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authorPalmer Dabbelt <palmer@dabbelt.com>2018-01-29 10:30:24 -0800
committerPalmer Dabbelt <palmer@dabbelt.com>2018-01-29 10:43:15 -0800
commitc5061557092769e2440e1f7a41552db1de1fc486 (patch)
tree3128313ef8c705b1d7c2bd53f5457b6295125493
parent2268c4337ce97283c0b507ef1bfd8934edbe9b96 (diff)
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RISC-V: Build Infastructure
This patch lays out the top-level orginazition of the RISC-V port. It contains all the Implies files as well as various other fragments of build infastructure for the RISC-V port. This contains the only change to a shared file: config.h.in. RISC-V is a family of base ISAs with optional extensions. The base ISAs are RV32I and RV64I, which are 32-bit and 64-bit integer-only ISAs, but this port currently only supports RV64I based systems. Support for RISC-V lives in in sysdeps/riscv. In addition to these ISAs, our glibc port supports most of the currently-defined extensions: the A extension for atomics, the M extension for multiplication, the C extension for compressed instructions, and the F/D extensions for single/double precision IEEE floating-point. Most of these extensions are handled by GCC, but glibc defines various floating-point wrappers and emulation routines as well as some atomic wrappers. We support running glibc-based programs on Linux, the support for which lives in sysdeps/unix/sysv/linux/riscv. 2018-01-29 Palmer Dabbelt <palmer@sifive.com> * sysdeps/riscv/Implies: New file. * sysdeps/riscv/Makefile: Likewise. * sysdeps/riscv/configure: Likewise. * sysdeps/riscv/configure.ac: Likewise. * sysdeps/riscv/nptl/Makefile: Likewise. * sysdeps/riscv/preconfigure: Likewise. * sysdeps/riscv/rv64/Implies-after: Likewise. * sysdeps/riscv/rv64/rvd/Implies: Likewise. * sysdeps/riscv/rv64/rvf/Implies: Likewise. * sysdeps/unix/sysv/linux/riscv/Implies: Likewise. * sysdeps/unix/sysv/linux/riscv/Makefile: Likewise. * sysdeps/unix/sysv/linux/riscv/Versions: Likewise. * sysdeps/unix/sysv/linux/riscv/configure: Likewise. * sysdeps/unix/sysv/linux/riscv/configure.ac: Likewise. * sysdeps/unix/sysv/linux/riscv/ldd-rewrite.sed: Likewise. * sysdeps/unix/sysv/linux/riscv/rv64/Implies: Likewise. * sysdeps/unix/sysv/linux/riscv/rv64/Makefile: Likewise. * sysdeps/unix/sysv/linux/riscv/shlib-versions: Likewise.
-rw-r--r--ChangeLog18
-rw-r--r--sysdeps/riscv/Implies5
-rw-r--r--sysdeps/riscv/Makefile7
-rw-r--r--sysdeps/riscv/configure4
-rw-r--r--sysdeps/riscv/configure.ac4
-rw-r--r--sysdeps/riscv/nptl/Makefile26
-rw-r--r--sysdeps/riscv/preconfigure71
-rw-r--r--sysdeps/riscv/rv64/Implies-after1
-rw-r--r--sysdeps/riscv/rv64/rvd/Implies3
-rw-r--r--sysdeps/riscv/rv64/rvf/Implies1
-rw-r--r--sysdeps/unix/sysv/linux/riscv/Implies1
-rw-r--r--sysdeps/unix/sysv/linux/riscv/Makefile25
-rw-r--r--sysdeps/unix/sysv/linux/riscv/Versions11
-rwxr-xr-xsysdeps/unix/sysv/linux/riscv/configure219
-rw-r--r--sysdeps/unix/sysv/linux/riscv/configure.ac38
-rw-r--r--sysdeps/unix/sysv/linux/riscv/ldd-rewrite.sed1
-rw-r--r--sysdeps/unix/sysv/linux/riscv/rv64/Implies3
-rw-r--r--sysdeps/unix/sysv/linux/riscv/rv64/Makefile4
-rw-r--r--sysdeps/unix/sysv/linux/riscv/shlib-versions9
19 files changed, 451 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog
index 2ecbbb5db7..5f167cbd38 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -144,6 +144,24 @@
* sysdeps/unix/sysv/linux/riscv/rv64/libnsl.abilist: Likewise.
* sysdeps/unix/sysv/linux/riscv/rv64/librt.abilist: Likewise.
