X-Git-Url: https://git.sur5r.net/?a=blobdiff_plain;ds=sidebyside;f=doc%2Fld65.sgml;h=457893ffc33a467ff9e8828827f118b0f76777b0;hb=7ab3ede933ca2307b948cd6a218d1f49a4a8aa72;hp=3cd238f3f31ab48a8d1dd8643fa1f5cbd8304fd7;hpb=00555c26fa8bcc0b15be6b4bf73856eb98b9b2d6;p=cc65

diff --git a/doc/ld65.sgml b/doc/ld65.sgml
index 3cd238f3f..457893ffc 100644
--- a/doc/ld65.sgml
+++ b/doc/ld65.sgml
@@ -55,7 +55,10 @@ The linker is called as follows:
 ---------------------------------------------------------------------------
 Usage: ld65 [options] module ...
 Short options:
+  -(                    Start a library group
+  -)                    End a library group
   -C name               Use linker config file
+  -D sym=val            Define a symbol
   -L path               Specify a library search path
   -Ln name              Create a VICE label file
   -S addr               Set the default start address
@@ -64,6 +67,7 @@ Short options:
   -m name               Create a map file
   -o name               Name the default output file
   -t sys                Set the target system
+  -u sym                Force an import of symbol `sym'
   -v                    Verbose mode
   -vm                   Verbose map file
 
@@ -71,7 +75,10 @@ Long options:
   --cfg-path path       Specify a config file search path
   --config name         Use linker config file
   --dbgfile name        Generate debug information
+  --define sym=val      Define a symbol
   --dump-config name    Dump a builtin configuration
+  --end-group           End a library group
+  --force-import sym    Force an import of symbol `sym'
   --help                Help (this text)
   --lib file            Link this library
   --lib-path path       Specify a library search path
@@ -80,6 +87,7 @@ Long options:
   --obj file            Link this object file
   --obj-path path       Specify an object file search path
   --start-addr addr     Set the default start address
+  --start-group         Start a library group
   --target sys          Set the target system
   --version             Print the linker version
 ---------------------------------------------------------------------------
@@ -146,26 +154,47 @@ Here is a description of all the command line options:
 
   <itemize>
   <item>none
+  <item>module
   <item>apple2
+  <item>apple2enh
   <item>atari
   <item>atmos
   <item>c16 (works also for the c116 with memory up to 32K)
   <item>c64
   <item>c128
-  <item>plus4
   <item>cbm510 (CBM-II series with 40 column video)
   <item>cbm610 (all CBM series-II computers with 80 column video)
-  <item>pet (all CBM PET systems except the 2001)
-  <item>geos
+  <item>geos-apple
+  <item>geos-cbm
   <item>lunix
-  <item>atmos
+  <item>lynx
   <item>nes
+  <item>pet (all CBM PET systems except the 2001)
+  <item>plus4
+  <item>supervision
+  <item>vic20
   </itemize>
 
   There are a few more targets defined but neither of them is actually
   supported.
 
 
+  <tag><tt>-u sym[:addrsize], --force-import sym[:addrsize]</tt></tag>
+
+  Force an import of a symbol. While object files are always linked to the
+  output file, regardless if there are any references, object modules from
+  libraries get only linked in if an import can be satisfied by this module.
+  The <tt/--fore-import/ option may be used to add a reference to a symbol and
+  as a result force linkage of the module that exports the identifier.
+
+  The name of the symbol may optionally be followed by a colon and an address
+  size specifier. If no address size is specified, the default address size
+  for the target machine is used.
+
+  Please note that the symbol name needs to have the internal representation,
+  meaning you have to prepend an underline for C identifiers.
+
+
   <label id="option-v">
   <tag><tt>-v, --verbose</tt></tag>
 
@@ -191,6 +220,15 @@ Here is a description of all the command line options:
   id="option-t" name="-t"></tt>.
 
