Index of /pub/NetBSD/NetBSD-release-10/src/compat

Icon  Name                               Last modified      Size  Description
[PARENTDIR] Parent Directory                                        -   
[DIR] sparc64/                           2022-12-18 05:30    -   
[DIR] riscv64/                           2022-12-18 05:30    -   
[DIR] powerpc64/                         2022-12-18 05:30    -   
[DIR] mips64/                            2022-12-18 05:30    -   
[   ] m32.mk                             2011-06-18 10:22  313   
[TXT] exec.mk                            2021-05-31 11:10  1.4K  
[DIR] dirshack/                          2022-12-18 05:30    -   
[   ] compatsubdir.mk                    2015-07-23 17:03  1.0K  
[DIR] arm/                               2024-11-02 12:23    -   
[   ] archdirs.mk                        2021-06-08 02:11  773   
[DIR] amd64/                             2022-12-18 05:30    -   
[TXT] README                             2012-03-30 03:35  2.3K  
[TXT] Makefile.compat                    2012-08-24 06:21  852   
[   ] Makefile                           2022-05-29 19:47  288   
[DIR] CVS/                               2024-11-02 12:23    -   

$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