Minix Beagleboard Essentials

[James T. Sprinkle]

I am thinking of picking up a BeagleBone Black to do some Minix porting and development.  Other than the base kit, what would be some recommended accessories to get up and running quickly and provide the best Minix user experience?

Thanks!

Jim

[David van Moolenbroek]

Hey Jim,

On Saturday, September 9, 2017 at 7:42:58 PM UTC+2, James T. Sprinkle wrote:

I am thinking of picking up a BeagleBone Black to do some Minix porting and development.  Other than the base kit, what would be some recommended accessories to get up and running quickly and provide the best Minix user experience?

Cool! Just to make sure: you are definitely going to need a 2+GB micro-SD card from which to boot a minix image, and an appropriate serial cable [1] which will be the only way of communicating with the system [2]. Other than that, I cannot really recommend anything particular I think. For an overview of which on-board components are currently supported and which are not, please refer to the appropriate wiki page [3]. Unfortunately, the only cape currently supported by minix, the weather cape (BB-BONE-WTHR-01), has been discontinued and (as far as I can tell) can only be bought for a ridiculously high price these days.

In terms of porting and development: as you may have heard already, minix-current has a serious problem with gcc/arm, to the point that it does not boot at all on beaglebones [4]. The best option right now is to compile minix-current including an experimental (and as-yet unmerged) switch to clang/arm [5]. That change still has issues of its own (e.g. with floating-point numbers), but at least it should result in a system that boots. We do hope to fix the remaining issues as soon as possible, but there is no ETA, so don't let that stop you. Another option is to go back to the latest "good" commit listed in the gcc/arm issue on github [4], but then you'll miss some of the newer stuff.

Regards,

David

[1] http://elinux.org/Beagleboard:BeagleBone_Black_Serial

[2] You can use the serial connection to configure networking and go from there, but no ssh daemon is available on minix/arm yet (telnet should work once enabled though)

[3] http://wiki.minix3.org/doku.php?id=developersguide:minixonarm

[4] https://github.com/Stichting-MINIX-Research-Foundation/minix/issues/104

[5] https://github.com/Stichting-MINIX-Research-Foundation/minix/pull/195

[James T. Sprinkle]

Awesome! 

Thanks David!

Jim

[James T. Sprinkle]

Hi David!  I got my kit now.  Any suggestions on what OS/version would make a good build environment for cross compiling?  I am thinking of dedicating a laptop to this project work and would like to be running similar, if not the same, as the rest of the folks working on Minix.

Thanks!

Jim

[James T. Sprinkle]

Hi David!  I was wondering.  How can I get the code you mention in option 5 below?  Also, how can I get back to the latest good gcc/arm commit?  I got a couple extra SD cards so I can try both.  Just need some pointers on how to get the source trees right in each instance.

Thanks!

Jim

[James T. Sprinkle]

Just in case anyone is interested, here is how I built out my dev platform:

Ubuntu 12.04.05 32bit installed and updated
Downloaded Minix git repo
Downloaded Linaro git repo
Built Linaro qemu environment
Downgraded Minix git repo to hash 8933525
Built ARM sdcard image using releasetools/arm_sdimage.sh
Booted in Linaro QEMU environment
Rebuilt using BBB .settings
Booted on BBB
Upgraded Ubuntu to 14.04 32bit with latest patches
Created copy of releasetools/arm_sdimage.sh that allowed for larger filesystems and usage of all 512M of RAM.
Rebuilt using BBB .settings
Booted on BBB

The only thing I haven't figured out yet was how to pull over the switch to clang code David mentioned in item 5 of his previous post.  If that is the direction Minix is going, I would rather move to that.  If someone could assist in getting that code on my local git, that would be great!

Jim