*This method is useful for those looking to run bleeding-edge versions of RRG/iceman's client. Keep this in mind when attempting to update your HomeBrew tap formula as this procedure could easily cause a build to break if an update is unstable on macOS.*
With your Proxmark3 unplugged from your machine, press and hold the button on your Proxmark3 as you plug it into a USB port. You can release the button, two of the four LEDs should stay on. You're un bootloader mode, ready for the next step. In case the two LEDs don't stay on when you're releasing the button, you've an old bootloader, start over and keep the button pressed during the whole flashing procedure.
These instructions will show how to setup the environment on OSX to the point where you'll be able to clone and compile the repo by yourself, as on Linux, Windows, etc.
1. Install homebrew if you haven't yet already done so: http://brew.sh/
Now you're ready to follow the [compilation instructions](/doc/md/Use_of_Proxmark/0_Compilation-Instructions.md).
To use the compiled client and flasher, the only difference is that the Proxmark3 port is `/dev/tty.usbmodemiceman1`.
To flash: With your Proxmark3 unplugged from your machine, press and hold the button on your Proxmark3 as you plug it into a USB port. You can release the button, two of the four LEDs should stay on. You're un bootloader mode, ready for the next step. In case the two LEDs don't stay on when you're releasing the button, you've an old bootloader, start over and keep the button pressed during the whole flashing procedure.
In principle, the helper script `flash-all.sh` should auto-detect your port, so you can just try:
```sh
./flash-all.sh
```
If port detection failed, you'll have to call the flasher manually and specify the correct port: