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Access UART ports

67 points| ytch | 10 years ago |developer.sonymobile.com

21 comments

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[+] kelnos|10 years ago|reply
I'm of two minds on this. On one hand, articles like this seem to indicate that Sony has become incredibly developer-friendly... but on the other hand, the recent Xperia phones wipe a DRM partition if you unlock the bootloader, irretrievably destroying keys that allow a bunch of things not work, such as some software that makes the camera actually good.

So we're stuck either not unlocking and rooting at all, or waiting for an (unlikely?) root exploit to be found that allows a custom recovery to be installed. And even then, running a custom kernel still requires unlocking the bootloader, so you can't run AOSP or CM, or any of the other mods. (Fortunately, with a root exploit, you can back up the DRM partition and restore it later, but still, it's not ideal.)

[+] someone755|10 years ago|reply
It's not just recent phones. This has been in use since at least the Xperia S, though back then you hardly lost anything by wiping it lol. I've been wondering for a while now if Sony could use eFuses (such as the qcom qFuse, seen very recently on the Nexus 6P) to store data, but I've yet to see any change. Perhaps with the Z6 line that launches with 6.0? You do not really need root to run a recovery, as it's the bootloader's (and until a few days ago, the boot image's) responsibility to boot it up, meaning you need to have your bootloader unlocked. (Unless we're talking of /system recoveries, but those are hacky workarounds at best.) A few years back there was a CM10 build that could run off the stock boot images, so people who had root but also had locked bootloaders could very easily run CM.
[+] rodgerd|10 years ago|reply
> it's not ideal.)

I'd bet good money that at least some of it is patent crapulence and the like.

[+] miander|10 years ago|reply
This is generous of them to provide this information when most manufacturers are doing everything they can to prevent people from modifying their devices.
[+] cornellwright|10 years ago|reply
Wow this is way more transparency than I'm used to seeing from Sony. Hopefully it's not just a one-off thing.
[+] tw04|10 years ago|reply
They've been focusing on being open on the mobile front for several years now. I'm still waiting for them to drop their horrible skins and move to stock android. Or at least make the skins optional. The Z#c line-up is, imo, in a class of it's own. It's nice to have a phone that's actually small, light, with a great camera, and amazing battery life. If only they'd ditch the skin!
[+] rodgerd|10 years ago|reply
Ever since they split from Ericsson they've been hewing a progressively better and better path. They have had a supported unlock mechanism for the bootloader for several years, they've been dropping bits of their drive trees into repos, and for the Z-series phones they're supporting upgrades for a decent-by-the-shitty-standards-of-Android length of time.
[+] kholk|10 years ago|reply
The parameters are 115200, -> 8n1 <-…… Remember to enable kmsg to UART in the kernel commandline and … personally, I use PuTTY on Linux as well (just give the right permissions to the tty device you're going to use).

About cmdline parms, note that downstream and mainline DO differ, so take this as reference: Downstream 3.4/3.10/QC kernels: console=ttyHSL0,115200,n8 Mainline, korg 4.4-rc4 currently: console=ttyMSM0,115200,n8

Aside from this, and if you're a developer you actually should know, here's a lil cool info: you can also use an Arduino to communicate with your device on UART…. Just be sure to NOT connect any VCC to the board, otherwise … you'll have to say goodbye!

Wiring UART is a serious thing and requires soldering experience: use good, non-conductive flux in VERY SMALL quantities and possibly thin-as-hair insulated wires.

My suggestion is to fix those wires somewhere in your phone and "export" thicker ones outside of the phone, practicing a small hole in the housing: this will make your "mod" to last longer, and will make it "safer" since you won't be never anymore touching the mainboard with a soldering iron.

That said… this post finally gives wonderful pieces of informations to all of the very experienced developers out there who want to experiment very new, wonderful things, opening nearly endless possibilities on Sony platforms.

Also, Sony has got a wonderful open device "section" on their Developer World website, you may want to check it out: http://developer.sonymobile.com/knowledge-base/open-source/o...

...and even if it seems that they are just playing with AOSP, they are effectively creating a good, sane base with clean code that can be also easily used for porting/running alternative OSes, like Sailfish, FirefoxOS etc, like you can see on the Mozilla page here: https://hacks.mozilla.org/2015/10/build-and-run-firefox-os-o...

So..... hands up for Sony's friendship with the opensource community!

[+] jonmrodriguez|10 years ago|reply
This seems like it would make Xperia phones a potentionally great platform for prototyping of IoT devices that would benefit from a cellular radio. The UART port would be used to connect to a microcontroller which would use protocols such as I2C, SPI, and SDIO to connect to peripherals.
[+] Raed667|10 years ago|reply
Just FYI: this is also available for most Chinese Android phones.
[+] DanBC|10 years ago|reply
Is there a reliable site for reviews of Chinese Android phones?

I'm tempted, but it's hard to know which are good and which are terrible.

[+] ytch|10 years ago|reply
TL;DR: Sony shows how to access UART ports of some Xperia devices