Maylong M-285 Tablet

[chateau]

This is my first Android Tablet.

I have discovered the following about the M-285;

1 Android 4.0.3 operating system, Kernel 3.0.8+ and Root Access from factory.
2 SU is installed from factory. System, rootfs and data files all appear to be rw instead of ro from the
factory (cat /proc/mounts to verify). Also using a Terminal Emulator I get the $ prompt initally and after typing su I get the # prompt.
3 SuperUser installs from Google Play,appears to work and was able to update SU Binaries.
4 Root Check Basic installs from Google Play and verifies that I have Root Access.
5 Titanium Backup installs from Google Play and appears to work. Purchased Pro Version and all seems to work.
6 Hold Power and Menu Button during power up to enter Recovery Mode.(None of the keys work and must hold Power Button down to get out of the mode).
7 Was able to enter Safe Mode once but don't remember what keys I held down during power up.
8 Has an undocumented HDMI output that requires an HDMI Mini to HDMI cable. My TV reported it as 1080P. Also when connected to my TV via HDMI the TV displays whatever is on the M-285 display.
9 The camera is front facing only, has options for 5,3,2,1 M Pixels or VGA plus Video or Panoramic mode.
10 Will charge from the USB Port in addition to the supplied AC Wall Charger.

While playing with the tablet and ADB trying to get CWM Recovery installed I managed to pretty much kill the thing. Boots to the Maylong Screen three times and then hangs. ADB commands and shell still work so all is not lost.

I found the following post after the disaster and was able to get CWM V5.5.0.4 installed and it appears to work very well. Unfortunately I don't have a backup to restore from.

Link http://www.slatedroid.com/topic/31501-rom-pwn3d-momo11907cs9000/

If you feel "brave" and are already on an ICS based rom you can just flash CWM image to nandg device.
Download this file, unzip it and push recovery.img file to /sdcard.
Then you have to execute this command, with root priviledges, on "Terminal Emulator" or "adb shell":

cat /sdcard/recovery.img > /dev/block/nandg
sync; sync; sync

Now CWM is installed on your device.

Using CWM I was able to install the latest ROM from this link http://www.androidfilehost.com/main/Allwinner_A10_Developers/christiantroy/roms/ and it loaded but the touch screen does not work.

Not exactly what finally worked but the tablet is now restored (I think using the Christian Troy ROM above). Somewhere along the line the touchscreen started to working again.

I did not have a backup of my stock ROM as stated but did have Titanium Backup of all my apps and data which I used to restore all my apps at the end. I also had backed up my original /dev/block/nanda, nandb, nandc, nandd, nande, nandf, nandh and nandi files to my sdcard.

I found that information at this link http://androidforums.com/coby-kyros-mid9742/542637-creating-backup-image-mid9742.html

I'm basing this on my experience (and the experience of others) on other A10 architectured devices. To my knowledge no one has ran this on the MidXX42 series yet...so this process may not work. If it doesn't let me know and I'll come up with another...and another...until will hash this thing out.

The process is dependent upon ABD shell, and busybox.

Open ABD shell and enter the following a line at a time.

mkdir /sdcard/dump
cat /dev/block/nanda > /sdcard/dump/bootloader.img
cat /dev/block/nandc > /sdcard/dump/boot.img
cat /dev/block/nandg > /sdcard/dump/recovery.img

By using the following syntax I was able to restore the original Maylong bootloader.img and boot.img which allowed me to get back into CWM Recovery in one case.

cd /mnt/sdcard
cat bootloader.img > /dev/block/nanda
cat boot.img > /dev/block/nandc
cat recovery.img > /dev/block/nandg (Note: This recovery.img was downloaded and is not the original)

NOTE: None of this may work in another case and is probably not all that helped me recover the M-285. I have now also made two backups using CWM Recovery. Should be OK in the future.

NOTE: To boot into CWM Recovery, hold down the Power and Menu buttons. Seems like I remember you also have to hold down the Menu button when using the ' ADB reboot recovery ' command to get into CWM Recovery.

 

[chateau]

EDIT: !!!! DOES NOT WORK. I MUST HAVE MISSED A STEP IN MY ORIGINAL SUCCESS. THE FOLLOWING DOES NOT WORK NOW. I BOOTED INTO RECOVERY, WIPED DATA/FACTORY RESET, WIPED CACHE PARTITION, WIPED DALVIK CACHE, installed CM9_nightly_20120711.zip as before, did the cat bootloader.img and recovery.img as below but the touchscreen does not work now. NOT SURE WHAT I DID THE FIRST TIME NOW.

Using this link [rom] cm9 nightlies - SlateDroid.com

I installed CM9_nightly_20120711.zip on my Maylong M-285 and it booted OK but the touchscreen would not work. The only way I could get out of it was to power down using the Power Button.

None of the comparability zips that I tried would work. I always ended up with a white screen or white screen with vertical colored lines.

Having previously made a backup of my original M-285 files, I had been restoring my M-285 by using ADB and the following syntax;

cd /sdcard
cat bootloader.img > /dev/block/nanda
cat boot.img > /dev/block/nandc
cat recovery.img > /dev/block/nandg

and then booting into recovery and restoring an original M-285 backup that I had previous done with ClockWork Recovery.

Once by accident after trying CM9 and one of the comparability zips and getting the white screen I only did

cat bootloader.img > /dev/block/nanda
cat recovery.img > /dev/block/nandg

and discovered that the M-285 would boot into CM9, the touch screen worked and all buttons worked except the BACK button which appeared to function as a MENU Button.

After a couple of Googles I discovered the keyboard files were in /system/usr/keylayout and by using ADB pull to get the files, ADB push to put the file back, trial, error and comparing these files to my original M-285 files I found that editing ' sun4i-keyboard.kl ' file using Windows WordPad to the following syntax fixed the BACK Button;


key 115 MENU WAKE_DROPPED
key 139 VOLUME_UP
key 217 VOLUME_DOWN
key 102 HOME WAKE
key 1 BACK WAKE


Note: key 1 BACK (was WAKE-DROPPED just like the MENU Button.)

All seems well at this point except my Screen Rotation has stopped working. It worked at one time to my knowledge and I am not sure what killed it. I have checked all the options and it is turned on.