diff mbox series

[v2,4/6] arch: add support for RISC-V 64-bit (riscv64) architecture

Message ID 20180912102256.3164-5-mark.corbin@embecosm.com
State Accepted
Headers show
Series Add RISC-V 64-bit architecture support | expand

Commit Message

Mark Corbin Sept. 12, 2018, 10:22 a.m. UTC 
This enables a riscv64 system to be built with a Buildroot generated
toolchain (gcc >= 7.x, binutils >= 2.30, glibc only).

This configuration has been used to successfully build a qemu-bootable
riscv-linux-4.15 kernel (https://github.com/riscv/riscv-linux.git).

Signed-off-by: Mark Corbin <mark.corbin@embecosm.com>
---
Changes v1 -> v2:
  - updated DEVELOPERS file (Thomas P)
  - changed BR2_riscv64 to BR2_riscv to match kernel architecture
    (Arnout)
  - MMU now mandatory instead of optional (Thomas P)
  - moved selection of minimum gcc version to BR2_riscv
    (Thomas P)
  - forced selection of ISA atomic extensions as it is required for
    glibc (Thomas P)
  - add blind BR2_RISCV_64 option for later use with a 32-bit option
    (Arnout)
  - updated generation of GCC_TARGET_ARCH to use new override feature
    in arch/arch.mk (Thomas P)
  - added library path override for glibc to avoid default paths that
    include the ABI
  - disable selection of linux header versions for versions that
    don't support RISC-V (Arnout)
  - removed explicit selection of default C library (Thomas P)
  - removed comment relating to atomic instructions with glibc (Arnout)
  - removed explicit selection of default binutils version (Thomas P)
---
 DEVELOPERS                              |   4 +
 Makefile                                |   1 +
 arch/Config.in                          |  15 ++++
 arch/Config.in.riscv                    | 104 ++++++++++++++++++++++++
 arch/arch.mk.riscv                      |  30 +++++++
 package/binutils/Config.in.host         |   2 +
 package/glibc/glibc.mk                  |  30 +++++--
 package/linux-headers/Config.in.host    |   5 ++
 toolchain/toolchain-buildroot/Config.in |   6 +-
 9 files changed, 187 insertions(+), 10 deletions(-)
 create mode 100644 arch/Config.in.riscv
 create mode 100644 arch/arch.mk.riscv

Comments

Thomas Petazzoni Sept. 12, 2018, 3:21 p.m. UTC | #1 
Hello,

On Wed, 12 Sep 2018 11:22:54 +0100, Mark Corbin wrote:

> +GLIBC_CONF_OPTS = \
> +		--with-pkgversion="Buildroot" \
> +		--without-cvs \
> +		--disable-profile \
> +		--without-gd \
> +		--enable-obsolete-rpc \
> +		--enable-kernel=$(call qstrip,$(BR2_TOOLCHAIN_HEADERS_AT_LEAST)) \
> +		--with-headers=$(STAGING_DIR)/usr/include
> +
> +ifeq ($(BR2_x86_64),y)
> +GLIBC_CONF_OPTS += --enable-lock-elision
> +endif
> +
> +# Override the default library locations of /lib64/<abi> and
> +# /usr/lib64/<abi>/ for RISC-V.
> +ifeq ($(BR2_riscv),y)
> +GLIBC_CONF_OPTS += libc_cv_slibdir=/lib64 libc_cv_rtlddir=/lib
> +endif
> +
>  define GLIBC_CONFIGURE_CMDS
>  	mkdir -p $(@D)/build
>  	# Do the configuration
> @@ -98,14 +118,8 @@ define GLIBC_CONFIGURE_CMDS
>  		--build=$(GNU_HOST_NAME) \
>  		--prefix=/usr \
>  		--enable-shared \
> -		$(if $(BR2_x86_64),--enable-lock-elision) \
> -		--with-pkgversion="Buildroot" \
> -		--without-cvs \
> -		--disable-profile \
> -		--without-gd \
> -		--enable-obsolete-rpc \
> -		--enable-kernel=$(call qstrip,$(BR2_TOOLCHAIN_HEADERS_AT_LEAST)) \
> -		--with-headers=$(STAGING_DIR)/usr/include)
> +		$(GLIBC_CONF_OPTS) \
> +	)

This refactor of GLIBC_CONF_OPTS should have been a preparatory patch,
so that the small addition of GLIBC_CONF_OPTS specifically related to
RISC-V is the only portion part of the RISC-V architecture patch.

