36bd9a3cb4
This uses the ev3dev linux extension to compile the ev3dev drivers for LEGO MINDSTORMS EV3. Signed-off-by: David Lechner <david@lechnology.com> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
88 lines
2.4 KiB
Plaintext
88 lines
2.4 KiB
Plaintext
Lego Mindstorms EV3
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Intro
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=====
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This is the buildroot basic board support for the Lego Mindstorms EV3
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programmable brick.
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The Lego Mindstorms EV3 brick comprises a Texas Instruments AM1808 SoC, with
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an ARM 926EJ-S main processor running at 300 MHz.
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See:
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- https://en.wikipedia.org/wiki/Lego_Mindstorms_EV3
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- http://www.lego.com/en-us/mindstorms/products/ev3/31313-mindstorms-ev3/
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- http://www.ti.com/product/am1808
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The buildroot configuration uses the Linux kernel of the ev3dev project.
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See:
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- https://github.com/ev3dev/ev3-kernel/
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- https://github.com/ev3dev/lego-linux-drivers/
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- http://www.ev3dev.org/
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How it works
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============
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Boot process :
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--------------
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The EV3 boots from an EEPROM. This loads whatever is on the built-in 16MB flash
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(usually U-Boot) and runs it. The U-Boot from the official LEGO firmware and
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mainline U-Boot will attempt to boot a Linux kernel from the external µSD card.
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It will try to load a uImage (and optional boot.scr) from the first µSD card
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partition, which must be formatted with a FAT filesystem. If no µSD is found or
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it does not contain a uImage file, then the EV3 will boot the uImage from the
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built-in 16MB flash.
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How to build it
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===============
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Configure Buildroot
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-------------------
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The lego_ev3_defconfig configuration provides basic support to boot on the Lego
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Mindstorms EV3 programmable brick:
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$ make lego_ev3_defconfig
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Build everything
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----------------
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Note: you will need to have access to the network, since Buildroot will
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download the packages' sources.
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$ make
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Result of the build
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-------------------
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After building, you should obtain this tree:
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output/images/
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├── boot.vfat
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├── flash.bin
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├── rootfs.ext2
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├── rootfs.ext3 -> rootfs.ext2
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├── rootfs.squashfs
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├── sdcard.img
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├── u-boot.bin
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└── uImage
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Installation
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============
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You can use either flash.bin or the sdcard.img. To load flash.bin, use the
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official Lego Mindstorms EV3 programming software firmware update tool to load
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the image. To use sdcard.img, use a disk writing tool such as Etcher or dd to
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write the image to the µSD card.
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Finish
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======
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To have a serial console, you will need a proper USB to Lego serial port
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adapter plugged into the EV3 sensors port 1.
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See:
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- http://botbench.com/blog/2013/08/15/ev3-creating-console-cable/
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- http://botbench.com/blog/2013/08/05/mindsensors-ev3-usb-console-adapter/
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The serial port config to use is 115200/8-N-1.
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