Technically minded Weblog

No new years post this year…

My current interest is Asus T100TA Windows 8 tablet. More precisely: newer Z3775 powered version with a 500GB HDD inside keyboard dock and 32 GB internal (couldn’t find a 64 GB version).
A very nice and very capable piece of hardware with only one problem: Windows 8
While Windows 8 runs very nicely on this tablet (except for buggy Broadcom Wifi/Bluetooth drivers) there aren’t many good touch friendly apps available for it.

Windows Store you say ?
Most of my favorite apps aren’t there. And there are only about 200K Apps in Windows Store. The competitors Google Play and App Store have about 1.4 million (according to Wikipedia).

That’s where Android x86 comes to the rescue.
I won’t go into details of porting (that would require several posts) and just tell you that I’ve built a version of Android x86 4.4.4 KitKat which works on T100TA.
Not everything works yet (bluetooth, rotation, camera), but otherwise Android is fast and runs quite well on T100TA.

You can download my T100TA0 Android build, as well as some development files, from here:
http://raspis.ddscentral.org/pub/downloads/android-x86/

P.S. If you wonder about my old TF300T’s fate, I accidentally dropped it and damaged the touch digitizer… This requires a screen replacement and isn’t worth fixing as the new screen would cost as much as a new tablet. There’s another TF300T in my family. It isn’t mine, but I’m allowed to use it if I need to. It runs KitKat Cyanogenmod. Didn’t install Ubuntu there yet.

2014. Another year of our existence.

I know, I should have posted this more than a month ago, but I guess now is better than never.

There have been some changes since I last posted. I’ll mention a few:

I upgraded my system with a new GPU, the R9 290x. Great GPU except for cooling. Have to ramp up the fan to get acceptable temperatures under load.

Another thing worth mentioning is my experiments with Ubuntu on ARM processor (no, not Ubuntu Touch, but the full desktop version).

The target system is my Asus TF300T.

Here’s the story.

———

If I haven’t mentioned previously, I’ve bought a convertible tablet, the Asus TF300T with Android 4.1 some time ago. It ran OK, but the keyboard dock was not of much use in Android (except for being a great alternative to onscreen keyboard) as not many apps have support for the keyboard dock, let alone the touchpad.

I’ve deciced that this little machine needs a OS which can truly make use of the keyboard dock.

At first, I have tried an easy solution: Ubuntu in a chroot container on top of Android with VNC for UI. This solution worked, but it was REALLY SLOW, even with a quad core Tegra 3.

Then I found out that Nvidia does provide Tegra 2/3 drivers for normal Linux distros. So I have started searching, maybe someone already got native desktop Linux to run on TF300T.

And indeed, I did find a working port of Xubuntu 12.10 on XDA. It was for TF300TG, but I got it to work on my TF300T with some tweaking (mainly, to get Bluetooth and Audio working).

Later, my TF300T went through 2 Ubuntu upgrades and some kernel rebuilds (mainly to add more drivers, but I’ve also applied the kernel patch to enable running of some Windows RT programs).

It now runs Ubuntu 13.10 (with MATE for desktop) from a 32GB SD card in the keyboard dock. The system runs fast enough for internet browsing and some light work. It’s not as fast as a fully fledged laptop, but It’s good enough as a netbook.
Batteries last for about 8 hours, sometimes shorter, depending on use.
There’s also a hardware video decoder for playing videos without using CPU for decoding but it only works with old versions of Totem and Parole media players and it’s not perfect with these programs either. There’s also a command line based Nvgstplayer from Nvidia themselves, but it’s not easy to use and it’s not bug free either.

