NetBSD

History

christos 20f77b55bf 1. All Makefiles that use ARM_APCS_FLAGS add -marm unconditionally and bsd.own.mk also adds it for gcc only (so we end up with 2 -marm for gcc). Just add -marm unconditionally in bsd.own.mk in ARM_APCS_FLAGS and remove it from everywhere else. 2. gcc-8 now warns about thumb internetwork in APCS mode. This does not make sense because the documentation says that this flag does not make a difference in apcs mode, but might produce larger code in non-APCS mode. So we just add it to silence the warnings.		2019-10-24 18:46:20 +00:00
..
amd64/i386	add LIBGCC_MACHINE_ARCH	2016-10-22 20:33:51 +00:00
arm	1. All Makefiles that use ARM_APCS_FLAGS add -marm unconditionally and	2019-10-24 18:46:20 +00:00
dirshack
mips64	fix a comment.	2018-02-06 10:00:00 +00:00
powerpc64/powerpc
riscv64/rv32	- various updates for GCC 7 riscv definitions: -mabi and -march changed	2019-04-18 10:07:07 +00:00
sparc64/sparc
archdirs.mk	make all lines look the same, and put one arch per line.	2019-06-13 21:17:54 +00:00
compatsubdir.mk
exec.mk	don't build kernel grovelling tools as n64 on sgimips - we don't actually have	2018-09-20 02:51:21 +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