Start support for the RISC-V 64-bit architecture developed by UC Berkeley.

RISC-V is a new ISA designed to support computer research and education, and
is now become a standard open architecture for industry implementations.

This is a minimal set of changes required to run 'make kernel-toolchain'
using external (GNU) toolchain.

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

Reviewed by:	andrew, bdrewery, emaste, imp
Sponsored by:	DARPA, AFRL
Sponsored by:	HEIF5
Differential Revision:	https://reviews.freebsd.org/D4445

6 files changed, 26 insertions, 3 deletions

diff --git a/share/mk/bsd.cpu.mk b/share/mk/bsd.cpu.mk
index 1ab7595..d54a354 100644
--- a/share/mk/bsd.cpu.mk
+++ b/share/mk/bsd.cpu.mk
@@ -18,6 +18,8 @@ MACHINE_CPU = i486
 MACHINE_CPU = mips
 . elif ${MACHINE_CPUARCH} == "powerpc"
 MACHINE_CPU = aim
+. elif ${MACHINE_CPUARCH} == "riscv"
+MACHINE_CPU = riscv
 . elif ${MACHINE_CPUARCH} == "sparc64"
 MACHINE_CPU = ultrasparc
 . endif
@@ -148,6 +150,8 @@ _CPUCFLAGS = -march=${CPUTYPE}
 #	sb1, xlp, xlr
 _CPUCFLAGS = -march=${CPUTYPE:S/^mips//}
 . endif
+. elif ${MACHINE_CPUARCH} == "riscv"
+_CPUCFLAGS = -msoft-float # -march="RV64I" # RISCVTODO
 . elif ${MACHINE_ARCH} == "sparc64"
 .  if ${CPUTYPE} == "v9"
 _CPUCFLAGS = -mcpu=v9
@@ -277,6 +281,9 @@ MACHINE_CPU = mips
 .  if ${CPUTYPE} == "e500"
 MACHINE_CPU = booke softfp
 .  endif
+########## riscv
+. elif ${MACHINE_CPUARCH} == "riscv"
+MACHINE_CPU = riscv
 ########## sparc64
 . elif ${MACHINE_ARCH} == "sparc64"
 .  if ${CPUTYPE} == "v9"
@@ -313,6 +320,10 @@ CFLAGS += -mfloat-abi=softfp
 .endif
 .endif
 
+.if ${MACHINE_CPUARCH} == "riscv"
+CFLAGS += -msoft-float
+.endif
+
 # NB: COPTFLAGS is handled in /usr/src/sys/conf/kern.pre.mk
 
 .if !defined(NO_CPU_CFLAGS)
diff --git a/share/mk/bsd.endian.mk b/share/mk/bsd.endian.mk
index 2d1a53e..c7ec42c 100644
--- a/share/mk/bsd.endian.mk
+++ b/share/mk/bsd.endian.mk
@@ -4,6 +4,7 @@
     ${MACHINE_ARCH} == "amd64" || \
     ${MACHINE_ARCH} == "i386" || \
     (${MACHINE} == "arm" && ${MACHINE_ARCH:Marm*eb*} == "") || \
+    ${MACHINE_CPUARCH} == "riscv" || \
     ${MACHINE_ARCH:Mmips*el} != ""
 TARGET_ENDIANNESS= 1234
 .elif ${MACHINE_ARCH} == "powerpc" || \
diff --git a/share/mk/bsd.sys.mk b/share/mk/bsd.sys.mk
index 6eae174..de62195 100644
--- a/share/mk/bsd.sys.mk
+++ b/share/mk/bsd.sys.mk
@@ -109,6 +109,11 @@ CWARNFLAGS+=	-Werror
 CWARNFLAGS+=	-Wno-format
 .endif # NO_WFORMAT || NO_WFORMAT.${COMPILER_TYPE}
 
