Marcin Juszkiewicz, an Arm Linux developer, writes about AArch64 hardware, desktops, boards and distribution support.
HN commenters link it for his AArch64 desktop experience, the lack of good Arm desktops, and his tables of Arm SoC features.
See also: The most expensive chip in the ARM world by Marcin Juszkiewicz [0]. It's written by a core AArch64 developer on the lack of a full-function boot ROM on most ARM single-board computers, forcing developers and users to fight with vendor-specific bootloaders.
> So SBC… Which means playing with U-Boot. In the past it meant random fork of it. [...] you have bootloader(s) built. The next step is taking microsd card, finding out which offsets to use. Then put bootloader(s) at proper places so CPU can read them and boot. Usually it also means that you have to use MBR style formatting [...]
The reason? A EEPROM chip is too expensive, an astronomical cost of $3! The author was half-joking, but only serious - $3 is really expensive for most single-board computers.
> The solution is SPI flash chip. But it is very expensive - 3 (three) EUR for 512Mb (64MB) chip (if bought 1000 of them). Far too much for 99.99% of SBC probably. Probably 64/128Mb will be enough even. And they are cheaper (128Mb is 1.7 EUR). Still too expensive…
[0] https://marcin.juszkiewicz.com.pl/2020/01/29/the-most-expensive-chip-in-the-arm-world/
Note that parts like this are more easily replaced using a hot air station than a soldering iron.
Looks like the audio amp fed by the MOSFET is a Realtek ALC1304, which I can't find any data on, but searching for the pin names finds that it could be a clone/compatible to the TI TPA3131D2/TPA3132D2. This part has a power limiter, but if the Realtek one is configured the same way, then as implemented in the laptop, it has no power limit.
It is very likely that the reason the transistor failed was because of poor cooling, as it is a low cost, high-resistance transistor that is running near its design limits.
The MOSFET that blew up is rated for 2A continuous, and it's in the ~19-20V VIN circuit, so it begs the question of just how loud he was playing his music when it happened!
That said, not the first time laptops have come with sub-par audio circuitry:
https://news.ycombinator.com/item?id=7205759
https://marcin.juszkiewicz.com.pl/2012/12/10/how-to-fry-speakers-in-your-chromebook/
https://apple.stackexchange.com/questions/100530/can-volume-booster-software-like-boom-damage-macbook-pros-internal-speakers
Can we please edit the title to clarify that it's only x86_64?
The 32-bit version has been "coming soon" for many years now (very relatable!), but this page still pollutes my search results when looking for 32-bit syscall tables (although thankfully the ChromiumOS docs page has recently supplanted it, linked elsewhere in this thread)
To be clear I'm not mad at the author, it's a useful resource and I'm thankful for it's existence, but search engines still suck.
See also:
https://marcin.juszkiewicz.com.pl/download/tables/syscalls.html
https://chromium.googlesource.com/linux-syscall-support/
One of the first chromebooks would melt and burn if you fired up alsamixer and tried toggling a few of the toggles.
I encountered this myself fiddling with the audio settings and ended up with magic smoke and melting plastic before I quickly powered it off.
https://marcin.juszkiewicz.com.pl/2012/12/10/how-to-fry-speakers-in-your-chromebook/
https://groups.google.com/g/comp.os.linux.advocacy/c/QslNrtxo__A/m/9o2VKW0dDAAJ
(note it doesn't actually require installing another distro - alsamixer was available in the base chromeos install)
I'm glad there is finally some standardization. The previous "Standards in Arm space" articles[1] are good illustration why this was needed.
The LBBR spec seems nice, the article does mention that its for some hyperscale datacenter stuff but to me it seems like it could work well for sbcs too, but I don't know if I'm missing something.
[1] https://marcin.juszkiewicz.com.pl/2020/10/12/standards-in-arm-space-part-i/
Reminds me of the self-destructing speakers on the old Samsung Chromebook. Set wrong mixer settings and they silently burn up. In my case they melted through the case before I realized what was wrong.
https://marcin.juszkiewicz.com.pl/2012/12/10/how-to-fry-speakers-in-your-chromebook/