 
+  <label id="option-D">
+  <tag><tt>-D sym=value, --define sym=value</tt></tag>
+
+  This option allows to define an external symbol on the command line. Value
+  may start with a '&dollar;' sign or with <tt/0x/ for hexadecimal values,
+  otherwise a leading zero denotes octal values. See also the <ref
+  id="SYMBOLS" name="SYMBOLS section"> in the configuration file.
+
+
   <label id="option--lib-path">
   <tag><tt>-L path, --lib-path path</tt></tag>
 
@@ -215,8 +253,8 @@ Here is a description of all the command line options:
 
   Using -S you may define the default starting address. If and how this
   address is used depends on the config file in use. For the builtin
-  configurations, only the "none" system honors an explicit start address,
-  all other builtin config provide their own.
+  configurations, only the "none", "apple2" and "apple2enh" systems honor an
+  explicit start address, all other builtin config provide their own.
 
 
   <tag><tt>-V, --version</tt></tag>
@@ -243,7 +281,7 @@ Here is a description of all the command line options:
   written to this file. Using the <tt/-g/ option for the compiler and assembler
   will increase the amount of information available. Please note that debug
   information generation is currently being developed, so the format of the
-  file and it's contents are subject to change without further notice.
+  file and its contents are subject to change without further notice.
 
 
   <tag><tt>--lib file</tt></tag>
@@ -289,9 +327,8 @@ The library search path contains in this order:
 <item>A compiled in library path which is often <tt>/usr/lib/cc65/lib</tt> on
       Linux systems.
 <item>The value of the environment variable <tt/LD65_LIB/ if it is defined.
-<item>The value of the environment variable <tt/CC65_LIB/ if it is defined.
-      Please note that use of this environment variable is obsolete and may
-      get removed in future versions.
+<item>A subdirectory named <tt/lib/ of the directory defined in the environment
+      variable <tt/CC65_HOME/, if it is defined.
 <item>Any directory added with the <tt><ref id="option--lib-path"
       name="--lib-path"></tt> option on the command line.
 </enum>
@@ -303,12 +340,11 @@ The object file search path contains in this order:
 
 <enum>
 <item>The current directory.
-<item>A compiled in directory which is often <tt>/usr/lib/cc65/lib</tt> on
+<item>A compiled in directory which is often <tt>/usr/lib/cc65/obj</tt> on
       Linux systems.
 <item>The value of the environment variable <tt/LD65_OBJ/ if it is defined.
-<item>The value of the environment variable <tt/CC65_LIB/ if it is defined.
-      Please note that use of this environment variable is obsolete and may
-      get removed in future versions.
+<item>A subdirectory named <tt/obj/ of the directory defined in the environment
+      variable <tt/CC65_HOME/, if it is defined.
 <item>Any directory added with the <tt><ref id="option--obj-path"
       name="--obj-path"></tt> option on the command line.
 </enum>
@@ -320,9 +356,11 @@ The config file search path contains in this order:
 
 <enum>
 <item>The current directory.
-<item>A compiled in directory which is often <tt>/usr/lib/cc65/lib</tt> on
+<item>A compiled in directory which is often <tt>/usr/lib/cc65/cfg</tt> on
       Linux systems.
 <item>The value of the environment variable <tt/LD65_CFG/ if it is defined.
+<item>A subdirectory named <tt/cfg/ of the directory defined in the environment
+      variable <tt/CC65_HOME/, if it is defined.
 <item>Any directory added with the <tt><ref id="option--cfg-path"
       name="--cfg-path"></tt> option on the command line.
 </enum>
@@ -364,7 +402,7 @@ for the segments and define any linker symbols (see <ref id="config-files"
 name="Configuration files">).
 
 After that, the linker is ready to produce an output file. Before doing that,
-it checks it's data for consistency. That is, it checks for unresolved
+it checks its data for consistency. That is, it checks for unresolved
 externals (if the output format is not relocatable) and for symbol type
 mismatches (for example a zero page symbol is imported by a module as absolute
 symbol).
@@ -471,15 +509,13 @@ What we are doing here is telling the linker, that all segments go into the
 the linker will first write the <tt/CODE/ segment, then the <tt/RODATA/
 segment, then the <tt/DATA/ segment - but it will not write the <tt/BSS/
 segment. Why? Enter the segment type: For each segment specified, you may also
-specify a segment attribute. There are five possible segment attributes:
+specify a segment attribute. There are four possible segment attributes:
 
 <tscreen><verb>
 	ro   	means readonly
-	wprot	same as ro but will be marked as write protected in
-		the VICE label file if -Lp is given
-	rw   	means read/write
-	bss  	means that this is an uninitialized segment
-	zp	a zeropage segment
+      	rw   	means read/write
+      	bss  	means that this is an uninitialized segment
+      	zp	a zeropage segment
 </verb></tscreen>
 
 So, because we specified that the segment with the name BSS is of type bss,
@@ -532,7 +568,7 @@ example above. Let's have a look at it now.
 