* sysdeps/unix/sysv/linux/riscv/rv64/libutil.abilist: Likewise.
+ * sysdeps/riscv/Implies: New file.
+ * sysdeps/riscv/Makefile: Likewise.
+ * sysdeps/riscv/configure: Likewise.
+ * sysdeps/riscv/configure.ac: Likewise.
+ * sysdeps/riscv/nptl/Makefile: Likewise.
+ * sysdeps/riscv/preconfigure: Likewise.
+ * sysdeps/riscv/rv64/Implies-after: Likewise.
+ * sysdeps/riscv/rv64/rvd/Implies: Likewise.
+ * sysdeps/riscv/rv64/rvf/Implies: Likewise.
+ * sysdeps/unix/sysv/linux/riscv/Implies: Likewise.
+ * sysdeps/unix/sysv/linux/riscv/Makefile: Likewise.
+ * sysdeps/unix/sysv/linux/riscv/Versions: Likewise.
+ * sysdeps/unix/sysv/linux/riscv/configure: Likewise.
+ * sysdeps/unix/sysv/linux/riscv/configure.ac: Likewise.
+ * sysdeps/unix/sysv/linux/riscv/ldd-rewrite.sed: Likewise.
+ * sysdeps/unix/sysv/linux/riscv/rv64/Implies: Likewise.
+ * sysdeps/unix/sysv/linux/riscv/rv64/Makefile: Likewise.
+ * sysdeps/unix/sysv/linux/riscv/shlib-versions: Likewise.
2018-01-29 Florian Weimer <fweimer@redhat.com>
diff --git a/sysdeps/riscv/Implies b/sysdeps/riscv/Implies
new file mode 100644
index 0000000000..c88325b8be
--- /dev/null
+++ b/sysdeps/riscv/Implies
@@ -0,0 +1,5 @@
+init_array
+
+ieee754/ldbl-128
+ieee754/dbl-64
+ieee754/flt-32
diff --git a/sysdeps/riscv/Makefile b/sysdeps/riscv/Makefile
new file mode 100644
index 0000000000..20a9968106
--- /dev/null
+++ b/sysdeps/riscv/Makefile
@@ -0,0 +1,7 @@
+ifeq ($(subdir),misc)
+sysdep_headers += sys/asm.h
+endif
+
+# RISC-V's assembler also needs to know about PIC as it changes the definition
+# of some assembler macros.
+ASFLAGS-.os += $(pic-ccflag)
diff --git a/sysdeps/riscv/configure b/sysdeps/riscv/configure
new file mode 100644
index 0000000000..53f5f1b5f1
--- /dev/null
+++ b/sysdeps/riscv/configure
@@ -0,0 +1,4 @@
+# This file is generated from configure.ac by Autoconf. DO NOT EDIT!
+ # Local configure fragment for sysdeps/riscv/elf.
+
+$as_echo "#define PI_STATIC_AND_HIDDEN 1" >>confdefs.h
diff --git a/sysdeps/riscv/configure.ac b/sysdeps/riscv/configure.ac
new file mode 100644
index 0000000000..34f62d4b4b
--- /dev/null
+++ b/sysdeps/riscv/configure.ac
@@ -0,0 +1,4 @@
+GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
+# Local configure fragment for sysdeps/riscv/elf.
+
+AC_DEFINE(PI_STATIC_AND_HIDDEN)
diff --git a/sysdeps/riscv/nptl/Makefile b/sysdeps/riscv/nptl/Makefile
new file mode 100644
index 0000000000..c3cc7f36da
--- /dev/null
+++ b/sysdeps/riscv/nptl/Makefile
@@ -0,0 +1,26 @@
+# Makefile for sysdeps/riscv/nptl.
+# Copyright (C) 2005-2018 Free Software Foundation, Inc.
+# This file is part of the GNU C Library.
+#
+# The GNU C Library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# The GNU C Library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with the GNU C Library; if not, see
+# <http://www.gnu.org/licenses/>.
