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author	Uros Bizjak <ubizjak@gmail.com>	2007-03-26 08:08:54 +0200
committer	Uros Bizjak <uros@gcc.gnu.org>	2007-03-26 08:08:54 +0200
commit	04375334a4faf46528727cb54400e7d60aa80e22 (patch)
tree	412e505a8d9c44e77b76e429a0edd1bd75e6dc22 /libjava/classpath/java/util
parent	420b320a128ea120c41e235d6ef7b455d02ebf54 (diff)
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use_[567].f90: Use correct cleanup-modules dg directive.

* gfortran.dg/use_[567].f90: Use correct cleanup-modules dg directive. From-SVN: r123209

Diffstat (limited to 'libjava/classpath/java/util')

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/** @page build_sys Build system @section overview Overview Building an Etherboot image consists of three stages: -# @ref compilation : Compiling all the source files into object files -# @ref linking : Linking a particular image from selected object files -# @ref finalisation : Producing the final output binary Though this is a remarkably complex process, it is important to note that it all happens automatically. Whatever state your build tree is in, you can always type, for example @code make bin/rtl8139.dsk @endcode and know that you will get a floppy disk image with an RTL8139 driver built from the current sources. @section compilation Compilation @subsection comp_overview Overview Each source file (a @c .c or a @c .S file) is compiled into a @c .o file in the @c bin/ directory. Etherboot makes minimal use of conditional compilation (see @ref ifdef_harmful), and so you will find that all objects get built, even the objects that correspond to features that you are not intending to include in your image. For example, all network card drivers will be compiled even if you are just building a ROM for a 3c509 card. This is a deliberate design decision; please do @b not attempt to "fix" the build system to avoid doing this. Source files are defined to be any @c .c or @c .S files found in a directory listed in the Makefile variable #SRCDIRS. You therefore do @b not need to edit the Makefile just because you have added a new source file (although you will need to edit the Makefile if you have added a new source directory). To see a list of all source directories and source files that the build system currently knows about, you can use the commands @code make srcdirs make srcs @endcode Rules for compiling @c .c and @c .S files are defined in the Makefile variables #RULE_c and #RULE_S. Makefile rules are automatically generated for each source file using these rules. The generated rules can be found in the @c .d file corresponding to each source file; these are located in <tt>bin/deps/</tt>. For example, the rules generated for <tt>drivers/net/rtl8139.c</tt> can be found in <tt>bin/deps/drivers/net/rtl8139.c.d</tt>. These rules allow you to type, for example @code make bin/rtl8139.o @endcode and have <tt>rtl8139.o</tt> be built from <tt>drivers/net/rtl8139.c</tt> using the generic rule #RULE_c for compiling @c .c files. You can see the full list of object files that will be built using @code make bobjs @endcode @subsection comp_ar After compilation Once all objects have been compiled, they will be collected into a build library ("blib") in <tt>bin/blib.a</tt>. @subsection comp_custom Customising compilation The Makefile rules for a particular object can be customised to a certain extent by defining the Makefile variable CFLAGS_@<object@>. For example, if you were to set @code CFLAGS_rtl8139 = -DFOO @endcode then <tt>bin/rtl8139.o</tt> would be compiled with the additional flags <tt>-DFOO</tt>. To see the flags that will be used when compiling a particular object, you can use e.g. @code make bin/rtl8139.flags @endcode If you need more flexibility than the CFLAGS_@<object@> mechanism provides, then you can exclude source files from the automatic rule generation process by listing them in the Makefile variable #NON_AUTO_SRCS. The command @code make autosrcs @endcode will show you which files are currently part of the automatic rule generation process. @subsection comp_multiobj Multiple objects A single source file can be used to generate multiple object files. This is used, for example, to generate the decompressing and the non-decompressing prefixes from the same source files. By default, a single object will be built from each source file. To override the list of objects for a source file, you can define the Makefile variable OBJS_@<object@>. For example, the <tt>arch/i386/prefix/dskprefix.S</tt> source file is built into two objects, <tt>bin/dskprefix.o</tt> and <tt>zdskprefix.o</tt> by defining the Makefile variable @code OBJS_dskprefix = dskprefix zdskprefix @endcode Since there would be little point in building two identical objects, customised compilation flags (see @ref comp_custom) are defined as @code CFLAGS_zdskprefix = -DCOMPRESS @endcode Thus, <tt>arch/i386/prefix/dskprefix.S</tt> is built into @c dskprefix.o using the normal set of flags, and into @c zdskprefix.o using the normal set of flags plus <tt>-DCOMPRESS</tt>. @subsection comp_debug Special debugging targets In addition to the basic rules #RULE_c and #RULE_S for compiling source files into object files, there are various other rules that can be useful for debugging. @subsubsection comp_debug_c_to_c Preprocessed C You can see the results of preprocessing a @c .c file (including the per-object flags defined via CFLAGS_@<object@> if applicable) using e.g. @code make bin/rtl8139.c @endcode and examining the resulting file (<tt>bin/rtl8139.c</tt> in this case). @subsubsection comp_debug_x_to_s Assembler You can see the results of assembling a @c .c file, or of preprocessing a @c .S file, using e.g. @code make bin/rtl8139.s make bin/zdskprefix.s @endcode @subsubsection comp_debug_dbg Debugging-enabled targets You can build