes;
769 ZEROPAGE: load = ZP, type = zp;
772 CONDES: segment = RODATA,
774 label = __CONSTRUCTOR_TABLE__,
775 count = __CONSTRUCTOR_COUNT__;
776 CONDES: segment = RODATA,
778 label = __DESTRUCTOR_TABLE__,
779 count = __DESTRUCTOR_COUNT__;
783 <tag><tt>plus4</tt></tag>
786 ZP: start = $02, size = $1A, type = rw;
787 RAM: start = $0fff, size = $7001, file = %O;
790 CODE: load = RAM, type = wprot;
791 RODATA: load = RAM, type = wprot;
792 DATA: load = RAM, type = rw;
793 BSS: load = RAM, type = bss, define = yes;
794 ZEROPAGE: load = ZP, type = zp;
797 CONDES: segment = RODATA,
799 label = __CONSTRUCTOR_TABLE__,
800 count = __CONSTRUCTOR_COUNT__;
801 CONDES: segment = RODATA,
803 label = __DESTRUCTOR_TABLE__,
804 count = __DESTRUCTOR_COUNT__;
808 <tag><tt>cbm610</tt></tag>
811 ZP: start = $02, size = $1A, type = rw;
812 RAM: start = $0001, size = $FFF0, file = %O;
815 CODE: load = RAM, type = wprot;
816 RODATA: load = RAM, type = wprot;
817 DATA: load = RAM, type = rw;
818 BSS: load = RAM, type = bss, define = yes;
819 ZEROPAGE: load = ZP, type = zp;
822 CONDES: segment = RODATA,
824 label = __CONSTRUCTOR_TABLE__,
825 count = __CONSTRUCTOR_COUNT__;
826 CONDES: segment = RODATA,
828 label = __DESTRUCTOR_TABLE__,
829 count = __DESTRUCTOR_COUNT__;
833 <tag><tt>pet</tt></tag>
836 ZP: start = $02, size = $1A, type = rw;
837 RAM: start = $03FF, size = $7BFF, file = %O;
840 CODE: load = RAM, type = wprot;
841 RODATA: load = RAM, type = wprot;
842 DATA: load = RAM, type = rw;
843 BSS: load = RAM, type = bss, define = yes;
844 ZEROPAGE: load = ZP, type = zp;
847 CONDES: segment = RODATA,
849 label = __CONSTRUCTOR_TABLE__,
850 count = __CONSTRUCTOR_COUNT__;
851 CONDES: segment = RODATA,
853 label = __DESTRUCTOR_TABLE__,
854 count = __DESTRUCTOR_COUNT__;
858 <tag><tt>apple2</tt></tag>
861 ZP: start = $00, size = $1A, type = rw;
862 RAM: start = $800, size = $8E00, file = %O;
865 CODE: load = RAM, type = ro;
866 RODATA: load = RAM, type = ro;
867 DATA: load = RAM, type = rw;
868 BSS: load = RAM, type = bss, define = yes;
869 ZEROPAGE: load = ZP, type = zp;
872 CONDES: segment = RODATA,
874 label = __CONSTRUCTOR_TABLE__,
875 count = __CONSTRUCTOR_COUNT__;
876 CONDES: segment = RODATA,
878 label = __DESTRUCTOR_TABLE__,
879 count = __DESTRUCTOR_COUNT__;
883 <tag><tt>geos</tt></tag>
886 HEADER: start = $204, size = 508, file = %O;
887 RAM: start = $400, size = $7C00, file = %O;
890 HEADER: load = HEADER, type = ro;
891 CODE: load = RAM, type = ro;
892 RODATA: load = RAM, type = ro;
893 DATA: load = RAM, type = rw;
894 BSS: load = RAM, type = bss, define = yes;
897 CONDES: segment = RODATA,
899 label = __CONSTRUCTOR_TABLE__,
900 count = __CONSTRUCTOR_COUNT__;
901 CONDES: segment = RODATA,
903 label = __DESTRUCTOR_TABLE__,
904 count = __DESTRUCTOR_COUNT__;
910 The "<tt/start/" attribute for the <tt/RAM/ memory area of the CBM systems is
911 two less than the actual start of the basic RAM to account for the two bytes
912 load address that is needed on disk and supplied by the startup code.
916 <sect>Bugs/Feedback<p>
918 If you have problems using the linker, if you find any bugs, or if you're
919 doing something interesting with it, I would be glad to hear from you. Feel
920 free to contact me by email (<htmlurl url="mailto:uz@cc65.org"
921 name="uz@cc65.org">).
927 ld65 (and all cc65 binutils) are (C) Copyright 1998-2000 Ullrich von
928 Bassewitz. For usage of the binaries and/or sources the following
931 This software is provided 'as-is', without any expressed or implied
932 warranty. In no event will the authors be held liable for any damages
933 arising from the use of this software.
935 Permission is granted to anyone to use this software for any purpose,
936 including commercial applications, and to alter it and redistribute it
937 freely, subject to the following restrictions:
940 <item> The origin of this software must not be misrepresented; you must not
941 claim that you wrote the original software. If you use this software
942 in a product, an acknowledgment in the product documentation would be
943 appreciated but is not required.
944 <item> Altered source versions must be plainly marked as such, and must not
945 be misrepresented as being the original software.
946 <item> This notice may not be removed or altered from any source