diff --git a/gcc/ada/Makefile.rtl b/gcc/ada/Makefile.rtl
index f69170d9fe3..374c60b576e 100644
--- a/gcc/ada/Makefile.rtl
+++ b/gcc/ada/Makefile.rtl
@@ -2468,6 +2468,34 @@ ifeq ($(strip $(filter-out %x32 linux%,$(target_cpu) $(target_os))),)
   LIBRARY_VERSION := $(LIB_VERSION)
 endif
 
+# RISC-V Linux
+ifeq ($(strip $(filter-out riscv% linux%,$(target_cpu) $(target_os))),)
+  LIBGNAT_TARGET_PAIRS = \
+  a-intnam.ads<libgnarl/a-intnam__linux.ads \
+  s-inmaop.adb<libgnarl/s-inmaop__posix.adb \
+  s-intman.adb<libgnarl/s-intman__posix.adb \
+  s-linux.ads<libgnarl/s-linux__riscv.ads \
+  s-osinte.adb<libgnarl/s-osinte__posix.adb \
+  s-osinte.ads<libgnarl/s-osinte__linux.ads \
+  s-osprim.adb<libgnat/s-osprim__posix.adb \
+  s-taprop.adb<libgnarl/s-taprop__linux.adb \
+  s-tasinf.ads<libgnarl/s-tasinf__linux.ads \
+  s-tasinf.adb<libgnarl/s-tasinf__linux.adb \
+  s-taspri.ads<libgnarl/s-taspri__posix-noaltstack.ads \
+  s-tpopsp.adb<libgnarl/s-tpopsp__posix-foreign.adb \
+  g-sercom.adb<libgnat/g-sercom__linux.adb \
+  system.ads<libgnat/system-linux-riscv.ads
+
+  TOOLS_TARGET_PAIRS = indepsw.adb<indepsw-gnu.adb
+
+  EXTRA_GNATRTL_TASKING_OBJS=s-linux.o
+  EH_MECHANISM=-gcc
+  THREADSLIB = -lpthread
+  GNATLIB_SHARED = gnatlib-shared-dual
+  GMEM_LIB = gmemlib
+  LIBRARY_VERSION := $(LIB_VERSION)
+endif
+
 # Darwin (Mac OS X)
 ifeq ($(strip $(filter-out darwin%,$(target_os))),)
   SO_OPTS = -shared-libgcc
diff --git a/gcc/ada/libgnarl/s-linux__riscv.ads b/gcc/ada/libgnarl/s-linux__riscv.ads
new file mode 100644
index 00000000000..74420f39f1b
--- /dev/null
+++ b/gcc/ada/libgnarl/s-linux__riscv.ads
@@ -0,0 +1,133 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS               --
+--                                                                          --
+--                          S Y S T E M .  L I N U X                        --
+--                                                                          --
+--                                  S p e c                                 --
+--                                                                          --
+--             Copyright (C) 2009-2018, Free Software Foundation, Inc.      --
+--                                                                          --
+-- GNARL is free software; you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+------------------------------------------------------------------------------
+
+--  This is the RISC-V version of this package
+
+--  This package encapsulates cpu specific differences between implementations
+--  of GNU/Linux, in order to share s-osinte-linux.ads.
