August 27, 2012 / gbl08ma / 0 Comments
I was playing around with my cheap Flytouch Android tablet, using dd to create images of the different partitions of the internal storage (which is, in fact, just a microSD card).
Turns out I discovered that there is a 256MB FAT partition living on /dev/block/mmcblk2p6. By this time, geek users already know what to do: with root privileges, mount the partition in some directory..
So, open a terminal on your rooted Flytouch 3 (P041 and DK1031 models should have this partition). Type:
~# mkdir /mnt/sdcard/256MBfat
~# mount -t vfat /dev/block/mmcblk2p6 /mnt/sdcard/256MBfat
This should result in a new folder in your sdcard directory. This folder is a filesystem node, like the sdcard1, udisk1 and udisk2 folders.
This FAT partition is empty and should have about 256MB space. If it isn’t, or if the mount command returned an error, then that’s interesting đ
Why is this partition in these tablets? Well, I have a theory. These tablets support having a recovery partition, even though most firmware updates provide no recovery image files. The fact that this is a 256MB partition may indicate that it is meant to hold contents similar to the system partition, and in this case, it should be formatted as EXT3 and not FAT.
As most firmware versions for this tablet available on the internet don’t include a recovery image, this partition just gets formatted as FAT by the updater kernel at update time.
But what if the updater never touches this partition? This would be pretty good news. You could use this more or less hidden partition to store the owner information, so if your tablet ever gets stolen you’d always have a way to recover it.
If that was the case, you could also use this partition to store essential APK files and configuration so it would be easier to recover from a firmware update or factory reset.
As a last and kind of unrelated statement, I’d like to point out that the bootloader of InfoTM tablets is much more complex than it may appear at first.
Through a serial line that I believe to be the A-A USB connection used by IUW to burn updates, the bootloader can provide a serial console, that can be used to change the boot parameters for Android and maybe even boot other operating systems from the external SD card.
This thing of the bootloader is something I’m figuring out slowly by analysing the uBoot update file I have, u-boot-nand.bin.
If you have one of these InfoTMIC tablets, feel free to comment below with any important additional information.
NOTE: this post was written months ago but was sitting on a text file on my desktop for months, waiting to be posted. So this isn’t a recent discovery, but still an interesting one.
January 12, 2012 / gbl08ma / 0 Comments
Some time ago, I posted here in the blog that the cheap Android tablet I had bought four days before, broke. Turns out the problem indeed was the corruption of the internal microSD card, which acts as the main memory of the thing.
The tablet in question is a âFlytouch 3âł, P041 model with silver back. The processor is an Infotmic one, as usual with these cheap tablets (fortunately, Â Chinese makers are now moving to better dual-core Cortex processors). The original internal microSD had 16GB, no brand and said it was a class 4 card. Finally, after disassembling the tablet and taking the card into a reader on the PC (to try and format the card, since the tablet wouldnât want to write to it and would fail every system update attempt), the microSD finally broke and now itâs not recognized on any reader â a low-quality card, now dead.
I ordered from Amazon another 16GB card, this time a class 10. I put it on the tablet, assembled it back, and the bootloader could flash a new update to it fine. Android is now blazing fast, either because the card is a class 10 or because the old one was very damaged.
So far, everythingâs working except the hardware wifi switch I accidentally broke when the tablet was open. Again, I had some luck, as the switch was left on the ON position â and curiously, the wifi connection seems stable than before.
Letâs wish this thing keeps working as it has until now⊠itâs been almost 24 hours since I put the new microSD in.
November 19, 2011 / gbl08ma / 1 Comment
Iâve met the Raspberry Pi project around three months ago, and immediately fell in love for its concept and idea: to build a extremely cheap Linux box that could be used to teach children the world of programming, Linux and even open source in general. But when I first knew about this project (it was on Slashdot if I remember correctly), me and lots of other people were skeptical about it, specially because of the aim price (USD $25/18,5âŹ), because of the size of the prototype board (the first one presented was no big than a USB flash drive, and in fact, was smaller than many of them), and because their website consisted of a single page with an image of that prototype board and a few technical details; it also said the Raspberry Pi Foundation was a charity (non-profit).
