Tag Archives: debian

Let’s install Debian on AArch64

Today I took a small break and decided to install Debian on APM Mustang. How it went? Read on.

Requirements: – kernel and initramfs from Debian daily d-i builds – USB stick with GRUB from Fedora (one from my second Fedora installation – APM Mustang with UEFI – serial cable connected to Mustang and other computer – Ethernet cable to get network on Mustang

Why did I used GRUB from Fedora? Debian one had issues with finding own modules (or something like that).

Ok, so let’s boot into GRUB. Once there load kernel and initramfs:

linux /debian/vmlinux console=ttyS0,115220
initrd /debian/initrd.gz
boot

Installation went smooth. To the point when installer tried to install GRUB :(

Rebooted, loaded freshly installed kernel/initramfs from Fedora boot loader but still failed:

Begin: Loading essential drivers ... done.
Begin: Running /scripts/init-premount ... done.
Begin: Mounting root file system ... Begin: Running /scripts/local-top ... done.
Begin: Waiting for root file system ... done.
Gave up waiting for root device.  Common problems:
 - Boot args (cat /proc/cmdline)
   - Check rootdelay= (did the system wait long enough?)
   - Check root= (did the system wait for the right device?)
 - Missing modules (cat /proc/modules; ls /dev)

So will not check how Debian works on APM Mustang. But bug will be reported.

2 years of AArch64 work

I do not remember exactly when I started working on ARMv8 stuff. Checked old emails from Linaro times and found that we discussed AArch64 bootstrap using OpenEmbedded during Linaro Connect Asia (June 2012). But it had to wait a bit…

First we took OpenEmbedded and created all tasks/images we needed but built them for 32-bit ARM. But during September we had all toolchain parts available: binutils was public, gcc was public, glibc was on a way to be released. I remember that moment when built first “helloworld” — probably as one of first people outside ARM and their hardware partners.

At first week of October we had ARMv8 sprint in Cambridge, UK (in Linaro and ARM offices). When I arrived and took a seat I got information that glibc just went public. Fetched, rebased my OpenEmbedded tree to drop traces of “private” patches and started build. Once finished all went public at git.linaro.org repository.

But we still lacked hardware… The only thing available was Versatile Express emulator which required license from ARM Ltd. But then free (but proprietary) emulator was released so everyone was able to boot our images. OMG it was so slow…

Then fun porting work started. Patched this, that, sent patches to OpenEmbedded and to upstream projects and time was going. And going.

In January 2013 I started X11 on emulated AArch64. Had to wait few months before other distributions went to that point.

February 2013 was nice moment as Debian/Ubuntu team presented their AArch64 port. It was their first architecture bootstrapped without using external toolchains. Work was done in Ubuntu due to different approach to development than Debian has. All work was merged back so some time later Debian also had AArch64 port.

It was March or April when OpenSUSE did mass build of whole distribution for AArch64. They had biggest amount of packages built for quite long time. But I did not tracked their progress too much.

And then 31st May came. A day when I left Linaro. But I was already after call with Red Hat so future looked quite bright ;D

June was month when first silicon was publicly presented. I do not know what Jon Masters was showing but it probably was some prototype from Applied Micro.

On 1st August I got officially hired by Red Hat and started month later. My wife was joking that next step would be Retired Software Engineer ;D

So I moved from OpenEmbedded to Fedora with my AArch64 work. Lot of work here was already done as Fedora developers were planning 64-bit ARM port few years before — when it was at design phase. So when Fedora 15 was bootstrapped for “armhf” it was done as preparation for AArch64. 64-bit ARM port was started in October 2012 with Fedora 17 packages (and switched to Fedora 19 during work).

My first task at Red Hat was getting Qt4 working properly. That beast took few days in foundation model… Good that we got first hardware then so it went faster. 1-2 months later and I had remote APM Mustang available for my porting work.

In January 2014 QEmu got AArch64 system emulation. People started migrating from foundation model.

Next months were full of hardware announcements. AMD, Cavium, Freescale, Marvell, Mediatek, NVidia, Qualcomm and others.

In meantime I decided to make crazy experiment with OpenEmbedded. I was first to use it to build for AArch64 so why not be first to build OE on 64-bit ARM?

And then June came. With APM Mustang for use at home. Finally X11 forwarding started to be useful. One of first things to do was running firefox on AArch64 just to make fun of running software which porting/upstreaming took me biggest amount of time.

