add basic build info to README.md

README.md

@@ -1,2 +1,62 @@
 # fiatlux
 
+### Cloning
+
+```bash
+git clone --recursive https://git.neulandlabor.de/j3d1/fiatlux.git
+```
+or after cloning normally
+```bash
+git submodule update --init --recursive
+```
+
+### Build Requirements
+
+ - make
+ - bash gawk perl
+ - g++ gcc
+ - libc6-dev
+ - flex bison
+ - automake autoconf
+ - gperf
+ - wget
+ - git
+ - bzip2 unzip zip unrar-free
+ - help2man texinfo
+ - libtool libtool-bin
+ - ncurses-dev libexpat-dev
+ - python3 python3-serial python-dev
+   
+
+### Build Steps
+
+#### Workarounds for submodules   
+```bash
+sed -i 's/GNU bash, version (3\\\.\[1-9\]|4)/GNU bash, version (3.[1-9]|4|5)/g' modules/sdk/crosstool-NG/configure.ac
+mkdir -p modules/sdk/crosstool-NG/.build/tarballs
+wget https://github.com/libexpat/libexpat/releases/download/R_2_1_0/expat-2.1.0.tar.gz -O modules/sdk/crosstool-NG/.build/tarballs/expat-2.1.0.tar.gz
+```
+
+#### Build Toolchain
+```bash
+make -C modules/sdk standalone=y -j$(nproc)
+export PATH=$(pwd)/modules/sdk/xtensa-lx106-elf/bin:$PATH
+```
+
+#### Compile Firmware
+```bash
+make firmware -j$(nproc)
+```
+
+#### Flash
+```bash
+make flash
+```
+
+### Build Steps (using docker)
+
+install `docker` on your platform and buil with
+
+```bash
+make firmware_docker -j$(nproc)
+```