+
+--  PLEASE DO NOT add any with-clauses to this package or remove the pragma
+--  Preelaborate. This package is designed to be a bottom-level (leaf) package
+
+with Interfaces.C;
+
+package System.Linux is
+   pragma Preelaborate;
+
+   ----------
+   -- Time --
+   ----------
+
+   subtype int         is Interfaces.C.int;
+   subtype long        is Interfaces.C.long;
+   subtype suseconds_t is Interfaces.C.long;
+   subtype time_t      is Interfaces.C.long;
+   subtype clockid_t   is Interfaces.C.int;
+
+   type timespec is record
+      tv_sec  : time_t;
+      tv_nsec : long;
+   end record;
+   pragma Convention (C, timespec);
+
+   type timeval is record
+      tv_sec  : time_t;
+      tv_usec : suseconds_t;
+   end record;
+   pragma Convention (C, timeval);
+
+   -----------
+   -- Errno --
+   -----------
+
+   EAGAIN    : constant := 11;
+   EINTR     : constant := 4;
+   EINVAL    : constant := 22;
+   ENOMEM    : constant := 12;
+   EPERM     : constant := 1;
+   ETIMEDOUT : constant := 110;
+
+   -------------
+   -- Signals --
+   -------------
+
+   SIGHUP     : constant := 1; --  hangup
+   SIGINT     : constant := 2; --  interrupt (rubout)
+   SIGQUIT    : constant := 3; --  quit (ASCD FS)
+   SIGILL     : constant := 4; --  illegal instruction (not reset)
+   SIGTRAP    : constant := 5; --  trace trap (not reset)
+   SIGIOT     : constant := 6; --  IOT instruction
+   SIGABRT    : constant := 6; --  used by abort, replace SIGIOT in the  future
+   SIGBUS     : constant := 7; --  bus error
+   SIGFPE     : constant := 8; --  floating point exception
+   SIGKILL    : constant := 9; --  kill (cannot be caught or ignored)
+   SIGUSR1    : constant := 10; --  user defined signal 1
+   SIGSEGV    : constant := 11; --  segmentation violation
+   SIGUSR2    : constant := 12; --  user defined signal 2
+   SIGPIPE    : constant := 13; --  write on a pipe with no one to read it
+   SIGALRM    : constant := 14; --  alarm clock
+   SIGTERM    : constant := 15; --  software termination signal from kill
+   SIGSTKFLT  : constant := 16; --  coprocessor stack fault (Linux)
+   SIGCLD     : constant := 17; --  alias for SIGCHLD
+   SIGCHLD    : constant := 17; --  child status change
+   SIGCONT    : constant := 18; --  stopped process has been continued
+   SIGSTOP    : constant := 19; --  stop (cannot be caught or ignored)
+   SIGTSTP    : constant := 20; --  user stop requested from tty
+   SIGTTIN    : constant := 21; --  background tty read attempted
+   SIGTTOU    : constant := 22; --  background tty write attempted
+   SIGURG     : constant := 23; --  urgent condition on IO channel
+   SIGXCPU    : constant := 24; --  CPU time limit exceeded
+   SIGXFSZ    : constant := 25; --  filesize limit exceeded
+   SIGVTALRM  : constant := 26; --  virtual timer expired
+   SIGPROF    : constant := 28; --  profiling timer expired
+   SIGWINCH   : constant := 28; --  window size change
+   SIGPOLL    : constant := 29; --  pollable event occurred
+   SIGIO      : constant := 29; --  I/O now possible (4.2 BSD)
+   SIGPWR     : constant := 30; --  power-fail restart
+   SIGSYS     : constant := 31; --  bad system call
+
+   SIGLTHRRES : constant := 0; --  GNU/LinuxThreads restart signal
+   SIGLTHRCAN : constant := 0; --  GNU/LinuxThreads cancel signal
+   SIGLTHRDBG : constant := 0; --  GNU/LinuxThreads debugger signal
+
+   --  These don't exist for Linux/RISC-V.  The constants are present
+   --  so that we can continue to use a-intnam-linux.ads.
+   SIGLOST    : constant := 0; --  File lock lost
+   SIGUNUSED  : constant := 0; --  unused signal (GNU/Linux)
+   SIGEMT     : constant := 0; --  EMT
+
+   --  struct_sigaction offsets
+
+   sa_handler_pos : constant := 0;
+   sa_mask_pos    : constant := long'Size / 8;
+   sa_flags_pos   : constant := long'Size / 8 + 128;
+
+   SA_SIGINFO  : constant := 16#04#;
+   SA_ONSTACK  : constant := 16#08000000#;
+
+end System.Linux;
diff --git a/gcc/ada/libgnat/system-linux-riscv.ads b/gcc/ada/libgnat/system-linux-riscv.ads
new file mode 100644
index 00000000000..8e43b401450
--- /dev/null
+++ b/gcc/ada/libgnat/system-linux-riscv.ads
@@ -0,0 +1,147 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                        GNAT RUN-TIME COMPONENTS                          --
+--                                                                          --
+--                               S Y S T E M                                --
+--                                                                          --
+--                                 S p e c                                  --
+--                          (GNU-Linux/RISC-V Version)                      --
+--                                                                          --
+--          Copyright (C) 1992-2018, Free Software Foundation, Inc.         --
+--                                                                          --
+-- This specification is derived from the Ada Reference Manual for use with --
+-- GNAT. The copyright notice above, and the license provisions that follow --
+-- apply solely to the  contents of the part following the private keyword. --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- GNAT was originally developed  by the GNAT team at  New York University. --
+-- Extensive contributions were provided by Ada Core Technologies Inc.      --
+--                                                                          --
+------------------------------------------------------------------------------
+
+package System is
+   pragma Pure;
+   --  Note that we take advantage of the implementation permission to make
+   --  this unit Pure instead of Preelaborable; see RM 13.7.1(15). In Ada
+   --  2005, this is Pure in any case (AI-362).
