unrelenting.technology

Noticed the mgb driver for Microchip LAN7430 (/31) NIC in FreeBSD commit logs. Huh, interesting stuff: Microchip publishes so much documentation.. a “Programmer’s Guide” PDF with lots of driver pseudocode, and even evaluation board design files!

Burstable Graviton2 instances are now a thing. Cool! Changed the instance type for this website from a1.medium to t4g.micro so that Jeff Bezos gets less of my money :P (Basically no money until the end of this year, even — there’s a free trial for t4g.micro for all AWS accounts!)

The touchscreen (both finger and pen support) on my Pixelbook has been broken for a while (the Wacom digitizer was always present on i2c but it wasn’t sending events). There was like one time where I managed to get it to work briefly by holding the pen against it in some way, but that was it. Today I took the laptop out of the bag by the middle part, squeezing the lid a bit. Aaaand… touch works now! Something was going on with wiring somehow inside the lid (not the hinge) I guess? :/

Wi-Fi not connecting (well, getting instantly deauthed due to AP-STA-POSSIBLE-PSK-MISMATCH after connecting) is apparently a relatively common problem with IoT devices. And most people seem to point to ESP8266-based ones.

Well, I’ve never had a problem with ESP, but today I’ve been setting up an RTL8711AF based device (Xiaomi qmi.powerstrip.v1) and it was failing just like that.

Turns out this device just completely fails when 802.11w Management Frame Protection is on (even optionally). Ugh. Thanks Realtek.

Raspberry Pi 4 with the outer metal part of the micro HDMI connector sticking out of the port, micro HDMI adapter with naked pins
Photo parameters4.755 mm ISO 2500 1/10 ƒ/1.65 Download original

Wow. micro HDMI is the worst connector ever.

(well, at least this particular adapter is terrible.. or the Pi 4 grabs too hard?)

Wow, about a month ago Spot (ex-Spotinst), the service that can auto-restore an EC2 spot instance after it gets killed, fixed their arm64 support! (Used to be that it would always set the AMI’s “architecture” metadata to amd64, haha.)

And of course their support didn’t notify me that it was fixed , the service didn’t auto-notify me that an instance finally was successfully restored after months of trying and failing, AWS didn’t notify either (it probably can but I haven’t set anything up?), so I wasted a few bucks running a spare inaccessible clone server of my website. Oh well, at least now I can use a spot instance again without worrying about manual restore.

UPD: hmm, it still tried i386 on another restore! dang it.

Ported the Firefox Profiler to FreeBSD in order to investigate why WebRender has some jank when scrolling some walls of text on my 4K/HiDPI setup.

The profiler code initially looked somewhat scary: some Google Breakpad code is used, a custom stack unwinder called LUL is used on Linux (which also partially derived from Breakpad code)…

Initially, I got it working with “pre-symbolication” (an option to build the goblin ELF parser into Firefox for this purpose) only, ifdef’ing any Breakpad code out.

Turns out:

  • the only part of Breakpad used is extracting build IDs from shared objects (and in fact the “base profiler”, a copy (for now) of the Gecko profiler used for profiling during the early startup phase, just copied all the relevant code);
  • devel/breakpad was there in FreeBSD Ports (but expires in like three days!), and its patches showed that it’s really trivial to get all it working.

So I got the main symbolication system working. Which, it turns out, runs WebAssembly-compiled goblin in a web worker! Fun stuff. Requires stripping libxul for now tho.

In the end, the patch turned out to be mostly just ifdef‘s! The only meaningful parts are: thr_self/thr_kill2 instead of gettid/tgkill, supporting the different mcontext structs, and (for the pre-symbolication code path) ignoring symbol names returned by dladdr because they’re hilariously bad.

BTW, earlier in the dev-tools-on-FreeBSD space: heaptrack! I even used it to find a real memory leak in Wayfire.

Screenshot of Shadertoy in Firefox, with procstat showing C flag on firefox processes
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Firefox content process sandboxing with Capsicum: it’s alive! Work in progress, but I have WebGL and audio working :)

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Current Windows 10 has a feature called “Windows Sandbox“ which spawns a tiny Hyper-V VM with allegedly a very smart slim disk image thing that shares the OS files with the host, and smart memory management, and so on.. and virtualized GPU support, like virgl in the free world.

So can it run Crysis, or at least Quake? Is it what we need for isolating old games? Well.. it has the ability to load up the host GPU with work and to show the results, but it’s absolutely unsuitable for gaming in its current state. Seems like it uses regular RDP for the window, and there aren’t any special optimizations that make 3D fast. The frame pacing is awful, framerate is weirdly limited, etc.

Also, this is not obviously found on google right now: if you have a compressed disk, you need to decompress C:\ProgramData\Microsoft\Windows\Containers for it to work.

Was wondering for a month why Firefox on my laptop would forget my GitHub session (and some other sessions) after restarting. Turns out “Delete cookies and site data when Firefox is closed” got enabled somehow. Facepalm.