--- config.sub	2016-12-01 14:15:39.000000000 +0100
+++ config.sub	2016-12-01 14:16:53.000000000 +0100
@@ -1376,6 +1376,7 @@
 	-gnu* | -bsd* | -mach* | -minix* | -genix* | -ultrix* | -irix* \
 	      | -*vms* | -sco* | -esix* | -isc* | -aix* | -cnk* | -sunos | -sunos[34]*\
 	      | -hpux* | -unos* | -osf* | -luna* | -dgux* | -auroraux* | -solaris* \
+        | -mittos64* \
 	      | -sym* | -kopensolaris* | -plan9* \
 	      | -amigaos* | -amigados* | -msdos* | -newsos* | -unicos* | -aof* \
 	      | -aos* | -aros* | -cloudabi* | -sortix* \

--- gcc/config.gcc	2016-12-01 16:08:28.000000000 +0100
+++ gcc/config.gcc	2016-12-01 16:08:12.000000000 +0100
@@ -612,6 +612,12 @@
 
 # Common parts for widely ported systems.
 case ${target} in
+*-*-mittos64)
+  gas=yes
+  gnu_ld=yes
+  default_use_cxa_atexit=yes
+  use_gcc_stdint=wrap
+  ;;
 *-*-darwin*)
   tmake_file="t-darwin ${cpu_type}/t-darwin"
   tm_file="${tm_file} darwin.h"
@@ -907,6 +912,12 @@
 esac
 
 case ${target} in
+i[34567]86-*-mittos64*)
+	tm_file="${tm_file} i386/unix.h i386/att.h dbxelf.h elfos.h newlib-stdint.h i386/i386elf.h mittos64.h"
+	;;
+x86_64-*-mittos64*)
+	tm_file="${tm_file} i386/unix.h i386/att.h dbxelf.h elfos.h newlib-stdint.h i386/i386elf.h i386/x86-64.h mittos64.h"
+	;;
 aarch64*-*-elf | aarch64*-*-rtems*)
 	tm_file="${tm_file} dbxelf.h elfos.h newlib-stdint.h"
 	tm_file="${tm_file} aarch64/aarch64-elf.h aarch64/aarch64-elf-raw.h"

--- /dev/null	2016-12-01 16:23:01.000000000 +0100
+++ gcc/config/mittos64.h	2016-12-01 16:15:32.000000000 +0100
@@ -0,0 +1,20 @@
+#undef TARGET_MITTOS64
+#define TARGET_MITTOS64 1
+
+#define LIB_SPEC "-lc"
+
+#define STARTFILE_SPEC "crt0.o%s crti.o%s crtbegin.o%s"
+#define ENDFILE_SPEC "crtend.o%s crtn.o%s"
+
+#undef NO_IMPLICIT_EXTERN_C
+#define NO_IMPLICIT_EXTERN_C 1
+
+#undef TARGET_OS_CPP_BUILTINS
+#define TARGET_OS_CPP_BUILTINS() \
+  do { \
+    builtin_define ("__mittos64__"); \
+    builtin_define ("__unix__"); \
+    builtin_assert ("system=mittos64"); \
+    builtin_assert ("system=unix"); \
+    builtin_assert ("system=posix"); \
+  } while(0);

--- libstdc++-v3/crossconfig.m4	2016-12-01 16:16:26.000000000 +0100
+++ libstdc++-v3/crossconfig.m4	2016-12-01 16:17:22.000000000 +0100
@@ -5,6 +5,12 @@
 AC_DEFUN([GLIBCXX_CROSSCONFIG],[
 # Base decisions on target environment.
 case "${host}" in
+  *-mittos64*)
+    GLIBCXX_CHECK_COMPILER_FEATURES
+    GLIBCXX_CHECK_LINKER_FEATURES
+    GLIBCXX_CHECK_MATH_SUPPORT
+    GLIBCXX_CHECK_STDLIB_SUPPORT
+    ;;
   arm*-*-symbianelf*)
     # This is a freestanding configuration; there is nothing to do here.
     ;;

--- libgcc/config.host	2016-12-01 16:17:44.000000000 +0100
+++ libgcc/config.host	2016-12-01 16:20:42.000000000 +0100
@@ -327,6 +327,14 @@
 esac
 
 case ${host} in
+i[34567]86-*-mittos64*)
+	extra_parts="$extra_parts crtbegin.o crtend.o"
+	tmake_file="$tmake_file i386/t-crtstuff t-crtstuff-pic t-libgcc-pic"
+	;;
+x86_64-*-mittos64*)
+	extra_parts="$extra_parts crtbegin.o crtend.o"
+	tmake_file="$tmake_file i386/t-crtstuff t-crtstuff-pic t-libgcc-pic"
+	;;
 aarch64*-*-elf | aarch64*-*-rtems*)
 	extra_parts="$extra_parts crtbegin.o crtend.o crti.o crtn.o"
 	extra_parts="$extra_parts crtfastmath.o"

--- fixincludes/mkfixinc.sh	2016-12-01 16:22:08.000000000 +0100
+++ fixincludes/mkfixinc.sh	2016-12-01 16:22:41.000000000 +0100
@@ -11,6 +11,7 @@
 
 # Check for special fix rules for particular targets
 case $machine in
+    *-mittos64* | \
     i?86-*-cygwin* | \
     i?86-*-mingw32* | \
     x86_64-*-mingw32* | \