However, I think those variables lib_cv_* should not go in
GLIBC_CONF_OPTS, but in GLIBC_CONF_ENV, since that's how we do it in
all other autotools-based packages. But we indeed have a bunch of such
variables already:

                ac_cv_path_BASH_SHELL=/bin/bash \
                libc_cv_forced_unwind=yes \
                libc_cv_ssp=no \

So perhaps we need a first preparatory patch that move these to
GLIBC_CONF_ENV, and then your RISC-V architecture patch.

At this point, no need to resend such for this, this is the sort of
thing that we can fixup while applying. We'll see if there are more
comments on the rest of the series that require a new iteration.

Best regards,

Thomas
Thomas Petazzoni Sept. 25, 2018, 8:06 p.m. UTC | #2 
Hello,

On Wed, 12 Sep 2018 11:22:54 +0100, Mark Corbin wrote:
> This enables a riscv64 system to be built with a Buildroot generated
> toolchain (gcc >= 7.x, binutils >= 2.30, glibc only).
> 
> This configuration has been used to successfully build a qemu-bootable
> riscv-linux-4.15 kernel (https://github.com/riscv/riscv-linux.git).
> 
> Signed-off-by: Mark Corbin <mark.corbin@embecosm.com>

I have applied this commit, after doing a few changes, see below.


> +ifeq ($(BR2_riscv),y)
> +
> +ifeq ($(BR2_ARCH_IS_64),y)
> +RISCV_GCC_ARCH = rv64i
> +endif
> +
> +ifeq ($(BR2_RISCV_ISA_RVM),y)
> +RISCV_GCC_ARCH := $(RISCV_GCC_ARCH)m
> +endif
> +ifeq ($(BR2_RISCV_ISA_RVA),y)
> +RISCV_GCC_ARCH := $(RISCV_GCC_ARCH)a
> +endif
> +ifeq ($(BR2_RISCV_ISA_RVF),y)
> +RISCV_GCC_ARCH := $(RISCV_GCC_ARCH)f
> +endif
> +ifeq ($(BR2_RISCV_ISA_RVD),y)
> +RISCV_GCC_ARCH := $(RISCV_GCC_ARCH)d
> +endif
> +ifeq ($(BR2_RISCV_ISA_RVC),y)
> +RISCV_GCC_ARCH := $(RISCV_GCC_ARCH)c
> +endif
> +
> +GCC_TARGET_ARCH := $(RISCV_GCC_ARCH)

In this file, I didn't see the point of the intermediate
RISCV_GCC_ARCH variable. So I've changed to use GCC_TARGET_ARCH
directly.

> +GLIBC_CONF_OPTS = \
> +		--with-pkgversion="Buildroot" \
> +		--without-cvs \
> +		--disable-profile \
> +		--without-gd \
> +		--enable-obsolete-rpc \
> +		--enable-kernel=$(call qstrip,$(BR2_TOOLCHAIN_HEADERS_AT_LEAST)) \
> +		--with-headers=$(STAGING_DIR)/usr/include
> +
> +ifeq ($(BR2_x86_64),y)
> +GLIBC_CONF_OPTS += --enable-lock-elision
> +endif
> +
> +# Override the default library locations of /lib64/<abi> and
> +# /usr/lib64/<abi>/ for RISC-V.
> +ifeq ($(BR2_riscv),y)
> +GLIBC_CONF_OPTS += libc_cv_slibdir=/lib64 libc_cv_rtlddir=/lib
> +endif
> +
>  define GLIBC_CONFIGURE_CMDS
>  	mkdir -p $(@D)/build
>  	# Do the configuration
> @@ -98,14 +118,8 @@ define GLIBC_CONFIGURE_CMDS
>  		--build=$(GNU_HOST_NAME) \
>  		--prefix=/usr \
>  		--enable-shared \
> -		$(if $(BR2_x86_64),--enable-lock-elision) \
> -		--with-pkgversion="Buildroot" \
> -		--without-cvs \
> -		--disable-profile \
> -		--without-gd \
> -		--enable-obsolete-rpc \
> -		--enable-kernel=$(call qstrip,$(BR2_TOOLCHAIN_HEADERS_AT_LEAST)) \
> -		--with-headers=$(STAGING_DIR)/usr/include)
> +		$(GLIBC_CONF_OPTS) \
> +	)

As I commented in an earlier review, libc_cv_* should be passed in the
environment, like other autoconf cache variables. So I did a
preliminary commit that creates a GLIBC_CONF_ENV variable, passed in
the glibc ./configure script environment, and that contains the
existing autoconf cache variables we were passing.

