RISCV64: add buildroot toolchain support

This is work in a progress, still got build issues
defined by mlx_riscv64_defconfig

Signed-off-by: Noam Camus <noamca@mellanox.com>

arch/Config.in.riscv

@@ -7,3 +7,11 @@ config BR2_ENDIAN
 
 config BR2_READELF_ARCH_NAME
 	default "RISC-V"
+
+config BR2_GCC_TARGET_ARCH
+	default "rv32g"	if BR2_riscv32
+	default "rv64g"	if BR2_riscv64
+
+config BR2_GCC_TARGET_ABI
+	default "lp32d"	if BR2_riscv32
+	default "lp64d"	if BR2_riscv64

configs/mlx_riscv64_defconfig

@@ -0,0 +1,11 @@
+BR2_riscv64=y
+BR2_GLIBC_VERSION_2_23=y
+BR2_LINUX_KERNEL=y
+BR2_LINUX_KERNEL_CUSTOM_GIT=y
+BR2_LINUX_KERNEL_CUSTOM_REPO_URL="https://github.com/riscv/riscv-linux.git"
+BR2_LINUX_KERNEL_CUSTOM_REPO_VERSION="riscv-next"
+BR2_LINUX_KERNEL_PATCH="$(TOPDIR)/linux/riscv.patch"
+BR2_LINUX_KERNEL_DEFCONFIG="riscv64_spike"
+BR2_TARGET_ROOTFS_INITRAMFS=y
+# BR2_TARGET_ROOTFS_TAR is not set
+BR2_PACKAGE_HOST_MKE2IMG=y

linux/riscv.patch

@@ -0,0 +1,10 @@
+diff -urN linux-headers.orig/arch/riscv/include/uapi/asm/setup.h linux-headers/arch/riscv/include/uapi/asm/setup.h
+--- linux-headers.orig/arch/riscv/include/uapi/asm/setup.h	1970-01-01 02:00:00.000000000 +0200
++++ linux-headers/arch/riscv/include/uapi/asm/setup.h	2017-06-13 08:46:15.567800383 +0300
+@@ -0,0 +1,6 @@
++/*
++ * setup.h is part of userspace header ABI so UAPI scripts have to generate it
++ * even if there's nothing to export - causing empty <uapi/asm/setup.h>
++ * However to prevent "patch" from discarding it we add this placeholder
++ * comment
++ */

package/binutils/binutils.mk

@@ -20,6 +20,12 @@ BINUTILS_SITE = $(call github,foss-for-synopsys-dwc-arc-processors,binutils-gdb,
 BINUTILS_SOURCE = binutils-$(BINUTILS_VERSION).tar.gz
 BINUTILS_FROM_GIT = y
 endif
+ifeq ($(BR2_riscv64),y)
+BINUTILS_VERSION = riscv-next
+BINUTILS_SITE = https://github.com/riscv/riscv-binutils-gdb.git
+BINUTILS_SITE_METHOD = git
+BINUTILS_SOURCE = binutils-$(BINUTILS_VERSION).tar.gz
+endif
 BINUTILS_SITE ?= $(BR2_GNU_MIRROR)/binutils
 BINUTILS_SOURCE ?= binutils-$(BINUTILS_VERSION).tar.bz2
 BINUTILS_EXTRA_CONFIG_OPTIONS = $(call qstrip,$(BR2_BINUTILS_EXTRA_CONFIG_OPTIONS))