+
+ifeq ($(subdir),csu)
+gen-as-const-headers += tcb-offsets.sym
+endif
+
+ifeq ($(subdir),nptl)
+libpthread-sysdep_routines += nptl-sysdep
+libpthread-shared-only-routines += nptl-sysdep
+endif
diff --git a/sysdeps/riscv/preconfigure b/sysdeps/riscv/preconfigure
new file mode 100644
index 0000000000..d9adb31b64
--- /dev/null
+++ b/sysdeps/riscv/preconfigure
@@ -0,0 +1,71 @@
+case "$machine" in
+riscv*)
+ xlen=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_xlen \(.*\)/\1/p'`
+ flen=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_flen \(.*\)/\1/p'`
+ float_abi=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | sed -n 's/^#define __riscv_float_abi_\([^ ]*\) .*/\1/p'`
+ atomic=`$CC $CFLAGS $CPPFLAGS -E -dM -xc /dev/null | grep '#define __riscv_atomic' | cut -d' ' -f2`
+
+ case "$xlen" in
+ 32)
+ echo "glibc does not yet support 32-bit systems" >&2
+ exit 1
+ ;;
+ 64)
+ ;;
+ *)
+ echo "Unable to determine XLEN" >&2
+ exit 1
+ ;;
+ esac
+
+ case "$flen" in
+ 64)
+ float_machine=rvd
+ with_fp_cond=1
+ ;;
+ 32)
+ echo "glibc does not yet support systems with the F but not D extensions" >&2
+ exit 1
+ ;;
+ "")
+ with_fp_cond=0
+ ;;
+ *)
+ echo "Unable to determine FLEN" >&2
+ exit 1
+ ;;
+ esac
+
+ case "$float_abi" in
+ soft)
+ abi_flen=0
+ ;;
+ single)
+ echo "glibc does not yet support the single floating-point ABI" >&2
+ exit 1
+ ;;
+ double)
+ abi_flen=64
+ ;;
+ *)
+ echo "Unable to determine floating-point ABI" >&2
+ exit 1
+ ;;
+ esac
+
+ case "$atomic" in
+ __riscv_atomic)
+ ;;
+ *)
+ echo "glibc requires the A extension" >&2
+ exit 1
+ ;;
+ esac
+
+ base_machine=riscv
+ machine=riscv/rv$xlen/$float_machine
+
+ $as_echo "#define RISCV_ABI_XLEN $xlen" >>confdefs.h
+ $as_echo "#define RISCV_ABI_FLEN $abi_flen" >>confdefs.h
+ ;;
+esac
diff --git a/sysdeps/riscv/rv64/Implies-after b/sysdeps/riscv/rv64/Implies-after
new file mode 100644
index 0000000000..a8cae95f9d
--- /dev/null
+++ b/sysdeps/riscv/rv64/Implies-after
@@ -0,0 +1 @@
+wordsize-64
diff --git a/sysdeps/riscv/rv64/rvd/Implies b/sysdeps/riscv/rv64/rvd/Implies
new file mode 100644
index 0000000000..42fb132d12
--- /dev/null
+++ b/sysdeps/riscv/rv64/rvd/Implies
@@ -0,0 +1,3 @@
+riscv/rv64/rvf
+riscv/rvd
+riscv/rvf
diff --git a/sysdeps/riscv/rv64/rvf/Implies b/sysdeps/riscv/rv64/rvf/Implies
new file mode 100644
index 0000000000..66c401443b
--- /dev/null
+++ b/sysdeps/riscv/rv64/rvf/Implies
@@ -0,0 +1 @@
+riscv/rvf
diff --git a/sysdeps/unix/sysv/linux/riscv/Implies b/sysdeps/unix/sysv/linux/riscv/Implies
new file mode 100644
index 0000000000..6faec70115
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/Implies
@@ -0,0 +1 @@
+riscv/nptl
diff --git a/sysdeps/unix/sysv/linux/riscv/Makefile b/sysdeps/unix/sysv/linux/riscv/Makefile
new file mode 100644
index 0000000000..b47858769f
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/Makefile
@@ -0,0 +1,25 @@
+ifeq ($(subdir),elf)
+sysdep_routines += dl-vdso
+ifeq ($(build-shared),yes)
+# This is needed for DSO loading from static binaries.
