GNU Embedded Toolchain for ARM on Rasbian Jessie Lite

Shoot me. Shoot me now.

And if you don’t, don’t blame me.

~~~

I dislike GUIs for holding my coding environment, because they present me with new and therefore terrifying technology. So, I elected to put the mbed cli onto Raspbian Lite. This is already devoid of a GUI, and nothing could go wrong.

Gentle Reader, it went wrong. Mostly because the instructions for compiling from source were in a pdf which I couldn’t read without downloading it elsewhere, and by the time I had done that the schnapps I was taking medicinally had betrayed me.

Once I’d opened that, the instructions started with ‘install Ubuntu’ so I swore a bit and didn’t install Ubuntu. But I did apt-get install software-properties-common and that nearly worked. I didn’t have 7z on Rasbian Lite, and when I managed to get p7zip, I had to amend ./install-sources.h by hand, to take out mentions of 7z and add p7zip -d which got me to the point where I had everything installed and could start the build. At which point, more stuff broke.

‘This does not look like a tar archive’ is a bad message to get when you believe you are messing with tar archives. So, it was into build-common.sh to have a look-see.

I had a curious error that tar -cf – . which should – I thought – have compressed stuff, wasn’t. As far as I could read from the error message it was decompressing instead. Obviously I was not drunk enough. But there was a failure to find zlib, and that was the only thing that was compressed as a .tar.gz instead of a .tar.bz2. So I could do that by hand, right?

cd src
tar -xf zlibwhatever
cd -

Now we’re cooking with Calor.

Until there’s no usable m4 in $PATH. And I have no idea what m4 is.

So I install that:

apt-get install m4
sudo !!

!! is the most useful shortcut I have ever found. It’s the entire last line you typed. sudo !! is the thing I probably type most.

Then I attempt another build. I’m on a roll here!

./build-rerequisites.sh

And I wait. Clouds of text pass upward. My pi light blinks. I drink more. More scroll happens. I have no desk. I have no keyboard. The world is an illusion. I experience sudden horror as the scrolling stops but it is only a momentary pause for a large file. I recognise fragments of names. The word ‘pedantic’ catches my eye and I laugh. The ‘caution something or other about make check’ board scrolls past. I drink again. Makefiles are made. I hug the bottle. The scrolling is giving me a headache. Or else I am hung over. The lighting waxes and wanes as text pauses and passes on. I am at one with the Schnapps. The Schnapps is at one with me, but is also precariously balanced on the tin of shoe polish I am using as a coaster. Now we are checking the locale and it isn’t saying Drowned Ys or Property of Randolph J Carter, so I think we’re OK. ‘Making all in .’ is a travesty of grammar, but a wonderful statement from the command line. More drink. Sacrifice a goat to the old ones. Eat raw goat liver. I finish a conversation online and start another. The dragons drift by. I click things with a useless mouse. There is more scroll. The C compiler works. We check together, the computer and I, whether we are cross-compiling. … And then .configure aborts.

‘Compiler error reporting is too harsh for ./configure (perhaps remove -Werror).’

Well, there’s lovely.

I don’t know how to remove that, because I don’t know why or where it was set in the first place. Somewhere in the haze of alcohol I remember that I must already have the GCC working to make all this stuff, and I sigh and look up the error message because that’s the sensible thing, and sleeping could stop me from thinking.

A stack exchange discussion of this problem has something that cheers me up. “The compiler is too harsh simply because there is no compiler…” At least my problem is not that.

In looking up what might be going wrong I have scrolled away from the error messages and I don’t want to look for logs so I run this again. There is a pleasing object with the word polyhedron in the file name. And now we have found warnings. Makefile.in seems to ignore the datarootdir setting. Is that bad? And then a bit of scroll later we bork.

I read back up a bit. pushd allows one to play with the directory stack. So in one of those directories, perhaps, there is a ./configure.

ls build-mingw/zlib has a configure file. There is a configure log. The configure file tells me that
try
:
else .

