What is Miklos hacking - en

ged2dot, a GEDCOM to Graphviz converter

Miklos Vajna — Sat, 02 Nov 2013 19:35:37 +0000

It’s All Souls' Day, so let’s celebrate it by writing Free Software that helps us to remember our ancestors. I already enjoyed ancestry.com as a GEDCOM editor, but it always just shows a small part of the family tree. So here comes ged2dot, that will convert your GEDCOM file to a DAG, resulting in a layout similar to this:

Of course you can also feed more sensitive info into it, like disabling anonymous mode: then it’ll show the name and birth/death date on the nodes; it’ll also show something more useful than placeholder images. ;-)

Are you open?

Miklos Vajna — Fri, 04 Jan 2013 22:23:44 +0000

Sounds like an easy question, but I learned over the past few years that for software projects, the answer is typically not a yes or no question.

Technically — for example — Virtualbox OSE is considered opensource, even the OSE abbreviation suggests that it’s a stripped down version of the real codebase, that is kept as a secret. At first thought I wouldn’t even imagine it’s possible to contribute back a patch from someone not working on the original — closed — codebase, but of course I may be wrong in case of Virtualbox.

There is also the question of what is open. Only tarballs of releases, or also the SCM repo used for development? Think of Amazon’s custom kernels where the code is open, but it’s obviously only a code dump, one is not supposed to contribute to it, and the individual changesets are not public.

Finally, even if the software itself is developed in a truly free manner, some enterprise version (which is based on the free version) may not be publicly developed, e.g. only the resulting tarball is public. I’m happy to see that at $dayjob even this last detail is quite public, think of LibreOffice or the Linux kernel.

CyanogenMod

Miklos Vajna — Thu, 27 Sep 2012 19:28:43 +0000

So even if I bookmarked a thread to have a look at the CyanogenMod install on my phone last year, I didn’t have a look at that till yesterday. The final motivation was that I thought that CM 9.1 (not containing any Samsung code) will not be vulnerable wrt. the issue reported 2 days ago. Later turned out that installing this app is enough, even if you stick to the older firmware supplied by Samsung, but once CM was installed, I haven’t looked back.

The install guide was easy to follow, it seems that newer Samsung devices have download mode enabled by default, so you need no cracking, the ClockworkMod Recovery and then CyanogenMod can be installed without any problems. Probably the only nontrivial part is that you do want Google Apps, even if you disable most of that stuff later, as the Play Store is part of that collection as well. As the guide suggests, I made a full backup, then after the install I restored the important part of my settings.

For the reference, here is how my home screen looked before and after the reinstall:

TL-WN422GC

Miklos Vajna — Sun, 26 Feb 2012 20:51:06 +0000

The title is a wireless card usable for desktop machines. Why I can recommend it:

It’s better than those cheap wifi stricks, having a high(er) gain antenna.
It has proper Linux support. Kernel module name: ath9k_htc, the required htc_9271.fw firmware is part of kernel-firmware, so it works out of the box on any modern distro.

LCA 2012 Videos

Miklos Vajna — Thu, 26 Jan 2012 01:40:01 +0000

I think last year it was the systemd video I watched, now it was btrfs. Especially the "can’t you do online corruptions?" part. ;)

Also: did you know the filefrag and sum commands? (e2fsprogs, coreutils)

Samsung Galaxy S

Miklos Vajna — Thu, 22 Dec 2011 21:08:00 +0000

As this post already suggested, about a week ago I replaced my S40 with $title. (Yes, I know that S II is just released, but that pushed down the price of S a bit, and I don’t want to waste so much money for a phone.)

So far I’m quite pleased about the product, here are the tools I used to migrate data:

gammu, to convert the calendar to ics, which can be imported by the calendar
gammu2gcontacts to extract contacts from the gammu backup (earlier post)
mgmaps can export to kml, which can be imported to my maps
finally a throw-away (use once, and never look back) script to generate emails from my notes, which can be imported by gnotes

The hardware is supported by CyanogenMod, but I did not experiment with that so far. (bookmark)

S40 applications I use

Miklos Vajna — Thu, 15 Dec 2011 01:38:23 +0000

See this post for motivation.

readmaniac for book reading
anyremote for controlling okular
opera mini for web browsing (the native browser of the S40s is a joke)
gmail for email reading
mgmaps for offline maps
midpssh for ssh access

KVM port forwarding

Miklos Vajna — Wed, 24 Aug 2011 17:28:35 +0000

This is going to be like my mysql password set post, I got tired of looking up the docs all the time, so here it is.