+sysdep-dl-routines += dl-static
+endif
+endif
+
+ifeq ($(subdir),misc)
+sysdep_headers += sys/cachectl.h
+sysdep_routines += flush-icache
+endif
+
+ifeq ($(subdir),stdlib)
+gen-as-const-headers += ucontext_i.sym
+endif
+
+abi-variants := lp64 lp64d
+
+ifeq (,$(filter $(default-abi),$(abi-variants)))
+$(error Unknown ABI $(default-abi), must be one of $(abi-variants))
+endif
+
+abi-lp64-condition := defined __LP64__ && defined __riscv_float_abi_soft
+abi-lp64d-condition := defined __LP64__ && defined __riscv_float_abi_double
diff --git a/sysdeps/unix/sysv/linux/riscv/Versions b/sysdeps/unix/sysv/linux/riscv/Versions
new file mode 100644
index 0000000000..5625d2a0b8
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/Versions
@@ -0,0 +1,11 @@
+ld {
+ GLIBC_PRIVATE {
+ # used for loading by static libraries
+ _dl_var_init;
+ }
+}
+libc {
+ GLIBC_2.27 {
+ __riscv_flush_icache;
+ }
+}
diff --git a/sysdeps/unix/sysv/linux/riscv/configure b/sysdeps/unix/sysv/linux/riscv/configure
new file mode 100755
index 0000000000..816e9145eb
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/configure
@@ -0,0 +1,219 @@
+# This file is generated from configure.ac by Autoconf. DO NOT EDIT!
+ # Local configure fragment for sysdeps/unix/sysv/linux/riscv.
+
+arch_minimum_kernel=4.15.0
+
+libc_cv_riscv_int_abi=no
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for grep that handles long lines and -e" >&5
+$as_echo_n "checking for grep that handles long lines and -e... " >&6; }
+if ${ac_cv_path_GREP+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ if test -z "$GREP"; then
+ ac_path_GREP_found=false
+ # Loop through the user's path and test for each of PROGNAME-LIST
+ as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH$PATH_SEPARATOR/usr/xpg4/bin
+do
+ IFS=$as_save_IFS
+ test -z "$as_dir" && as_dir=.
+ for ac_prog in grep ggrep; do
+ for ac_exec_ext in '' $ac_executable_extensions; do
+ ac_path_GREP="$as_dir/$ac_prog$ac_exec_ext"
+ as_fn_executable_p "$ac_path_GREP" || continue
+# Check for GNU ac_path_GREP and select it if it is found.
+ # Check for GNU $ac_path_GREP
+case `"$ac_path_GREP" --version 2>&1` in
+*GNU*)
+ ac_cv_path_GREP="$ac_path_GREP" ac_path_GREP_found=:;;
+*)
+ ac_count=0
+ $as_echo_n 0123456789 >"conftest.in"
+ while :
+ do
+ cat "conftest.in" "conftest.in" >"conftest.tmp"
+ mv "conftest.tmp" "conftest.in"
+ cp "conftest.in" "conftest.nl"
+ $as_echo 'GREP' >> "conftest.nl"
+ "$ac_path_GREP" -e 'GREP$' -e '-(cannot match)-' < "conftest.nl" >"conftest.out" 2>/dev/null || break
+ diff "conftest.out" "conftest.nl" >/dev/null 2>&1 || break
+ as_fn_arith $ac_count + 1 && ac_count=$as_val
+ if test $ac_count -gt ${ac_path_GREP_max-0}; then
+ # Best one so far, save it but keep looking for a better one
+ ac_cv_path_GREP="$ac_path_GREP"
+ ac_path_GREP_max=$ac_count
+ fi
+ # 10*(2^10) chars as input seems more than enough
+ test $ac_count -gt 10 && break
+ done
+ rm -f conftest.in conftest.tmp conftest.nl conftest.out;;
+esac
+
+ $ac_path_GREP_found && break 3
+ done
+ done
+ done
+IFS=$as_save_IFS
+ if test -z "$ac_cv_path_GREP"; then
+ as_fn_error $? "no acceptable grep could be found in $PATH$PATH_SEPARATOR/usr/xpg4/bin" "$LINENO" 5
+ fi
+else
+ ac_cv_path_GREP=$GREP
+fi
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_path_GREP" >&5
+$as_echo "$ac_cv_path_GREP" >&6; }
+ GREP="$ac_cv_path_GREP"
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for egrep" >&5
+$as_echo_n "checking for egrep... " >&6; }
+if ${ac_cv_path_EGREP+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ if echo a | $GREP -E '(a|b)' >/dev/null 2>&1
+ then ac_cv_path_EGREP="$GREP -E"
+ else
+ if test -z "$EGREP"; then
+ ac_path_EGREP_found=false
+ # Loop through the user's path and test for each of PROGNAME-LIST
+ as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH$PATH_SEPARATOR/usr/xpg4/bin
+do
+ IFS=$as_save_IFS
+ test -z "$as_dir" && as_dir=.
+ for ac_prog in egrep; do
+ for ac_exec_ext in '' $ac_executable_extensions; do
+ ac_path_EGREP="$as_dir/$ac_prog$ac_exec_ext"
+ as_fn_executable_p "$ac_path_EGREP" || continue
+# Check for GNU ac_path_EGREP and select it if it is found.
+ # Check for GNU $ac_path_EGREP
+case `"$ac_path_EGREP" --version 2>&1` in
+*GNU*)
+ ac_cv_path_EGREP="$ac_path_EGREP" ac_path_EGREP_found=:;;
+*)
+ ac_count=0
+ $as_echo_n 0123456789 >"conftest.in"
+ while :
+ do
+ cat "conftest.in" "conftest.in" >"conftest.tmp"
+ mv "conftest.tmp" "conftest.in"
+ cp "conftest.in" "conftest.nl"
+ $as_echo 'EGREP' >> "conftest.nl"
+ "$ac_path_EGREP" 'EGREP$' < "conftest.nl" >"conftest.out" 2>/dev/null || break
+ diff "conftest.out" "conftest.nl" >/dev/null 2>&1 || break
+ as_fn_arith $ac_count + 1 && ac_count=$as_val
+ if test $ac_count -gt ${ac_path_EGREP_max-0}; then
+ # Best one so far, save it but keep looking for a better one
+ ac_cv_path_EGREP="$ac_path_EGREP"
+ ac_path_EGREP_max=$ac_count
+ fi
+ # 10*(2^10) chars as input seems more than enough
+ test $ac_count -gt 10 && break
+ done
+ rm -f conftest.in conftest.tmp conftest.nl conftest.out;;
+esac
+
+ $ac_path_EGREP_found && break 3
+ done
+ done
+ done
+IFS=$as_save_IFS
+ if test -z "$ac_cv_path_EGREP"; then
+ as_fn_error $? "no acceptable egrep could be found in $PATH$PATH_SEPARATOR/usr/xpg4/bin" "$LINENO" 5
+ fi
+else
+ ac_cv_path_EGREP=$EGREP
+fi
+
+ fi
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_path_EGREP" >&5
+$as_echo "$ac_cv_path_EGREP" >&6; }
+ EGREP="$ac_cv_path_EGREP"
+
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+__SIZEOF_INT__ __SIZEOF_LONG__ __SIZEOF_POINTER__
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+ $EGREP "4 8 8" >/dev/null 2>&1; then :
+ libc_cv_riscv_int_abi=lp64
+fi
+rm -f conftest*
+
+if test $libc_cv_riscv_int_abi = no; then
+ as_fn_error $? "Unable to determine integer ABI" "$LINENO" 5
+fi
+
+libc_cv_riscv_float_abi=no
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+#ifdef __riscv_float_abi_double
+ yes
+ #endif
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+ $EGREP "yes" >/dev/null 2>&1; then :
+ libc_cv_riscv_float_abi=d
+fi
+rm -f conftest*
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+#ifdef __riscv_float_abi_soft
+ yes
+ #endif
+
+_ACEOF
+if (eval "$ac_cpp conftest.$ac_ext") 2>&5 |
+ $EGREP "yes" >/dev/null 2>&1; then :
+ libc_cv_riscv_float_abi=
+fi
+rm -f conftest*
+
+if test $libc_cv_riscv_float_abi = no; then
+ as_fn_error $? "Unable to determine floating-point ABI" "$LINENO" 5
+fi
+
+config_vars="$config_vars
+default-abi = $libc_cv_riscv_int_abi$libc_cv_riscv_float_abi"
+
+case $libc_cv_riscv_int_abi$libc_cv_riscv_float_abi-$machine in
+lp64-riscv/rv64/*)
+ test -n "$libc_cv_slibdir" ||
+case "$prefix" in
+/usr | /usr/)
+ libc_cv_slibdir='/lib64/lp64'
+ libc_cv_rtlddir='/lib'
+ if test "$libdir" = '${exec_prefix}/lib'; then
+ libdir='${exec_prefix}/lib64/lp64';
+ # Locale data can be shared between 32-bit and 64-bit libraries.
+ libc_cv_complocaledir='${exec_prefix}/lib/locale'
+ fi
+ ;;
+esac
+ ;;
+lp64d-riscv/rv64/*)
+ test -n "$libc_cv_slibdir" ||
+case "$prefix" in
+/usr | /usr/)
+ libc_cv_slibdir='/lib64/lp64d'
+ libc_cv_rtlddir='/lib'
+ if test "$libdir" = '${exec_prefix}/lib'; then
+ libdir='${exec_prefix}/lib64/lp64d';
+ # Locale data can be shared between 32-bit and 64-bit libraries.