So now I try to remember what try means. I scroll up to find what options $CC has. The irony of me doing the scrolling makes me smile. I have the horrible feeling that this is using CC not GCC and I have no idea what that means. The bottle is calling me again. I comment out the line that is forcing me to leave, because errors are fine because it is midnight and I am drunk. I do not expect this to go well, but I am interested in what will work. Probably that file will not be regenerated and this is all safe. Perhaps I should have checked at least the start and end of the configure log before I began. The cloud scrolls past again. I can smell hamsters. long long ints exist. doubles exist. I play with the refresh rate of the scroll by blinking. I converse online about novelty fish. I open up a different terminal to rest my eyes. I scroll back in time to find out that CC=gcc. I reach the point where we make all in . The tension is acutely bearable. I have no expectations. Hope is a deceiver. I lie to myself about not hoping. The conversation about novelty fish turns to gravel and rakes. I consider Phlebas, who was tall, and is now dead. I consider how I could have learned to get along with a GUI, but no, I had to do it my way. I look lovingly at the screen, now showing me built objects that will die when ./configure fails. I love these things. They do not know that hopes are liars. Maybe once I was like them.

Everything dies. I look up the ./configure, and sure enough it’s a generated file so I cannot change it. I’ve learned a thing. I look in the configure log and I’m apparently building some cross-compiling something-or-other for the windows toolchain so I re-start without that. I can live without windows. The pain of the GUI is enough that I am doing this to avoid windows.

./build-prerequisites.sh --skip_steps=mingw32

The temperature warning for the Pi comes on. I blow over the CPU, with the tenderness of Achilles teasing Patrokleos. The air is warm. I have enclosed the main board in too many breakout boards.

The objects are created again. They never complain about this. The temperature warning has not returned. .io files click in orderly procession down the screen. More scroll. Is this further than I have gone before?… exit 0. No errors. The little coloured directory indicator is a checkpoint flag. They are playing my tune.

Ladies and Gentlemen, we are halfway!

./build-toolchain --skip_steps=mingw32 holds no fears for me now. I believe!

I take a moment to marvel at the complexity of the compiler building a compiler. So many people worked on this. Hardly any of them need to be destroyed. I blow on the CPU again. I wonder if I have built this in the wrong place. Awww. Error 2. recipe for target failed up above somewhere. I can hear the Glory. I should probably sleep. The Pi can cool down overnight.

Dear reader, I came back to it in the morning, and tried again with TeX installed. Why TeX, I do not know. It seems to have been making make all fail, even though it was almost certainly optional in the minds of the writers. I added flex to give me gengtype-lex.c, and ran into what was probably a memory issue. So, I increased the swap file from 100MB to 400MB. df –total showed that I still had 10% of my space free. (At this point, I decided to build the toolchain on my desktop machine as well, to find out if it was just the Pi being awkward. It’s the Pi being awkward, *and* I failed to build on ARCH.) I installed bison, and increased the swap file to 800MB. The temperature warning light stayed on, meaning that the CPU was being throttled. However, finally, I ran out of space on the device. One last gambit was to decrease the swap file to 600, because I didn’t know if the installation of bison could fix the earlier issue. Again, I ran out of space. More in next week’s exciting episode, folks.

Arch Flotilla

My Pimoroni Flotilla kit arrived today, and I didn’t have a Raspberry Pi left in workable condition. So, I looked for a set-up that would allow me not to use one. I found a write-up on using Ubuntu and that was hugely useful.

I already had git, so I hit

git clone https://github.com/pimoroni/Flotilla-Daemon-VS.git

in my build area. The daemon is the non-GUI backing that does the hard work of talking to the USB device. It comes without all the dependencies, though. The first one, mentioned in the Ubuntu guide, is libserial. That’s in the AUR. I already had autoconf and libtool. As it happened, I didn’t need to make libserial. This is fortunate, as I found out before I looked in the AUR that pushd was not going to play nicely and I had no idea what that meant.

