Newsletter #2 - August 2018 (Patreon)

Grab a coffee and lean back, it's time for another newsletter.

This month's newsletter is a tiny bit late, but this is because a whole lot of things happened to me in real life.

My pet died, veterinarian costs took a big bite out of me (financially), my wife and I had to help tear down a shed at my parent's place, and in general, a whole lot of things needed to be taken care of.

Now to the actual beef of things: What went down this month?

GPD has silently released a new model of their GPD XD+ handheld, which, other than its headphone jack, seems to be identical to the launch model.

This posed a problem, as the jack sense default status on these units has been reversed (compared to launch units).

For convenience's sake I will refer to the launch model as revision 1 and the new model as revision 2.

Given that these newsletters are my way of rambling about technology, I will give a technical explanation of what this change means.

Computer hardware requires drivers to function and those drivers often employ something called interrupts to get notifications from the hardware and react upon them. Think of them as pre-registered changes that the system is waiting for.

Think you just ordered something from Amazon, and you know your package is out for delivery... so you wait for the mailman to arrive.

You know exactly what the change will be: "Receiving your package."

And you wait for the change to occur.

This is how the headphone jack works on the GPD XD+, the pins are either closed (electricity is flowing, the pin is "HIGH"), or the pin is open (no electricity is flowing, the pin is "LOW").

The revision 1 units have a default state of "HIGH", and they register a callback to trigger when these pins become "LOW", which is the case when you plug in or pull out a jack.

The revision 2 units on the other hand have a default "LOW" state, and they register a callback to trigger when the pins become "HIGH".

Due to this, running revision 1 kernel (and thus drivers) on a revision 2 unit will cause the headphone jack detection inversion bug... while the same is true the other way around.

This month was mostly spent analyzing this issue, finding its cause, and releasing a fix for CleanROM so that, once again, all GPD XD+ users can enjoy a clean and stable operating system, regardless of what model they have received from their reseller.

For those that are into compiling their own kernel, the default headphone jack pin interrupt wait state can be configured in the Accdet.c file inside the kernel source. Set it to HIGH for revision 2 or LOW (default in our github kernel source) for revision 1 models.

Another small change that occured this month was the introduction of a 1.8GHz kernel option to CleanROM, as I've found that my own test unit has a tendency to overheat running on the full 2.1GHz clock speed.

Given the fact that I know people like options, I decided to let people choose what works best for themselves.

So what else happened? Quite a lot actually.

I've started dabbling a little bit into development for the Nintendo Switch, and am actually working on a manga reader app, which will be a Patreon exclusive release on here sometime next month or the month after.

So far it supports the top 5 online manga directories (MangaFox, MangaSee, MangaHere, KissManga, ReadMangaToday), but it still needs a good month or so of tweaking before its ready to go.

After all I don't want to underdeliver on GUI user experience.

Moving onto the last point of this month's newsletter, Alldocube's new Alldocube X tablet has finally surfaced on Geekbench's database, and yes, it runs on Android Oreo 8.1.

Why is this exciting for us? Well, it's running on an MT8176 SoC, the same chipset the GPD XD+ runs on.

This means I can use its ROM as a source for updated PowerVR drivers, and a whole lot of other drivers that will make it a lot easier for me to push an Android Oreo 8.1 update for the GPD XD+.

Of course, the ROM hasn't been released yet, but the fact that it is just around the corner fills me with excitement, mostly because the current 1.7 PowerVR drivers in use on the GPD XD+ are quite lacking. (I still cringe when I think about the rendering issues in the Yaba Sanshiro Sega Saturn emulator...)

This pretty much sums up the happenings of August.

As always, let me end this newsletter by thanking all of my patrons for the support they've shown me (and hopefully will continue to show me in the future).

Thank you everyone!

I will keep all of you posted!

- Black Seraph