+
+   pragma No_Elaboration_Code_All;
+   --  Allow the use of that restriction in units that WITH this unit
+
+   type Name is (SYSTEM_NAME_GNAT);
+   System_Name : constant Name := SYSTEM_NAME_GNAT;
+
+   --  System-Dependent Named Numbers
+
+   Min_Int               : constant := Long_Long_Integer'First;
+   Max_Int               : constant := Long_Long_Integer'Last;
+
+   Max_Binary_Modulus    : constant := 2 ** Long_Long_Integer'Size;
+   Max_Nonbinary_Modulus : constant := Integer'Last;
+
+   Max_Base_Digits       : constant := Long_Long_Float'Digits;
+   Max_Digits            : constant := Long_Long_Float'Digits;
+
+   Max_Mantissa          : constant := 63;
+   Fine_Delta            : constant := 2.0 ** (-Max_Mantissa);
+
+   Tick                  : constant := 0.000_001;
+
+   --  Storage-related Declarations
+
+   type Address is private;
+   pragma Preelaborable_Initialization (Address);
+   Null_Address : constant Address;
+
+   Storage_Unit : constant := 8;
+   Word_Size    : constant := Standard'Word_Size;
+   Memory_Size  : constant := 2 ** Word_Size;
+
+   --  Address comparison
+
+   function "<"  (Left, Right : Address) return Boolean;
+   function "<=" (Left, Right : Address) return Boolean;
+   function ">"  (Left, Right : Address) return Boolean;
+   function ">=" (Left, Right : Address) return Boolean;
+   function "="  (Left, Right : Address) return Boolean;
+
+   pragma Import (Intrinsic, "<");
+   pragma Import (Intrinsic, "<=");
+   pragma Import (Intrinsic, ">");
+   pragma Import (Intrinsic, ">=");
+   pragma Import (Intrinsic, "=");
+
+   --  Other System-Dependent Declarations
+
+   type Bit_Order is (High_Order_First, Low_Order_First);
+   Default_Bit_Order : constant Bit_Order := Low_Order_First;
+   pragma Warnings (Off, Default_Bit_Order); -- kill constant condition warning
+
+   --  Priority-related Declarations (RM D.1)
+
+   Max_Priority           : constant Positive := 30;
+   Max_Interrupt_Priority : constant Positive := 31;
+
+   subtype Any_Priority       is Integer      range  0 .. 31;
+   subtype Priority           is Any_Priority range  0 .. 30;
+   subtype Interrupt_Priority is Any_Priority range 31 .. 31;
+
+   Default_Priority : constant Priority := 15;
+
+private
+
+   type Address is mod Memory_Size;
+   Null_Address : constant Address := 0;
+
+   --------------------------------------
+   -- System Implementation Parameters --
+   --------------------------------------
+
+   --  These parameters provide information about the target that is used
+   --  by the compiler. They are in the private part of System, where they
+   --  can be accessed using the special circuitry in the Targparm unit
+   --  whose source should be consulted for more detailed descriptions
+   --  of the individual switch values.
+
+   Backend_Divide_Checks     : constant Boolean := False;
+   Backend_Overflow_Checks   : constant Boolean := True;
+   Command_Line_Args         : constant Boolean := True;
+   Configurable_Run_Time     : constant Boolean := False;
+   Denorm                    : constant Boolean := True;
+   Duration_32_Bits          : constant Boolean := False;
+   Exit_Status_Supported     : constant Boolean := True;
+   Fractional_Fixed_Ops      : constant Boolean := False;
+   Frontend_Layout           : constant Boolean := False;
+   Machine_Overflows         : constant Boolean := False;
+   Machine_Rounds            : constant Boolean := True;
+   Preallocated_Stacks       : constant Boolean := False;
+   Signed_Zeros              : constant Boolean := True;
+   Stack_Check_Default       : constant Boolean := False;
+   Stack_Check_Probes        : constant Boolean := True;
+   Stack_Check_Limits        : constant Boolean := False;
+   Support_Aggregates        : constant Boolean := True;
+   Support_Composite_Assign  : constant Boolean := True;
+   Support_Composite_Compare : constant Boolean := True;
+   Support_Long_Shifts       : constant Boolean := True;
+   Always_Compatible_Rep     : constant Boolean := False;
+   Suppress_Standard_Library : constant Boolean := False;
+   Use_Ada_Main_Program_Name : constant Boolean := False;
+   Frontend_Exceptions       : constant Boolean := False;
+   ZCX_By_Default            : constant Boolean := True;
+
+end System;