targets with debug messages (DBG()) enabled using e.g. @code make bin/rtl8139.dbg.o make bin/rtl8139.dbg2.o @endcode You will probably not need to use these targets directly, since a mechanism exists to select debugging levels at build time; see @ref debug. @section linking Linking @subsection link_overview Overview Etherboot is designed to be small and extremely customisable. This is achieved by linking in only the features that are really wanted in any particular build. There are two places from which the list of desired features is obtained: -# @ref link_config_h -# @ref link_cmdline @subsection link_config_h config.h The config.h file is used to define global build options that are likely to apply to all images that you build, such as the console types, supported download protocols etc. See the documentation for config.h for more details. @subsection link_cmdline The make command line When you type a command such as @code make bin/dfe538.zrom @endcode it is used to derive the following information: - We are building a compressed ROM image - The DFE538 is a PCI NIC, so we need the decompressing PCI ROM prefix - The PCI IDs for the DFE538 are 1186:1300 - The DFE538 is an rtl8139-based card, therefore we need the rtl8139 driver You can see this process in action using the command @code make bin/dfe538.zrom.info @endcode which will print @code Elements : dfe538 Prefix : zrom Drivers : rtl8139 ROM name : dfe538 Media : rom ROM type : pci PCI vendor : 0x1186 PCI device : 0x1300 LD driver symbols : obj_rtl8139 LD prefix symbols : obj_zpciprefix LD ID symbols : pci_vendor_id=0x1186 pci_device_id=0x1300 LD target flags : -u obj_zpciprefix --defsym check_obj_zpciprefix=obj_zpciprefix -u obj_rtl8139 --defsym check_obj_rtl8139=obj_rtl8139 -u obj_config --defsym check_obj_config=obj_config --defsym pci_vendor_id=0x1186 --defsym pci_device_id=0x1300 @endcode This should be interpreted as follows: @code Elements : dfe538 Prefix : zrom @endcode "Elements" is the list of components preceding the first dot in the target name. "Prefix" is the component following the first dot in the target name. (It's called a "prefix" because the code that makes it a @c .zrom (rather than a @c .dsk, @c .zpxe or any other type of target) usually ends up at the start of the resulting binary image.) @code Drivers : rtl8139 @endcode "Drivers" is the list of drivers corresponding to the "Elements". Most drivers support several network cards. The PCI_ROM() and ISA_ROM() macros are used in the driver source files to list the cards that a particular driver can support. @code ROM name : dfe538 @endcode "ROM name" is the first element in the "Elements" list. It is used to select the PCI IDs for a PCI ROM. @code Media : rom @endcode "Media" is the "Prefix" minus the leading @c z, if any. @code ROM type : pci PCI vendor : 0x1186 PCI device : 0x1300 @endcode These are derived from the "ROM name" and the PCI_ROM() or ISA_ROM() macros in the driver source files. @code LD driver symbols : obj_rtl8139 LD prefix symbols : obj_zpciprefix @endcode This is the interesting part. At this point, we have established that we need the rtl8139 driver (i.e. @c rtl8139.o) and the decompressing PCI prefix (i.e. @c zpciprefix.o). Our build system (via the compiler.h header file) arranges that every object exports a symbol obj_@<object@>; this can be seen by e.g. @code objdump -t bin/rtl8139.o @endcode which will show the line @code 00000000 g *ABS* 00000000 obj_rtl8139 @endcode By instructing the linker that we need the symbols @c obj_rtl8139 and @c obj_zpciprefix, we can therefore ensure that these two objects are included in our build. (The linker will also include any objects that these two objects require, since that's the whole purpose of the linker.) In a similar way, we always instruct the linker that we need the symbol @c obj_config, in order to include the object @c config.o. @c config.o is used to drag in the objects that were specified via config.h; see @ref link_config_h. @code LD target flags : -u obj_zpciprefix --defsym check_obj_zpciprefix=obj_zpciprefix -u obj_rtl8139 --defsym check_obj_rtl8139=obj_rtl8139 -u obj_config --defsym check_obj_config=obj_config --defsym pci_vendor_id=0x1186 --defsym pci_device_id=0x1300 @endcode These are the flags that we pass to the linker in order to include the objects that we want in our build, and to check that they really get included. (This latter check is needed to work around what seems to be a bug in @c ld). The linker does its job of linking all the required objects together into a coherent build. The best way to see what is happening is to look at one of the resulting linker maps; try, for example @code make bin/dfe538.dsk.map @endcode The linker map includes, amongst others: - A list of which objects are included in the build, and why. - The results of processing the linker script, line-by-line. - A complete symbol table of the resulting build. It is worth spending time examining the linker map to see how an Etherboot image is assembled. Whatever format is selected, the Etherboot image is built into an ELF file, simply because this is the default format used by @c ld. @section finalisation Finalisation @subsection final_overview Overview The ELF file resulting from @ref linking "linking" needs to be converted into the final binary image. Usually, this is just a case of running @code objcopy -O binary <elf file> <output file> @endcode to convert the ELF file into a raw binary image. Certain image formats require special additional treatment. @subsection final_rom ROM images ROM images must be rounded up to a suitable ROM size (e.g. 16kB or 32kB), and certain header information such as checksums needs to be filled in. This is done by the @c makerom.pl program. @section debug Debugging-enabled builds */


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