+ libc_cv_complocaledir='${exec_prefix}/lib/locale'
+ fi
+ ;;
+esac
+ ;;
+esac
+
+ldd_rewrite_script=sysdeps/unix/sysv/linux/riscv/ldd-rewrite.sed
diff --git a/sysdeps/unix/sysv/linux/riscv/configure.ac b/sysdeps/unix/sysv/linux/riscv/configure.ac
new file mode 100644
index 0000000000..4fae013ec9
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/configure.ac
@@ -0,0 +1,38 @@
+sinclude(./aclocal.m4)dnl Autoconf lossage
+GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
+# Local configure fragment for sysdeps/unix/sysv/linux/riscv.
+
+arch_minimum_kernel=4.15.0
+
+libc_cv_riscv_int_abi=no
+AC_EGREP_CPP(4 8 8, [__SIZEOF_INT__ __SIZEOF_LONG__ __SIZEOF_POINTER__
+ ], libc_cv_riscv_int_abi=lp64)
+if test $libc_cv_riscv_int_abi = no; then
+ AC_MSG_ERROR([Unable to determine integer ABI])
+fi
+
+libc_cv_riscv_float_abi=no
+AC_EGREP_CPP(yes, [#ifdef __riscv_float_abi_double
+ yes
+ #endif
+ ],libc_cv_riscv_float_abi=d)
+AC_EGREP_CPP(yes, [#ifdef __riscv_float_abi_soft
+ yes
+ #endif
+ ],libc_cv_riscv_float_abi=)
+if test $libc_cv_riscv_float_abi = no; then
+ AC_MSG_ERROR([Unable to determine floating-point ABI])
+fi
+
+LIBC_CONFIG_VAR([default-abi], [$libc_cv_riscv_int_abi$libc_cv_riscv_float_abi])
+
+case $libc_cv_riscv_int_abi$libc_cv_riscv_float_abi-$machine in
+lp64-riscv/rv64/*)
+ LIBC_SLIBDIR_RTLDDIR([lib64/lp64], [lib])
+ ;;
+lp64d-riscv/rv64/*)
+ LIBC_SLIBDIR_RTLDDIR([lib64/lp64d], [lib])
+ ;;
+esac
+
+ldd_rewrite_script=sysdeps/unix/sysv/linux/riscv/ldd-rewrite.sed
diff --git a/sysdeps/unix/sysv/linux/riscv/ldd-rewrite.sed b/sysdeps/unix/sysv/linux/riscv/ldd-rewrite.sed
new file mode 100644
index 0000000000..377a9c6ef4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/ldd-rewrite.sed
@@ -0,0 +1 @@
+s_^\(RTLDLIST=\)\(.*lib/\)\(ld-linux\)-\(riscv64\)-\(lp64\)\(d*\)\(\.so\.[0-9.]*\)_\1"\2\3-\4-\5\7 \2\3-\4-\5d\7"_
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/Implies b/sysdeps/unix/sysv/linux/riscv/rv64/Implies
new file mode 100644
index 0000000000..f042343bf7
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/Implies
@@ -0,0 +1,3 @@
+unix/sysv/linux/riscv
+unix/sysv/linux/generic
+unix/sysv/linux/wordsize-64
diff --git a/sysdeps/unix/sysv/linux/riscv/rv64/Makefile b/sysdeps/unix/sysv/linux/riscv/rv64/Makefile
new file mode 100644
index 0000000000..cb60d74047
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/rv64/Makefile
@@ -0,0 +1,4 @@
+ifeq ($(subdir),socket)
+CFLAGS-recv.c += -fexceptions
+CFLAGS-send.c += -fexceptions
+endif
diff --git a/sysdeps/unix/sysv/linux/riscv/shlib-versions b/sysdeps/unix/sysv/linux/riscv/shlib-versions
new file mode 100644
index 0000000000..98c9b29cc4
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/shlib-versions
@@ -0,0 +1,9 @@
+DEFAULT GLIBC_2.27
+
+%if RISCV_ABI_XLEN == 64 && RISCV_ABI_FLEN == 64
+ld=ld-linux-riscv64-lp64d.so.1
+%elif RISCV_ABI_XLEN == 64 && RISCV_ABI_FLEN == 0
+ld=ld-linux-riscv64-lp64.so.1
+%else
+%error cannot determine ABI
+%endif