First posting here, so I hope I don't make a complete fool of myself. My apologies in advance for the lengthy
posting, but I haven't found anywhere else that looks to be relevant, and I'm totally new to Android
tablets, so please bear with me.
Here's the story. I recently got two 7" Chinese Allwinner 13 tablets - they are item number 180981598828 on ###########,
and appear to be very similar to those mentioned previously in this topic. For example, see post #63 from novadaemon.
The details from the "About Tablet" screen are as follows:
Model number: SoftwinerEvb
Android Version: 4.0.4
Baseband version: 1.5
Kernel version: 3.0.8+
Fri Oct 19 10:15:54 CST 2012
Build number: nuclear_evb-eng 4.0.4 IMM76D 20121019 test-keys
(The second, identical tablet, has a slightly different build number: nuclear_evb-eng 4.0.4 IMM76D 20121108)
They appear to be rooted and already have busybox installed.
I have managed to bugger up one of them. I found I was unable to write to the external SD card (/mnt/extsd) so I tried
modifying the /etc/permissions/platform.xml file as describe elsewhere on the web. Not only did this not help, I now
don't have WiFi, despite it appearing to connect. Sure enough, this problem is also mentioned on the web -
"DO NOT modify the system framework directly especially permissions/platform.xml"! (From http://tiny.cc/qddypw
I have spent the last few days trying to understand more about these devices and not realling getting to the bottom
of things. I feel that what I really want to be able to do now is to make a copy of the complete firmware
from the remaining good tablet and flash it to the buggered one. I have some questions about this, and I'd
be extremely grateful if anybody could help out. I'm going to buy an another identical tablet (only £60, including
a keyboard + case), but I want to be able to mess around with the tablet and be able to restore it to the original
firmware when something goes wrong.
I should point out that, at this stage, I'm not interested in custom firmware or anything, I just want to be able
to re-flash the stock version.
1) Difference between "recovery" and "bootloader". My current understanding that "recovery" refers to an actual
separate partition which you boot into, and you then get options for recovering, updating etc., and that
"bootloader" is like what you get on a desktop computer when you have e.g. Windows, Linux etc installed side-by-side
and you have to choose which one on startup. Is this correct? I have seen several posts here saying that these tablets
don't have a recovery partition. How can this be? Is there a risk of screwing up the recovery mode when flashing
2) I find it's possible to reboot into a recovery mode by going through System Settings -> Backup & Reset ->
Recovery Mode (Reboot into the system recovery mode. Can clear the data or system upgrade). When I do that, it
powers off, the starts up showing the "belly-up" robot with red warning triangle, and a text-based menu
headed "Android system recovery <3e>". It has various options for doing things, and responds to volume up/down
buttons and power button clicks.
However, I find it is impossible to get into this recovery mode EXCEPT by going through System Settings in Android
itself. I've tried all button combinations I can think of during power-on - the only one that seems to do anything
is press and hold power, vol up and vol down. That gets me to the belly-up robot with red triangle again, but there
is nothing else on the screen - no "Android system recovery <3e>" menu or anything.
I have also tried using ADB commands like "adb reboot recovery" and "adb reboot bootloader" but these just
load up the normal Android system. So, I'm really afraid to attempt anything in case I screw up Android itself and
find it impossible to get back in to recovery mode to flash another ROM.
Do you know of a button combination that works on startup to show the recovery mode? Or is there a way of
flashing a ROM without needing to go into recovery?
3) How to create a dump of the firmware. I tried RomDump, but it produced a "segmentation fault". I then followed
the instructions given here - http://www.techknow....p?topic=3184.30
("Yes! It is possible to
make a backup: ") - and successfully ended up with four files: bootloader.img, boot.img, recovery.img, and system.tgz.
The sizes are 16MB, 32MB, 32MB, and 152MB respectively. However I haven't a clue what to do with them, if I wanted
to burn these on to another device!
Are these the only files needed? How do I create a "update.zip" or other usable means of flashing the firmware? I see
some other posters have said they backed up or copied off the firmware.
I'm sure something is possible, it's just that I'm so new to this. As a last question, the thing that started all
this was the inability to write files, pictures, documents etc to the external SD card - everything would write
OK to the "internal" SD card (/mnt/sdcard), but not the external one. Has anyone come across this, and of a fix?
My thanks in advance for any help you can offer!
Best regards, and Merry Christmas,
Mr. Lindsay Wilson