Updated README

README.md

@@ -1,2 +1,85 @@
-# empty-pkcs11
-PKCS#11 library with no implementation
+EMPTY-PKCS11
+===========
+**PKCS#11 library with the simplest possible implementation**
+
+## Table of Contents
+
+* [Overview](#overview)
+* [Download](#download)
+* [Building the source](#building-the-source)
+  * [Windows](#windows)
+  * [Linux](#linux)
+  * [Mac OS X](#mac-os-x)
+  * [Android](#android)
+  * [iOS](#ios)
+* [License](#license)
+* [About](#about)
+
+## Overview
+
+EMPTY-PKCS11 is minimalistic C library that implements [PKCS#11 v2.20](https://github.com/Pkcs11Interop/PKCS11-SPECS/tree/master/v2.20) API in the simplest possible way - all PKCS#11 functions except `C_GetFunctionList` function return `CKR_FUNCTION_NOT_SUPPORTED` return value.
+
+It has been tested on several desktop and mobile platforms and as such can be used as a lightweight skeleton for the development of portable PKCS#11 libraries.
+
+## Download
+
+Signed precompiled binaries as well as source code releases can be downloaded from [releases page](https://github.com/Pkcs11Interop/empty-pkcs11/releases).  
+Archives with source code are signed with [GnuPG key of Jaroslav Imrich](https://www.jimrich.sk/crypto/).  
+Windows libraries are signed with [code-signing certificate of Jaroslav Imrich](https://www.jimrich.sk/crypto/).
+
+## Building the source
+
+### Windows
+
+Execute the build script on a 64-bit Windows machine with [Visual Studio 2017 Community](https://visualstudio.microsoft.com/vs/) (or newer) installed:
+
+	cd build/windows/
+	build.bat
+
+The script should use Visual Studio to build both 32-bit (`empty-pkcs11-x86.dll`) and 64-bit (`empty-pkcs11-x64.dll`) versions of the library.
+
+### Linux
+
+Execute the build script on a 64-bit Linux machine with GCC, GNU Make and GCC multilib support installed (available in [build-essential](https://packages.ubuntu.com/bionic/build-essential) and [gcc-multilib](https://packages.ubuntu.com/bionic/gcc-multilib) packages on Ubuntu 18.04 LTS):
+
+	cd build/linux/
+	sh build.sh
+
+The script should use GCC to build both 32-bit (`empty-pkcs11-x86.so`) and 64-bit (`empty-pkcs11-x64.so`) versions of the library.
+
+### Mac OS X
+
+Execute the build script on a 64-bit Mac OS X machine with [Xcode](https://developer.apple.com/xcode/) and its "Command Line Tools" extension installed:
+
+	cd build/osx/
+	sh build.sh
+
+The script should use GCC to build both 32-bit (`empty-pkcs11-x86.dylib`) and 64-bit (`empty-pkcs11-x64.dylib`) versions of the library.
+
+### Android
+
+Execute the build script on a 64-bit Windows machine with [Android NDK r19](https://developer.android.com/ndk/) (or newer) unpacked in `C:\android-ndk` folder:
+
+	cd build/android/
+	build.bat
+
+The script should use Android NDK to build the library for all supported architectures. Results will be located in `libs` directory and its subdirectories.
+
+### iOS
+
+Execute the build script on a 64-bit Mac OS X machine with [Xcode](https://developer.apple.com/xcode/) and its "Command Line Tools" extension installed:
+
+	cd build/ios/
+	sh build.sh
+
+The script should use Xcode to build Mach-O universal binary (`libempty-pkcs11.a`) usable on all supported architectures.
+
+## License
+
+EMPTY-PKCS11 is available under the terms of the [Apache License, Version 2.0](https://www.apache.org/licenses/LICENSE-2.0).  
+[Human friendly license summary](https://tldrlegal.com/l/apache2) is available at tldrlegal.com but the [full license text](LICENSE.md) always prevails.
+
+## About
+
+EMPTY-PKCS11 has been developed as a part of [Pkcs11Interop](https://www.pkcs11interop.net/) project by [Jaroslav Imrich](https://www.jimrich.sk/).  
+Please visit project website - [pkcs11interop.net](https://www.pkcs11interop.net) - for more information.