🍇Mining with a SBC

The following guide will show you how to compile a CPU miner (XMRig) for SBCs like the Raspberry Pi.

If you're using a RPi3 or RPi3B+, check out this guide for a more optimized setup.

What are the benefits of compiling XMRig from scratch?

• You'll have the most up-to-date version of XMRig

• You can optimize XMRig for specific SBCs (improves hash rate)

• You can compile XMRig with different releases of GCC (may improve hash rate)

• It's possible to disable certain features of XMRig (more info)

Setup

First we want to make sure your SBC's software is up to date:

sudo apt-get update && sudo apt-get upgrade

After that's done, we're going to install some tools that are important for the process:

sudo apt-get install git build-essential cmake make libuv1-dev libmicrohttpd-dev gcc g++ automake autoconf pkg-config libcurl4-openssl-dev libjansson-dev libssl-dev libgmp-dev

Compiling XMRig

At this step we'll obtain the latest binaries of XMRig and create a directory called build:

cd ~
git clone https://github.com/xmrig/xmrig.git
cd xmrig && mkdir build && cd build

Now we specify the build flags to optimize XMRig for your SBC in particular. You'll have to only choose one of these:

• for any SBC:

cmake ..

• for the Raspberry Pi 2:

cmake .. -DCMAKE_C_FLAGS="-mcpu=cortex-a7 -mtune=cortex-a7" -DCMAKE_CXX_FLAGS="-mcpu=cortex-a7 -mtune=cortex-a7"

• for the Raspberry Pi 2 if the command above doesn't work:

cmake .. -DARM_TARGET=7

• for the Raspberry Pi 3:

cmake .. -DCMAKE_C_FLAGS="-mcpu=cortex-a53 -mtune=cortex-a53" -DCMAKE_CXX_FLAGS="-mcpu=cortex-a53 -mtune=cortex-a53"

• for the Raspberry Pi 4:

cmake .. -DCMAKE_C_FLAGS="-mcpu=cortex-a72 -mtune=cortex-a72" -DCMAKE_CXX_FLAGS="-mcpu=cortex-a72 -mtune=cortex-a72"

• for the Asus Tinker Board:

cmake .. -DCMAKE_C_FLAGS="-march=armv7-a" -DCMAKE_CXX_FLAGS="-march=armv7-a"

You may find the right flags for your board here. I was only able to test these on a Raspberry Pi 2 and the Asus Tinker Board. Also, this guide is not perfect, so feel free to add/edit flags or devices!

To finish the compilation type:

make

To speed up the compilation you can add -j [amount_of_CPU_cores]. On a Raspberry Pi 2/3 this would be make -j 4 for example.

Configuring and Running XMRig

First we need to copy config.json to the same directory the XMRig executable is located:

cp ~/xmrig/src/config.json config.json

Now we have to edit the configuration file properly. In this guide we'll be using nano, but any other text editor should also work fine:

nano config.json

Your terminal should display the contents of config.json.

• In order to mine Kryptokrona, we tell XMRig what algorithm you want to mine. Look out for the "algo": setting and change it to "algo": "cryptonight-pico/trtl",

• In place of "url": "donate.v2.xmrig.com:3333", you'll need to choose a pool to mine towards. Make sure to choose the right port. You can learn more about choosing a pool here.

• Instead of "user": "YOUR_WALLET_ADDRESS", simply paste your Kryptokrona wallet address.

  If you don't have one yet, you can find out how to create a wallet here.

When you're done with that, press:

CTRL + O to save, confirm with Enter. And after that, hit CTRL + X to close the file.

Then start the miner:

./xmrig

After entering this command, the miner will start scanning your hardware and begin to mine.

Congratulations! You did it! :)