NetBSD

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mrg 0537635d0c for 64 bit mips platforms where we built userland largely as n32 by default, build a handful of tools as n64 so they work properly. unfortunately, they're also static as dynamic n64 has a problem. of these tools pstat is probably the lowest hanging fruit to convert to sysctl. systat would be close were it not for the netstat screen, which includes netstat itself. the rest are difficult to perhaps foolish. the upside is that netstat, pmap and fstat all work properly now.		2016-12-23 10:19:57 +00:00
..
amd64/i386
arm
dirshack
mips64
powerpc64/powerpc
riscv64/rv32
sparc64/sparc
archdirs.mk
compatsubdir.mk
exec.mk	for 64 bit mips platforms where we built userland largely as n32 by	2016-12-23 10:19:57 +00:00
m32.mk
Makefile
Makefile.compat
README

README

$NetBSD: README,v 1.8 2012/03/29 18:35:11 wiz Exp $


Building multi-ABI libraries for NetBSD platforms.


src/compat has a framework to (re)build the libraries shipped with
NetBSD for a different ABI than the default for that platform.  This
allows 32-bit libraries for the amd64 and sparc64 ports, and enables
the mips64 port to support all three of old-style 32-bit ("o32"), the
new 32-bit (default, "n32", 64-bit CPU required) or the 64-bit ABI.


The basic premise is to re-set $MAKEOBJDIR to fresh subdirectory
underneath src/compat and rebuild the libraries with a different set
of options.  Each platform wanting support should create their port
subdirectory directly in src/compat, and then one subdirectory in here
for each ABI required, e.g., src/compat/amd64/i386 is where we build
the 32-bit compat libraries for the amd64 port.  In each of these
subdirectories, a small Makefile and makefile fragment should exist.  The
Makefile should set BSD_MK_COMPAT_FILE to equal the fragment, and then
include "../../compatsubdir.mk".  E.g., amd64/i386/Makefile has:

	BSD_MK_COMPAT_FILE=${.CURDIR}/bsd.i386.mk

	.include "../../compatsubdir.mk"

In the makefile fragment any changes to ABI flags are passed here
and the MLIBDIR variable must be set to the subdirectory in /usr/lib
where libraries for the ABI will be installed.  There are a couple of
helper Makefiles around.  amd64/i386/bsd.i386.mk looks like:

	LD+=			-m elf_i386
	MLIBDIR=		i386
	LIBC_MACHINE_ARCH=	${MLIBDIR}
	COMMON_MACHINE_ARCH=	${MLIBDIR}
	KVM_MACHINE_ARCH=	${MLIBDIR}
	PTHREAD_MACHINE_ARCH=	${MLIBDIR}
	BFD_MACHINE_ARCH=	${MLIBDIR}
	CSU_MACHINE_ARCH=	${MLIBDIR}
	CRYPTO_MACHINE_CPU=	${MLIBDIR}
	LDELFSO_MACHINE_CPU=	${MLIBDIR}

	.include "${NETBSDSRCDIR}/compat/m32.mk"

and the referenced m32.mk looks like:

	COPTS+=			-m32
	CPUFLAGS+=		-m32
	LDADD+=			-m32
	LDFLAGS+=		-m32
	MKDEPFLAGS+=		-m32

	.include "Makefile.compat"


compatsubdir.mk holds the list of subdirectories (the libraries and
ld.elf_so) to build with this ABI.

archdirs.mk holds the list of subdirectories for each port.

Makefile.compat has the basic framework to force the right paths for
library and ld.elf_so linkage.  It contains a hack to create subdirectories
in the build that should be fixed.

dirshack/Makefile is a hack to get objdirs created timely, and should
be fixed in a better way.



mrg@eterna.com.au
december 2009