diff --git a/Readme.md b/Readme.md
index 7a1377c..bdd61aa 100644
--- a/Readme.md
+++ b/Readme.md
@@ -9,9 +9,9 @@ Therefore, the resulting binaries may differ significantly from Atmel's. And you
 
 Edit the `build.conf` file, currently the only thing worth changing is `AVR_VERSION` on the first line to match whatever the [latest version is](http://distribute.atmel.no/tools/opensource/Atmel-AVR-GNU-Toolchain/).
 
-At time of writing, the latest toolchain available is based on Atmel 3.5.4 version. It contains:
+At time of writing, the latest toolchain available is based on Atmel 3.6.1 version. It contains:
  - binutils-2.26
- - gcc-4.9.2
+ - gcc-5.4.0
  - avr-libc-2.0.0
  - gdb-7.8
  
diff --git a/atpack.build.bash b/atpack.build.bash
new file mode 100755
index 0000000..0d33d8f
--- /dev/null
+++ b/atpack.build.bash
@@ -0,0 +1,88 @@
+#!/bin/bash -ex
+# Copyright (c) 2017 Arduino LLC
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+# 
+# This program 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 General Public License for more details.
+# 
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+
+source build.conf
+
+mkdir -p atpack
+cd atpack
+rm -rf *
+mv ../*.atpack .
+
+mv ${ATMEL_ATMEGA_PACK_FILENAME}.atpack ${ATMEL_ATMEGA_PACK_FILENAME}.zip
+unzip ${ATMEL_ATMEGA_PACK_FILENAME}.zip
+
+ALL_FILES=`find ../objdir`
+
+#copy relevant files to the right folders
+# 1- copy includes definitions
+EXTRA_INCLUDES=`diff -q ../objdir/avr/include/avr ../atpack/include/avr | grep "Only in" | grep atpack | cut -f4 -d" "`
+for x in $EXTRA_INCLUDES; do
+  cp include/avr/${x} ../objdir/avr/include/avr
+done
+
+# 2 - compact specs into a single folder
+SPECS_FOLDERS=`ls gcc/dev`
+mkdir temp
+for folder in $SPECS_FOLDERS; do
+  cp -r gcc/dev/${folder}/* temp/
+done
+
+# 3 - find different files (device-specs)
+EXTRA_SPECS=`diff -q ../objdir/lib/gcc/avr/${GCC_VERSION}/device-specs/ temp/device-specs | grep "Only in" | grep temp | cut -f4 -d" "`
+for x in $EXTRA_SPECS; do
+  cp temp/device-specs/${x} ../objdir/lib/gcc/avr/${GCC_VERSION}/device-specs/
+done
+
+#since https://github.com/gcc-mirror/gcc/commit/21a6b87b86defda10ac903a9cd49e34b1f8ce6fb a lot of devices has specs but avr-libc doesn't support them yet
+ALL_DEVICE_SPECS=`ls temp/device-specs`
+rm -rf temp/device-specs
+
+EXTRA_LIBS=`diff -r -q ../objdir/avr/lib temp/ | grep "Only in" | grep temp | cut -f4 -d" "`
+for x in $EXTRA_LIBS; do
+  if [ ! -d temp/${x} ]; then
+  cd temp
+  LOCATION=`find . | grep ${x}`
+  cd ..
+  else
+  LOCATION=${x}
+  fi
+  cp -r temp/${LOCATION} ../objdir/avr/lib/${LOCATION}
+done
+
+# 4 - extract the correct includes and add them to io.h
+# ARGH! difficult!
+for x in $ALL_DEVICE_SPECS; do
+  DEFINITION=`cat ../objdir/lib/gcc/avr/${GCC_VERSION}/device-specs/${x} | grep __AVR_DEVICE_NAME__ | cut -f1 -d" " | cut -f2 -d"D"`
+  FANCY_NAME=`cat ../objdir/lib/gcc/avr/${GCC_VERSION}/device-specs/${x} | grep __AVR_DEVICE_NAME__ | cut -f2 -d"="`
+  LOWERCASE_DEFINITION="${DEFINITION,,}"
+  HEADER_TEMP="${LOWERCASE_DEFINITION#__avr_atmega}"
+  HEADER="${HEADER_TEMP%__}"
+  _DEFINITION="#elif defined (${DEFINITION})"
+  _HEADER="#  include <avr/iom${HEADER}.h>"
+  if [ "$(grep -c "${DEFINITION}" ../objdir/avr/include/avr/io.h)" == 0 ]; then
+    NEWFILE=`awk '/iom3000.h/ { print; print "____DEFINITION____"; print "____HEADER____"; next }1' ../objdir/avr/include/avr/io.h | sed "s/____DEFINITION____/$_DEFINITION/g" |  sed "s@____HEADER____@$_HEADER@g"`
+    echo "$NEWFILE" > ../objdir/avr/include/avr/io.h
+  fi
+done
+
+#NEW_ALL_FILES=`find ../objdir`
+
+#echo "NEW FILES ADDED: "
+#diff  <(echo "$ALL_FILES" ) <(echo "$NEW_ALL_FILES")
+
+cd ..
+
diff --git a/automake-patches/0001-fix-perl-522.patch b/automake-patches/0001-fix-perl-522.patch
new file mode 100644
index 0000000..62e2391
--- /dev/null
+++ b/automake-patches/0001-fix-perl-522.patch
@@ -0,0 +1,11 @@
+--- /automake.in	2017-12-18 12:26:59.455263520 +0100
++++ /automake.in	2017-12-18 12:27:21.228596603 +0100
+@@ -4110,7 +4110,7 @@
+ sub substitute_ac_subst_variables ($)
+ {
+   my ($text) = @_;
+-  $text =~ s/\${([^ \t=:+{}]+)}/&substitute_ac_subst_variables_worker ($1)/ge;
++  $text =~ s/\$[{]([^ \t=:+{}]+)}/substitute_ac_subst_variables_worker ($1)/ge;
+   return $text;
+ }
+ 
diff --git a/avr-gcc-patches/0001-gcc-lto-wrapper.patch b/avr-gcc-patches/0001-gcc-lto-wrapper.patch
index 8fc612e..1e48f33 100644
--- a/avr-gcc-patches/0001-gcc-lto-wrapper.patch
+++ b/avr-gcc-patches/0001-gcc-lto-wrapper.patch
@@ -1,5 +1,5 @@
---- gcc/lto-wrapper.c.orig	2016-06-14 21:13:06.985134945 +0200
-+++ gcc/lto-wrapper.c	2016-06-14 21:15:37.825167119 +0200
+--- gcc/lto-wrapper.c	2016-08-22 11:19:17.000000000 +0200
++++ gcc/lto-wrapper.c	2017-12-18 12:48:25.685248735 +0100
 @@ -594,7 +594,7 @@
  	  filename[p - argv[i]] = '\0';
  	  file_offset = (off_t) loffset;
diff --git a/binutils.build.bash b/binutils.build.bash
index d930231..993f4b8 100755
--- a/binutils.build.bash
+++ b/binutils.build.bash
@@ -23,6 +23,10 @@ then
 	exit 1
 fi
 
