README
1$NetBSD: README,v 1.9 2021/07/12 07:59:51 mrg Exp $
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3GMP in NetBSD. We need GMP for GCC >= 4.2.
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6Building GMP without configure - how to port GMP build to a new platform.
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8The GMP build doesn't map very well to normal make. The ./configure phase
9creates a bunch of symlinks and weeds out the sources lists, and there are
10files with the same name in different subdirectories linked into the same
11final product. All of these issues need to be dealt with.
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13There is a mostly-working "mknative" for GMP now. If this fails, see the
14section below for the old instructions.
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16 - run a "./build tools libs", possibly setting MKGCC=no if the
17 GMP port is currently not working at all.
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19 - cd to tools/gmp, and run $TOOLDIR/bin/nbmake-$arch native-gmp
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21 - if that works, commit the files it changed in the source tree.
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23 - set NEWCONFIGDIR=/writeable/src if eg /usr/src is read-only.
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25These are the old steps, that maybe are necessary to fix the automated
26output:
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28 - run ./configure, save the output. you can use the makefile
29 "Makefile.netbsd-gmp" in this directory to run this with the
30 right options, etc. run it with nbmake-$MACHINE.
31
32 - create src/external/gpl3/gmp/lib/libgmp/arch/${MACHINE_ARCH} dir,
33 and copy these files into it:
34 config.h
35 config.m4
36 gmp-mparam.h
37 gmp.h
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39 some of these files might have src/obj references. in particular
40 fix GMP_MPARAM_H_SUGGEST to start from ./mpn/... and make sure
41 we #define __GMP_CC to just "gcc", and make sure that
42 CONFIG_TOP_SRCDIR is not defined in config.m4
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44 the "Makefile.netbsd-gmp" has a "copy-files" target that performs
45 these tasks.
46
47 - parse the ./configure output and note all created symlinks
48 for mpn. these need to be converted into a new Makefile.inc.
49 there is a script in this subdir build-gmp-Makefile.inc.awk
50 that can be used to do this. it should just work to generate
51 the first section of Makefile.inc if fed the entire configure
52 output.
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54 assembler files generally want -DOPERATION_${foo} defined for
55 each way they are compiled or pre-processed. the pre-processor
56 used is m4 to parse, and we and create .s files from the .asm
57 files that we then we feed into $CC.
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59 this part needs to be automated, but requires that the first
60 part's ./configure output be stored for it. this is not done.
61
62 it would be good to convert the Makefile.inc into a pair of
63 files -- srcs.mk generated from build-gmp-Makefile.inc.awk, and
64 the remaining static part of the Makefile.inc left with the
65 include of srcs.mk.
66
67The amd64 port is a good reference to compare.
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70mrg@netbsd.org
71- 2021/07/11
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