Mirabox dist-upgrade causes system to deadlock/hang on bootup

I think there’s something bad going on between GlobalScales patches in the rootfs images they have for download for the mirabox when doing an apt-get dist-upgrade to the latest version of debian. This causes a complete lockup during boot of the device (network seems to work, but ssh and services are not started in time, and the console is completely locked up). There is pretty much nothing that works in this state, and I’ve found no way to skip ahead and get a login prompt.

I tried booting to Single user mode, but this is not possible because GlobalScale make pretty much everything start in rcS.d. I’m stuck in the same position as in a normal boot as described above, nothing possible to do.

Finally I resorted to using init=/bin/bash and managed to locate the issue down to the S07mountall.sh and/or the S08mountall-bootclean.sh. It seems S07mountall.sh will mount everything from fstab, which also seems to mount “something” on /dev, causing all dev entries to go missing, and hence several different things will just not boot. rm -rf’ing the S07mountall.sh and S08mountall-bootclean.sh script seems to have fixed the issue for me. However,  I’ve severely remade the whole rc.d structure since I think it’s a really bad idea to start so much services in rcS.d as it will block single user mode and kind of against the design philosophy of the init system. This rework may have made the situation better or worse, I’m not completely sure.

If anyone is willing to go more in depth I’d be happy to go into the details with them on what I found.

As for the Mirabox, I think it’s a good device so far, but this is my second GlobalScale device (had a Guruplug Server Plus for almost 2 years as my home server). There are a few things that nags at me so far though:

The file system is having the same issues as the Guruplug Server Plus, strange scripts running at strange times in the bootup procedure (for example, all the stuff that’s gone into the rcS.d directory), the rc.local script calling the /root/init_setup.sh script which in turn is loading a bunch of binary blob drivers and so on and so forth. The device as it is looks really well engineered, but the software is really butchered because of these strange setups. Putting in some good time to create a good integration with Debian (since that’s what they are using anyways) would help insanely much. Also, documenting the reflashing processes and so forth could also be very much helpful.

Reflashing GlobalScale Mirabox filesystem

I just worked my way through reflashing the mirabox and figured I’d post some instructions on how to do it. I’ve used the descriptions from this http://www.newit.co.uk/forum/index.php?topic=3880.0 post but found it to be lacking a few steps that could be construed as obvious… perhaps. Especially the use of ubifs is quite new to me, even though the commands are quite straight forward I got snagged up a bit in understanding how it works.

I’ve used the following rescue disk image:

https://docs.google.com/file/d/0B0imSF-34b8dZEc0SFo3N1Fzb0E/edit

And this rootfs image:

http://code.google.com/p/mirabox/downloads/list

Download and install the rescue disk on a microSD card:

1. fdisk the microSD, create on FAT16 partition of 100mb size, the rest of the device as EXT3.
2. Unpack the rescue disk
3. Copy the mirabox file to the FAT16 partition
4. Extract the rootfs.tgz file to the EXT3 partition.
5. sync and umount the microSD card
6. Connect a USB flash device to the computer
7. Extract the rootfs image downloaded above
8. Copy the rootfs to the USB flash device.
9. Disconnect USB device.
10. Connect micro-sd with mirabox kernel and rootfs to mirabox
11. Plug in the mirabox to a computer via USB.
12. Start the mirabox
13. Hit a key at uboot
14. >> set bootcmd ‘usb start; fatload usb 1 0×6400000 mirabox; bootm 0×6400000′
15. >> set bootargs ‘console=ttyS0,115200 root=/dev/sdb2 rootwait’
16. >> boot
17. login as root password nosoup4u
18. connect USB disk with rootfs on it to mirabox
19. # cd /media/usbX where the rootfs img is located
20. # ubiformat /dev/mtd2 –flash-image=rootfs-debian6.0-gti-mirabox-v5-0-1-120924.img
21. # sync
22. # reboot
23. disconnect USB disk and remove devices.
24. login to your hopefully working new filesystem using root/nosoup4u credentials.

 

FMEA of Door and conclusions

Finding the Zone.