More details about my ARM adventures in the next post (can’t fit everything in a single post 🙂 )

I have recently replaced my TP-LINK (used as a temporary replacement for my old Linksys, which has met it’s demise) router with Asus RT-N66U and added a Gigabit switch to upgrade my home network to Gigabit.
RT-N66U is a really decent router. It’s OF (called AsusWrt) seems to be based on Tomato and is open source. The OF also supports Optware OOB (uses Oleg feed) and can install apps directly from WebUI.
Another great feature is Telnet access, which enables to directly control the underlying Linux OS without using the WebUI (most routers do not have this feature, even though they run Linux as their OS).
I am currently using a slightly modified version of OF, which enables some nice features, like a writable flash partition (separate 13MB JFFS partition), startup applications, etc.
Since this router has enough power to run both my routing and my network apps (BT, Samba, etc.), I have retired my custom modded Belkin modem-router (which ran a modified version of DD-WRT) and moved all my network apps to RT-N66U.

Although the Web UI is nice, I have setup most of my apps from Linux terminal because I needed a greater degree of customization than that offered by the web interface.
Using a terminal allows you to customize all configurations directly and allows you to do more than just routing and running network apps. I have even installed Debian’s MIPS port (in chroot) which, with it’s wast collection of apps, offers endless possibilities (heck, I can even install gcc and build apps from source directly on the router).
I have even tried TightVNC with LXDE desktop ! (Just for fun. The desktop is pretty slow though, too slow for anything more than playing solitaire and light web browsing).

On the hardware side, the WiFi range is also great, much better than I expected. 5Ghz WiFi is nice too (especially combined with my 5Ghz capable Linksys AE3000 dongle), too bad it’s range is very short.
I also like 256MB RAM, dual radio WiFi (with three antennas) and onboard MicroSD slot (too bad it’s installed in a way that it cannot be used without voiding the warranty).

Technical specs of RT-N66U:
CPU: Broadcom BCM4706 @ 600 MHz MIPS
RAM: 256MB
LAN: 4xGigabit LAN, 1xGigabit WAN
WLAN: 2x Broadcom BCM4733, 2.4Ghz and 5Ghz capable.
USB: 2x USB 2.0
Storage: 32MB onboard flash, internal MicroSD card slot.

After serving me for around 5 years, my old Linksys WRT150N (flashed with DD-WRT) has died completely today. No response at all from Telnet or http and no Internet connection. The only thing that still works is the dumb switch.

Because most of my jobs require Internet connection, I went emergency router-shopping. I was hoping to find something like Asus RT-N16 or better, but couldn’t find anything decent (the best routers I could find had worse specs than my hacked F7D3402) so I had to get some cheap device as a temporary replacement.

TP-Link TL-WR740N is a really cheap device, around 20 Euro. Although, the device feels really cheap, the hardware inside is more than enough for a basic router.

Specs: CPU: Atheros AR9330 SOC (MIPS) @ IIRC 400Mhz, 32MB RAM, 4 ethernet ports, 1 WAN port, Wireless Lite-N (150 mbps).

I initially planned to use this device with DD-WRT, but found that my device’s hardware revision is 4.21, while DD-WRT only supports version 2.x.

Fortunately, the latest OpenWrt trunk seems to support this device, so I compiled my own build and flashed it.

The router works fine, but there’s no WebUI, so I had to configure my PPPoE DSL connection and WiFi settings manually. Fortunately, the root FS is JFFS2 which is writable, so I didn’t have to reflash the device to make changes. The version of OpenWrt which I have flashed seems to use raw JFFS2 for rootfs, although a SquashFS version is also available.

Now I need to free some space (removing some of those extra packages which I have added) and install a WebUI, so I can properly setup port-forwarding. But that’s another story.

This router is a really good device for the money, especially with OpenWrt (but the stock FW isn’t half bad either).
But I still treat it as a temporary replacement until I get something more decent. After that, I will probably use this little router as an additional WiFi hotspot to extend my WiFi range.

OK, that’s the whole story. R.I.P. WRT150N.

Decided to do some more router hacking on my F7D3402.