Did not took me long to get idea of transforming APM Mustang (which I named “pinkiepie” as all machines at my home are named after cartoon characters) into ARMv8 desktop. Still waiting for PCI Express riser and USB host support.

Now we have October. Soon will be 2 years since people got foundation model available. And there are rumors about AArch64 development boards in production with prices below 100 USD. Will do what needed to get one of them on my desk ;)

From a diary of AArch porter –- testsuites

More and more software come with testsuites. But not every distribution runs them for each package (nevermind is it Debian, Fedora or Ubuntu). Why it matters? Let me give example from yesterday: HDF 4.2.10.

There is a bug reported against libhdf with information that it built fine for Ubuntu. As I had issues with hdf in Fedora I decided to look and found even simpler patch than one I wrote. Tried it and got package built. But that’s all…

Running testsuite is easy: “make check”. But result was awesome:

!!! 31294 Error(s) were detected !!!

It does not look good, right? So yesterday I spent some time yesterday on searching for architecture related check and found main reason for so big amount of errors — unknown systems are treated as big endian… Simple switch there and from 31294 it dropped to just 278 ones.

Took me a while to find all 27 places where miscellaneous variations of “#if defined(__aarch64__)” were needed and finally got to point where “make check” simply worked as it should.

So if you port software do not assume it is fine once it builds. Run testsuite to be sure that it runs properly.

AArch64 is in the house

Today FedEx courier delivered me a package. Inside was APM Mustang in 19″ rack case.

I unpacked, grabbed all required cables from my cable boxes (power, Ethernet, serial), connected it and booted. It arrived at very good moment as we are in a middle of Fedora 21 mass rebuild so I do not have to use remote machines anymore.

Will not write about technical details cause those are already known (8 cores, 16GB ram, SATA storage, 1GbE networking). Do not expect benchmarks as I am not allowed to publish results. If you want to compare build speed then go to Launchpad and check how long it takes to build Ubuntu packages for arm64 target.

My plans for machine? Run Fedora rawhide, fix building issues. I also plan to play with virtualization to check how Ubuntu and Debian work.

ARM7 != ARMv7

ARM architecture is fun when it comes to names and numbers. And it is around 30 years old as well. So from time to time I have a discussion where I say something like in title…

There are few sources of mistakes when it comes to ARM. Family names, instruction sets, core names and marketing. Hard to tell which makes biggest mess…

Anything below ARMv7a is history — there is ARMology about it so please read it. But it does not mean that we have clear situation now :D

ARMv7a (and higher) means Cortex-A family. But due to companies like AllWinner and Apple we have it more complicated:

  • A4 is Apple cpu with Cortex-A8 core
  • A5 is low-end Cortex-A5 core but also Apple cpu with Cortex-A9 cores (there was also A5X)
  • A6 is Apple cpu with their own core (also A6X)
  • A7 is Cortex-A7 core but also Apple cpu with 64-bit ARMv8 cores
  • A8 is Cortex-A8 core (the only single core Cortex-A)
  • A9 is Cortex-A9 core
  • A10 is AllWinner cpu with Cortex-A8 core (there was also A10s)
  • A12 is Cortex-A12 core
  • A13 is AllWinner cpu with Cortex-A8 core (stripped down A10)
  • A15 is Cortex-A15 core
  • A17 is Cortex-A17 core
  • A20 is AllWinner cpu with Cortex-A7 cores
  • A23 is AllWinner cpu with Cortex-A7 cores
  • A31 is AllWinner cpu with Cortex-A7 cores (also A31s)
  • A53 is Cortex-A53 core (64-bit ARMv8)
  • A57 is Cortex-A57 core (64-bit ARMv8)
  • A80 is AllWinner cpu with eight cores (4xA7 + 4xA15)

There are also other Cortex cores but their name do not start with “A” :) But the good thing is that all ARMv7a cpus can run same code. ARMv8 ones can run own code — 32-bit support is optional. All all major distros like Debian, Fedora, OpenSUSE or Ubuntu work on support for both families.

UPDATE: Arnd Bergmann wrote in comment (switch to Blog below article) there is also A2, which is the PowerPC core used in BlueGene. Further, AMD has x86 CPUs called A4, A6, A8 and A10, which are also not ARM. Fun, isn’t it?