 The "file" attribute (the keyword may also be written as "FILE" if you like
 that better) takes a string enclosed in double quotes (`"') that specifies the
-file, where the data is written. You may specifiy the same file several times,
+file, where the data is written. You may specify the same file several times,
 in that case the data for all memory areas having this file name is written
 into this file, in the order of the memory areas defined in the <tt/MEMORY/
 section. Let's specify some file names in the <tt/MEMORY/ section used above:
@@ -565,6 +601,19 @@ empty (for example because they are of type bss). In that case, the linker
 will create an empty output file. This may be suppressed by assigning an empty
 file name to that memory area.
 
+The <tt/%O/ sequence is also allowed inside a string. So using
+
+<tscreen><verb>
+      	MEMORY {
+       	    ROM1:  start = $A000, size = $2000, file = "%O-1.bin";
+      	    ROM2:  start = $E000, size = $2000, file = "%O-2.bin";
+      	}
+</verb></tscreen>
+
+would write two files that start with the name of the output file specified on
+the command line, with "-1.bin" and "-2.bin" appended respectively. Because
+'%' is used as an escape char, the sequence "%%" has to be used if a single
+percent sign is required.
 
 <sect1>LOAD and RUN addresses (ROMable code)<p>
 
@@ -587,7 +636,7 @@ about <tt/DATA/? <tt/DATA/ contains initialized data, that is, data that was
 explicitly assigned a value. And your program will rely on these values on
 startup. Since there's no other way to remember the contents of the data
 segment, than storing it into one of the ROMs, we have to put it there. But
-unfortunately, ROM is not writeable, so we have to copy it into RAM before
+unfortunately, ROM is not writable, so we have to copy it into RAM before
 running the actual code.
 
 The linker cannot help you copying the data from ROM into RAM (this must be
@@ -613,7 +662,7 @@ Let's have a closer look at this <tt/SEGMENTS/ section. We specify that the
 goes into <tt/ROM2/. Read/write data will be loaded into <tt/ROM2/ but is run
 in <tt/RAM2/. That means that all references to labels in the <tt/DATA/
 segment are relocated to be in <tt/RAM2/, but the segment is written to
-<tt/ROM2/. All your startup code has to do is, to copy the data from it's
+<tt/ROM2/. All your startup code has to do is, to copy the data from its
 location in <tt/ROM2/ to the final location in <tt/RAM2/.
 
 So, how do you know, where the data is located? This is the second point,
@@ -650,17 +699,20 @@ useful for things like a software stack, or an i/o area.
      	}
 </verb></tscreen>
 
-This will define three external symbols that may be used in your code:
+This will define some external symbols that may be used in your code:
 
 <tscreen><verb>
        	__STACK_START__	  	This is set to the start of the memory
-     	     		  	area, $C000 in this example.
+     	     	      	  	area, $C000 in this example.
      	__STACK_SIZE__	  	The size of the area, here $1000.
         __STACK_LAST__		This is NOT the same as START+SIZE.
-     	     	    		Instead, it it defined as the first
-     	     			address that is not used by data. If we
-     	     			don't define any segments for this area,
-     	     			the value will be the same as START.
+     	     	      		Instead, it it defined as the first
+     	     	      		address that is not used by data. If we
+     	     	      		don't define any segments for this area,
+     	     	      		the value will be the same as START.
+        __STACK_FILEOFFS__      The binary offset in the output file. This
+                                is not defined for relocatable output file
+                                formats (o65).
 </verb></tscreen>
 
 A memory section may also have a type. Valid types are
@@ -684,6 +736,13 @@ the one defined in the <ref id="FEATURES" name="FEATURES"> section, or the
 value given on the command line with the <tt><ref id="option-S" name="-S"></tt>
 option).
 