Several years ago at one of my first jobs, right smack at the end of the dot-com boom over here, we had a dartboard. What good is a dartboard you ask? I don’t know, we also had a pinball machine, but I never quite liked it as much as the dartboard. I’d take short breaks from answering phone calls and e-mail or problematic pieces of text to throw a few darts. Personally, it gave me one thing however, I learnt to shut out everything else and find my Zone, you know the one where you’re at your most efficient, solving problems, kicking off e-mail and answering calls in a furious flurry.

For me, I focus on the bulls-eye of the dartboard, relax all muscles in my head, letting my scalp feel like a smashed egg running down from the skull. It feels like my head gets lighter and all pressure on my brain dissipates. Nothing else exists but bulls-eye. Ears are shut off, and all focus is on bulls-eye, nothing else distracts my eyes. At this point I’m there, and ready to hit bulls-eye. It’s simple, it’s fast, and it works. Under extreme pressure and stress, it sometimes takes closing my eyes to get the process started, but almost always I reach the “Zone” within a minute or so.

After the few darts, I’d get my headphones on and listen to music, work my hardest to shut everything else out and maintain the Zone for as long as possible. Reaching it takes concentration and loosing the concentration is always easily lost. Getting back on your train of thought on a complex problem after loosing it is hard work, often taking 15-30 minutes. I absolutely hate having that elusive thread of clarity vanish into thin air due to someone breaking Zone or loosing the almost ready to implement solution to a particularly bothersome problem.

My wife knitted me a pair of special fingerless gloves, ending just before the first knuckle on my ringfinger. I use them while coding or otherwise writing at the computer, to keep my hands warm, just to be able to maintain the Zone for that bit longer, not having to bother about getting cold hands. Cozy, to say the least, but people look funny at me for using them so it’s not often I use them at work. Also, I like to wall myself in as I’m easily distracted by movements and foreign objects. Open office space is complete devastation on these trips into the Zone, where people talk, walk around, gesticulate, strange things happening on other peoples screens, and so forth. I barely ever manage to stay in the Zone for more than 45 minutes or so. On that note, open office planning must have been among the most stupid things ever invented, short term savings at huge cost in productivity.

So, that is how I reach my Zone. Do you have a Zone, and how do you reach it? How do you maintain it from collapsing?

Bugs, bugs and more bugs

Lately, I’ve come to realize more and more that bug handling in open source, and specifically in Ubuntu has dramatically declined in efficiency. For years I’ve been extremely satisfied with using Linux because it’s bug free, there has simply not been any serious bugs that I’ve run into. In the last weeks, I’ve run into several more or less serious bugs in Ubuntu, which got me looking at how the bug handling is done.

First off, a few weeks ago, I ran into a bug with Ubuntu 10.10 Ubiquity (the Live CD installer) where I accidentally marked my old /home drive as ext4 when it was ext3 (but not to reformat it). The installer complied happily, and set it up as ext4, but once it got back online, the harddrive was completely wiped. No warning, no nothing. I started looking around, after a while I’ve found several reports on the same matter on launchpad.  For example this and this.

This lead me to take a look at Ubiquity’s other bugs in launchpad, and it’s not very promising. The main installer of Ubuntu 10.10 has 1528 Open bugs as of writing this, of which 846 bugs are new, 35 bugs are marked High importance — and the bugs I found (dare I say, they seem Critical to me, are still not marked with any importance at all). Only 12 bugs are marked as having a patch.

Fine, maybe this is not the poster child of open source. However, the last few days I’ve been severely annoyed by the password popup which is misbehaving. I enter the password, and hit enter (or hit the Authenticate button) and the password field disappears, but the rest of the dialog stays up, and nothing works in it. The only thing you can do is to kill it with the x button. When you do this, you get authenticated…

Since I’m not sure exactly how the authentication is performed in Ubuntu for the update manager etc, I decided to check the update-manager package for Ubuntu on Launchpad. What do I see, if not another package with gigantic mass of bugs filed, but noone dealing with them. 1017 Open bugs, 520 of those are New and 15 marked as High importance. This bug I’ve been having has been reported all over the net, but noone seems to be dealing with it and it isn’t really reported in launchpad. Some computers has it, some doesn’t. It’s nowhere near a critical bug, or even a high importance one, but it’s annoying none the less and it looks extremely crude and comes off giving a fairly unstable feeling.