I forgot about the project for a few weeks: like many other people, I thought this was no more than vaporware. Later, when I visited their website again, I found it to be much more complete, and it already had some more information and more facts had been confirmed. From then on, I began to check the website much more frequently and, currently, the Raspberry Pi doesnât look like vaporware anymore: there are alpha boards built that have been distributed to various people doing software work on them, and the project staff has ran demos of the Alpha boards at many meetings. The Raspberry Pi was and continues to be responsible by news articles, sometimes front-page articles, on many technology sites. They also shown on UK television and radio. All this, and they havenât released a final product to the market yet!
So what is the Raspberry Pi, in conclusion? Itâs a extremely cheap, cheaper than many books, embedded Linux board. At launch, there will be two models: A and B. The model B has better features than the A, they will cost $35 and $25 respectively. Behind the project thereâs a charity with the same name, the UK-based Raspberry Pi Foundation.
Both models feature an ARM11 Broadcom CPU clocked at 700MHz and a GPU capable of drawing Full HD H.264 videos at 30fps, and supporting OpenGL ES 2.0; a SD/MMC/SDIO card slot from which the OS will boot. For video output, the Pi has both an HDMI connector and a good old composite video connector, which means the Pi will be able to display not only on a modern LCD with HDMI connectors, but also on older TV sets and displays that feature composite video input(s). The RAM varies according to each model, and is presented stacked on top of the CPU (PoP configuration). Both models have some GPIO (General Purpose Input/Output) pins, although nowhere as many as things like the Arduino.
As for power supply, the Raspberry Pi will ask for a 5V input, and it should run off 4 AA cells. It will use a micro-USB connector for power supply, but note that it doesnât act as a USB client device (it only draws power from micro-USB, no data). The energy consumption of the board is also incredibly low, and I believe it is lower than the consumption of many devices in standby mode.
The publicly shown Raspberry Pi Alpha board
Model A will only have 1 USB port, no ethernet and 128MB of RAM, whereas the model B will feature 2 USB ports, an ethernet jack and 256MB RAM. The final PCB design has been released, after lots of work doing the routing of the tracks of the PCB to ensure the maximum efficiency of the Raspberry Pi; the board will have the same area as a credit card (itâs amazing how could they fit all the connectors in such a small size board).
Oh, and I forgot to say: the Pi also has a 3.5 mm jack audio output; combine this with the small form factor of the board, some portable power supply and buttons connected to the GPIO, and there you have a very powerful MP3 player that also turns into a full-featured PC when you connect a display, keyboard and mice to its USB port(s). Or you could bring a touchscreen and make your very own Android/Ubuntu/whatever Linux tablet!
The circuit scheme of the final board
As for the software, the board is designed to run ARM Linux distros, but people are already planning on porting other lightweight OS â donât expect Windows in any way though as a) this device is simply too open-source for Microsoftâs mind and b) Thereâs not enough RAM to run Windows 8 in any way. Plus, WINE and other Windows abstraction layer software will not work, as these are not designed for ARM. Apart from these limitations (that most certainly donât affect you unless you were expecting to make a hardcore gaming machine out of it), the Pi will do, better or worse, practically everything you do with a PC: web browsing, email, word processing, spreadsheet, instant messaging⊠for more advanced users, this is also a perfect server, either for serving files on USB drives, or hosting websites. For those (of any age!) willing to learn (embedded) software development, this is also the perfect device â specially because itâs cheap as hell, when compared to things like the successful Beagleboard.
I guess that we only need to allow time for humans to develop uses for the Raspberry Pi, and some of them will drive our minds crazy Iâm sure. Enough presenting the Pi, if you want to know more you can do researchâŠ
Why I think the Pi will make a difference
You already saw what the Pi is from my quite long introduction above. I wonât say this is a revolutionary device, that will change the way we see technology. I wonât say that this is going to cause an impact as big as the iPhone caused on mobile phones or as the iPod on digital music, either, specially because a) the Pi doesnât have an Apple on the back, b) the iPhone/iPod werenât news either, since things like them already existed before; that fruit company only made them friendly to the masses (and credit to them for that).
