Update 25/11: Now supports M003 as well, and it appears the M002 may be able to boot from the M001 build.
Update 27/11: New build posted, now with better functioning Wifi!
Android 2.2 on dirt cheap WM8505 tablets. I said it may not be possible. Since then, I've spent hours and hours trying to reverse-engineer the custom calls that the WM8505 Android port uses to set up the correct graphics modes. I still can't replicate their process successfully.
However, on Sunday I had what my friend Adam has called "an a-ha moment"1. Android's own porting guide says the graphics mode has to be RGB565 with double-buffering (aka page-flipping), but apparently this is not strictly true.
Now, a few busy evenings later, I can offer a hacky alpha for people to check out, and hopefully build upon. However, this is not the same as "the Eken M001 now supports Android 2.2".
Get to the Android already!
OK, here it is. This build is configured to boot entirely from the SD card, to minimise the chances of bricking a tablet and to make it easy for people to check it out. You should be able to run this without any impact on the OS installed in the tablet.
This image is a dodgy hack, pre-release quality, and totally unsupported, btw. Do not expect very much.
Installing from Linux/OS X
zcat image-m001.gz | dd of=/dev/sdX
(where sdX is your SD card device. You'll need to unmount the SD card, first.)
Installing from Windows
If you're unfortunate enough to be stuck on Windows, you can download a zip file with the image (M001 or M003). First, unzip the image. Then, the Slatedroid forums have instructions on how to flash the Debian SD card image from Windows. If that doesn't work, you can try these instructions. The Debian image is the same format as the Froyo image, so the same steps should apply.
Installing the SD Card manually
If you have a smaller SD card, or you just want to make your own, then I also uploaded tarballs containing the FAT and ext2 partitions for each tablet. You can unpack these onto any SD card, with the following partition & formatting scheme:
- FAT16 (for script/ directory)
- linux-swap (optional)
- ext2 (for root filesystem)
(NB: The partitioning scheme has changed since the first set of posted images.)
The first boot from the SD card will take a few minutes longer than usual, because the Dalvik VM is generating its cache. I think mine takes around 5 minutes the first time.
The following things work:
- Basic Android UI
- Blanking the screen when idle
- Swap partition on SD card
The following things should work, please test:
- SetCPU & other CPU scaling (will need to "root" first)
The following things are untested and probably don't work:
- Video playback (probably will be choppy)
- Battery level tracking
- Automatic screen rotation (I hope you like landscape)
However I expect all those things should be fairly easy to implement, except for smooth video playback.
The following things definitely don't work:
- Graphics acceleration, there isn't even page flipping/double buffering at the moment, let alone OpenGL ES (which there will never be.) It isn't as painfully slow as I thought it might be, but it definitely isn't fast. There are also a few artifacts, like lock screen redraw when turning back on. Also, some apps may not work as expected due to the odd graphics mode.
- Touchscreen calibration. The device ships with my Eken M001 calibration on it. If mine is no good then you can copy your /data/wmt/touchcal to /etc/touchcal on the SD card to bring it across. But there's no WM8505 calibration app installed, so someone either needs to port Wondermedia's or write a new one from scratch.
- Suspend/Resume (was broken in 1.6, still broken in 2.2 as it's a kernel deficiency.)
Installing to the flash in the tablet
At the moment, this only supports booting from SD card. However, there's no reason why someone clever couldn't build an alternate version that installs to the tablet's internal flash - all the required pieces exist AFAIK.
Building On This
All the scripts & patches I used are available on github. There should be enough there for a savvy person to fairly easily build this again from an AOSP release.
If you do build anything using this, please please please share source/instructions for what you improve. Every "secret" someone hoards away is a step away from making these devices properly usable.
This Froyo build comes unsupported (sorry), and I'm not likely to do a whole lot more on it. However, one thing I do intend to do is get it running on my Eken M003 (my M001 has serious hardware problems so I can't really use it as a tablet any more.)
However, I really hope that others will jump in, build on it, and make something good. Enjoy!
- I called it a doh! moment [↩]