+To support systems with banked memory, a special attribute named <tt/bank/ is
+available. The attribute value is an arbitrary 32 bit integer. The assembler
+has a builtin function named <tt/.BANK/ which may be used with an argument
+that has a segment reference (for example a symbol). The result of this
+function is the value of the bank attribute for the run memory area of the
+segment.
+
 
 <sect1>Other SEGMENT attributes<p>
 
@@ -702,14 +761,14 @@ page boundary, use
 </verb></tscreen>
 
 If an alignment is requested, the linker will add enough space to the output
-file, so that the new segment starts at an address that is divideable by the
+file, so that the new segment starts at an address that is dividable by the
 given number without a remainder. All addresses are adjusted accordingly. To
 fill the unused space, bytes of zero are used, or, if the memory area has a
 "<tt/fillval/" attribute, that value. Alignment is always needed, if you have
-the used the <tt/.ALIGN/ command in the assembler. The alignment of a segment
+used the <tt/.ALIGN/ command in the assembler. The alignment of a segment
 must be equal or greater than the alignment used in the <tt/.ALIGN/ command.
 The linker will check that, and issue a warning, if the alignment of a segment
-is lower than the alignment requested in a <tt/.ALIGN/ command of one of the
+is lower than the alignment requested in an <tt/.ALIGN/ command of one of the
 modules making up this segment.
 
 For a given segment you may also specify a fixed offset into a memory area or
@@ -740,7 +799,7 @@ The "<tt/align/", "<tt/start/" and "<tt/offset/" attributes change placement
 of the segment in the run memory area, because this is what is usually
 desired. If load and run memory areas are equal (which is the case if only the
 load memory area has been specified), the attributes will also work. There is
-also a "<tt/align_load/" attribute that may be used to align the start of the
+also an "<tt/align_load/" attribute that may be used to align the start of the
 segment in the load memory area, in case different load and run areas have
 been specified. There are no special attributes to set start or offset for
 just the load memory area.
@@ -768,7 +827,8 @@ look like this:
 </verb></tscreen>
 
 The only other available output format is the o65 format specified by Andre
-Fachat. It is defined like this:
+Fachat (see the <htmlurl url="http://www.6502.org/users/andre/o65/fileformat.html"
+name="6502 binary relocation format specification">). It is defined like this:
 
 <tscreen><verb>
      	FILES {
@@ -785,8 +845,9 @@ The necessary o65 attributes are defined in a special section labeled
 
 The <tt/FORMAT/ section is used to describe file formats. The default (binary)
 format has currently no attributes, so, while it may be listed in this
-section, the attribute list is empty. The second supported format, o65, has
-several attributes that may be defined here.
+section, the attribute list is empty. The second supported format,
+<htmlurl url="http://www.6502.org/users/andre/o65/fileformat.html" name="o65">,
+has several attributes that may be defined here.
 
 <tscreen><verb>
     FORMATS {
@@ -798,9 +859,7 @@ several attributes that may be defined here.
 
 
 
-
-
-<sect1>Features<label id="FEATURES"><p>
+<sect1>The FEATURES section<label id="FEATURES"><p>
 
 In addition to the <tt/MEMORY/ and <tt/SEGMENTS/ sections described above, the
 linker has features that may be enabled by an additional section labeled
@@ -881,10 +940,10 @@ which can be referenced by the <tt/%S/ symbol. The builtin default for the
 linker is &dollar;200.
 
 <tscreen><verb>
-	FEATURES {
+       	FEATURES {
             # Default start address is $1000
-	    STARTADDRESS:       default = $1000;
-	}
+       	    STARTADDRESS:       default = $1000;
+       	}
 </verb></tscreen>
 
 Please note that order is important: The default start address must be defined
@@ -893,14 +952,105 @@ mean, that the <tt/FEATURES/ section has to go to the top of the config file.
 
