Merge pull request #5 from sryze/patch-1

Add Windows (MinGW) build instructions

README.md

@@ -5,6 +5,9 @@ Tool to convert Android sparse images to raw images.
 
 Since image tools are not part of Android SDK, this standalone port of AOSP libsparse aims to avoid complex building chains.
 
+Usage
+-----
+
 ```
 $ make
 $ simg2img /path/to/Android/images/system.img /output/path/system.raw.img
@@ -13,3 +16,14 @@ system.img: Android sparse image, version: 1.0, Total of 262144 4096-byte output
 $ file /output/path/system.raw.img
 system.raw.img: Linux rev 1.0 ext4 filesystem data, UUID=57f8f4bc-abf4-655f-bf67-946fc0f9f25b (extents) (large files)
 ```
+
+Windows
+-------
+
+If you want to build simg2img on Windows you'll need to [install MinGW](http://www.mingw.org/wiki/howto_install_the_mingw_gcc_compiler_suite)
+and also zlib and libasprintf (go to MinGW Libraries in the installer and check `mingw32-libz` and `mingw32-libasprintf`).
+Once you've done that run the following command to build simg2img:
+
+```
+CFLAGS=-DUSE_MINGW LDFLAGS=-lasprintf mingw32-make
+```