If you have a host running kvm instances and you want to forward the TCP port $hostport of the host machine $host to a port $guestport of the guest machine $guest, then you need:

iptables -t nat -A PREROUTING -p tcp -d $host --dport $hostport -j DNAT --to-destination $guest:$guestport

T520

Miklos Vajna — Thu, 18 Aug 2011 18:12:28 +0000

So I’m testing a ThinkPad T520 for about 3 weeks now.

My motivations were:

so far I was using a netbook as my primary desktop, but recently did too much hacking on it, so I needed something more powerful
it’s interesting how many people I respect is a happy ThinkPad user, so I wanted to join the fun
I got fed up with not having any 3D acceleration on the netbook, I wanted back the sane Intel VGA that requires no blob drivers and still satisfies a non-gamer, like me
sometimes I did miss a larger screen, while 12" is handy, hacking in Eclipse (when I have to), watching a movie with family, etc is not really optimal

The official homepage is here, the exact model I got has the following spec:

display: 15.6" WUXGA FULL HD (1920x1080), AntiGlare
cpu: Intel Core i7-2630QM 2,0
memory: 8GB (2x4GB) DDR3, 1333MHz
hdd: 500GB, 7200rpm, SATA
dvd writer
vga: Nvidia Quadro NVS 4200M, 1024MB + Optimus
wireless: 802.11a/g/n
bluetooth: 2.1 + EDR
card reader: 4 in 1 (SD, SDHC, SDXC, MMC)
interfaces: 3xUSB2.0, 1xeSATA/USB2.0 combo, fingerprint reader, 1xRJ45, 1xExpressCard/34, 1xDisplay port, 1xVGA, 1xmic, 1xheadphone
webcam: 1 Mpixel
battery: 9 cells, 94Whr, marketing says 14h
warranty: 36 months

What I did not test:

Nvidia
fingerprint reader
RJ45, eSATA, ExpressCard

Driver support: every portion works with Linux 2.6.39 without installing any external drivers, except the out-of-core vga.

Notes:

the cpu is an x86_64 4-core 2GHz (in case the above link would became 404), so far it seems that enabling hyper-threading just causes trouble, once I turned that off, I no longer got random failures when doing multithread builds
I considered SSD but so far I think it’s too new technology for me, probably I’ll consider for the next machine
luckily the Nvidia card in it did not cost too much, since it would just eat my battery, one of the first things I did was to enable the in-core intel vga
the external vga port is nice, when I plug the external monitor in, a KDE gui pops up and manually typing xrandr commands seems to be unnecessary
the wireless works fine with the iwlagn Linux kernel module, but so far I was unable to connect to hidden access points (need to debug later, I only use advertised ESSID + wpa2 on a daily basis)
the fingerprint reader is a joke, I did not try this one, but with a similar model it seemed to work 9 times from 10 cases, but in case it did not, repeating the read did not help and finally you just had to type in your password
battery: with my usecase, it’s around 8h when I do nothing cpu-intensive, otherwise around 3h
my mini benchmark: build of LibreOffice master took more than 24h on my netbook, now it’s under an hour, an in case there were minimal changes only (so ccache has many hits), it’s around 20 minutes — and that includes installing the product and running the testsuite as well. ;)

KVM vs Windows 2003

Miklos Vajna — Fri, 01 Apr 2011 00:01:48 +0000

A few days ago I wanted to try out Windows 2003 (to be used for a task at the university) in KVM, to be exact using libvirt. First I didn’t do any non-intuitive trick, but later it turned out what virtio should be enabled for the block devices or the whole machine will be slow as hell. For the records, here is what worked for me:

wget http://alt.fedoraproject.org/pub/alt/virtio-win/latest/images/bin/virtio-win-1.1.16.vfd
virt-install --name=vmiklos-w2003 --arch=x86_64 --vcpus=1 --ram=2048 \
        --os-type=windows --os-variant=win2k3 --connect=qemu:///system \
        --network network=default \
        --cdrom=/virt/vmiklos-w2003/en_windows_server_2003_with_sp1_enterprise.iso \
        --disk path=/virt/vmiklos-w2003/vmiklos-w2003.img,size=24,bus=virtio \
        --disk path=/virt/vmiklos-w2003/virtio-win-1.1.16.vfd,device=floppy \
        --accelerate --vnc --noautoconsole --keymap=us

When the installer asks if you have a special SCSI driver floppy, ask for it, then you can select the virtio driver.