###
  # This makefile is used to generate the kernel documentation,
  # primarily based on in-line comments in various source files.
  # See Documentation/kernel-doc-nano-HOWTO.txt for instruction in how

  # to document the SRC - and how to read it.

  # To add a new book the only step required is to add the book to the
  # list of DOCBOOKS.

  DOCBOOKS := z8530book.xml mcabook.xml device-drivers.xml \

  	    kernel-hacking.xml kernel-locking.xml deviceiobook.xml \

  	    writing_usb_driver.xml networking.xml \

  	    kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \

  	    gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \

  	    genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \

  	    80211.xml debugobjects.xml sh.xml regulator.xml \

  	    alsa-driver-api.xml writing-an-alsa-driver.xml \

  	    tracepoint.xml drm.xml media_api.xml
  
  include $(srctree)/Documentation/DocBook/media/Makefile

  
  ###
  # The build process is as follows (targets):

  #              (xmldocs) [by docproc]
  # file.tmpl --> file.xml +--> file.ps   (psdocs)   [by db2ps or xmlto]
  #                        +--> file.pdf  (pdfdocs)  [by db2pdf or xmlto]
  #                        +--> DIR=file  (htmldocs) [by xmlto]
  #                        +--> man/      (mandocs)  [by xmlto]

  
  # for PDF and PS output you can choose between xmlto and docbook-utils tools
  PDF_METHOD	= $(prefer-db2x)
  PS_METHOD	= $(prefer-db2x)

  ###
  # The targets that may be used.

  PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs cleandocs

  
  BOOKS := $(addprefix $(obj)/,$(DOCBOOKS))

  xmldocs: $(BOOKS)

  sgmldocs: xmldocs
  
  PS := $(patsubst %.xml, %.ps, $(BOOKS))
  psdocs: $(PS)
  
  PDF := $(patsubst %.xml, %.pdf, $(BOOKS))
  pdfdocs: $(PDF)

  HTML := $(sort $(patsubst %.xml, %.html, $(BOOKS)))

  htmldocs: $(HTML)

  	$(call build_main_index)

  	$(call build_images)

  	$(call install_media_images)

  
  MAN := $(patsubst %.xml, %.9, $(BOOKS))
  mandocs: $(MAN)
  
  installmandocs: mandocs

  	mkdir -p /usr/local/man/man9/
  	install Documentation/DocBook/man/*.9.gz /usr/local/man/man9/

  
  ###
  #External programs used

  KERNELDOC = $(srctree)/scripts/kernel-doc

  DOCPROC   = $(objtree)/scripts/docproc

  XMLTOFLAGS = -m $(srctree)/Documentation/DocBook/stylesheet.xsl

  XMLTOFLAGS += --skip-validation

  
  ###
  # DOCPROC is used for two purposes:
  # 1) To generate a dependency list for a .tmpl file
  # 2) To preprocess a .tmpl file and call kernel-doc with
  #     appropriate parameters.
  # The following rules are used to generate the .xml documentation
  # required to generate the final targets. (ps, pdf, html).
  quiet_cmd_docproc = DOCPROC $@
        cmd_docproc = SRCTREE=$(srctree)/ $(DOCPROC) doc $< >$@
  define rule_docproc
  	set -e;								\
          $(if $($(quiet)cmd_$(1)),echo '  $($(quiet)cmd_$(1))';) 	\
          $(cmd_$(1)); 							\
          ( 								\
            echo 'cmd_$@ := $(cmd_$(1))'; 				\
            echo $@: `SRCTREE=$(srctree) $(DOCPROC) depend $<`; 		\
          ) > $(dir $@).$(notdir $@).cmd
  endef

  %.xml: %.tmpl FORCE

  	$(call if_changed_rule,docproc)
  
  ###

  #Read in all saved dependency files

  cmd_files := $(wildcard $(foreach f,$(BOOKS),$(dir $(f)).$(notdir $(f)).cmd))
  
  ifneq ($(cmd_files),)
    include $(cmd_files)
  endif
  
  ###
  # Changes in kernel-doc force a rebuild of all documentation
  $(BOOKS): $(KERNELDOC)

  # Tell kbuild to always build the programs
  always := $(hostprogs-y)

  notfoundtemplate = echo "*** You have to install docbook-utils or xmlto ***"; \
  		   exit 1
  db2xtemplate = db2TYPE -o $(dir $@) $<
  xmltotemplate = xmlto TYPE $(XMLTOFLAGS) -o $(dir $@) $<
  
  # determine which methods are available
  ifeq ($(shell which db2ps >/dev/null 2>&1 && echo found),found)
  	use-db2x = db2x
  	prefer-db2x = db2x
  else
  	use-db2x = notfound
  	prefer-db2x = $(use-xmlto)
  endif
  ifeq ($(shell which xmlto >/dev/null 2>&1 && echo found),found)
  	use-xmlto = xmlto
  	prefer-xmlto = xmlto
  else
  	use-xmlto = notfound
  	prefer-xmlto = $(use-db2x)
  endif

  # the commands, generated from the chosen template
  quiet_cmd_db2ps = PS      $@
        cmd_db2ps = $(subst TYPE,ps, $($(PS_METHOD)template))

