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
349 So, because we specified that the segment with the name BSS is of type bss,
350 the linker knows that this is uninitialized data, and will not write it to an
351 output file. This is an important point: For the assembler, the <tt/BSS/
352 segment has no special meaning. You specify, which segments have the bss
353 attribute when linking. This approach is much more flexible than having one
354 fixed bss segment, and is a result of the design decision to supporting an
355 arbitrary segment count.
357 If you specify "<tt/type = bss/" for a segment, the linker will make sure that
358 this segment does only contain uninitialized data (that is, zeroes), and issue
359 a warning if this is not the case.
361 For a <tt/bss/ type segment to be useful, it must be cleared somehow by your
362 program (this happens usually in the startup code - for example the startup
363 code for cc65 generated programs takes care about that). But how does your
364 code know, where the segment starts, and how big it is? The linker is able to
365 give that information, but you must request it. This is, what we're doing with
366 the "<tt/define = yes/" attribute in the <tt/BSS/ definitions. For each
367 segment, where this attribute is true, the linker will export three symbols.
370 __NAME_LOAD__ This is set to the address where the
372 __NAME_RUN__ This is set to the run address of the
373 segment. We will cover run addresses
375 __NAME_SIZE__ This is set to the segment size.
378 Replace <tt/NAME/ by the name of the segment, in the example above, this would
379 be <tt/BSS/. These symbols may be accessed by your code.
381 Now, as we've configured the linker to write the first three segments and
382 create symbols for the last one, there's only one question left: Where does
383 the linker put the data? It would be very convenient to have the data in a
386 <sect1>Output files<p>
388 We don't have any files specified above, and indeed, this is not needed in a
389 simple configuration like the one above. There is an additional attribute
390 "file" that may be specified for a memory area, that gives a file name to
391 write the area data into. If there is no file name given, the linker will
392 assign the default file name. This is "a.out" or the one given with the
393 <tt><ref id="option-o" name="-o"></tt> option on the command line. Since the
394 default behaviour is ok for our purposes, I did not use the attribute in the
395 example above. Let's have a look at it now.
397 The "file" attribute (the keyword may also be written as "FILE" if you like
398 that better) takes a string enclosed in double quotes (`"') that specifies the
399 file, where the data is written. You may specifiy the same file several times,
400 in that case the data for all memory areas having this file name is written
401 into this file, in the order of the memory areas defined in the <tt/MEMORY/
402 section. Let's specify some file names in the <tt/MEMORY/ section used above:
406 RAM1: start = $0800, size = $9800, file = %O;
407 ROM1: start = $A000, size = $2000, file = "rom1.bin";
408 RAM2: start = $C000, size = $1000, file = %O;
409 ROM2: start = $E000, size = $2000, file = "rom2.bin";
413 The <tt/%O/ used here is a way to specify the default behaviour explicitly:
414 <tt/%O/ is replaced by a string (including the quotes) that contains the
415 default output name, that is, "a.out" or the name specified with the <tt><ref
416 id="option-o" name="-o"></tt> option on the command line. Into this file, the
417 linker will first write any segments that go into <tt/RAM1/, and will append
418 then the segments for <tt/RAM2/, because the memory areas are given in this
419 order. So, for the RAM areas, nothing has really changed.
421 We've not used the ROM areas, but we will do that below, so we give the file
422 names here. Segments that go into <tt/ROM1/ will be written to a file named
423 "rom1.bin", and segments that go into <tt/ROM2/ will be written to a file
424 named "rom2.bin". The name given on the command line is ignored in both cases.
427 <sect1>LOAD and RUN addresses (ROMable code)<p>
429 Let us look now at a more complex example. Say, you've successfully tested
430 your new "Super Operating System" (SOS for short) for the C64, and you
431 will now go and replace the ROMs by your own code. When doing that, you
432 face a new problem: If the code runs in RAM, we need not to care about
433 read/write data. But now, if the code is in ROM, we must care about it.
