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developersguide:minixonarm

This page describes how to build and run Minix/ARM.

Target

The Minix ARM port targets the BeagleBoard-xM and its QEMU based emulator, the BeagleBone and the BeagleBone Black products from the BeagleBoard community. These are all based on system on chip designs from TI and all contain a Cortex-A8 ARM core.

The code is developed and integrated in the same (master) code branch as the official MINIX3 x86 port.

Feature Matrix

This is a preliminary list of what's supported and what isn't. Feel free to add anything important that was left off the list and/or update the list with the latest developments.

DriversBeagleBone BlackBeagleBone (White) BeagleBoard-xM
tty (Terminal)yes yes yes
mmc (Multimedia Card)yes yes yes
eMMC (Internal Multimedia Card)yes no no
i2c (Inter-Integrated Circuit)yes yes yes
fb (Frame Buffer)no no yes
EDID Reading (Extended Display Identification Data)yes yes yes
eeprom yes yes yes
gpio (General Purpose Input/Output)yes yes yes
readclock yes yes yes
PMIC (Power Management IC)yes yes yes
ethernet yes yes no
usb (Universal Serial Bus) HCDyes yes no
usb mass storageyes yes no
usb hubsyes yes no
spi (Serial Peripheral Interface Bus)no no no
pwm (Pulse-width modulation)no no no
adc (Analog to Digital Converter)no no no
audio no no no
Kernel FeaturesBeagleBone BlackBeagleBone (White) BeagleBoard-xM
reboot yes yes yes
Power-Off yes yes no
Miscellaneous FeaturesBeagleBone BlackBeagleBone (White) BeagleBoard-xM
Capes / Expansion Boards yes yes no
Supported Capes / Expansion BoardsStatus
BeagleBone Weather yes

Please note that pkgsrc, the package repository used by MINIX3, is not yet available on ARM at this moment. See this document for an explanation as to why and how we hope to move forward on this.

Note that the framebuffer (fb) driver is not supported on the Black and White models. You will need a serial interface cable to connect. Please review Dave Cheney's article on connecting via the serial port. Users of Apple products may want to review Mike's PBX Cookbook article on using Terminal for serial communication. In Terminal, the command 'screen /dev/tty.usbmodem* 115200' works well (replace the * with the appropriate label).

Building Minix/ARM

First do a checkout of the code

$ mkdir -p $HOME/minix
$ cd $HOME/minix
$ git clone git://git.minix3.org/minix src
$ cd src

Secondly configure your build by creating a .settings file.

For the BeagleBoard-xM use these settings:

# beagleboard-xm
U_BOOT_BIN_DIR=build/omap3_beagle/
CONSOLE=tty02

For the BeagleBone(s) use the following settings:

#beaglebone (and black)
U_BOOT_BIN_DIR=build/am335x_evm/
CONSOLE=tty00

Now launch the build by calling the image creation script (This will call the Crosscompiling script with a machine set to “evbearm-el”. NOTE: if you get errors during this step, please check that page!):

$ ./releasetools/arm_sdimage.sh

If you receive the error “**Skipping image creation: missing tool 'mcopy'” do

pkgin install mtools

If there are no errors, the result is a file called minix_arm_sd.img in your src directory. This image can be copied onto an SD-Card using dd:

sudo dd if=minix_arm_sd.img of=/dev/mmcblk0 bs=1M oflag=direct

WARNING Just make sure your file system did not mount the sd-card while you where dd'ing.

Running Minix/ARM

Once the sd-card is inserted on the BeagleBoard-xM (or BeagleBone) press the reset button and watch the serial for messages. Alternatively you can start the same image in the emulator (Read about that in minixonlinaroqemuarm). for information on network booting, see the Netbooting ARM article.

## Starting application at 0x80200000 ...
MINIX booting

MINIX 3.2.1. Copyright 2012, Vrije Universiteit, Amsterdam, The Netherlands
MINIX is open source software, see http://www.minix3.org
Started VFS: 8 worker thread(s)
starting mmc driver
mmc_block(info)Initializing the MMC block device
mmc_host_mmchs(info)Using instance number 0
mmc_block(info)System event framework fresh start
Root device name is /dev/c0d0p1s0
/dev/c0d0p1s0: clean
/dev/c0d0p1s0 is mounted on /
none is mounted on /proc
date: timed: no such device or address
Tue Jan  1 00:00:00 GMT 2013
/dev/c0d0p1s2: clean
/dev/c0d0p1s1: clean
size on /dev/imgrd set to 0kB
Multiuser startup in progress ...
Starting services: randomrm /dev/eth0
rm /dev/eth
mknod /dev/psip0 c 7 1
ln /dev/psip0 /dev/psip
mknod /dev/ip0 c 7 2
ln /dev/ip0 /dev/ip
mknod /dev/tcp0 c 7 3
ln /dev/tcp0 /dev/tcp
mknod /dev/udp0 c 7 4
ln /dev/udp0 /dev/udp
mknod /dev/ipstat c 7 0
inet: unable to read random data from /dev/random: resource temporarily unavailable
inet: using current time for random-number seed
 inet ipc.
Starting daemons: update cron syslogd.
Starting networking: nonamed.
Local packages (start):  done.
 Minix  Release 3 Version 2.1  (console)

10.0.0.1 login:

Ethernet Configuration

If you're using a BeagleBone or BeagleBone Black, there is an ethernet driver available. It's configured through /etc/inet.conf. Running netconf as usual will let you select the right driver, which is lan8710a.

To enable services like telnet/ftp/etc you can create an rc.daemons file.

mv /etc/rc.daemons.dist /etc/rc.daemons
vi /etc/rc.daemons

Restart the system for the changes to take effect.

reboot

If the system hangs on reboot after starting the service 'random,' shut down the board entirely, then bring it back up. This will completely reset the ethernet chip and prevent issues when bringing up the inet interface from a non-default configuration. Typing 'Control-c' will interrupt the multi-user boot process and go to single user. Type

shutdown -h now

to properly unmount the file system and shut down. Unplug the power supply from the board, wait briefly, then plug the power supply back in.

Videos

  • A video showing the above steps of obtaining and building the system is here.
  • A video showing how to use gdb to debug a minix from a qemu is here.
  • A video showing how to use Code Composer studio to debug the BeagleBone White is here.

Want to contribute?

Great, that's what I wanted to hear! Help with documentation, making the above procedure more clean, hardware support, debugging, running the test set and finding and debugging problems! Check the resources page for more information on how to join the community.

See ARM-specific (or not ARM-specific!) points on the Wishlist page for the current list of todo's.

ARM Manuals

The ARM Cortex-A8 processor is used in the Minix-supported BeagleBoard and BeagleBone devices. Many ARM documents require registration and some are behind a paywall, but the following is freely available from the ARM site as of October 2016:

developersguide/minixonarm.txt · Last modified: 2021/07/10 15:29 by stux