Got sick of DD-WRT on my F7D3402 (due to it’s outdated kernel and because I could not use my USB WiFi dongle, because I couldn’t build the needed drivers, again due to outdated kernel), decided to ditch it and install OpenWrt instead.
OpenWrt seems to support BCM4718 chip, so this should not be a big problem. Current release in SVN trunk (which I will be using) uses Linux 3.3.7 which is a recent version. Nice. (see Update 1)

Patched the kernel (needed due to Belkin’s nonstandard TRX magic):
/drivers/mtd/maps/bcm47xx-flash.c -> change TRX_MAGIC to 00017517
/drivers/mtd/bcm47xxpart.c -> change TRX_MAGIC to 00017517

Now it boots (at least I can see it booting). But it does not mount root. It seems that it does not like Belkin’s mksquashfs 3.0 (perhaps it’s too old), because it sees the flash partitions, but does not mount anything.
Will try to rebuild with mksquashfs 4.2 instead.
Also, it tries to use JFFS2, would be nice if that worked as we could install OpenWrt packages (we can still use Optware though, even without JFFS2).

Will try to rebuild again and update this post.
When it’s done, will upload the TRX binary here in case if anyone needs it.

__________________________________________________

Update 1: It boots but nothing works, except the shell and USB. No Wifi or LAN. It seems that OpenWrt still does not fully support the BCM4718 chipset.

Update 2: I won’t be messing with this, it’s not yet usable. Switching back to DD-WRT for now. Will probably buy a more decent device to mess with in near future.

I was given a PC for repair with one major problem: it does not turn on at all, not even fans spin.
The reason of failure was likely a bad PSU. The owner told me that when they tried to turn it on, the PSU went boom.
I have opened the PSU (Branded “ISO”, a Channel Well budget series. They are OK PSUs except for capacitors) and found 2 bad capacitors (the infamous F*u branded capacitors). The PSU still sort-of worked (5Vsby was 5.24V) but it whistled badly when powered up (didn’t try jump-starting it).

I have installed by bench supply (a 350W FSP) and tried to power the system on, it was dead.
Then I started examining other components. Removed the processor and installed it back, checked RAM.
Then, out of curiosity, tried to turn it on again and it worked ! Booted to XP without problems.
I thought “OK, it looks like only the PSU bit the dust, the itself system is fine” and bought a new PSU (400W FSP).

Installed this PSU to the system and tried turning the system on and… it wad dead. WTF ?!!?!??
Again, checked cables, components, tried clearing CMOS, tried my bench PSU again. Nothing. The system was stone-dead.
(I did manage to get the system to at least try to turn on once, but it turned itself off after a few seconds).
Well, it seems that the old PSU did damage something when it exploded…

The happy part for me is that the owner decided to give away the system to me (for parts) at the cost of recovering information from the hard drive.

System specs (from memory, too lazy to look up):
MB: Gigabyte, Socket AM2
CPU: Some AMD Athlon 64 (single core)
RAM: 2x512MB (1GB)
VGA: GeForce 7400 or 7600 PCI-E
HDD: 250GB Samsung SATA (in perfect condition)
Also, some optical drive and a generic black mid-tower case.

HDD went to my NAS (a hacked F7D3402, mentioned in the previous post, had to do some mods so that the HDDs would mount properly when connected to USB Hub, but thats a different story), other parts are still in the case.

Lesson learnt: Avoid cheap PSUs. Always remember to check your PSU from time to time. If it whistles or makes any unusual sounds (eg. whine), you should stop using it, unless you know the PSU should behave like that (my new Corsair TX850 V2 did whistle on standby when it was new, but stopped whistling after some time).
A bad PSU can take the rest of your system with it when it dies !

P.S.: I had another system brought to me for an upgrade (a LGA775 based PC with 2.8Ghz Celeron D and 512MB RAM with XP on it, upgaded to a 3.4 Ghz P4, 1GB RAM and Windows 7)
Before upgrading, I decided to check the PSU, as it looked very much like one of those generic chinese cheapies (even though it had “Q-tec, The Netherlands” on the label), and, surely enough, found a bad capacitor in it (again, one of these damn F*u caps). Replaced this PSU with a 400W FSP (mentioned earlier).

Enough for now…