Target ARMV6 for the arm crossbuild of TF

With this change, we can run the generated .so on a raspberry pi zero,
this doesn't seem to affect performance on the armv7 pi3, at least from
the few benches I ran, so we're not providing a specific armv7 deb for
now

Author: fredszaq

compile-arm.sh

@@ -18,7 +18,7 @@ mkdir $TARGET
 
 CURRENT_DIR=$(pwd)
 
-git clone https://github.com/raspberrypi/tools "$TARGET/$TOOLS_DIR"
+git clone https://github.com/raspberrypi/tools "$TARGET/$TOOLS_DIR" --depth 1
 
 ./cross-compile.sh $CURRENT_DIR/$TARGET/$TOOLS_DIR/$TOOLCHAIN_ROOT $TOOLCHAIN_NAME $VERSION
 

cross-compile.sh

@@ -44,4 +44,4 @@ yes ''|./configure || exit 1
 
 echo "launching bazel with flags '$BAZEL_FLAGS'"
 
-bazel build $BAZEL_FLAGS -c opt --copt="-mfpu=neon-vfpv4" --copt="-funsafe-math-optimizations" --copt="-ftree-vectorize" --copt="-fomit-frame-pointer"   tensorflow:libtensorflow.so --cpu=armeabi-v7a --crosstool_top=//tools/arm_compiler:toolchain --verbose_failures
+bazel build $BAZEL_FLAGS -c opt --copt="-march=armv6" --copt="-mfpu=vfp" --copt="-funsafe-math-optimizations" --copt="-ftree-vectorize" --copt="-fomit-frame-pointer"  tensorflow:libtensorflow.so --cpu=armeabi --crosstool_top=//tools/arm_compiler:toolchain --verbose_failures

debian/versions.sh

@@ -1,4 +1,4 @@
 #/usr/env/bin bash
 export TF_VERSION="v1.0.0"
-export TF_DEB_VERSION="1.0.0-snips-5"
+export TF_DEB_VERSION="1.0.0-snips-6"
 

tf-crosscompile.patch

@@ -126,7 +126,7 @@ index 000000000..ccddd6d50
 +cc_toolchain_suite(
 +  name = 'toolchain',
 +  toolchains = {
-+    'armeabi-v7a|compiler':':cc-compiler-armeabi-v7a',
++    'armeabi|compiler':':cc-compiler-armeabi',
 +    "local|compiler": ":cc-compiler-local",
 +  },
 +)
@@ -159,10 +159,10 @@ index 000000000..ccddd6d50
 +
 +
 +cc_toolchain(
-+  name = 'cc-compiler-armeabi-v7a',
++  name = 'cc-compiler-armeabi',
 +  all_files = ':linaro_linux_all_files',
 +  compiler_files = ':linaro_linux_all_files',
-+  cpu = 'armeabi-v7a',
++  cpu = 'armeabi',
 +  dwp_files = ':empty',
 +  dynamic_runtime_libs = [':empty'],
 +  linker_files = ':linaro_linux_all_files',
@@ -198,7 +198,7 @@ index 000000000..3ff006da8
 +  toolchain_identifier: "local_freebsd"
 +}
 +default_toolchain {
-+  cpu: "armeabi-v7a"
++  cpu: "armeabi"
 +  toolchain_identifier: "%%CT_NAME%%"
 +}
 +default_toolchain {
@@ -219,21 +219,21 @@ index 000000000..3ff006da8
 +}
 +
 +toolchain {
-+  abi_version: "armeabi-v7a"
-+  abi_libc_version: "armeabi-v7a"
++  abi_version: "armeabi"
++  abi_libc_version: "armeabi"
 +  builtin_sysroot: ""
 +  compiler: "compiler"
-+  host_system_name: "armeabi-v7a"
++  host_system_name: "armeabi"
 +  needsPic: true
 +  supports_gold_linker: false
 +  supports_incremental_linker: false
 +  supports_fission: false
 +  supports_interface_shared_objects: false
 +  supports_normalizing_ar: false
 +  supports_start_end_lib: false
-+  target_libc: "armeabi-v7a"
-+  target_cpu: "armeabi-v7a"
-+  target_system_name: "armeabi-v7a"
++  target_libc: "armeabi"
++  target_cpu: "armeabi"
++  target_system_name: "armeabi"
 +  toolchain_identifier: "%%CT_NAME%%"
 +
 +  tool_path { name: "ar" path: "%%CT_ROOT_DIR%%/bin/%%CT_NAME%%-ar" }