+if [[ x$CROSS_COMPILE != x ]] ; then
+	EXTRA_CONFARGS="--host=$OUTPUT_TAG"
+fi
+
 cd toolsdir/bin
 TOOLS_BIN_PATH=`pwd`
 cd -
@@ -58,12 +62,13 @@ CONFARGS=" \
 	--disable-werror \
 	--enable-install-libiberty \
 	--enable-install-libbfd \
-	--enable-lto \
-	--enable-plugins\
-	--with-pic \
+	--disable-libdecnumber \
+	--disable-gdb \
+	--disable-readline \
+	--disable-sim \
 	--target=avr"
 
-CFLAGS="-w -O2 -g0 $CFLAGS" CXXFLAGS="-w -O2 -g0 $CXXFLAGS" LDFLAGS="-s $LDFLAGS" ../binutils/configure $CONFARGS
+CFLAGS="-w -O2 -g0 $CFLAGS" CXXFLAGS="-w -O2 -g0 $CXXFLAGS" LDFLAGS="-s $LDFLAGS" ../binutils/configure $CONFARGS $EXTRA_CONFARGS
 
 if [ -z "$MAKE_JOBS" ]; then
 	MAKE_JOBS="2"
diff --git a/build.conf b/build.conf
index ef0e2d6..947b431 100644
--- a/build.conf
+++ b/build.conf
@@ -1,7 +1,8 @@
-AVR_VERSION=3.5.4
+AVR_VERSION=3.6.1
 BUILD_NUMBER=arduino2
 
