Improve build, installation, and use in README.

README.md

@@ -20,22 +20,64 @@ Features:
 * Output in two high-level languages: C and a Python-like language.
 * Generation of call graphs, control-flow graphs, and various statistics.
 
-## Requirements
+## Installation and Use
 
-* A compiler supporting C++14
-  * On Windows, only Microsoft Visual C++ is supported (version >= Visual Studio 2015 Update 2).
-* CMake (version >= 3.6)
-* Perl
-  * On Windows, [Active Perl](https://www.activestate.com/activeperl) needs to be the first Perl in `PATH`, or it has to be provided to CMake using `CMAKE_PROGRAM_PATH` variable, e.g. `-DCMAKE_PROGRAM_PATH=/c/perl/bin`.
-* [GNU Bison](https://www.gnu.org/software/bison/), [Flex](https://www.gnu.org/software/flex/), [GNU Tar](https://www.gnu.org/software/tar/), `wget`, `sha256sum`.
-  * On Windows, you can follow RetDec's Windows environment setup [guide](https://github.com/avast-tl/retdec/wiki/Windows-Environment) to help you get everything you need.
+Currently, we support only Windows and Linux.
 
-Additionally, to run the decompiler once it is built and installed the following tools are needed:
-* [GNU Bash](https://www.gnu.org/software/bash/), [UPX](https://upx.github.io/), [bc](https://www.gnu.org/software/bc/), [dot](http://www.graphviz.org/).
-  * As before, you can follow RetDec's Windows environment setup [guide](https://github.com/avast-tl/retdec/wiki/Windows-Environment) to help you get everything you need on Windows.
+### Windows
+
+1. Either download and unpack a pre-built package, or build and install the decompiler by yourself (the process is described below):
+
+    * 32b Windows: TBA
+    * 64b Windows: TBA
+
+2. Install [MSYS2](http://www.msys2.org/) and other needed applications by following RetDec's [Windows environment setup guide](https://github.com/avast-tl/retdec/wiki/Windows-Environment).
+
+3. Now, you are all set to run the decompiler. To decompile a binary file named `test.exe`, go into `$RETDEC_INSTALLED_DIR/bin` and run:
+
+    ```
+    bash decompile.sh test.exe
+    ```
+
+   For more information, run `bash decompile.sh --help`.
+
+### Linux
+
+1. There are currently no pre-built packages for Linux. You will have to build and install the decompiler by yourself. The process is described below.
+
+2. After you have built the decompiler, you will need to install the following packages via your distribution's package manager:
+
+    * [GNU Bash](https://www.gnu.org/software/bash/)
+    * [UPX](https://upx.github.io/)
+    * [bc](https://www.gnu.org/software/bc/)
+    * [Graphviz](http://www.graphviz.org/)
+
+3. Now, you are all set to run the decompiler. To decompile a binary file named `test.exe`, go into `$RETDEC_INSTALLED_DIR/bin` and run:
+
+    ```
+    ./decompile.sh test.exe
+    ```
+
+   For more information, run `./decompile.sh --help`.
 
 ## Build and Installation
 
+This section describes a manual build and installation of RetDec.
+
+### Requirements
+
+* Linux:
+  * A compiler supporting C++14
+  * [CMake](https://cmake.org/) (version >= 3.6)
+  * [Perl](https://www.perl.org/)
+  * standard tools (e.g. `sh`, `wget`, `sha256sum`)
+* Windows:
+  * Microsoft Visual C++ (version >= Visual Studio 2015 Update 2)
+  * [MSYS2](http://www.msys2.org/) and some other applications. Follow RetDec's [Windows environment setup guide](https://github.com/avast-tl/retdec/wiki/Windows-Environment) to get everything you need on Windows.
+  * [Active Perl](https://www.activestate.com/activeperl). It needs to be the first Perl in `PATH`, or it has to be provided to CMake using `CMAKE_PROGRAM_PATH` variable, e.g. `-DCMAKE_PROGRAM_PATH=/c/perl/bin`.
+
+### Process
+
 * Recursively clone the repository (it contains submodules):
   * `git clone --recursive https://github.com/avast-tl/retdec`
 * Linux:
@@ -45,15 +87,14 @@ Additionally, to run the decompiler once it is built and installed the following
   * `make && make install`
 * Windows:
   * Open MSBuild command prompt, or any terminal that is configured to run the `msbuild` command.
-  * Make sure you can run required commands listed in the Requirements section.
   * `cd retdec`
   * `mkdir build && cd build`
   * `cmake .. -DCMAKE_INSTALL_PREFIX=<path> -G<generator>`
   * `msbuild /m /p:Configuration=Release retdec.sln`
   * `msbuild /m /p:Configuration=Release INSTALL.vcxproj`
   * Alternatively, you can open `retdec.sln` generated by `cmake` in Visual Studio IDE.
 
-You must pass the following parameters to `cmake`:
+You have to pass the following parameters to `cmake`:
 * `-DCMAKE_INSTALL_PREFIX=<path>` to set the installation path to `<path>`.
 * (Windows only) `-G<generator>` is `-G"Visual Studio 14 2015"` for 32-bit build using Visual Studio 2015, or `-G"Visual Studio 14 2015 Win64"` for 64-bit build using Visual Studio 2015. Later versions of Visual Studio may be used.
 
@@ -63,15 +104,6 @@ You can pass the following additional parameters to `cmake`:
 * `-DCMAKE_BUILD_TYPE=Debug` to build with debugging information, which is useful during development. By default, the project is built in the `Release` mode. This has no effect on Windows, but the same thing can be achieved by running `msbuild` with the `/p:Configuration=Debug` parameter.
 * `-DCMAKE_PROGRAM_PATH=<path>` to use Perl at `<path>` (probably useful only on Windows).
 
-## Usage Example
-
-To decompile a binary file named `test.bin` run:
-```
-./decompile.sh test.bin
-```
-
-Run `./decompile.sh --help` to list all the available options.
-
 ## Repository Overview
 
 This repository contains the following libraries: