There are some invisible companies in China. Some are quit big. For example there's a mobile phone company called TRANSSION HOLDING in Shenzhen. In Feb it's mobile phone production is No.2 in China, next to Huawei, more than Xiaomi which is No.4. It's brand is even unknown inside China. How such a company is unknown even within China while producing so many phones? Because its market is in Africa. Its brand, Tecno, is the No.1 mobile phone in Africa
Wow, I didn't expect the Red Bend hypervisor. This seems like a total disaster from a security and privacy perspective.
I really don't understand why this makes sense to do. What is so special and secret about the baseband that makes it worth the effort of running a hypervisor on such an underpowered phone?
Even the cheapest baseband chip will add a significant cost to a phone. If they can get rid of the physical baseband processor they get a major cost savings.
As for why user a hypervisor vs a user mode or kernel driver: Modularity.
Some company can specialize in producing soft-basebands (software eats the world!) and ship a simple image blob that you can drop into your virtualization host, set it to use 5% of CPU time and you're away to the races.
Might be able to bring up a baseband on a new platform inside a day.
Also don't expect this "hypervisor" to be a complete software package like Xen or VMware. I'm speculating here, but all that's needed is a rather fixed allocation of peripherals, interrupts and RAM for each guest (radio+SIM+a few MB RAM to baseband, everything else to Android), likely compiled statically for this particular platform. No fancy emulation of hardware or device-drivers giving paravirtualized access to complicated peripherals necessary.
In that case, and with a CPU and peripherals designed with keeping this concept in mind, the overhead will be almost non-existant compared to, for example, running the baseband functionality as a "regular kernel module"; with the added advantage of clearly separating both worlds, and isolating the realtime-requirements of the baseband from the Linux kernel.
For some similar concept, have a loot at "RTlinux", where the Linux-Kernel runs as the lowest-priority task in a very thin realtime-OS to achieve guaranteed reaction times for, e.g. motor control applications.
Aren't all (or most) baseband OSes real-time OSes? You can't really run a baseband with Linux. I imagine the virtualization software is there to run the baseband OS and the Android OS side by side on the same CPU.
"iFixit would approve of the H3. All you need to take it apart is a Phillips head screwdriver."
Would that imply hand-assembly in a small factory rather than large batch production?
I gather from the OA that this is basically a reference design using SoC components. Just wondering if there will ever be a Web site where I could spec a made-to-order phone in the same way that I can spec a cheap laptop? So I could have (say) a high quality sound recorder chip with 3.5mm input socket for an external microphone added to an otherwise standard phone? Or a really good camera chip?
"Like most phones, the H3 won’t power on without a battery connected"
Instead of a battery, I often use a constant voltage constant current 3.7V SMPS regulator board to switch on my old phones when I want to experiment with them. Connect the positive lead, ground the other two leads, and most of them (i.e., 7 out of 8) turn on just fine.
I think it's safe to say that most smartphone mainboards will look roughly the same, due to the high level of integration; although name-brand phones from Samsung and Apple tend to have higher-density layouts and actually lower integration.
The SR1019A is $0.564, SC2330B is $0.876, and SC6825C is $3.83. I found the VC5282 on a different site for 2.30RMB ($0.37 USD), and prices for KMN9X000RM seem to vary a lot but vary between $0.14 (possibly a scam) and $15.
It's hard to estimate the BOM cost because of all the other pieces' unknown specs, but I don't think it's more than ~$20.
When the phone is assembled you can trigger it by holding ‘Volume Down’ while the phone is off, and simultaneously plugging it into USB. I haven’t tried ‘ResearchDownload’ yet, unfortunately it sounds like it can only write images not read them – taking a backup involves flashing a working CWM for the phone model first.
That's the same method used on Mediatek smartphones; they have the bootloader in ROM too, and this is also what is used to load initial firmware on blank devices at the factory. (It's also how to recover from a "hard brick".) The ResearchDownload utility looks like a clone of Mediatek's SpFlashTool, and if the bootloader mode works in a similar fashion, dumping the full eMMC should also be possible like it is in MTK. All the bootloader does is provide commands to write data into memory and execute it.
I'd be very surprised if they were actually virtualising the baseband and applications processors on the same CPU, since the former needs hard realtime constraints. The MTK SoCs use a separate Cortex-R4 core for each modem (two in the case of dual-SIM) to do this. They could be using vLM to emulate a "virtual" SoC, allowing them to change the underlying hardware while still running the same Linux kernel. The possibility that they're virtualising Mediatek's Linux kernel on their hardware is not so far-fetched...
What I'm wondering is if they could be using the hypervisor to just partition the CPU, and permanently assign one of the cores to the baseband VM, and leave the rest assigned to the Android VM.
Although, the article didn't say it had an odd number of cores, so I guess not (unless it's really a tri- or penta-core SoC)
The site you mention looks veryh interesting, but they probably only give access to industry people. Is there any similar site where regular people can see reliable prices ?
About storage, either look at /dev/block or install Diskinfo.
Likely the device have a number of smaller partitions (A huawei phone i have handy have no less that 19 different ones) that for various reasons are not mounted.
Hey, maybe someone of the hardware folks in here can help me out: couple friends and I want to do a student project with gsm-enabled IoT devices. Does anyone know a chipset vendor that is willing to work with students?! Chipset requirements are not huge, it should support 3G or EDGE, Wifi, CSI/DSI for screens and camera and if possible a couple of GPIOs.
We don't really want to go the route of using unlicensed phones like this one or hacks with a rpi and dozens of shields, so it'd be cool if there's anything available...
Have you seen JanOS from JSConf.eu? [Home page here](http://janos.io/)
Long story short. Mozilla are making dirt cheap phones, Buy their motherboard direct from china that goes into the phone and put a headless build of firefoxOS on it. All the hardware interfacing has been done for you.
I've no idea how this project is going. Still hard to get those phones in the UK so I've not bothered to look more than the talk and the site.
It's amazing that you can have a fully working internet device in your pocket now for $34. It'll be $5 in a few years. Think of the world disruption then, when all of the internet is available to everyone who can afford a $5 meal.
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