Then I adjusted your commit to simply add those libc_cv_* variables to
GLIBC_CONF_ENV:

+# Override the default library locations of /lib64/<abi> and
+# /usr/lib64/<abi>/ for RISC-V.
+ifeq ($(BR2_riscv),y)
+GLIBC_CONF_ENV += libc_cv_slibdir=/lib64 libc_cv_rtlddir=/lib
+endif

Thanks a lot for this contribution!

Thomas
diff mbox series

Patch

diff --git a/DEVELOPERS b/DEVELOPERS
index 8c43ce1b17..1c29da4038 100644
--- a/DEVELOPERS
+++ b/DEVELOPERS
@@ -1286,6 +1286,10 @@  F:	package/lynx/
 N:	Mario Rugiero <mrugiero@gmail.com>
 F:	package/ratpoison/
 
+N:	Mark Corbin <mark.corbin@embecosm.com>
+F:	arch/arch.mk.riscv
+F:	arch/Config.in.riscv
+
 N:	Markos Chandras <markos.chandras@imgtec.com>
 F:	package/harfbuzz/
 F:	package/libsecret/
diff --git a/Makefile b/Makefile
index d636aaeaae..8cec717cdd 100644
--- a/Makefile
+++ b/Makefile
@@ -433,6 +433,7 @@  KERNEL_ARCH := $(shell echo "$(ARCH)" | sed -e "s/-.*//" \
 	-e s/parisc64/parisc/ \
 	-e s/powerpc64.*/powerpc/ \
 	-e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
+	-e s/riscv.*/riscv/ \
 	-e s/sh.*/sh/ \
 	-e s/microblazeel/microblaze/)
 
diff --git a/arch/Config.in b/arch/Config.in
index 7d1aeb2174..8bd57fe1cc 100644
--- a/arch/Config.in
+++ b/arch/Config.in
@@ -198,6 +198,17 @@  config BR2_powerpc64le
 	  http://www.power.org/
 	  http://en.wikipedia.org/wiki/Powerpc
 
+config BR2_riscv
+	bool "RISCV"
+	select BR2_ARCH_HAS_MMU_MANDATORY
+	select BR2_ARCH_NEEDS_GCC_AT_LEAST_7
+	help
+	  RISC-V is an open, free Instruction Set Architecture created
+	  by the UC Berkeley Architecture Research group and supported
+	  and promoted by RISC-V Foundation.
+	  https://riscv.org/
+	  https://en.wikipedia.org/wiki/RISC-V
+
 config BR2_sh
 	bool "SuperH"
 	select BR2_ARCH_HAS_MMU_OPTIONAL
@@ -423,6 +434,10 @@  if BR2_powerpc || BR2_powerpc64 || BR2_powerpc64le
 source "arch/Config.in.powerpc"
 endif
 