 AVR_SOURCES="http://distribute.atmel.no/tools/opensource/Atmel-AVR-GNU-Toolchain/${AVR_VERSION}"
+ATMEL_PACKS_SOURCES="http://packs.download.atmel.com/"
 GNU_SOURCES="http://mirror.switch.ch/ftp/mirror/gnu"
 MPC_SOURCES="http://www.multiprecision.org/downloads"
 
@@ -15,6 +16,10 @@ MPC_SOURCES="http://www.multiprecision.org/downloads"
 # MPFR_VERSION=3.0.0
 # MPC_VERSION=0.9
 
+ATMEL_ATMEGA_PACK_VERSION=1.2.203
+ATMEL_ATMEGA_PACK_FILENAME=Atmel.ATmega_DFP.${ATMEL_ATMEGA_PACK_VERSION}
+ATMEL_ATMEGA_PACK_URL=${ATMEL_PACKS_SOURCES}/${ATMEL_ATMEGA_PACK_FILENAME}.atpack
+
 # With any luck, you don't need to edit the below
 ################################################################################
 
diff --git a/gcc.build.bash b/gcc.build.bash
index f81d91b..7b82dc6 100755
--- a/gcc.build.bash
+++ b/gcc.build.bash
@@ -57,20 +57,20 @@ fi
 
 tar xfv avr-gcc.tar.bz2
 
-pushd gcc
+#pushd gcc
 #pushd gcc/config/avr/
 #sh genopt.sh avr-mcus.def > avr-tables.opt
 #cat avr-mcus.def | awk -f genmultilib.awk FORMAT="Makefile" > t-multilib 
 #popd
-pushd gcc
-for p in ../../avr-gcc-patches/*.patch
-do
-	echo Applying $p
-	patch -p1 < $p
-done
-autoconf
-popd
-popd
+#pushd gcc
+#for p in ../../avr-gcc-patches/*.patch
+#do
+#	echo Applying $p
+#	patch -p1 < $p
+#done
+#autoconf
+#popd
+#popd
 
 mv gmp-${GMP_VERSION} gcc/gmp
 mv mpfr-${MPFR_VERSION} gcc/mpfr
@@ -81,6 +81,10 @@ cd objdir
 PREFIX=`pwd`
 cd -
 
+if [[ x$CROSS_COMPILE != x ]] ; then
+	EXTRA_CONFARGS="--host=$OUTPUT_TAG"
+fi
+
 mkdir -p gcc-build
 cd gcc-build
 
@@ -88,25 +92,16 @@ CONFARGS=" \
 	--enable-fixed-point \
 	--enable-languages=c,c++ \
 	--prefix=$PREFIX \
-	--enable-long-long \
 	--disable-nls \
-	--disable-checking \
 	--disable-libssp \
-        --disable-libada \
+    --disable-libada \
 	--disable-shared \
-	--enable-lto \
-        --with-avrlibc=yes \
+    --with-avrlibc=yes \
 	--with-dwarf2 \
-        --disable-doc \
+    --disable-doc \
 	--target=avr"
 
-if [ `uname -s` == "Darwin" ]
-then
-	# Use default system libraries (no other Macports libraries)
-	LDFLAGS="$LDFLAGS -L/usr/lib"
-fi
-
-CFLAGS="-w -O2 -g0 $CFLAGS" CXXFLAGS="-w -O2 -g0 $CXXFLAGS" LDFLAGS="-s $LDFLAGS" ../gcc/configure $CONFARGS
+CFLAGS="-w -O2 -g0 $CFLAGS" CXXFLAGS="-w -O2 -g0 $CXXFLAGS" LDFLAGS="-s $LDFLAGS" ../gcc/configure $CONFARGS $EXTRA_CONFARGS
 
 if [ -z "$MAKE_JOBS" ]; then
 	MAKE_JOBS="2"
diff --git a/gdb.build.bash b/gdb.build.bash
index 967b574..065679b 100755
--- a/gdb.build.bash
+++ b/gdb.build.bash
@@ -27,6 +27,10 @@ cd toolsdir/bin
 TOOLS_BIN_PATH=`pwd`
 cd -
 