434 Remember the default segments (you may of course specify your own):
438 RODATA read only data
440 BSS uninitialized data, read/write
443 Since <tt/BSS/ is not initialized, we must not care about it now, but what
444 about <tt/DATA/? <tt/DATA/ contains initialized data, that is, data that was
445 explicitly assigned a value. And your program will rely on these values on
446 startup. Since there's no other way to remember the contents of the data
447 segment, than storing it into one of the ROMs, we have to put it there. But
448 unfortunately, ROM is not writeable, so we have to copy it into RAM before
449 running the actual code.
451 The linker cannot help you copying the data from ROM into RAM (this must be
452 done by the startup code of your program), but it has some features that will
453 help you in this process.
455 First, you may not only specify a "<tt/load/" attribute for a segment, but
456 also a "<tt/run/" attribute. The "<tt/load/" attribute is mandatory, and, if
457 you don't specify a "<tt/run/" attribute, the linker assumes that load area
458 and run area are the same. We will use this feature for our data area:
462 CODE: load = ROM1, type = ro;
463 RODATA: load = ROM2, type = ro;
464 DATA: load = ROM2, run = RAM2, type = rw, define = yes;
465 BSS: load = RAM2, type = bss, define = yes;
469 Let's have a closer look at this <tt/SEGMENTS/ section. We specify that the
470 <tt/CODE/ segment goes into <tt/ROM1/ (the one at $A000). The readonly data
471 goes into <tt/ROM2/. Read/write data will be loaded into <tt/ROM2/ but is run
472 in <tt/RAM2/. That means that all references to labels in the <tt/DATA/
473 segment are relocated to be in <tt/RAM2/, but the segment is written to
474 <tt/ROM2/. All your startup code has to do is, to copy the data from it's
475 location in <tt/ROM2/ to the final location in <tt/RAM2/.
477 So, how do you know, where the data is located? This is the second point,
478 where you get help from the linker. Remember the "<tt/define/" attribute?
479 Since we have set this attribute to true, the linker will define three
480 external symbols for the data segment that may be accessed from your code:
483 __DATA_LOAD__ This is set to the address where the segment
484 is loaded, in this case, it is an address in
486 __DATA_RUN__ This is set to the run address of the segment,
487 in this case, it is an address in RAM2.
488 __DATA_SIZE__ This is set to the segment size.
491 So, what your startup code must do, is to copy <tt/__DATA_SIZE__/ bytes from
492 <tt/__DATA_LOAD__/ to <tt/__DATA_RUN__/ before any other routines are called.
493 All references to labels in the <tt/DATA/ segment are relocated to <tt/RAM2/
494 by the linker, so things will work properly.
497 <sect1>Other MEMORY area attributes<p>
499 There are some other attributes not covered above. Before starting the
500 reference section, I will discuss the remaining things here.
502 You may request symbols definitions also for memory areas. This may be
503 useful for things like a software stack, or an i/o area.
507 STACK: start = $C000, size = $1000, define = yes;
511 This will define three external symbols that may be used in your code:
514 __STACK_START__ This is set to the start of the memory
515 area, $C000 in this example.
516 __STACK_SIZE__ The size of the area, here $1000.
517 __STACK_LAST__ This is NOT the same as START+SIZE.
518 Instead, it it defined as the first
519 address that is not used by data. If we
520 don't define any segments for this area,
521 the value will be the same as START.
524 A memory section may also have a type. Valid types are
527 ro for readonly memory
528 rw for read/write memory.
531 The linker will assure, that no segment marked as read/write or bss is put
532 into a memory area that is marked as readonly.
534 Unused memory in a memory area may be filled. Use the "<tt/fill = yes/"
535 attribute to request this. The default value to fill unused space is zero. If
536 you don't like this, you may specify a byte value that is used to fill these
537 areas with the "<tt/fillval/" attribute. This value is also used to fill unfilled
538 areas generated by the assemblers <tt/.ALIGN/ and <tt/.RES/ directives.