  %.ps : %.xml

  	$(call cmd,db2ps)

  quiet_cmd_db2pdf = PDF     $@

        cmd_db2pdf = $(subst TYPE,pdf, $($(PDF_METHOD)template))

  %.pdf : %.xml

  	$(call cmd,db2pdf)

  index = index.html
  main_idx = Documentation/DocBook/$(index)

  build_main_index = rm -rf $(main_idx); \

  		   echo '<h1>Linux Kernel HTML Documentation</h1>' >> $(main_idx) && \
  		   echo '<h2>Kernel Version: $(KERNELVERSION)</h2>' >> $(main_idx) && \
  		   cat $(HTML) >> $(main_idx)

  quiet_cmd_db2html = HTML    $@

        cmd_db2html = xmlto xhtml $(XMLTOFLAGS) -o $(patsubst %.html,%,$@) $< && \

  		echo '<a HREF="$(patsubst %.html,%,$(notdir $@))/index.html"> \

          $(patsubst %.html,%,$(notdir $@))</a><p>' > $@

  
  %.html:	%.xml

  	@(which xmlto > /dev/null 2>&1) || \

  	 (echo "*** You need to install xmlto ***"; \

  	  exit 1)
  	@rm -rf $@ $(patsubst %.html,%,$@)
  	$(call cmd,db2html)
  	@if [ ! -z "$(PNG-$(basename $(notdir $@)))" ]; then \
              cp $(PNG-$(basename $(notdir $@))) $(patsubst %.html,%,$@); fi

  quiet_cmd_db2man = MAN     $@

        cmd_db2man = if grep -q refentry $<; then xmlto man $(XMLTOFLAGS) -o $(obj)/man $< ; gzip -f $(obj)/man/*.9; fi
  %.9 : %.xml
  	@(which xmlto > /dev/null 2>&1) || \

  	 (echo "*** You need to install xmlto ***"; \

  	  exit 1)

  	$(Q)mkdir -p $(obj)/man

  	$(call cmd,db2man)
  	@touch $@

  
  ###

  # Rules to generate postscripts and PNG images from .fig format files

  quiet_cmd_fig2eps = FIG2EPS $@
        cmd_fig2eps = fig2dev -Leps $< $@
  
  %.eps: %.fig
  	@(which fig2dev > /dev/null 2>&1) || \
  	 (echo "*** You need to install transfig ***"; \
  	  exit 1)
  	$(call cmd,fig2eps)
  
  quiet_cmd_fig2png = FIG2PNG $@
        cmd_fig2png = fig2dev -Lpng $< $@
  
  %.png: %.fig
  	@(which fig2dev > /dev/null 2>&1) || \
  	 (echo "*** You need to install transfig ***"; \
  	  exit 1)
  	$(call cmd,fig2png)
  
  ###
  # Rule to convert a .c file to inline XML documentation

         gen_xml = :
   quiet_gen_xml = echo '  GEN     $@'
  silent_gen_xml = :

  %.xml: %.c

  	@$($(quiet)gen_xml)

  	@(                            \
  	   echo "<programlisting>";   \
  	   expand --tabs=8 < $< |     \
  	   sed -e "s/&/\\&amp;/g"     \
  	       -e "s/</\\&lt;/g"      \
  	       -e "s/>/\\&gt;/g";     \
  	   echo "</programlisting>")  > $@
  
  ###
  # Help targets as used by the top-level makefile
  dochelp:

  	@echo  ' Linux kernel internal documentation in different formats:'
  	@echo  '  htmldocs        - HTML'

  	@echo  '  pdfdocs         - PDF'
  	@echo  '  psdocs          - Postscript'
  	@echo  '  xmldocs         - XML DocBook'

  	@echo  '  mandocs         - man pages'
  	@echo  '  installmandocs  - install man pages generated by mandocs'
  	@echo  '  cleandocs       - clean all generated DocBook files'

  
  ###
  # Temporary files left by various tools
  clean-files := $(DOCBOOKS) \
  	$(patsubst %.xml, %.dvi,  $(DOCBOOKS)) \
  	$(patsubst %.xml, %.aux,  $(DOCBOOKS)) \
  	$(patsubst %.xml, %.tex,  $(DOCBOOKS)) \
  	$(patsubst %.xml, %.log,  $(DOCBOOKS)) \
  	$(patsubst %.xml, %.out,  $(DOCBOOKS)) \
  	$(patsubst %.xml, %.ps,   $(DOCBOOKS)) \
  	$(patsubst %.xml, %.pdf,  $(DOCBOOKS)) \
  	$(patsubst %.xml, %.html, $(DOCBOOKS)) \
  	$(patsubst %.xml, %.9,    $(DOCBOOKS)) \

  	$(index)

  clean-dirs := $(patsubst %.xml,%,$(DOCBOOKS)) man

  cleandocs: cleanmediadocs

  	$(Q)rm -f $(call objectify, $(clean-files))
  	$(Q)rm -rf $(call objectify, $(clean-dirs))

  # Declare the contents of the .PHONY variable as phony.  We keep that
  # information in a variable se we can use it in if_changed and friends.
  
  .PHONY: $(PHONY)