2014-06-15 15:56:37 +02:00
|
|
|
Lego Mindstorms EV3
|
|
|
|
|
|
|
|
|
|
Intro
|
|
|
|
|
=====
|
|
|
|
|
|
|
|
|
|
This is the buildroot basic board support for the Lego Mindstorms EV3
|
2016-11-02 04:15:56 +01:00
|
|
|
programmable brick.
|
2014-06-15 15:56:37 +02:00
|
|
|
|
|
|
|
|
The Lego Mindstorms EV3 brick comprises a Texas Instruments AM1808 SoC, with
|
|
|
|
|
an ARM 926EJ-S main processor running at 300 MHz.
|
|
|
|
|
See:
|
|
|
|
|
- https://en.wikipedia.org/wiki/Lego_Mindstorms_EV3
|
|
|
|
|
- http://www.lego.com/en-us/mindstorms/products/ev3/31313-mindstorms-ev3/
|
|
|
|
|
- http://www.ti.com/product/am1808
|
|
|
|
|
|
|
|
|
|
The buildroot configuration uses the Linux kernel of the ev3dev project.
|
|
|
|
|
See:
|
2016-10-15 18:51:55 +02:00
|
|
|
- https://github.com/ev3dev/ev3-kernel/
|
2016-11-02 04:15:56 +01:00
|
|
|
- https://github.com/ev3dev/lego-linux-drivers/
|
2016-10-15 18:51:55 +02:00
|
|
|
- http://www.ev3dev.org/
|
2014-06-15 15:56:37 +02:00
|
|
|
|
|
|
|
|
How it works
|
|
|
|
|
============
|
|
|
|
|
|
|
|
|
|
Boot process :
|
|
|
|
|
--------------
|
|
|
|
|
|
2016-11-02 04:15:54 +01:00
|
|
|
The EV3 boots from an EEPROM. This loads whatever is on the built-in 16MB flash
|
|
|
|
|
(usually U-Boot) and runs it. The U-Boot from the official LEGO firmware and
|
|
|
|
|
mainline U-Boot will attempt to boot a Linux kernel from the external µSD card.
|
|
|
|
|
It will try to load a uImage (and optional boot.scr) from the first µSD card
|
|
|
|
|
partition, which must be formatted with a FAT filesystem. If no µSD is found or
|
|
|
|
|
it does not contain a uImage file, then the EV3 will boot the uImage from the
|
|
|
|
|
built-in 16MB flash.
|
2014-06-15 15:56:37 +02:00
|
|
|
|
|
|
|
|
How to build it
|
|
|
|
|
===============
|
|
|
|
|
|
|
|
|
|
Configure Buildroot
|
|
|
|
|
-------------------
|
|
|
|
|
|
|
|
|
|
The lego_ev3_defconfig configuration provides basic support to boot on the Lego
|
|
|
|
|
Mindstorms EV3 programmable brick:
|
|
|
|
|
|
|
|
|
|
$ make lego_ev3_defconfig
|
|
|
|
|
|
|
|
|
|
Build everything
|
|
|
|
|
----------------
|
|
|
|
|
|
|
|
|
|
Note: you will need to have access to the network, since Buildroot will
|
|
|
|
|
download the packages' sources.
|
|
|
|
|
|
|
|
|
|
$ make
|
|
|
|
|
|
|
|
|
|
Result of the build
|
|
|
|
|
-------------------
|
|
|
|
|
|
|
|
|
|
After building, you should obtain this tree:
|
|
|
|
|
|
|
|
|
|
output/images/
|
2016-11-02 04:15:54 +01:00
|
|
|
├── boot.vfat
|
|
|
|
|
├── flash.bin
|
2014-06-15 15:56:37 +02:00
|
|
|
├── rootfs.ext2
|
|
|
|
|
├── rootfs.ext3 -> rootfs.ext2
|
2016-11-02 04:15:54 +01:00
|
|
|
├── rootfs.squashfs
|
|
|
|
|
├── sdcard.img
|
|
|
|
|
├── u-boot.bin
|
2014-06-15 15:56:37 +02:00
|
|
|
└── uImage
|
|
|
|
|
|
2016-11-02 04:15:54 +01:00
|
|
|
Installation
|
|
|
|
|
============
|
2014-06-15 15:56:37 +02:00
|
|
|
|
2016-11-02 04:15:54 +01:00
|
|
|
You can use either flash.bin or the sdcard.img. To load flash.bin, use the
|
|
|
|
|
official Lego Mindstorms EV3 programming software firmware update tool to load
|
|
|
|
|
the image. To use sdcard.img, use a disk writing tool such as Etcher or dd to
|
|
|
|
|
write the image to the µSD card.
|
2014-06-15 15:56:37 +02:00
|
|
|
|
|
|
|
|
Finish
|
|
|
|
|
======
|
|
|
|
|
|
|
|
|
|
To have a serial console, you will need a proper USB to Lego serial port
|
|
|
|
|
adapter plugged into the EV3 sensors port 1.
|
|
|
|
|
See:
|
|
|
|
|
- http://botbench.com/blog/2013/08/15/ev3-creating-console-cable/
|
|
|
|
|
- http://botbench.com/blog/2013/08/05/mindsensors-ev3-usb-console-adapter/
|
|
|
|
|
|
|
|
|
|
The serial port config to use is 115200/8-N-1.
|