package/binutils/riscv-next/0001-FIX-verlapping-FDEs-when-linking-libc.patch

@@ -0,0 +1,133 @@
+diff -urN binutils.orig/bfd/bfd-in2.h binutils/bfd/bfd-in2.h
+--- binutils.orig/bfd/bfd-in2.h	2017-05-20 01:49:31.000000000 +0300
++++ binutils/bfd/bfd-in2.h	2017-06-13 15:52:19.961649468 +0300
+@@ -4769,6 +4769,7 @@
+   BFD_RELOC_RISCV_SET8,
+   BFD_RELOC_RISCV_SET16,
+   BFD_RELOC_RISCV_SET32,
++  BFD_RELOC_RISCV_64_PCREL,
+
+ /* Renesas RL78 Relocations.  */
+   BFD_RELOC_RL78_NEG8,
+diff -urN binutils.orig/bfd/elfnn-riscv.c binutils/bfd/elfnn-riscv.c
+--- binutils.orig/bfd/elfnn-riscv.c	2017-05-20 01:49:31.000000000 +0300
++++ binutils/bfd/elfnn-riscv.c	2017-06-13 15:53:06.036956405 +0300
+@@ -1566,6 +1566,7 @@
+     case R_RISCV_SET8:
+     case R_RISCV_SET16:
+     case R_RISCV_SET32:
++    case R_RISCV_64_PCREL:
+     case R_RISCV_TLS_DTPREL32:
+     case R_RISCV_TLS_DTPREL64:
+       break;
+@@ -1853,6 +1854,7 @@
+ 	case R_RISCV_SET16:
+ 	case R_RISCV_SET32:
+ 	case R_RISCV_DELETE:
++	case R_RISCV_64_PCREL:
+ 	  /* These require no special handling beyond perform_relocation.  */
+ 	  break;
+
+diff -urN binutils.orig/bfd/elfxx-riscv.c binutils/bfd/elfxx-riscv.c
+--- binutils.orig/bfd/elfxx-riscv.c	2017-05-20 01:49:31.000000000 +0300
++++ binutils/bfd/elfxx-riscv.c	2017-06-13 15:53:51.780243045 +0300
+@@ -849,6 +849,22 @@
+ 	 0,				/* src_mask */
+ 	 MINUS_ONE,			/* dst_mask */
+ 	 FALSE),			/* pcrel_offset */
++
++  /* Deletes bytes after this address.  The addend specifies the number of
++   * bytes to delete, just like R_RISCV_ALIGN.  */
++   HOWTO (R_RISCV_64_PCREL,		/* type */
++	 0,				/* rightshift */
++	 4,				/* size */
++	 64,				/* bitsize */
++	 TRUE,				/* pc_relative */
++	 0,				/* bitpos */
++	 complain_overflow_dont,	/* complain_on_overflow */
++	 bfd_elf_generic_reloc,		/* special_function */
++	 "R_RISCV_64_PCREL",		/* name */
++	 FALSE,				/* partial_inplace */
++	 0,				/* src_mask */
++	 MINUS_ONE,			/* dst_mask */
++	 FALSE),			/* pcrel_offset */
+ };
+
+ /* A mapping from BFD reloc types to RISC-V ELF reloc types.  */
+@@ -910,6 +926,7 @@
+   { BFD_RELOC_RISCV_SET8, R_RISCV_SET8 },
+   { BFD_RELOC_RISCV_SET16, R_RISCV_SET16 },
+   { BFD_RELOC_RISCV_SET32, R_RISCV_SET32 },
++  { BFD_RELOC_RISCV_64_PCREL, R_RISCV_64_PCREL },
+ };
+
+ /* Given a BFD reloc type, return a howto structure.  */
+diff -urN binutils.orig/bfd/libbfd.h binutils/bfd/libbfd.h
+--- binutils.orig/bfd/libbfd.h	2017-05-20 01:49:31.000000000 +0300