All this being said, I am wondering how bug handling is done, and how it should be managed on “aggregate” projects such as Debian and Ubuntu. I think the idea is really nice, having upstream bug trackers for each package in the project, but maybe we are spreading too thin having several bug trackers for each minor project? Also, how do we as “normal” users know which package is the reason for the error? I am not so sure it is really the update-manager that is the error in this case, it might as well be some completely other thing behind all that dbus stuff etc. Ie, what is the point of me filing bug reports if I’m not sure they wind up in the right place, or are at all looked after?

Ubuntu 10.10 r8192se_pci driver on the Toshiba Satellite T130-17E (Realtek RTL8191SEvB)

I’ve been home for a few days with a really bad back, and the only thing I’ve been able to do is watch tv, and some minor work with the laptop. I’ve been running Windows 7 which it was delivered with for a few months to get a feel of it, and I must say I was pleasantly surprised for the most part. It hasn’t crashed more than once or twice in three months, and it is fairly snappy (except boottimes seems to get worse and worse, at this point it takes 2-3 minutes to boot). Anyways, for some reason I get a bit sad inside (and bored) every time I boot Windows, there is just “something” about the feel, the look or… I can’t really put my finger on it, that I can’t stand. How the windows open and close perhaps, I just don’t know.

So, yesterday I wanted to test android SDK, re-realized just how much of a bitch it is to install stuff on Windows, so I finally got around to installing Ubuntu 10.10 on it (Already running 10.10 on desktop and mediapc), removing the extra backup partition they deliver laptops with these days. Sidenote, isn’t it a bit like selling a candle with a flammable fire extinguisher to sell a laptop with 500gig harddrive, split it in half, and use on half for “backups”? I digress.

So, installation went almost flawless. The wireless card was identified, saw networks, but was unable to connect to any of them. I managed to pass the installation using trusty old cables, and after installation was done I started fiddling about, reading on the net etc, and found noone who had solved the combination or at least written about it.

Main problem seems to have been hardware wep encoding/decoding, which can be turned off using the hwwep flag to the r8192se_pci module. On Ubuntu 10.10, remove the module, and then reload it by doing this:

rmmod r8192se_pci
modprobe r8192se_pci hwwep=0

If your network works now, you can automate the setting by editing/adding the configuration to modprobe.d, by editing /etc/modprobe.d/realtek.conf and adding the following line:

options r8192se_pci hwwep=0

I hope this has been some help!

Guruplug arrived, sounds like a jet

The first few paragraphs here are rather harsh vs the Guruplug that I received, and yes, GlobalScale deserves some really bad critique for how this has been handled, but please read the final parts to get a full picture. In all honesty, sometimes I think I should just change name to “Grumpy Fart”.

I finally received the Guruplug Server Plus last week that I ordered 3 months ago. My first reaction is a big WTF on this machine. Apparently, they’ve had big troubles with overheating in the Guruplug, so badly so that a lot of units died from it. Someone over at GlobalScale Technologies had the absolutely idiotic idea to put a fan into the machine. It’s not just any fan, it’s a 2 cm maglev fan running at 3-4000 rpm, and no powermanagement whatsoever and it is directly hooked up to the power source inside the Guruplug, hence it will not be possible to vary the rpm, ever, without a hardware hack. Also, the fan is absolutely horribly placed as is evident from several pictures on the net (and by opening the machine, voiding the warranty) — it is placed with 80-90% of the back of the fan covered by a metal plate (the two gigabit ethernet interfaces), and when the machine is closed up as delivered, it has a big plastic plate (power source cover) covering the front of the fan, with less than 2 mm clearance. All this means is that it is incredibly noisy (easily 30-40dB, way louder than my core 2 quad machine with 8 gig ram and 4 fans in it, while in bootup and before the nvidia graphics card has gone into power management), and has close to no effect at all.

I bought this machine when there was no fan, and there wasn’t even talk of a fan or any mails to acknowledge this design change, so I was heavily inclined at sending the thing back for a refund, but I realized that with my normal luck, it would take several weeks to find a new machine matching my needs, and then another few months before receiving it. Because of this, I winded up simply ripping out the fan, and voiding the warranty. So far so good, and nothing bad has happened. The plug is still running approximately at the same temperature as before, but slightly higher, and I hope there will be no ill effects.