541 <sect1>Other SEGMENT attributes<p>
543 Segments may be aligned to some memory boundary. Specify "<tt/align = num/" to
544 request this feature. Num must be a power of two. To align all segments on a
549 CODE: load = ROM1, type = ro, align = $100;
550 RODATA: load = ROM2, type = ro, align = $100;
551 DATA: load = ROM2, run = RAM2, type = rw, define = yes,
553 BSS: load = RAM2, type = bss, define = yes, align = $100;
557 If an alignment is requested, the linker will add enough space to the output
558 file, so that the new segment starts at an address that is divideable by the
559 given number without a remainder. All addresses are adjusted accordingly. To
560 fill the unused space, bytes of zero are used, or, if the memory area has a
561 "<tt/fillval/" attribute, that value. Alignment is always needed, if you have
562 the used the <tt/.ALIGN/ command in the assembler. The alignment of a segment
563 must be equal or greater than the alignment used in the <tt/.ALIGN/ command.
564 The linker will check that, and issue a warning, if the alignment of a segment
565 is lower than the alignment requested in a <tt/.ALIGN/ command of one of the
566 modules making up this segment.
568 For a given segment you may also specify a fixed offset into a memory area or
569 a fixed start address. Use this if you want the code to run at a specific
570 address (a prominent case is the interrupt vector table which must go at
571 address $FFFA). Only one of <tt/ALIGN/ or <tt/OFFSET/ or <tt/START/ may be
572 specified. If the directive creates empty space, it will be filled with zero,
573 of with the value specified with the "<tt/fillval/" attribute if one is given.
574 The linker will warn you if it is not possible to put the code at the
575 specified offset (this may happen if other segments in this area are too
576 large). Here's an example:
580 VECTORS: load = ROM2, type = ro, start = $FFFA;
584 or (for the segment definitions from above)
588 VECTORS: load = ROM2, type = ro, offset = $1FFA;
592 File names may be empty, data from segments assigned to a memory area with
593 an empty file name is discarded. This is useful, if the a memory area has
594 segments assigned that are empty (for example because they are of type
595 bss). In that case, the linker will create an empty output file. This may
596 be suppressed by assigning an empty file name to that memory area.
598 The symbol <tt/%S/ may be used to access the default start address (that is,
599 $200 or the value given on the command line with the <tt><ref id="option-S"
600 name="-S"></tt> option).
606 In addition to the <tt/MEMORY/ and <tt/SEGMENTS/ sections described above, the
607 linker has features that may be enabled by an additional section labeled
608 <tt/FEATURES/. Currently, one such feature is available: <tt/CONDES/ is used
609 to tell the linker to emit module constructor/destructor tables.
613 CONDES: segment = RODATA,
615 label = __CONSTRUCTOR_TABLE__,
616 count = __CONSTRUCTOR_COUNT__;
620 The <tt/CONDES/ feature has several attributes:
624 <tag><tt>segment</tt></tag>
626 This attribute tells the linker into which segment the table should be
627 placed. If the segment does not exist, it is created.
630 <tag><tt>type</tt></tag>
632 Describes the type of the routines to place in the table. Type may be
633 one of the predefined types <tt/constructor/ or <tt/destructor/, or a
634 numeric value between 0 and 6.
637 <tag><tt>label</tt></tag>
639 This specifies the label to use for the table. The label points to the
640 start of the table in memory and may be used from within user written
644 <tag><tt>count</tt></tag>
646 This is an optional attribute. If specified, an additional symbol is
647 defined by the linker using the given name. The value of this symbol
648 is the number of entries (<em/not/ bytes) in the table. While this
649 attribute is optional, it is often useful to define it.
652 <tag><tt>order</tt></tag>
654 Optional attribute that takes one of the keywords <tt/increasing/ or
655 <tt/decreasing/ as an argument. Specifies the sorting order of the entries
656 within the table. The default is <tt/increasing/, which means that the
657 entries are sorted with increasing priority (the first entry has the lowest
658 priority). You may change this behaviour by specifying <tt/decreasing/ as
659 the argument, the order of entries is reversed in this case.
661 Please note that the order of entries with equal priority is undefined.
665 Without specifying the <tt/CONDES/ feature, the linker will not create any
666 tables, even if there are <tt/condes/ entries in the object files.
668 For more information see the <tt/.CONDES/ command in the <htmlurl
669 url="ca65.html" name="ca65 manual">.
