build: Add support for MSYS2

MSYS2 is a modern fork of Cygwin that is widely supported
and provides frequent releases and good support. It is
also the framework used by the official Windows Git port.
This patch adds MSYS2 support so that builds on Windows using
MSYS2 work properly.

Change-Id: Ia5743a410d1cff983a7aab37f8e3d8228cb8ae8e
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>

Makefile

@@ -24,7 +24,11 @@ endif
 MAKEFLAGS += -rR --include-dir=$(CURDIR)
 
 UNAME := $(shell uname)
-ifeq (MINGW, $(findstring MINGW, $(UNAME)))
+ifeq (MSYS, $(findstring MSYS, $(UNAME)))
+DISABLE_TRYRUN=y
+HOST_OS=MSYS
+PWD_OPT=-W
+else ifeq (MINGW, $(findstring MINGW, $(UNAME)))
 HOST_OS=MINGW
 PWD_OPT=-W
 DISABLE_TRYRUN=y

zephyr-env.sh

@@ -35,10 +35,10 @@ fi
 # zephyr-env_install.bash in your home directory. It will be automatically
 # run (if it exists) by this script.
 
-uname | grep -q MINGW && MINGW_OPT="-W"
+uname | grep -q -P "MINGW|MSYS" && PWD_OPT="-W"
 
 # identify OS source tree root directory
-export ZEPHYR_BASE=$( builtin cd "$( dirname "$DIR" )" && pwd ${MINGW_OPT})
+export ZEPHYR_BASE=$( builtin cd "$( dirname "$DIR" )" && pwd ${PWD_OPT})
 
 scripts_path=${ZEPHYR_BASE}/scripts
 scripts_path=$(echo "/$scripts_path" | sed 's/\\/\//g' | sed 's/://')