+if BR2_riscv
+source "arch/Config.in.riscv"
+endif
+
 if BR2_sh
 source "arch/Config.in.sh"
 endif
diff --git a/arch/Config.in.riscv b/arch/Config.in.riscv
new file mode 100644
index 0000000000..8889f81e9b
--- /dev/null
+++ b/arch/Config.in.riscv
@@ -0,0 +1,104 @@ 
+# RISC-V CPU ISA extensions.
+
+config BR2_RISCV_ISA_RVI
+	bool
+
+config BR2_RISCV_ISA_RVM
+	bool
+
+config BR2_RISCV_ISA_RVA
+	bool
+
+config BR2_RISCV_ISA_RVF
+	bool
+
+config BR2_RISCV_ISA_RVD
+	bool
+
+config BR2_RISCV_ISA_RVC
+	bool
+
+
+choice
+	prompt "Target Architecture Variant"
+	default BR2_riscv_g
+
+config BR2_riscv_g
+	bool "General purpose (G)"
+	select BR2_RISCV_ISA_RVI
+	select BR2_RISCV_ISA_RVM
+	select BR2_RISCV_ISA_RVA
+	select BR2_RISCV_ISA_RVF
+	select BR2_RISCV_ISA_RVD
+	help
+	  General purpose (G) is equivalent to IMAFD.
+
+config BR2_riscv_custom
+	bool "Custom architecture"
+	select BR2_RISCV_ISA_RVI
+	select BR2_RISCV_ISA_CUSTOM_RVA
+
+endchoice
+
+if BR2_riscv_custom
+
+comment "Instruction Set Extensions"
+
+config BR2_RISCV_ISA_CUSTOM_RVM
+	bool "Integer Multiplication and Division (M)"
+	select BR2_RISCV_ISA_RVM
+
+config BR2_RISCV_ISA_CUSTOM_RVA
+	bool "Atomic Instructions (A)"
+	select BR2_RISCV_ISA_RVA
+
+config BR2_RISCV_ISA_CUSTOM_RVF
+	bool "Single-precision Floating-point (F)"
+	select BR2_RISCV_ISA_RVF
+
+config BR2_RISCV_ISA_CUSTOM_RVD
+	bool "Double-precision Floating-point (D)"
+	depends on BR2_RISCV_ISA_RVF
+	select BR2_RISCV_ISA_RVD
+
+config BR2_RISCV_ISA_CUSTOM_RVC
+	bool "Compressed Instructions (C)"
+	select BR2_RISCV_ISA_RVC
+endif
+
+config BR2_RISCV_64
+	bool
+	default y
+	select BR2_ARCH_IS_64
+
+choice
+	prompt "Target ABI"
+	default BR2_RISCV_ABI_LP64
+
+config BR2_RISCV_ABI_LP64
+	bool "lp64"
+	depends on BR2_ARCH_IS_64
+
+config BR2_RISCV_ABI_LP64F
+	bool "lp64f"
+	depends on BR2_ARCH_IS_64 && BR2_RISCV_ISA_RVF
+
+config BR2_RISCV_ABI_LP64D
+	bool "lp64d"
+	depends on BR2_ARCH_IS_64 && BR2_RISCV_ISA_RVD
+endchoice
+
+config BR2_ARCH
+	default "riscv64" if BR2_ARCH_IS_64
+
+config BR2_ENDIAN
+	default "LITTLE"
+
+config BR2_GCC_TARGET_ABI
+	default "lp64" if BR2_RISCV_ABI_LP64
+	default "lp64f" if BR2_RISCV_ABI_LP64F
+	default "lp64d" if BR2_RISCV_ABI_LP64D
+
+config BR2_READELF_ARCH_NAME
+	default "RISC-V"
+
diff --git a/arch/arch.mk.riscv b/arch/arch.mk.riscv
new file mode 100644
index 0000000000..dded5a5943
--- /dev/null
+++ b/arch/arch.mk.riscv
@@ -0,0 +1,30 @@ 
+#
+# Configure the GCC_TARGET_ARCH variable and append the
+# appropriate RISC-V ISA extensions.
+#
+
+ifeq ($(BR2_riscv),y)
+
+ifeq ($(BR2_ARCH_IS_64),y)
+RISCV_GCC_ARCH = rv64i
+endif
+
+ifeq ($(BR2_RISCV_ISA_RVM),y)
+RISCV_GCC_ARCH := $(RISCV_GCC_ARCH)m
+endif
+ifeq ($(BR2_RISCV_ISA_RVA),y)
+RISCV_GCC_ARCH := $(RISCV_GCC_ARCH)a
+endif
+ifeq ($(BR2_RISCV_ISA_RVF),y)
+RISCV_GCC_ARCH := $(RISCV_GCC_ARCH)f
+endif
+ifeq ($(BR2_RISCV_ISA_RVD),y)
+RISCV_GCC_ARCH := $(RISCV_GCC_ARCH)d
+endif
+ifeq ($(BR2_RISCV_ISA_RVC),y)
+RISCV_GCC_ARCH := $(RISCV_GCC_ARCH)c
+endif
+
+GCC_TARGET_ARCH := $(RISCV_GCC_ARCH)
+
+endif
diff --git a/package/binutils/Config.in.host b/package/binutils/Config.in.host
index 21dc84e498..c8c02bca77 100644
--- a/package/binutils/Config.in.host
+++ b/package/binutils/Config.in.host
@@ -12,9 +12,11 @@  choice
 config BR2_BINUTILS_VERSION_2_28_X
 	bool "binutils 2.28.1"
 	depends on !BR2_arc
+	depends on !BR2_riscv
 
 config BR2_BINUTILS_VERSION_2_29_X
 	bool "binutils 2.29.1"
+	depends on !BR2_riscv
 