Other thing that makes me think the Pi wonât reach the intended audience so fast as some expect is itâs appearance. I donât want to make more analogies with Appleâs devices, but please allow for just another one: smartphones existed well before the iPhone, and I have an HTC phone from 2005 that did more (has 3G connectivity, for example) than the first iPhone, that was launched much later. Then why didnât the older smartphones make much success? I donât think expensive is the problem, but their look: most of them look ugly, to the masses at least, something the iPhone did better (just like with most recent Apple products).
Stopping with Apple analogies (I promise!)⊠the Pi is an innovative product by its size, its price and its main objective. If enough people know about it, it will suppress many markets, such as the thin clients one. From my point of view, this is the most cheap and minimal mini-ITX you can get, with the detail it doesnât run Windows, but that is a matter of getting the world used to Linux. Due to its small power supply requirements and the cheap price, it will also bring computing where it is very rare nowadays, enabling people in development countries to have their first PC (or PED â personal embedded device đ ). If we find a way to cheaply connect the Pi to the internet no matter where one is, it is even better, because people that have gain access to the ânet and to who we teach how to use it, will eventually become better informed people.
In other words, this is a bit like the OLPC project, except that, at least in my honest opinion, and based on what I know from the OLPC project (which might not be accurate), it is being done with much more responsibility and a true knowledge of the requirements of the target audience. It also uses emerging technologies such as Linux for the ARM architecture, contributing to the evolution of the open source universe. But still, I donât want to say the Pi is the perfect device: the Universe doesnât allow perfect things to be made, duh. So, not being the perfect device, thereâs always space for improvement, specially because one size doesnât always fit all, and people will always one to thinker with a Pi to make them more like their own definition of âperfectâ.
Other important difference in comparison with the OLPC project is that it isnât just for children: indeed, the first batch of 10000 Raspberry Pies will be more targeted at developers and hackers (that doesnât mean some âhackersâ arenât as young as meâŠ), however and unlike was wrongly stated in many news, any person can buy it. Detail: Iâm not yet sure if the first batch will be sold as a buy-one-donate-another project, making you pay for two Pis whereas youâll only receive one, having the other going to charity. Please enlighten me on this subject!
The defects of the Raspberry Pi
As I said, this isnât the perfect thing, and I think itâs important to point out its defects and limitations, because only this way we can improve on them. So, here are the things that according to my thoughts are yet to be solved or better discussed:
- Peripherals: the Pi can be considered nothing more than a PCâs motherboard; it still needs you to have all the peripherals, from keyboards, mice, SD cards, and specially, a screen where to show things. The screen is the most expensive part, if you assume people canât use an existing screen because of e.g. the lack of one.
- Power supply: well, this is a âdefectâ that comes with every device, so Iâm not considering it as a defect, but more of a âthing to discussâ â and many people are already discussing it, fortunately. Even if the Pi consumes such little power that it can run of standard AA cells, the things youâre going to connect to it wonât. And being the Pi basically just what a motherboard is to the PC, itâs pretty useless without some input/output devices â and these will consume much more power than the Pi. Well, we can assume you only connect a four-line character cell display to it, and a USB keyboard for input, and then use the display to show four lines of Linux shell â not very practical, obviously.
- Memory/CPU specifications: As I said above, itâs not going to run the traditional Windows, nor a recent Firefox on Linux, at least until they stop making memory-hungry Firefoxes. Itâs all a matter of studying the capabilities of the device and see if it applies for your project. I think the low specifications of the board also have a positive point: It will teach the young developers how to make apps that donât use 1GB of RAM after half an hour of use, thus teaching these developers how to manage the system resources.
- The case: itâs known that the Pi will ship without case. There will be cases available on the online store of Raspberry Pi, but of course these cost some money, increasing the price of the device if you must have a case. Of course, we canât see just the negative part of this: the lack of a case opens peopleâs mind to creativity and curiosity, making them poke inside the Pi. If it breaks⊠well, if you have enough money to buy another, thatâs not a problem. However, if we want to incentive children to learn programming with the Pi, it must be made somewhat attractive.
Finished! This is my long essay on the Raspberry Pi⊠please correct me if you find any errors on the facts presented here, and take the opportunity to express your own opinion by dropping a line on the comments. Oh, and of course donât forget to visit the official Raspberry Pi website for more amusement! đ