673 <sect1>Builtin configurations<label id="builtin-configs"><p>
675 Here is a list of the builin configurations for the different target
679 <tag><tt>none</tt></tag>
682 RAM: start = %S, size = $10000, file = %O;
685 CODE: load = RAM, type = rw;
686 RODATA: load = RAM, type = rw;
687 DATA: load = RAM, type = rw;
688 BSS: load = RAM, type = bss, define = yes;
691 CONDES: segment = RODATA,
693 label = __CONSTRUCTOR_TABLE__,
694 count = __CONSTRUCTOR_COUNT__;
695 CONDES: segment = RODATA,
697 label = __DESTRUCTOR_TABLE__,
698 count = __DESTRUCTOR_COUNT__;
702 <tag><tt>atari</tt></tag>
705 ZP: start = $82, size = $7E, type = rw;
706 HEADER: start = $0000, size = $6, file = %O;
707 RAM: start = $1F00, size = $9D1F, file = %O;
710 EXEHDR: load = HEADER, type = wprot;
711 CODE: load = RAM, type = wprot, define = yes;
712 RODATA: load = RAM, type = wprot;
713 DATA: load = RAM, type = rw;
714 BSS: load = RAM, type = bss, define = yes;
715 ZEROPAGE: load = ZP, type = zp;
716 AUTOSTRT: load = RAM, type = wprot;
719 CONDES: segment = RODATA,
721 label = __CONSTRUCTOR_TABLE__,
722 count = __CONSTRUCTOR_COUNT__;
723 CONDES: segment = RODATA,
725 label = __DESTRUCTOR_TABLE__,
726 count = __DESTRUCTOR_COUNT__;
730 <tag><tt>c64</tt></tag>
733 ZP: start = $02, size = $1A, type = rw;
734 RAM: start = $7FF, size = $c801, file = %O;
737 CODE: load = RAM, type = wprot;
738 RODATA: load = RAM, type = wprot;
739 DATA: load = RAM, type = rw;
740 BSS: load = RAM, type = bss, define = yes;
741 ZEROPAGE: load = ZP, type = zp;
744 CONDES: segment = RODATA,
746 label = __CONSTRUCTOR_TABLE__,
747 count = __CONSTRUCTOR_COUNT__;
748 CONDES: segment = RODATA,
750 label = __DESTRUCTOR_TABLE__,
751 count = __DESTRUCTOR_COUNT__;
757 <tag><tt>c128</tt></tag>
760 ZP: start = $02, size = $1A, type = rw;
761 RAM: start = $1bff, size = $a401, file = %O;
764 CODE: load = RAM, type = wprot;
765 RODATA: load = RAM, type = wprot;
766 DATA: load = RAM, type = rw;
767 BSS: load = RAM, type = bss, define = yes;
768 ZEROPAGE: load = ZP, type = zp;
771 CONDES: segment = RODATA,
773 label = __CONSTRUCTOR_TABLE__,
774 count = __CONSTRUCTOR_COUNT__;
775 CONDES: segment = RODATA,
777 label = __DESTRUCTOR_TABLE__,
778 count = __DESTRUCTOR_COUNT__;
782 <tag><tt>plus4</tt></tag>
785 ZP: start = $02, size = $1A, type = rw;
786 RAM: start = $0fff, size = $7001, file = %O;
789 CODE: load = RAM, type = wprot;
790 RODATA: load = RAM, type = wprot;
791 DATA: load = RAM, type = rw;
792 BSS: load = RAM, type = bss, define = yes;
793 ZEROPAGE: load = ZP, type = zp;
796 CONDES: segment = RODATA,
798 label = __CONSTRUCTOR_TABLE__,
799 count = __CONSTRUCTOR_COUNT__;
800 CONDES: segment = RODATA,
802 label = __DESTRUCTOR_TABLE__,
803 count = __DESTRUCTOR_COUNT__;
807 <tag><tt>cbm610</tt></tag>
810 ZP: start = $02, size = $1A, type = rw;
811 RAM: start = $0001, size = $FFF0, file = %O;
814 CODE: load = RAM, type = wprot;
815 RODATA: load = RAM, type = wprot;
816 DATA: load = RAM, type = rw;
817 BSS: load = RAM, type = bss, define = yes;
818 ZEROPAGE: load = ZP, type = zp;
821 CONDES: segment = RODATA,
823 label = __CONSTRUCTOR_TABLE__,
824 count = __CONSTRUCTOR_COUNT__;
