freebsd-dev/sys/conf/kern.mk
Ruslan Bukin 28029b68c0 Welcome the RISC-V 64-bit kernel.
This is the final step required allowing to compile and to run RISC-V
kernel and userland from HEAD.

RISC-V is a completely open ISA that is freely available to academia
and industry.

Thanks to all the people involved! Special thanks to Andrew Turner,
David Chisnall, Ed Maste, Konstantin Belousov, John Baldwin and
Arun Thomas for their help.
Thanks to Robert Watson for organizing this project.

This project sponsored by UK Higher Education Innovation Fund (HEIF5) and
DARPA CTSRD project at the University of Cambridge Computer Laboratory.

FreeBSD/RISC-V project home: https://wiki.freebsd.org/riscv

Reviewed by:	andrew, emaste, kib
Relnotes:	Yes
Sponsored by:	DARPA, AFRL
Sponsored by:	HEIF5
Differential Revision:	https://reviews.freebsd.org/D4982
2016-01-29 15:12:31 +00:00

234 lines
7.8 KiB
Makefile

# $FreeBSD$
#
# Warning flags for compiling the kernel and components of the kernel:
#
CWARNFLAGS?= -Wall -Wredundant-decls -Wnested-externs -Wstrict-prototypes \
-Wmissing-prototypes -Wpointer-arith -Winline -Wcast-qual \
-Wundef -Wno-pointer-sign ${FORMAT_EXTENSIONS} \
-Wmissing-include-dirs -fdiagnostics-show-option \
-Wno-unknown-pragmas \
${CWARNEXTRA}
#
# The following flags are next up for working on:
# -Wextra
# Disable a few warnings for clang, since there are several places in the
# kernel where fixing them is more trouble than it is worth, or where there is
# a false positive.
.if ${COMPILER_TYPE} == "clang"
NO_WCONSTANT_CONVERSION= -Wno-constant-conversion
NO_WSHIFT_COUNT_NEGATIVE= -Wno-shift-count-negative
NO_WSHIFT_COUNT_OVERFLOW= -Wno-shift-count-overflow
NO_WSELF_ASSIGN= -Wno-self-assign
NO_WUNNEEDED_INTERNAL_DECL= -Wno-unneeded-internal-declaration
NO_WSOMETIMES_UNINITIALIZED= -Wno-error-sometimes-uninitialized
NO_WCAST_QUAL= -Wno-cast-qual
# Several other warnings which might be useful in some cases, but not severe
# enough to error out the whole kernel build. Display them anyway, so there is
# some incentive to fix them eventually.
CWARNEXTRA?= -Wno-error-tautological-compare -Wno-error-empty-body \
-Wno-error-parentheses-equality -Wno-error-unused-function \
-Wno-error-pointer-sign
.if ${COMPILER_VERSION} >= 30700
CWARNEXTRA+= -Wno-error-shift-negative-value
.endif
CLANG_NO_IAS= -no-integrated-as
.if ${COMPILER_VERSION} < 30500
# XXX: clang < 3.5 integrated-as doesn't grok .codeNN directives
CLANG_NO_IAS34= -no-integrated-as
.endif
.endif
.if ${COMPILER_TYPE} == "gcc"
.if ${COMPILER_VERSION} >= 40300
# Catch-all for all the things that are in our tree, but for which we're
# not yet ready for this compiler. Note: we likely only really "support"
# building with gcc 4.8 and newer. Nothing older has been tested.
CWARNEXTRA?= -Wno-error=inline -Wno-error=enum-compare -Wno-error=unused-but-set-variable \
-Wno-error=aggressive-loop-optimizations -Wno-error=maybe-uninitialized \
-Wno-error=array-bounds -Wno-error=address \
-Wno-error=cast-qual -Wno-error=sequence-point -Wno-error=attributes \
-Wno-error=strict-overflow -Wno-error=overflow
.else
# For gcc 4.2, eliminate the too-often-wrong warnings about uninitialized vars.
CWARNEXTRA?= -Wno-uninitialized
.endif
.endif
# External compilers may not support our format extensions. Allow them
# to be disabled. WARNING: format checking is disabled in this case.
.if ${MK_FORMAT_EXTENSIONS} == "no"
FORMAT_EXTENSIONS= -Wno-format
.elif ${COMPILER_TYPE} == "clang" && ${COMPILER_VERSION} >= 30600
FORMAT_EXTENSIONS= -D__printf__=__freebsd_kprintf__
.else
FORMAT_EXTENSIONS= -fformat-extensions
.endif
#
# On i386, do not align the stack to 16-byte boundaries. Otherwise GCC 2.95
# and above adds code to the entry and exit point of every function to align the
# stack to 16-byte boundaries -- thus wasting approximately 12 bytes of stack
# per function call. While the 16-byte alignment may benefit micro benchmarks,
# it is probably an overall loss as it makes the code bigger (less efficient
# use of code cache tag lines) and uses more stack (less efficient use of data
# cache tag lines). Explicitly prohibit the use of FPU, SSE and other SIMD
# operations inside the kernel itself. These operations are exclusively
# reserved for user applications.
#
# gcc:
# Setting -mno-mmx implies -mno-3dnow
# Setting -mno-sse implies -mno-sse2, -mno-sse3 and -mno-ssse3
#
# clang:
# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa
# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42
#
.if ${MACHINE_CPUARCH} == "i386"
CFLAGS.gcc+= -mno-align-long-strings -mpreferred-stack-boundary=2
CFLAGS.clang+= -mno-aes -mno-avx
CFLAGS+= -mno-mmx -mno-sse -msoft-float
INLINE_LIMIT?= 8000
.endif
.if ${MACHINE_CPUARCH} == "arm"
INLINE_LIMIT?= 8000
.endif
.if ${MACHINE_CPUARCH} == "aarch64"
# We generally don't want fpu instructions in the kernel.
CFLAGS += -mgeneral-regs-only
# Reserve x18 for pcpu data
CFLAGS += -ffixed-x18
.endif
.if ${MACHINE_CPUARCH} == "riscv"
INLINE_LIMIT?= 8000
.endif
#
# For sparc64 we want the medany code model so modules may be located
# anywhere in the 64-bit address space. We also tell GCC to use floating
# point emulation. This avoids using floating point registers for integer
# operations which it has a tendency to do.
#
.if ${MACHINE_CPUARCH} == "sparc64"
CFLAGS.clang+= -mcmodel=large -fno-dwarf2-cfi-asm
CFLAGS.gcc+= -mcmodel=medany -msoft-float
INLINE_LIMIT?= 15000
.endif
#
# For AMD64, we explicitly prohibit the use of FPU, SSE and other SIMD
# operations inside the kernel itself. These operations are exclusively
# reserved for user applications.
#
# gcc:
# Setting -mno-mmx implies -mno-3dnow
# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3 and -mfpmath=387
#
# clang:
# Setting -mno-mmx implies -mno-3dnow and -mno-3dnowa
# Setting -mno-sse implies -mno-sse2, -mno-sse3, -mno-ssse3, -mno-sse41 and -mno-sse42
# (-mfpmath= is not supported)
#
.if ${MACHINE_CPUARCH} == "amd64"
CFLAGS.clang+= -mno-aes -mno-avx
CFLAGS+= -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -msoft-float \
-fno-asynchronous-unwind-tables
INLINE_LIMIT?= 8000
.endif
#
# For PowerPC we tell gcc to use floating point emulation. This avoids using
# floating point registers for integer operations which it has a tendency to do.
# Also explicitly disable Altivec instructions inside the kernel.
#
.if ${MACHINE_CPUARCH} == "powerpc"
CFLAGS+= -mno-altivec
CFLAGS.clang+= -mllvm -disable-ppc-float-in-variadic=true
CFLAGS.gcc+= -msoft-float
INLINE_LIMIT?= 15000
.endif
#
# Use dot symbols on powerpc64 to make ddb happy
#
.if ${MACHINE_ARCH} == "powerpc64"
CFLAGS.gcc+= -mcall-aixdesc
.endif
#
# For MIPS we also tell gcc to use floating point emulation
#
.if ${MACHINE_CPUARCH} == "mips"
CFLAGS+= -msoft-float
INLINE_LIMIT?= 8000
.endif
#
# GCC 3.0 and above like to do certain optimizations based on the
# assumption that the program is linked against libc. Stop this.
#
CFLAGS+= -ffreestanding
#
# The C standard leaves signed integer overflow behavior undefined.
# gcc and clang opimizers take advantage of this. The kernel makes
# use of signed integer wraparound mechanics so we need the compiler
# to treat it as a wraparound and not take shortcuts.
#
CFLAGS+= -fwrapv
#
# GCC SSP support
#
.if ${MK_SSP} != "no" && \
${MACHINE_CPUARCH} != "arm" && ${MACHINE_CPUARCH} != "mips"
CFLAGS+= -fstack-protector
.endif
#
# Add -gdwarf-2 when compiling -g. The default starting in clang v3.4
# and gcc 4.8 is to generate DWARF version 4. However, our tools don't
# cope well with DWARF 4, so force it to genereate DWARF2, which they
# understand. Do this unconditionally as it is harmless when not needed,
# but critical for these newer versions.
#
.if ${CFLAGS:M-g} != "" && ${CFLAGS:M-gdwarf*} == ""
CFLAGS+= -gdwarf-2
.endif
CFLAGS+= ${CWARNFLAGS} ${CWARNFLAGS.${.IMPSRC:T}}
CFLAGS+= ${CFLAGS.${COMPILER_TYPE}} ${CFLAGS.${.IMPSRC:T}}
# Tell bmake not to mistake standard targets for things to be searched for
# or expect to ever be up-to-date.
PHONY_NOTMAIN = afterdepend afterinstall all beforedepend beforeinstall \
beforelinking build build-tools buildfiles buildincludes \
checkdpadd clean cleandepend cleandir cleanobj configure \
depend dependall distclean distribute exe \
html includes install installfiles installincludes lint \
obj objlink objs objwarn realall realdepend \
realinstall regress subdir-all subdir-depend subdir-install \
tags whereobj
.PHONY: ${PHONY_NOTMAIN}
.NOTMAIN: ${PHONY_NOTMAIN}
CSTD= c99
.if ${CSTD} == "k&r"
CFLAGS+= -traditional
.elif ${CSTD} == "c89" || ${CSTD} == "c90"
CFLAGS+= -std=iso9899:1990
.elif ${CSTD} == "c94" || ${CSTD} == "c95"
CFLAGS+= -std=iso9899:199409
.elif ${CSTD} == "c99"
CFLAGS+= -std=iso9899:1999
.else # CSTD
CFLAGS+= -std=${CSTD}
.endif # CSTD