+# GCC 5.2.0
+.if ${COMPILER_TYPE} == "gcc" && ${COMPILER_VERSION} >= 50200
+CWARNFLAGS+=	-Wno-error=unused-function -Wno-error=enum-compare -Wno-error=logical-not-parentheses -Wno-error=bool-compare -Wno-error=uninitialized -Wno-error=array-bounds -Wno-error=clobbered -Wno-error=cast-align -Wno-error=extra -Wno-error=attributes -Wno-error=inline -Wno-error=unused-but-set-variable -Wno-error=unused-value -Wno-error=strict-aliasing -Wno-error=address
+.endif
+
 # How to handle FreeBSD custom printf format specifiers.
 .if ${COMPILER_TYPE} == "clang" && ${COMPILER_VERSION} >= 30600
 FORMAT_EXTENSIONS=	-D__printf__=__freebsd_kprintf__
diff --git a/share/mk/local.meta.sys.mk b/share/mk/local.meta.sys.mk
index a97f6f2..1aa749a 100644
--- a/share/mk/local.meta.sys.mk
+++ b/share/mk/local.meta.sys.mk
@@ -48,13 +48,14 @@ TARGET_ARCHES_arm64?=   aarch64
 TARGET_ARCHES_mips?=    mipsel mips mips64el mips64 mipsn32 mipsn32el
 TARGET_ARCHES_powerpc?= powerpc powerpc64
 TARGET_ARCHES_pc98?=    i386
+TARGET_ARCHES_riscv?=   riscv64
 
 # some corner cases
 BOOT_MACHINE_DIR.amd64 = boot/i386
 MACHINE_ARCH.host = ${_HOST_ARCH}
 
 # the list of machines we support
-ALL_MACHINE_LIST?= amd64 arm arm64 i386 mips pc98 powerpc sparc64
+ALL_MACHINE_LIST?= amd64 arm arm64 i386 mips pc98 powerpc riscv sparc64
 .for m in ${ALL_MACHINE_LIST:O:u}
 MACHINE_ARCH_LIST.$m?= ${TARGET_ARCHES_${m}:U$m}
 MACHINE_ARCH.$m?= ${MACHINE_ARCH_LIST.$m:[1]}
diff --git a/share/mk/src.opts.mk b/share/mk/src.opts.mk
index 094019d..f94e63a 100644
--- a/share/mk/src.opts.mk
+++ b/share/mk/src.opts.mk
@@ -229,12 +229,17 @@ __DEFAULT_YES_OPTIONS+=GCC GCC_BOOTSTRAP GNUCXX
 __DEFAULT_NO_OPTIONS+=CLANG CLANG_BOOTSTRAP CLANG_FULL CLANG_IS_CC
 .endif
 # In-tree binutils/gcc are older versions without modern architecture support.
-.if ${__T} == "aarch64"
+.if ${__T} == "aarch64" || ${__T} == "riscv64"
 BROKEN_OPTIONS+=BINUTILS BINUTILS_BOOTSTRAP GCC GCC_BOOTSTRAP GDB
 __DEFAULT_YES_OPTIONS+=ELFCOPY_AS_OBJCOPY
 .else
 __DEFAULT_NO_OPTIONS+=ELFCOPY_AS_OBJCOPY
 .endif
+.if ${__T} == "riscv64"
+BROKEN_OPTIONS+=PROFILE # "sorry, unimplemented: profiler support for RISC-V"
+BROKEN_OPTIONS+=TESTS   # "undefined reference to `_Unwind_Resume'"
+BROKEN_OPTIONS+=CXX     # "libcxxrt.so: undefined reference to `_Unwind_Resume_or_Rethrow'"
+.endif
 # LLVM lacks support for FreeBSD 64-bit atomic operations for ARMv4/ARMv5
 .if ${__T} == "arm" || ${__T} == "armeb"
 BROKEN_OPTIONS+=LLDB
diff --git a/share/mk/sys.mk b/share/mk/sys.mk
index f9ac418..8fe6b68 100644
--- a/share/mk/sys.mk
+++ b/share/mk/sys.mk
@@ -13,7 +13,7 @@ unix		?=	We run FreeBSD, not UNIX.
 # and/or endian.  This is called MACHINE_CPU in NetBSD, but that's used
 # for something different in FreeBSD.
 #
-MACHINE_CPUARCH=${MACHINE_ARCH:C/mips(n32|64)?(el)?/mips/:C/arm(v6)?(eb|hf)?/arm/:C/powerpc64/powerpc/}
+MACHINE_CPUARCH=${MACHINE_ARCH:C/mips(n32|64)?(el)?/mips/:C/arm(v6)?(eb|hf)?/arm/:C/powerpc64/powerpc/:C/riscv64/riscv/}
 .endif