It is 10 years of Linux on ARM for me

It was somewhere between 7th and 11th February 2004 when I got package with my first Linux/ARM device. It was Sharp Zaurus SL-5500 (also named “collie”) and all started…

At that time I had Palm M105 (still own) and Sony CLIE SJ30 (both running PalmOS/m68k) but wanted hackable device. But I did not have idea what this device will do with my life.

Took me about three years to get to the point where I could abandon my daily work as PHP programmer and move to a bit risky business of embedded Linux consulting. But it was worth it. Not only from financial perspective (I paid more tax in first year then earned in previous) but also from my development. I met a lot of great hackers, people with knowledge which I did not have and I worked hard to be a part of that group.

I was a developer in multiple distributions: OpenZaurus, Poky Linux, Ångström, Debian, Maemo, Ubuntu. My patches landed also in many other embedded and “normal” ones. I patched uncountable amount of software packages to get them built and working. Sure, not all of those changes were sent upstream, some were just ugly hacks but this started to change one day.

Worked as distribution leader in OpenZaurus. My duties (still in free time only) were user support, maintaining repositories and images. I organized testing of pre-release images with over one hundred users — we had all supported devices covered. There was “updates” repository where we provided security fixes, kernel updates and other improvements. I also officially ended development of this distribution when we merged into Ångström.

I worked as one of main developers of Poky Linux which later became Yocto Linux. Learnt about build automation, QA control, build-after-commit workflow and many other things. During my work with OpenedHand I also spent some time on learning differences between British and American versions of English.

Worked with some companies based in USA. This allowed me to learn how to organize teamwork with people from quite far timezones (Vernier was based in Portland so 9 hours difference). It was useful then and still is as most of Red Hat ARM team is US based.

I remember moments when I had to explain what I am doing at work to some people (including my mom). For last 1.5 year I used to say “building software for computers which do not exist” but this is slowly changing as AArch64 hardware exists but is not on a mass market yet.

Now I got to a point when I am recognized at conferences by some random people when at FOSDEM 2007 I knew just few guys from OpenEmbedded (but connected many faces with names/nicknames there).

Played with more hardware then wanted. I still have some devices which I never booted (FRI2 for example). There are boards/devices which I would like to get rid of but most of them is so outdated that may go to electronic trash only.

But if I would have an option to move back that 10 years and think again about buying Sharp Zaurus SL-5500 I would not change it as it was one of the best things I did.

The story of Qt/AArch64 patching

In over a year of my work as AArch64 porter I saw a lot of patches. But Qt one has the most interesting history.

Around year ago when I was building whatever possible during my Linaro work we got to the point when Qt jumped into a queue. Build failed but fixing was quite easy — all I had to do was to take “webkitgtk” patch written by Riku Voipio and apply it to Qt 4. Resulting file landed in “meta-aarch64″ layer of OpenEmbedded and is still there.

Time passed. More common distributions like Debian, Fedora, OpenSUSE, Ubuntu (alphabetical order) started working on their AArch64 ports. And one day Fedora and Ubuntu started working on building Qt 4. I do not know who wrote QAtomic stuff but I saw few versions/iterations of it and it took me quite long time (first on model, then on real hardware) to get it fully working in Fedora — used Ubuntu version of patches.

Up to this moment it was over 9 months and still no upstreaming was done. So one day I decided to go for it and opened QTBUG #35442. Then reopened issue #33 in “double-conversion” project (which is used in few places in Qt) as they got good fix and merged wrong one (but it is fixed now). For that one I opened a request to update to newer version of “double-conversion” as QTBUG #35528.

But story did not end there. As Qt 4 development is more or less ended I was asked to provide fixes for Qt 5. Took me a while. Had to create a graph of build time dependencies between Qt 5 components (had to break few in meantime) and slowly module after module I got most of it built.

There were 3 components which required patching:

First one is solved upstream and waits for Qt guys. I was told that 5.3 will get it updated. Second one is already reviewed and merged. Last one left and here is a problem as it looks like the only person who does QtWebKit code reviews is Allan Sandfeld Jensen but he can not review code he sent. I am not able to do that due to Qt Contributor License Agreement which needs to be signed and (due to legal stuff) I can not do that.

So how it looks now? I would say that quite good. One 3rd party project needs update (in two places of Qt 5) and one patch needs to get through code review. I still need to send package updates to Fedora bug tracker. Ubuntu will need to merge patches when they move to 5.2 version.