There has been a LOT of miscommunication recently, given Viewsonic's apparent change in development on the GTablet. This document will be a guide for new GTablet owners, to understand the terminology and how to better prepare yourself if you want to mod your device.
"Soft-brick". The device is not booting up properly anymore, but is potentially fixable by using a tool called "nvflash".
"APX Mode". The is a low-level mode on the GTablet where you can makes repairs and un-brick the device.
"Nvflash". This is the name of the actual tool you use, when you are in APX mode.
"Clockworkmod". This is an alternate recovery tool. It adds a few things that the 1.1-based stock recovery does not have, such as full image backups, wiping user data and SD repartitioning. The 1.2-based stock recovery is a little better, but clockworkmod still has more options than 1.2 standard recovery
"/data partition". This is the area on the device where all your user data and user apps reside. A factory reset will wipe this area.
"/sdcard partition". This is the area on the device where all your content resides. It's also the area that gets mounted on your PC.
"Data wipe" or "User data wipe". This is a factory reset -- all user apps and data will be erased. Content in the device's /sdcard is not touched.
"SD repartition". This is a data wipe and a wipe of /sdcard. So both areas are erased.
"ROM" as defined for use should be considered a BOOT ROM. This is the base program running on your tablet, like an operating system it is the first line of code to load and while not every rom is a full replacement of the viewsonic operating system only one can be loaded at a time. (thanks mERRIL!)
"Kernel" as used here is the tablets details and settings written out so the software knows how to interact with the hardware. This is where things like overclocking can be done, along with changing the way your backlight or wifi utilizes power. (thanks mERRIL for both of these!)
Two Development Branches, and How to Check which version you have
This is the FIRST thing any new Gtablet user should check, before you attempt to mod your device. Viewsonic recently moved to a new development branch with a new bootloader and kernel, and older mods do NOT play nice with it.
So, to check which branch you are on: Go to Settings -- About Tablet -- Tapu UI Version. If your firmware starts with "1.1", then you are on the 1.1 (old) branch. If your firmware starts with "1.2", then you are on the 1.2 (new) branch. Also an obvious difference between the two is that the 1.2 branch adds a lockscreen to the tablet.
The "Two Cliffs" analogy
Try to think of these two branches as two cliffs. If you are on either side and want to mod your device, the safest way is to use a mod that is built around the branch you are on. On the XDA Developers site, most of their mods and custom kernels are based on the 1.1 branch (as of this writing). On Slatedroid, we have several mods that are based on the 1.2 branch. So you have options regardless of which branch you are on. The main advantage to the 1.1 mods right now are customized kernels, which the 1.2 mods lack - this could change in the future, if Viewsonic opens up the 1.2 source code (5/2011 EDIT: 1.2 now has customized kernels). The 1.1 mods also have heavier development support and have been around for much longer - 1.2, in comparison, is fairly new.
It is possible to jump from 1.1 to 1.2, and back again. But think of this as a bridge between the two. I have done extensive tests in the last month on this, and it does work MOST of the time if you follow directions. But even when doing everything right , there is still a small chance that you will "fall of the bridge" and into the abyss (soft-brick). And if you attempt to jump between them with clockworkmod, you will fall for sure, 100% of the time. Think of clockworkmod as a "bridge that is out".
The most sturdy bridge, going on my own testing, is the one based on build 1.1-3588 full stock. This makes sense because this is what Viewsonic would want you to be on, before jumping to 1.2. The reverse (1.2-4349 stock, for example) is also fairly sturdy. But again, it is a higher risk than staying within the same branch.
I'm on a 1.2-based stock ROM. What are my modding options?
If you want to stay on the 1.2 branch, there are only a few options right now. Here on Slatedroid, we have a few 1.2-based mods that are fairly safe to attempt (look for "1.2", in the title). Or, you can jump to a 1.1 stock ROM using instructions like the one written by Gojimi here: http://forum.xda-dev...d.php?t=1036956
Just be aware that jumping works most of the time, but not 100% of the time. Again, understand the risks and prepare yourself.
The current 1.2 based options are:
- Century Eyes (a Froyo mod based off the Notion Ink Adam UI)
- Mountain Laurel (a Froyo mod based off Viewsonic TapnTap stock)
- Brilliant Corners (a Froyo mod based off the Advent VEGA and the Viewsonic Viewpad 10s)
Pershoot is also developing 1.2-based kernels (which I've started incorporating into my 1.2-based mods). His web site is here: http://droidbasement.com/db-blog/
I'm on a 1.1-based stock ROM. What are my modding options?
On XDA, there are a number of mod options and customized kernels, at your disposal. And some of them are mirrored here. Again, a 1.1 to 1.1 mod should be fairly safe to attempt. If you want to jump to 1.2, I would recommend waiting until Viewsonic re-releases their new firmware and you can jump to 1.2 via the stock upgrade path (that's probably the safest way to jump, and the one that Viewsonic themselves supports).
There are a LOT of 1.1-based options, if you want to stick to that path. To name a few:
- VEGAn-TAB (probably the most popular GTAB mod, so far)
- VEGAn-TAB Ginger Edition
- Calkulin's G-Tab ROM
- TNT Lite (similar to Calkulin's ROM, and currently retired)
- gADAM (currently retired, as well)
There are also a few custom kernels for 1.1, specifically the ones by Pershoot and Clemsyn, over at XDA.
I attempted a 1.1 to 1.2 (or vice versa) jump, and now I'm stuck at the birds. Is this a soft-brick?
Yes, it's a soft-brick if you are stuck at the birds. You'll need nvflash the device to fix it. See this post for details: http://www.slatedroi...mages-g-tablet/
I attempted a 1.1 to 1.2 (or vice versa) jump, and now I'm stuck at the GTablet screen, or I'm boot looping. Is this a soft-brick?
Probably not - more likely is that you just need to do a data wipe, or a SD repartition. I will explain the steps I personally take, if this happens to me.
1- Data wipe
1.2 systems have the data wipe functionality in its recovery. You would power up to recovery via the power up and volume up keys, then choose the data reset / factory restore option.
1.1 system have NO data wipe functionality in its recovery. You would install clockworkmod - details on how to install that tool are here: http://forum.xda-dev...d.php?t=1005080 (PART 2) Note that you need to install this specific version.
If that doesn't work, then I would recommend an SD repartition next.
2- SD repartition
1.2 systems would need a 1.2-based version of clockworkmod to do this. The 1.2 based cwm download is here: http://www.mediafire...ykn3jwq7kvegc4g You HAVE to use this version, if you are on a 1.2-based ROM. You'd install this like any update.zip.
1.1 system would still need clockworkmod (see the 1.1 data wipe info above).
Once clockworkmod is confirmed installed, you'd boot into recovery (power up and volume up) and then go to Advanced and then SD repartition. This takes about 10 minutes to run and WILL wipe both your user data and your content folder, so please be aware of that.
If neither of these things help, you could also try a ROM reflash, and the worst case scenario an nvflash.
I heard that I can use ROM Manager in the Google Market. Is that an option I can use?
Please do NOT use the clockworkmod that gets installed by ROM Manager. As of this writing, that clockworkmod does NOT work with most of the mods here, and it probably doesn't work with the 1.2 ROMs at all (which is probably a good thing). There are assorted issues that I won't go into here, but just remember this, please: DO NOT USE ROM MANAGER. You will likely soft-brick your device if you do.
I used ROM Manager before reading this post, and now I get a "type mismatch" error on boot. What do I do?
You've soft-bricked the device. Please see the nvflash link for details on how to fix your device.
This post has been edited by roebeet: 10 May 2011 - 04:31 PM