++++ binutils/bfd/libbfd.h	2017-06-13 15:54:06.212014046 +0300
+@@ -2212,6 +2212,7 @@
+   "BFD_RELOC_RISCV_SET8",
+   "BFD_RELOC_RISCV_SET16",
+   "BFD_RELOC_RISCV_SET32",
++  "BFD_RELOC_RISCV_64_PCREL",
+   "BFD_RELOC_RL78_NEG8",
+   "BFD_RELOC_RL78_NEG16",
+   "BFD_RELOC_RL78_NEG24",
+diff -urN binutils.orig/bfd/reloc.c binutils/bfd/reloc.c
+--- binutils.orig/bfd/reloc.c	2017-05-20 01:49:31.000000000 +0300
++++ binutils/bfd/reloc.c	2017-06-13 15:54:19.819796701 +0300
+@@ -5155,6 +5155,8 @@
+   BFD_RELOC_RISCV_SET16
+ ENUMX
+   BFD_RELOC_RISCV_SET32
++ENUMX
++  BFD_RELOC_RISCV_64_PCREL
+ ENUMDOC
+   RISC-V relocations.
+
+diff -urN binutils.orig/gas/config/tc-riscv.c binutils/gas/config/tc-riscv.c
+--- binutils.orig/gas/config/tc-riscv.c	2017-05-20 01:49:31.000000000 +0300
++++ binutils/gas/config/tc-riscv.c	2017-06-13 15:55:11.218965592 +0300
+@@ -1871,6 +1871,7 @@
+   bfd_byte *buf = (bfd_byte *) (fixP->fx_frag->fr_literal + fixP->fx_where);
+   bfd_boolean relaxable = FALSE;
+   offsetT loc;
++  segT sub_segment;
+
+   /* Remember value for tc_gen_reloc.  */
+   fixP->fx_addnumber = *valP;
+@@ -1919,6 +1920,23 @@
+       break;
+
+     case BFD_RELOC_64:
++      /* Use pc-relative relocation for FDE initial location.
++	 The symbol address in .eh_frame may be adjusted in
++	 _bfd_elf_discard_section_eh_frame, and the content of
++	 .eh_frame will be adjusted in _bfd_elf_write_section_eh_frame.
++	 Therefore, we cannot insert a relocation whose addend symbol is
++	 in .eh_frame. Othrewise, the value may be adjusted twice.*/
++      if (fixP->fx_addsy && fixP->fx_subsy
++	  && (sub_segment = S_GET_SEGMENT (fixP->fx_subsy))
++	  && strcmp (sub_segment->name, ".eh_frame") == 0
++	  && S_GET_VALUE (fixP->fx_subsy)
++	     == fixP->fx_frag->fr_address + fixP->fx_where)
++	{
++	  fixP->fx_r_type = BFD_RELOC_RISCV_64_PCREL;
++	  fixP->fx_subsy = NULL;
++	  break;
++	}
++      /* Fall through.  */
+     case BFD_RELOC_32:
+     case BFD_RELOC_16:
+     case BFD_RELOC_8:
+diff -urN binutils.orig/include/elf/riscv.h binutils/include/elf/riscv.h
+--- binutils.orig/include/elf/riscv.h	2017-05-20 01:49:31.000000000 +0300
++++ binutils/include/elf/riscv.h	2017-06-13 15:55:36.962544552 +0300
+@@ -87,6 +87,7 @@
+   RELOC_NUMBER (R_RISCV_SET8, 54)
+   RELOC_NUMBER (R_RISCV_SET16, 55)
+   RELOC_NUMBER (R_RISCV_SET32, 56)
++  RELOC_NUMBER (R_RISCV_64_PCREL, 57)
+ END_RELOC_NUMBERS (R_RISCV_max)
+
+ /* Processor specific flags for the ELF header e_flags field.  */