 
 
+<sect1>The SYMBOLS section<label id="SYMBOLS"><p>
+
+The configuration file may also be used to define symbols used in the link
+stage or to force symbols imports. This is done in the SYMBOLS section. The
+symbol name is followed by a colon and symbol attributes.
+
+The following symbol attributes are supported:
+
+<descrip>
+
+  <tag><tt>addrsize</tt></tag>
+
+  The <tt/addrsize/ attribute specifies the address size of the symbol and
+  may be one of
+<itemize>
+    <item><tt/zp/, <tt/zeropage/ or <tt/direct/
+    <item><tt/abs/, <tt/absolute/ or <tt/near/
+    <item><tt/far/
+    <item><tt/long/ or <tt/dword/.
+</itemize>
+
+Without this attribute, the default address size is <tt/abs/.
+
+  <tag><tt>type</tt></tag>
+
+  This attribute is mandatory. Its value is one of <tt/export/, <tt/import/ or
+  <tt/weak/. <tt/export/ means that the symbol is defined and exported from
+  the linker config. <tt/import/ means that an import is generated for this
+  symbol, eventually forcing a module that exports this symbol to be included
+  in the output. <tt/weak/ is similar as <tt/export/. However, the symbol is
+  only defined if it is not defined elsewhere.
+
+  <tag><tt>value</tt></tag>
+
+  This must only be given for symbols of type <tt/export/ or <tt/weak/. It
+  defines the value of the symbol and may be an expression.
+
+</descrip>
+
+The following example defines the stack size for an application, but allows
+the programmer to override the value by specifying <tt/--define
+__STACKSIZE__=xxx/ on the command line.
+
+<tscreen><verb>
+       	SYMBOLS {
+            # Define the stack size for the application
+       	    __STACKSIZE__:  type = weak, value = $800;
+       	}
+</verb></tscreen>
+
+
+
 <sect1>Builtin configurations<p>
 
-The builtin configurations are part of the linker source. They are also
-distributed together with the machine specific binary packages (usually in the
-doc directory) and don't have a special format. So if you need a special
-configuration, it's a good idea to start with the builtin configuration for
-your system. In a first step, just replace <tt/-t target/ by <tt/-C
-configfile/. The go on and modify the config file to suit your needs.
+The builtin configurations are part of the linker source. They can be retrieved
+with <tt/--dump-config/ and don't have a special format. So if you need a
+special configuration, it's a good idea to start with the builtin configuration
+for your system. In a first step, just replace <tt/-t target/ by <tt/-C
+configfile/. Then go on and modify the config file to suit your needs.
+
+
+
+<sect1>Secondary configurations<p>
+
+Several machine specific binary packages are distributed together with secondary
+configurations (in the cfg directory). These configurations can be used with
+<tt/-C configfile/ too.
+
+
+
+<sect>Special segments<p>
+
+The builtin config files do contain segments that have a special meaning for
+the compiler and the libraries that come with it. If you replace the builtin
+config files, you will need the following information.
+
+<sect1>INIT<p>
+
+The INIT segment is used for initialization code that may be reused once
+execution reaches main() - provided that the program runs in RAM. You
+may for example add the INIT segment to the heap in really memory
+constrained systems.
+
+<sect1>LOWCODE<p>
+
+For the LOWCODE segment, it is guaranteed that it won't be banked out, so it
+is reachable at any time by interrupt handlers or similar.
+
+<sect1>STARTUP<p>
+
+This segment contains the startup code which initializes the C software stack
+and the libraries. It is placed in its own segment because it needs to be
+loaded at the lowest possible program address on several platforms.
+
+<sect1>ZPSAVE<p>
+
+The ZPSAVE segment contains the original values of the zeropage locations used
+by the ZEROPAGE segment. It is placed in its own segment because it must not be
+initialized.
 
 
 
@@ -915,7 +1065,7 @@ name="uz@cc65.org">).
 
 <sect>Copyright<p>
 
-ld65 (and all cc65 binutils) are (C) Copyright 1998-2001 Ullrich von
+ld65 (and all cc65 binutils) are (C) Copyright 1998-2005 Ullrich von
 Bassewitz. For usage of the binaries and/or sources the following
 conditions do apply: