freebsd-dev/stand/i386/Makefile.inc
Ed Maste bcf99d2d99 Add WITH_PIE knob to build Position Independent Executables
Building binaries as PIE allows the executable itself to be loaded at a
random address when ASLR is enabled (not just its shared libraries).

With this change PIE objects have a .pieo extension and INTERNALLIB
libraries libXXX_pie.a.

MK_PIE is disabled for some kerberos5 tools, Clang, and Subversion, as
they explicitly reference .a libraries in their Makefiles.  These can
be addressed on an individual basis later.  MK_PIE is also disabled for
rtld-elf because it is already position-independent using bespoke
Makefile rules.

Currently only dynamically linked binaries will be built as PIE.

Discussed with:	dim
Reviewed by:	kib
MFC after:	1 month
Relnotes:	Yes
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D18423
2019-02-15 22:22:38 +00:00

43 lines
1016 B
Makefile

# Common defines for all of stand/i386/
#
# $FreeBSD$
.include "bsd.linker.mk"
LOADER_ADDRESS?=0x200000
LDFLAGS+= -nostdlib
LDFLAGS.lld+= -Wl,--no-rosegment
MK_PIE:= no
# BTX components
BTXDIR= ${BOOTOBJ}/i386/btx
BTXLDR= ${BTXDIR}/btxldr/btxldr
BTXKERN= ${BTXDIR}/btx/btx
BTXCRT= ${BTXDIR}/lib/crt0.o
BTXSRC= ${BOOTSRC}/i386/btx
BTXLIB= ${BTXSRC}/lib
CFLAGS+= -I${BTXLIB}
# compact binary with no padding between text, data, bss
LDSCRIPT= ${BOOTSRC}/i386/boot.ldscript
# LDFLAGS_BIN=-e start -Ttext ${ORG} -Wl,-T,${LDSCRIPT},-S,--oformat,binary
# LD_FLAGS_BIN=-static -T ${LDSCRIPT} --gc-sections
LDFLAGS_BIN=-e start -Ttext ${ORG} -Wl,-N,-S,--oformat,binary
.if ${LINKER_FEATURES:Mbuild-id} != ""
LDFLAGS_BIN+=-Wl,--build-id=none
.endif
LD_FLAGS_BIN=-static -N --gc-sections
.if ${MACHINE_CPUARCH} == "amd64"
DO32=1
.endif
.if defined(LOADER_FIREWIRE_SUPPORT)
MK_LOADER_FIREWIRE=yes
.warning "LOADER_FIREWIRE_SUPPORT deprecated, please move to WITH_LOADER_FIREWIRE"
.endif
.include "../Makefile.inc"