Second WTF when I finally got the machine started up was the installation — first off it is a really nice debian install, I was prepared to start straight off with the jtag interface and installing images and reinstalling etc etc, but there was a perfectly working machine there, straight off. Nice. I thought. Then came the wtf moment, the machine booted up and set an ip address for the uap0 interface (wifi access point interface) to 192.168.1.1. My plan is to use it hooked up to a wired network via gigabit, so I went straight at it, added the eth0 interface to /etc/network/interfaces with a static ip, delete routes and ip’s for uap0 and it worked… for an hour or so, then it stopped working. Reboot, still not working, notice that uap0 is back at it’s old location 192.168.1.1 and routes are back, but nothing in the bootup scripts. Finally find out they have a /etc/init.d/rc.local file point to a /root/init_setup.sh, which in turn does a heap of stuff — including setting up network parameters etc, overriding the normal configuration parameters in a nonstandard way.

Personally, I find this type of “hacked” environments to be despicable. For a private system in your home, fine do whatever you wish, but when it is a public server at a company, or something that you sell to customers, you wind up with a product that the other admins and/or customers can not trust the setup of. Luckily, the whole system is at least included in installed .deb packages. The init_setup.sh, together with the fact that there is no way of recovering if you do a simple screw up of the network setup without the JTAG interface is a major drawback imho.

So… that is the “bad” part of my experience so far. At this point I was rather underwhelmed, but I have been pleasantly surprised by the performance of the little bugger, and except for the startup scripts, it is rather nicely installed from what I have see so far. It would be interesting to gather up a complete list of the “hacks” they have performed to get it all together. The machine is currently able to do exactly what I set out to do, in less than a 2 days of configuration/fixing/fiddling about/etc. I didn’t manage to get the “auto connect” of my usb disk to work, but mount commands work and I didn’t really look at how it’s supposed to work (might be that you need to reboot machine etc). The idea with the machine on my part, is to set it up as a 24/7 machine, replacing my other machine doing this work, but at a lower power consumption. So far, the machine is running the following services for me:

• DHCP
• Dynamic DNS
• Samba and NFS filesharing
• Ssh network login server
• USB Disk/”NAS” function
• Bittorrent (transmission-daemon with transmission-remote on all other machines)

Additionally I hope to use it for the following as well:

• Printer server
• Zeroconf/avahi
• Firewall (possible use as a portable firewall?)
• Temperature sensors etc via GPIO?
• Bluetooth, still haven’t figured out what to do with this…

As you can see, the machine is very capable, and all at a very low power consumption of <5W compared to my old computer doing all this, running at 170W approximately. At current power costs, I am expecting to have made up the money I spent on the Guruplug within less than 9 months. Let’s just keep fingers crossed that the machine wont die of heat before that .

Conclusion

In conclusion, I am really afraid to say anything but this, I can not really recommend this product, not unless you’re either ready to do some serious hacking, or you plan to run it in a garage or some such place. A wardrobe or closet is simply not enough, it sounds too much as it is. The idea and the thought behind the machine is great, I just wish the execution of it was as good.

Shaving some time

I was talking to a colleague the other day and got into a discussion regarding some ways of coding c++, such as whether to use division or bit shifting — almost all modern  compilers can optimize this so it’s basically just a matter of what looks best. At the same time, we got into a minor discussion regarding references and pointers in c++. I made a small test and found some rather amusing results, which is quite obvious once you think about it, but still very scary considering how common it is to use the pointer construct:

// Compile using g++ -lrt -o lala lala.cpp
#include <iostream>
#include <time.h>

int* lala_ptr()
{
    int *y = new int;
    *y = 5;
    return y;
}

int& lala_ref()
{
    int x =5;
    int &y = x;
    return y;
}

timespec diff(timespec start, timespec end)
{
    timespec temp;
    if ((end.tv_nsec-start.tv_nsec)<0) {
        temp.tv_sec = end.tv_sec-start.tv_sec-1;
        temp.tv_nsec = 1000000000+end.tv_nsec-start.tv_nsec;
    } else {
        temp.tv_sec = end.tv_sec-start.tv_sec;
        temp.tv_nsec = end.tv_nsec-start.tv_nsec;
    }
    return temp;
}

int main(int argc, char **argv)
{
    timespec time1, time2, time3;

    clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time1);
    for (unsigned int i=0;i<(unsigned int)-1;i++)
    {
        int &z = lala_ref();
    }
    clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time2);
    for (unsigned int i=0;i<(unsigned int)-1;i++)
    {
        int *z = lala_ptr();
        delete z;
    }
    clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &time3);

    std::cout << "Reference diff(" << time1.tv_sec << ":" << 
                time1.tv_nsec << ", " << 
                time2.tv_sec << ":" << 
                time2.tv_nsec << ") = " << 
                diff(time1, time2).tv_sec << ":" << 
                diff(time1, time2).tv_nsec << std::endl;

    std::cout << "Pointer diff(" << time2.tv_sec << ":" << 
                time2.tv_nsec << ", " << 
                time3.tv_sec << ":" << 
                time3.tv_nsec << ") = " <<
                diff(time2, time3).tv_sec << ":" << 
                diff(time2, time3).tv_nsec << std::endl;
}

Below is a sample of the output generated by the test code above:

oan@laptop4:~/Projects/test$ ./testRefVsPointer 
Reference diff(0:3869272, 25:234466470) = 25:230597198
Pointer diff(25:234466470, 299:547382527) = 274:312916057

So, the question for you all, can you figure out what's wrong?

Screenmovie 1.1 released

A quick note that Screenmovie 1.1 has been released. It’s still very crude, but adds some sound recording and the ability to turn it on/off. Postprocessing is not supported yet but should be there in the next version.

Features:

• Record video
• Record sound
• Configure file format
• Configure video codec + settings (5-6 codecs chosen for now)
• Configure audio codec + settings (2 codecs for now)

I still have some problems, but I just found some info on how to possibly make some problems better at least.

Todo:

• Fix some high cpu usage problems
• Add global keybindings
• Postprocessing encoding
• Clean up and add some values specific for codecs (as required).

Unit testing and stubbing singletons

I got a bit curious about stubbing Singletons for testing during the weekend as well. We often find ourselves needing to test large codebases at work, and in the current project I’m in, we do complete end to end signal flow tests, but people are finally realizing that this will simply not do. For this reason, we’re doing a lot of work to try to split the entire project up into manageable chunks. One of the main problems has been the incessant use of singletons. A simply half-way-there to doing full out interfaces is to simply make all public function calls virtual and then create a stub class of the singleton saving the message or whatever passed on, into a variable which can be grabbed and tested from the actual unit test.

A sample of the general idea below:

#include 

class A
{
public:
    static A *instance()
    {
        std::cout << "A::instance()" << std::endl;
        if (!s_instance)
            s_instance = new A;
        return s_instance;
    };

    A()
    {
        std::cout << "A::A()" << std::endl;
    };
    // Virtual makes the difference
    virtual void send(int i)
    {
        std::cout << "A::send()" << std::endl;
        // Blah blah, send i or something
    };
    static A *s_instance;
private:
};

class stub_A: public A
{
public:
    static stub_A *instance()
    {
        std::cout << "stub_A::instance()" << std::endl;
        if (!s_instance)
        {
            s_instance = new stub_A;
            A::s_instance = s_instance;
        }
        return s_instance;
    };

    stub_A()
    {
        std::cout << "stub_A::stub_A()" << std::endl;
    };

    void send(int i)
    {
        std::cout << "stub_A::send()" << std::endl;
        y = i;
    };

    int getMessage()
    {
        return y;
    };
private:
    int y;
    static stub_A *s_instance;
};

A *A::s_instance = 0;
stub_A *stub_A::s_instance = 0;


int main(int argc, char **argv)
{
    stub_A::instance()->send(5);
    std::cout << "stub_A::instance()->getMessage() == " << 
        stub_A::instance()->getMessage() << std::endl;

    A::instance()->send(7);
    std::cout << "stub_A::instance()->getMessage() == " << 
        stub_A::instance()->getMessage() << std::endl;
}

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