package/gcc/gcc.mk

@@ -16,6 +16,12 @@ GCC_SOURCE = gcc-$(GCC_VERSION).tar.gz
 else ifeq ($(BR2_or1k),y)
 GCC_SITE = $(call github,openrisc,or1k-gcc,$(GCC_VERSION))
 GCC_SOURCE = gcc-$(GCC_VERSION).tar.gz
+else ifeq ($(BR2_riscv64),y)
+GCC_VERSION = riscv-next
+GCC_SITE = https://github.com/riscv/riscv-gcc.git
+HOST_GCC_INITIAL_SITE_METHOD = git
+GCC_SOURCE = gcc-$(GCC_VERSION).tar.gz
+BR_NO_CHECK_HASH_FOR += $(GCC_SOURCE)
 else
 GCC_SITE = $(BR2_GNU_MIRROR:/=)/gcc/gcc-$(GCC_VERSION)
 GCC_SOURCE = gcc-$(GCC_VERSION).tar.bz2

package/gcc/riscv-next/0001-remove-failed-s-selftest-target.patch

@@ -0,0 +1,12 @@
+diff -urN gcc.orig/gcc/Makefile.in gcc/gcc/Makefile.in
+--- gcc.orig/gcc/Makefile.in	2017-05-30 05:47:35.000000000 +0300
++++ gcc/gcc/Makefile.in	2017-06-12 17:43:22.140479147 +0300
+@@ -1908,7 +1908,7 @@
+ # Use "s-selftest" to ensure that we only run the selftests if the
+ # driver, cc1, or selftest data change.
+ .PHONY: selftest
+-selftest: s-selftest
++selftest: # s-selftest
+ s-selftest: $(GCC_PASSES) cc1$(exeext) stmp-int-hdrs \
+   $(srcdir)/testsuite/selftests
+ 	$(GCC_FOR_TARGET) $(SELFTEST_FLAGS)

package/glibc/glibc.mk

@@ -9,6 +9,13 @@ GLIBC_SITE = $(BR2_GNU_MIRROR)/libc
 GLIBC_SOURCE = glibc-$(GLIBC_VERSION).tar.xz
 GLIBC_SRC_SUBDIR = .
 
+ifeq ($(BR2_riscv64),y)
+GLIBC_VERSION = riscv-next
+GLIBC_SITE = https://github.com/riscv/riscv-glibc.git
+GLIBC_SITE_METHOD = git
+GLIBC_SOURCE = glibc-$(GLIBC_VERSION).tar.gz
+endif
+
 GLIBC_LICENSE = GPL-2.0+ (programs), LGPL-2.1+, BSD-3-Clause, MIT (library)
 GLIBC_LICENSE_FILES = $(addprefix $(GLIBC_SRC_SUBDIR)/,COPYING COPYING.LIB LICENSES)
 
@@ -84,6 +91,7 @@ define GLIBC_CONFIGURE_CMDS
 		--enable-shared \
 		$(if $(BR2_SOFT_FLOAT),--without-fp,--with-fp) \
 		$(if $(BR2_x86_64),--enable-lock-elision) \
+		$(if $(BR2_riscv64),--disable-werror) \
 		--with-pkgversion="Buildroot" \
 		--without-cvs \
 		--disable-profile \

package/linux-headers/Config.in.host

@@ -87,6 +87,10 @@ choice
 	  This is used to hide/show some packages that have strict
 	  requirements on the version of kernel headers.
 
+config BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_12
+	bool "4.12.x"
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_12
+
 config BR2_PACKAGE_HOST_LINUX_HEADERS_CUSTOM_4_11
 	bool "4.11.x"
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_11

toolchain/toolchain-buildroot/Config.in

@@ -47,7 +47,7 @@ config BR2_TOOLCHAIN_BUILDROOT_GLIBC
 		   BR2_mipsel      || BR2_mips64     || BR2_mips64el|| \
 		   BR2_powerpc     || BR2_powerpc64  || BR2_powerpc64le || \
 		   BR2_sh          || BR2_sparc64    || BR2_x86_64 || \
-		   BR2_microblaze || BR2_nios2
+		   BR2_microblaze || BR2_nios2       || BR2_riscv64
 	depends on BR2_USE_MMU
 	depends on !BR2_STATIC_LIBS
 	depends on !BR2_powerpc_SPE

toolchain/toolchain-common.in

@@ -247,10 +247,15 @@ config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_11
 	bool
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_10
 
+config BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_12
+	bool
+	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_11
+
 # This order guarantees that the highest version is set, as kconfig
 # stops affecting a value on the first matching default.
 config BR2_TOOLCHAIN_HEADERS_AT_LEAST
 	string
+	default "4.12" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_12
 	default "4.11" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_11
 	default "4.10" if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_10
 	default "4.9"  if BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_9