825 CONDES: segment = RODATA,
827 label = __DESTRUCTOR_TABLE__,
828 count = __DESTRUCTOR_COUNT__;
832 <tag><tt>pet</tt></tag>
835 ZP: start = $02, size = $1A, type = rw;
836 RAM: start = $03FF, size = $7BFF, file = %O;
839 CODE: load = RAM, type = wprot;
840 RODATA: load = RAM, type = wprot;
841 DATA: load = RAM, type = rw;
842 BSS: load = RAM, type = bss, define = yes;
843 ZEROPAGE: load = ZP, type = zp;
846 CONDES: segment = RODATA,
848 label = __CONSTRUCTOR_TABLE__,
849 count = __CONSTRUCTOR_COUNT__;
850 CONDES: segment = RODATA,
852 label = __DESTRUCTOR_TABLE__,
853 count = __DESTRUCTOR_COUNT__;
857 <tag><tt>apple2</tt></tag>
860 ZP: start = $00, size = $1A, type = rw;
861 RAM: start = $800, size = $8E00, file = %O;
864 CODE: load = RAM, type = ro;
865 RODATA: load = RAM, type = ro;
866 DATA: load = RAM, type = rw;
867 BSS: load = RAM, type = bss, define = yes;
868 ZEROPAGE: load = ZP, type = zp;
871 CONDES: segment = RODATA,
873 label = __CONSTRUCTOR_TABLE__,
874 count = __CONSTRUCTOR_COUNT__;
875 CONDES: segment = RODATA,
877 label = __DESTRUCTOR_TABLE__,
878 count = __DESTRUCTOR_COUNT__;
882 <tag><tt>geos</tt></tag>
885 HEADER: start = $204, size = 508, file = %O;
886 RAM: start = $400, size = $7C00, file = %O;
889 HEADER: load = HEADER, type = ro;
890 CODE: load = RAM, type = ro;
891 RODATA: load = RAM, type = ro;
892 DATA: load = RAM, type = rw;
893 BSS: load = RAM, type = bss, define = yes;
896 CONDES: segment = RODATA,
898 label = __CONSTRUCTOR_TABLE__,
899 count = __CONSTRUCTOR_COUNT__;
900 CONDES: segment = RODATA,
902 label = __DESTRUCTOR_TABLE__,
903 count = __DESTRUCTOR_COUNT__;
909 The "<tt/start/" attribute for the <tt/RAM/ memory area of the CBM systems is
910 two less than the actual start of the basic RAM to account for the two bytes
911 load address that is needed on disk and supplied by the startup code.
915 <sect>Bugs/Feedback<p>
917 If you have problems using the linker, if you find any bugs, or if you're
918 doing something interesting with it, I would be glad to hear from you. Feel
919 free to contact me by email (<htmlurl url="mailto:uz@cc65.org"
920 name="uz@cc65.org">).
926 ld65 (and all cc65 binutils) are (C) Copyright 1998-2000 Ullrich von
927 Bassewitz. For usage of the binaries and/or sources the following
930 This software is provided 'as-is', without any expressed or implied
931 warranty. In no event will the authors be held liable for any damages
932 arising from the use of this software.
934 Permission is granted to anyone to use this software for any purpose,
935 including commercial applications, and to alter it and redistribute it
936 freely, subject to the following restrictions:
939 <item> The origin of this software must not be misrepresented; you must not
940 claim that you wrote the original software. If you use this software
941 in a product, an acknowledgment in the product documentation would be
942 appreciated but is not required.
943 <item> Altered source versions must be plainly marked as such, and must not
944 be misrepresented as being the original software.
945 <item> This notice may not be removed or altered from any source