netbsd-src

History

mrg 2026b7285b update my email address.		2024-02-04 05:43:05 +00:00
..
amd64/i386	add LIBGCC_MACHINE_ARCH	2016-10-22 20:33:51 +00:00
arm	compat: Disable relro in 32-bit arm compat.	2023-05-13 10:56:54 +00:00
dirshack	compat: Nix trailing whitespace.	2023-05-13 10:56:08 +00:00
mips64	define BFD_MACHINE_ARCH. This worked by accident before since the default	2021-04-25 18:44:04 +00:00
powerpc64/powerpc	Support building the xorg X11 libraries under MKCOMPAT.	2015-06-24 22:20:24 +00:00
riscv64/rv32	- various updates for GCC 7 riscv definitions: -mabi and -march changed	2019-04-18 10:07:07 +00:00
sparc64/sparc	Support building the xorg X11 libraries under MKCOMPAT.	2015-06-24 22:20:24 +00:00
Makefile	fix various typos in comments and log messages.	2022-05-29 10:47:39 +00:00
Makefile.compat	…
README	update my email address.	2024-02-04 05:43:05 +00:00
archdirs.mk	Good bye oabi! Tested building earmv7hf.	2021-06-07 17:11:16 +00:00
compatsubdir.mk	remove the xfree86 reachover makefiles and the vast majority of	2015-07-23 08:03:24 +00:00
exec.mk	compat: Nix trailing whitespace.	2023-05-13 10:56:08 +00:00
m32.mk	…

README

$NetBSD: README,v 1.9 2024/02/04 05:43:05 mrg 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@eterna23.net
december 2009