+if [[ x$CROSS_COMPILE != x ]] ; then
+	EXTRA_CONFARGS="--host=$OUTPUT_TAG"
+fi
+
 export PATH="$TOOLS_BIN_PATH:$PATH"
 
 if [[ ! -f avr-gdb.tar.bz2  ]] ;
@@ -36,13 +40,13 @@ fi
 
 tar xfv avr-gdb.tar.bz2
 
-cd gdb
-for p in ../avr-gdb-patches/*.patch
-do
-	echo Applying $p
-	patch -p1 < $p
-done
-cd -
+#cd gdb
+#for p in ../avr-gdb-patches/*.patch
+#do
+#	echo Applying $p
+#	patch -p1 < $p
+#done
+#cd -
 
 mkdir -p objdir
 cd objdir
@@ -59,7 +63,7 @@ CONFARGS=" \
 	--disable-binutils \
 	--target=avr"
 
-CFLAGS="-w -O2 -g0 $CFLAGS" CXXFLAGS="-w -O2 -g0 $CXXFLAGS" LDFLAGS="-s $LDFLAGS" ../gdb/configure $CONFARGS
+CFLAGS="-w -O2 -g0 $CFLAGS" CXXFLAGS="-w -O2 -g0 $CXXFLAGS" LDFLAGS="-s $LDFLAGS" ../gdb/configure $CONFARGS $EXTRA_CONFARGS
 
 if [ -z "$MAKE_JOBS" ]; then
 	MAKE_JOBS="2"
diff --git a/package-avr-gcc.bash b/package-avr-gcc.bash
index 32eecf9..e4a7de4 100755
--- a/package-avr-gcc.bash
+++ b/package-avr-gcc.bash
@@ -28,7 +28,23 @@ if [[ $CROSS_COMPILE == "mingw" ]] ; then
   export CXX="i686-w64-mingw32-g++"
   export CROSS_COMPILE_HOST="i686-w64-mingw32"
   export TARGET_OS="Windows"
-  OUTPUT_TAG=i686-w64-mingw32
+  export OUTPUT_TAG=i686-w64-mingw32
+
+elif [[ $CROSS_COMPILE == "osxcross" ]] ; then
+
+  export CC="o32-clang"
+  export CXX="o32-clang++"
+  export CROSS_COMPILE_HOST="i386-apple-darwin13"
+  export TARGET_OS="OSX"
+  export OUTPUT_TAG=i386-apple-darwin13
+
+elif [[ $CROSS_COMPILE == "arm-cross" ]] ; then
+
+  export CC="arm-linux-gnueabihf-gcc"
+  export CXX="arm-linux-gnueabihf-g++"
+  export CROSS_COMPILE_HOST="arm-linux-gnueabihf"
+  export TARGET_OS="LinuxARM"
+  export OUTPUT_TAG=arm-linux-gnueabihf
 
 elif [[ $OS == "GNU/Linux" ]] ; then
 
@@ -83,6 +99,11 @@ rm -rf toolsdir objdir *-build
 
 rm -rf objdir/{info,man,share}
 
+if [[ -f ${ATMEL_ATMEGA_PACK_FILENAME}.atpack ]] ; then
+#add extra files from atpack (only if the package is altrady there)
+${BASH} ./atpack.build.bash
+fi
+
 # if producing a windows build, compress as zip and
 # copy *toolchain-precompiled* content to any folder containing a .exe
 if [[ ${OUTPUT_TAG} == *"mingw"* ]] ; then
diff --git a/toolchain-precompiled/libwinpthread-1.dll b/toolchain-precompiled/libwinpthread-1.dll
new file mode 100755
index 0000000..10e5670
Binary files /dev/null and b/toolchain-precompiled/libwinpthread-1.dll differ
diff --git a/tools.bash b/tools.bash
index 3d0a67a..723d771 100755
--- a/tools.bash
+++ b/tools.bash
@@ -58,6 +58,8 @@ tar xfjv automake-${AUTOMAKE_VERSION}.tar.bz2
 
 cd automake-${AUTOMAKE_VERSION}
 
+patch -p1 < ../automake-patches/0001-fix-perl-522.patch
+
 cp ../config.guess-am-1.11.4 lib/config.guess
 ./bootstrap