Add support for AArch32

gcc version 4.9.2 (Raspbian 4.9.2-10)
Tested on Linux raspberrypi 4.4.6-v7+ #875 SMP Tue Apr 12 16:33:02 BST 2016 armv7l GNU/Linux

CPUs may be little or big endian, detect with gcc flags, not the processor architecture
Add a new flag $(PLATFORM)_uses_openssl which allows to disable the link with openssl lib.

vlib/vlib/threads.c:
startup.conf must:
- specify the heapsize as we don't have hugepages on raspbian

cpu {
  main-core 3
}
heapsize 64M

Corrects in various files the assumption uword == u64 and replaces 'u64' cast with 'pointer_to_uword' and 'uword_to_pointer' where appropriate.
256 CPUs may create an OOM when testing with small memory footprint ( heapsize 64M ), allows the number of VLIB_MAX_CPUS to be set in platforms/*.mk

vppinfra/vppinfra/longjmp.S:
ARM - copy r1 (1st parameter of the setjmp call) to r0 (return value)

vppinfra/vppinfra/time.h:
On ARMv7 in AArch32 mode, we can access to a 64bit register to retreive the cycles count.
gcc on rpi only declare ARM_ARCH 6. Override this info, and check if it is possible to use 'mrrc'.
/!\ the time function will NOT work without allowing the user mode access to the PMU.
You may download the source of the kmod here:
https://github.com/christophefontaine/arm_rdtsc

Change-Id: I8142606436d9671a184133b935398427f08a8bd2
Signed-off-by: Christophe Fontaine <christophe.fontaine@qosmos.com>

build-data/packages/vnet.mk

@@ -6,14 +6,12 @@ vnet_configure_depend = 			\
 
 vnet_CPPFLAGS = $(call installed_includes_fn, 	\
     vppinfra 					\
-    openssl					\
     svm						\
     vlib 					\
     vlib-api)
 
 vnet_LDFLAGS = $(call installed_libs_fn, 	\
     vppinfra					\
-    openssl					\
     svm						\
     vlib					\
     vlib-api)
@@ -25,6 +23,12 @@ endif
 # Platform dependent configure flags
 vnet_configure_args += $(vnet_configure_args_$(PLATFORM))
 
+# include & link with openssl only if needed
+ifneq ($($(PLATFORM)_uses_openssl),no)
+vnet_CPPFLAGS += $(call installed_includes_fn, openssl)
+vnet_LDFLAGS += $(call installed_libs_fn, openssl)
+endif
+
 ifneq ($($(PLATFORM)_uses_dpdk),no)
 ifeq ($($(PLATFORM)_uses_external_dpdk),yes)
 vnet_CPPFLAGS += -I$($(PLATFORM)_dpdk_inc_dir)

build-data/packages/vpp.mk

@@ -18,7 +18,6 @@ vpp_configure_args += $(vpp_configure_args_$(PLATFORM))
 
 vpp_CPPFLAGS = $(call installed_includes_fn,	\
 	vppinfra				\
-        openssl					\
 	svm					\
 	vlib					\
 	vlib-api				\
@@ -26,12 +25,17 @@ vpp_CPPFLAGS = $(call installed_includes_fn,	\
 
 vpp_LDFLAGS = $(call installed_libs_fn,		\
 	vppinfra				\
-	openssl					\
 	svm					\
 	vlib					\
 	vlib-api				\
 	vnet)
 
+# include & link with openssl only if needed
+ifneq ($($(PLATFORM)_uses_openssl),no)
+vpp_CPPFLAGS += $(call installed_includes_fn, openssl)
+vpp_LDFLAGS += $(call installed_libs_fn, openssl)
+endif
+
 ifneq ($($(PLATFORM)_uses_dpdk),no)
 ifeq ($($(PLATFORM)_uses_external_dpdk),yes)
 vpp_CPPFLAGS += -I$($(PLATFORM)_dpdk_inc_dir)

build-data/platforms/arm32.mk

@@ -0,0 +1,37 @@
+# Copyright (c) 2016 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# vector packet processor
+arm32_arch = native
+arm32_native_tools = vppapigen
+
+arm32_uses_dpdk = no
+arm32_uses_openssl = no
+
+arm32_root_packages = vpp vlib vlib-api vnet svm vpp-api-test \
+	vpp-japi gmod
+
+vlib_configure_args_arm32 = --with-pre-data=128
+
+vnet_configure_args_arm32 = --without-vcgn --without-ipsec --without-ipv6sr
+vpp_configure_args_arm32 = --without-vcgn --without-ipsec --without-ipv6sr
+
+arm32_debug_TAG_CFLAGS = -g -O0 -DCLIB_DEBUG -DFORTIFY_SOURCE=2 -DVLIB_MAX_CPUS=4 -march=armv7-a \
+	-fstack-protector-all -fPIC -Werror
+arm32_debug_TAG_LDFLAGS = -g -O0 -DCLIB_DEBUG -DFORTIFY_SOURCE=2 -DVLIB_MAX_CPUS=4 -march=armv7-a \
+	-fstack-protector-all -fPIC -Werror
+
+arm32_TAG_CFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -DVLIB_MAX_CPUS=4 -march=armv7-a \
+	-fstack-protector -fPIC -Werror
+arm32_TAG_LDFLAGS = -g -O2 -DFORTIFY_SOURCE=2 -DVLIB_MAX_CPUS=4 -march=armv7-a \
+	-fstack-protector -fPIC -Werror