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Sun Apr 25 15:55:42 2021 GMT: vidmini - limit webcam resolution

Being fed up with the limited configurability of some of the more widely used software used for video conferencig, I have put together a small LD_PRELOAD-able shared library that limits the available resolutions a webcam reports. Have a look at the README or the source code.

Sun Apr 26 18:45:55 2020 GMT: Tizen on Orange Pi PC

Made some significant progress for running Tizen on an Orange Pi PC (and hopefully any other SBC with a similar Mali GPU). Main issue was that alignments in TBM (Tizen Buffer Manager) weren't in sync with what the actual GPU driver expected. With that fixed, rendering seems to work fine now and I was also able to enable Full HD (1920x1080) resolution.

Next step would be to get the Home Screen app auto started and find some way to get a "Home" button (to be able to switch between apps without completely closing them).

Mon Apr 20 19:02:27 2020 GMT: SIGCHLD si_pid Linux kernel bug

While trying to get Tizen working on my Orange Pi PC, I noticed some strange behaviour in the Linux kernel in that SIGCHLD signals sent to the parent process don't always set the "si_pid" field correctly. I tracked this down to a bug in the Linux kernel for multithreaded process termination, see SIGCHLD signal sometimes sent with si_pid==0 (Linux 5.6.5). Luckily, a patch has already been posted less than 24 hours later.

Sat Feb 29 23:41:48 2020 GMT: Rock Pi S Review

Got a $20 voucher code for a review of a Rock Pi S SBC. Although the cost of the board is only $13.90, with shipping at just over $8, it's a bit over $22 in total. When the board arrived, I did actually wonder if shipping could have been made a bit more economical by not putting the tiny board into a huge box (175 mm x 115 mm x 95 mm) which had a plastic case (70 mm x 50 mm x 25 mm) with the board in it.

Anyway, two things to note about the board are that the serial console uses 1.5 Mbps (which is different to the more common 115200 bps used by other boards), and uses a USB Type C connector for power (like the Raspberry Pi 4, but unlike older SBCs).

Downloading the Ubuntu image and writing it to a SanDisk Ultra 16 GB MicroSD card seemed to work fine to get it to boot. One thing I did notice was that the SSH server keys seemed to have been written to the image and not regenerated on first boot. The other thing to be aware of is that the kernel being used is fairly old (4.4.143) with mainline kernel support only starting to appear now.

One thing that appears strange to me is that total memory is only shown as "MemTotal: 432280 kB" - I am not entirely sure what this isn't (much) closer to 512 MB.

Finally, power consumption seems to be quite good. With WiFi turned on, but otherwise completely idle, my USB tester shows the device using only around 0.2 W. Doing a "ping" and it will go up to around 0.36 W. Reading from the MicroSD card also uses around 0.4 W. Keeping all 4 cores of the CPU busy and power consumption goes up to around 0.85 W.

Thu Oct 10 17:48:58 2019 GMT: kmscube Running on Orange Pi PC with Mainline Kernel

Managed to get kmscube running on my Orange Pi PC with a mainline Linux 5.3 kernel and an updated mesa package from Ubuntu's ubuntu-x-swat PPA. The amazing thing is that it's all just mainline now, no board-specific patches needed. Interestingly, a Raspberry Pi 3 still needs a kernel built from its own branch to get that level of hardware support.

On a slightly related note I have been looking at what level of support I get for my ODROID-C1 now. Unfortunately, there is still no HDMI output and no USB OTG support. Interestingly, HDMI output does work on NetBSD.

Fri Apr 19 19:51:15 2019 GMT: Outdoor Maps in Galaxy Store

Sun Dec 23 10:59:23 2018 GMT: Adding CircleCI builds

Sat Jul 21 09:57:47 2018 GMT: Roundup running on Python 3

Thu Jul 19 06:43:19 2018 GMT: Roundup Updated for wg21.cmeerw.net

Wed May 02 14:00:35 2018 GMT: Perforce Acquires PRQA

Wed Mar 14 17:29:41 2018 GMT: ACME DNS Validation

Mon Jul 03 20:45:44 2017 GMT: HikingMaps for Tizen


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Christof Meerwald <cmeerw@cmeerw.org>
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