RE: [ECOS] linking & cdl question

["Andy Dyer" <adyer at righthandtech dot com>]

> -----Original Message-----
> From: ecos-discuss-owner@sources.redhat.com
> [mailto:ecos-discuss-owner@sources.redhat.com]On Behalf Of Andy Dyer
> Sent: Saturday, July 19, 2003 8:00 PM
> To: ecos-discuss@sources.redhat.com
> Subject: [ECOS] linking & cdl question
> 
> 
> I have some Xilinx fpga configuration data used in my hal startup
> that I want to link into my ROM redboot images, but not in the RAM
> versions since presumably redboot has already dealt with the
> configuration at startup.
> 
> I have managed to get the raw binary data file into an
> elf .o file with a .rodata section and some symbols defining
> the start and end, but I'm not sure how to reference it in
> cdl and get it linked.
> 
> a couple of questions:
> 
> would it make sense to put it into the main library or should 
> it go into extras (will the rodata section get removed if
> there is no reference to the start and end symbols)?
> 
> How do i just specify a .o file to link with no build rule?
> 
> Would it be easier to have a make rule somewhere to say
> how to make the .o file from a raw binary file?
> How does one go about this?

For the sake of the archives, I managed to get this done by
defining a make rule in the cdl to add the .o file to the
library after it's built with ar.  Gentle suggestions on
making it less ugly would be appreciated.

	# custom build rule to add the fpga data into the libtarget.a 
	# library after its built in the .rodata section
	# 
	# FIXME - this is mostly just pure evil
	#
	# objcopy is forced to run from the source dir
	# because it creates symbols for the start and end of the data
	# (which we use) with the source filename (including path) 
	# embedded in it.  By running it in the source directory
	# we force the symbols to always be named the same no
	# matter where the source tree is
	#
	# $(shell pwd) gives a non-zero return code under cygwin
	# for some reason, so it's prefixed with a '-'
	#
	# objcopy doesn't like to overwrite it's output file so we
	# remove it by force

	make -priority 201 {
        spartan2_top.o : <PACKAGE>/src/spartan2_top.bin
		-CURDIR = $(shell pwd)
		@rm -f $@
		cd $(<D) ; \
	      $(OBJCOPY) -I binary -O elf32-littlemips \
	          --rename-section
.data=.rodata,alloc,load,readonly,data,contents \
              $(<F) $(CURDIR)/$@
		$(AR) rcs $(PREFIX)/lib/libtarget.a $@
    }





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