I also needed libserialport-git from the AUR and websocketpp from the standard repository. I found this out when the makefile borked, and each time there wasn’t a required dependency, I just found it. More than that, I needed to take out the version number in the Makefile. CC = g++-4.9 is probably not allowed because it’s not pure GCC. So, I replaced it with CC = g++ and that worked fine. I swapped OBJECT and LDFLAGS as per the Ubuntu instructions, although I don’t know if that made a difference.

Then I downloaded Rockpool, the interface.

git clone https://github.com/pimoroni/flotilla-offline

That should have run nicely with cd flotilla-offline/rockpool && python rockpool.py but as it happens I have python3 so I made it explicit: python2 rockpool.py and then I was done. Remember to click on Connect rather than waiting politely for the bar to load. You’re acting as a server on the USB connection, so although the address looks like the default, it is and it should be.

Learn C the Hard Way – Making and making and GNUmaking and throwing things across the room

Ex 2 of Learn C the Hard Way introduces how the makefile works. I’ve tried and failed to use this before, when trying to make an Arch package, so it’ll be good to work out how to do that. I’m not looking forward to failure, of course. This blog is basically a lie.

emacs Makefile

and I created the file as I was told to. My ex1 still has

#include<stdio.h>

in it, so it didn’t throw up any warnings, but when I commented that line out, it did. So my computer’s now in much the same state as what Zed was using to write, and I’m not getting my compiler screaming where his wasn’t. I did have to read down his page to a note saying that he had an unfixed ex1, but I was pretty sure that’s what had happened. I’d put that note up at the top.

If I have two tabs instead of none, I don’t have any errors thrown. This is unlike Python’s unexpected indent. I wonder why it needs an indent at all, but I’m going to go with BECAUSE and ignore that for the moment.

I had to go looking for more information for extra credit. According to
www.cs.colby.edu/maxwell/courses/tutorials/maketutor
‘make’ on its own will execute the first command in the file. So, my first attempt at putting all: ex1 into the file was after clean: and it didn’t work. My second attempt had line breaks, which was a guess at how to separate functions. I then went without separating functions at all. -o is a flag that should take one file name, and then the next bit of info should be separate by default. And whaddyaknow, this works. I have, readers may have noticed, a way of making things difficult for myself, mostly by assuming they will be more complicated than they actually are.

I’ve decided I want to add -d to the makefile flags, if that does what I think it will. I like debugging info.
-o seems to mean we’ve got an old file, which is… odd. So it must be that the internal makefile syntax and the syntax we use to call it are different. It sort of makes sense.

man make

has a typo in it.

$ man cc

– no manual entry for cc. Yerwhat? I assume cc is the c compiler…

$ which cc

– /usr/bin/cc . So I have it. I just don’t have a man page.

$ man -k '^cc$'

– nothing appropriate. This isn’t about an adult filter, either. This man page isn’t in my distro. So, over to

https://www.ma.utexas.edu/cgi-bin/man-cgi?cc+1

to get my fix. And aaaah. ‘gcc’ exists.

$ man gcc

– Result! And wow, that’s complicated. I mean, that’s a whole set of stuff that I could do, with huge options lists I can’t (yet) hope to comprehend. But here I am failing in public, so let’s look at the last bit of the Extra Credit. I don’t know what ‘better’ means in this case, for a future case of what a Makefile does.

Online research – http://mrbook.org/blog/tutorials/make/ is helpful. It’s coming from the angle of people who can code and want to automate it, but it’s still explaining things simply. all: is a default. Anything after the colon is dependencies. I think this should be expanded and explained more. I’m not getting it from Zed’s explanation, and a couple of sentences there would have made the first part of the Extra Credit much easier to understand. I think I’m learning too far ahead of things, though. I went back and stopped ex1 from being a dependency of all: and that’s where I’m leaving it. I’ve cruised through a few examples, but there’s too much to hold in my head to stay here. I need to move on and see how it works.