 config BR2_BINUTILS_VERSION_2_30_X
 	bool "binutils 2.30"
diff --git a/package/glibc/glibc.mk b/package/glibc/glibc.mk
index a2eb8714b1..ad5d79cee0 100644
--- a/package/glibc/glibc.mk
+++ b/package/glibc/glibc.mk
@@ -82,6 +82,26 @@  endif
 # Note that as mentionned in
 # http://patches.openembedded.org/patch/38849/, glibc must be
 # built with -O2, so we pass our own CFLAGS and CXXFLAGS below.
+
+GLIBC_CONF_OPTS = \
+		--with-pkgversion="Buildroot" \
+		--without-cvs \
+		--disable-profile \
+		--without-gd \
+		--enable-obsolete-rpc \
+		--enable-kernel=$(call qstrip,$(BR2_TOOLCHAIN_HEADERS_AT_LEAST)) \
+		--with-headers=$(STAGING_DIR)/usr/include
+
+ifeq ($(BR2_x86_64),y)
+GLIBC_CONF_OPTS += --enable-lock-elision
+endif
+
+# Override the default library locations of /lib64/<abi> and
+# /usr/lib64/<abi>/ for RISC-V.
+ifeq ($(BR2_riscv),y)
+GLIBC_CONF_OPTS += libc_cv_slibdir=/lib64 libc_cv_rtlddir=/lib
+endif
+
 define GLIBC_CONFIGURE_CMDS
 	mkdir -p $(@D)/build
 	# Do the configuration
@@ -98,14 +118,8 @@  define GLIBC_CONFIGURE_CMDS
 		--build=$(GNU_HOST_NAME) \
 		--prefix=/usr \
 		--enable-shared \
-		$(if $(BR2_x86_64),--enable-lock-elision) \
-		--with-pkgversion="Buildroot" \
-		--without-cvs \
-		--disable-profile \
-		--without-gd \
-		--enable-obsolete-rpc \
-		--enable-kernel=$(call qstrip,$(BR2_TOOLCHAIN_HEADERS_AT_LEAST)) \
-		--with-headers=$(STAGING_DIR)/usr/include)
+		$(GLIBC_CONF_OPTS) \
+	)
 	$(GLIBC_ADD_MISSING_STUB_H)
 endef
 
diff --git a/package/linux-headers/Config.in.host b/package/linux-headers/Config.in.host
index 4f79ccc991..817ad2c57a 100644
--- a/package/linux-headers/Config.in.host
+++ b/package/linux-headers/Config.in.host
@@ -29,22 +29,27 @@  config BR2_KERNEL_HEADERS_AS_KERNEL
 config BR2_KERNEL_HEADERS_3_2
 	bool "Linux 3.2.x kernel headers"
 	depends on !BR2_aarch64 && !BR2_arc && !BR2_nios2
+	depends on !BR2_riscv
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_2
 
 config BR2_KERNEL_HEADERS_4_1
 	bool "Linux 4.1.x kernel headers"
+	depends on !BR2_riscv
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_1
 
 config BR2_KERNEL_HEADERS_4_4
 	bool "Linux 4.4.x kernel headers"
+	depends on !BR2_riscv
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_4
 
 config BR2_KERNEL_HEADERS_4_9
 	bool "Linux 4.9.x kernel headers"
+	depends on !BR2_riscv
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_9
 
 config BR2_KERNEL_HEADERS_4_14
 	bool "Linux 4.14.x kernel headers"
+	depends on !BR2_riscv
 	select BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_14
 
 config BR2_KERNEL_HEADERS_4_16
diff --git a/toolchain/toolchain-buildroot/Config.in b/toolchain/toolchain-buildroot/Config.in
index 75e8191f46..7d9428c70e 100644
--- a/toolchain/toolchain-buildroot/Config.in
+++ b/toolchain/toolchain-buildroot/Config.in
@@ -46,14 +46,16 @@  config BR2_TOOLCHAIN_BUILDROOT_GLIBC
 		   BR2_aarch64_be  || BR2_i386       || BR2_mips    || \
 		   BR2_mipsel      || BR2_mips64     || BR2_mips64el|| \
 		   BR2_powerpc     || BR2_powerpc64  || BR2_powerpc64le || \
-		   BR2_sh          || BR2_sparc64    || BR2_x86_64 || \
-		   BR2_microblaze  || BR2_nios2      || BR2_archs38
+		   BR2_riscv       || BR2_sh         || BR2_sparc64     || \
+		   BR2_x86_64      || BR2_microblaze || BR2_nios2       || \
+		   BR2_archs38
 	depends on BR2_USE_MMU
 	depends on !BR2_STATIC_LIBS
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_2
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10 || !BR2_powerpc64le
 	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_4_5 || !BR2_MIPS_NAN_2008
 	depends on !BR2_powerpc_SPE
+	depends on BR2_RISCV_ISA_RVA || !BR2_riscv
 	select BR2_TOOLCHAIN_USES_GLIBC
 	# our glibc.mk enables RPC support
 	select BR2_TOOLCHAIN_HAS_NATIVE_RPC