[roebeet]

Future doc with explanations of GTAB firmware and modding options. Mostly done, but will add to it, over time....


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.

Terminology

"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
- G-Harmony
- 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

[massanutten]

Thanks Roebeet for keeping the new g-tabbers informed and grounded by explaining the new terms and observations mean.

This post has been edited by massanutten: 22 April 2011 - 06:53 PM

[gmoak]

Thank you for taking the time to explain this to a newbie

[roebeet]

No worries - trying to think about what else to dump out of my head that might be helpful.

[kwak]

Whatever you get asked repeatedly about.

[roebeet]

kwak, on 22 April 2011 - 10:26 PM, said:

Whatever you get asked repeatedly about.

You nailed it! EXACTLY. The 1.2 stuff is on my mind since I expect it to be even more of a confusing item once that firmware is re-released.

This post has been edited by roebeet: 22 April 2011 - 11:03 PM

[ed1field]

Thanks again Roebeet. Besides being one of the top devs, you and Rev are two of the top teachers. I know it takes a lot of your time to help others and it is clearly appreciated by all of us gtab newbies.

[blade78]

Hello

I'm blade78. I have the Viewsonic Gtablet and it rooted. I have use Roebeets roms before. I'm currently running TNT 4.4 rom. I'm looking forward to using other roms.

This post has been edited by mrsburnout: 27 April 2011 - 12:27 AM
Reason for edit: removed quote of entire first post

[rebelgator]

Thanks for all your help, I was easily able to upgrade my gtab to a new rom w/o any problems. Unfortunately the battery stopped charging so I had to reflash to the original rom and return and am waiting on a new one to arrive. Hopefully I can restore my backup from clockwork mod so I do not have to reinstall all the apps.

[GoinEasy9]

Putting it all together in one place, will make finding info easier for users and make it easier for you to modify instructions. So, I guess you're not wasting your time with the newest version of Angry Birds Seasons like some of us. Oh well, wee wee ye ha owww.

[kwak]

Thanks Roebeet. Gathering this information together in one place is a great help.

[roebeet]

Any requests would be appreciated, btw. I thought about 1.2 initially because the whole 1.1/1.2 thing is confusing to most people (even on XDA). But any other things that you can think of I can add.

[GoinEasy9]

Would you want to add information about kernels? When I first installed TnT Lite v4.4 on my Gtab, a link appeared on XDA from a site called Blendblog. It had a step by step way of installing TnT and upating the Pershoot kernel. It was a clear how-to made for first time modders and it contained the steps for updating the kernel. Here's the link:
http://www.blendblog...70/Default.aspx
I don't know how you feel about this how-to, but I like the fact that the folks who wrote it gave credit where credit was due, and seemed to do a good job of simplifying things.

This post has been edited by GoinEasy9: 07 May 2011 - 08:44 AM

[jimmyjamesmt]

First, I want to express my sincere gratitude for the excellent work of roebeet and others. My gtab has come alive since modding it! Unfortunately, in trying to navigate back to stock (from Vegan-gingerbread-love it except video playback)I seemed to have fallen off the cliff whilst trying to prepare to cross the bridge.

I followed the directions at the top of this thread, but I am now stuck on the boot screen. It will go from gtab screen to tap n tap, then back to "n" then tap n tap, etc. until it shuts off. not sure what i did wrong. I tried initially to go back to 3588 using NVflash. everything seemed to go well, until boot up, then the above loop happened. from there i decided to see if could get back to Clockworkmod so I tried pwr and vol +, to no avail. finally decided cwm must have been deleted, so decided to reflash with new 4339, since nothing else was working (I am sure this was unwise), but it was 1 am and I wanted to try something.

Currently, if i use pwr and vol + i get a different screen and a symbol of a cresent wrench and screwdriver, so i'm guessing cwm is gone. problem is i still get looped on the same screen sequence as before bird, gtab, then tap n tap, then "n", then back to tap n tap, etc.

any help would be greatly appreciated.


jrl

[jimmyjamesmt]

one other thing...when i do press pwr and vol+ key it boots into Android system recovery <3e> at the bottom it says:
E:Can't mount /dev/block/mmcblk2
(No such file or directory)
E:Can't mount SDCARD2:recovery/command

not sure it that help.

thanks again,

jrl

[mERRIL]

I believe you should add Kernel and ROM to the terminology list as well, since you use the terms later in your post.

You should whip up your own definitions but:

A 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.

A 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.

[roebeet]

GoinEasy9, on 28 April 2011 - 11:46 AM, said:

Would you want to add information about kernels? When I first installed TnT Lite v4.4 on my Gtab, a link appeared on XDA from a site called Blendblog. It had a step by step way of installing TnT and upating the Pershoot kernel. It was a clear how-to made for first time modders and it contained the steps for updating the kernel. Here's the link:
http://www.blendblog...70/Default.aspx
I don't know hoe you feel about this how-to, but I like the fact that the folks who wrote it gave credit where credit was due, and seemed to do a good job of simplifying things.

I actually had a PM exchange with the admin over there, a few weeks back -- not for anything bad, but only because he was hosting the files himself and some Woot! users were using it and asked me about it. I told them I had no idea if the files were intact or not. The admin then started posting on XDA so it was cleared up.

mERRIL, on 29 April 2011 - 11:58 AM, said:

I believe you should add Kernel and ROM to the terminology list as well, since you use the terms later in your post.

You should whip up your own definitions but:

A 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.

A 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.

Good ones, both. I take it for granted sometimes that people know what this means.

jimmyjamesmt, on 29 April 2011 - 02:07 AM, said:

First, I want to express my sincere gratitude for the excellent work of roebeet and others. My gtab has come alive since modding it! Unfortunately, in trying to navigate back to stock (from Vegan-gingerbread-love it except video playback)I seemed to have fallen off the cliff whilst trying to prepare to cross the bridge.

I followed the directions at the top of this thread, but I am now stuck on the boot screen. It will go from gtab screen to tap n tap, then back to "n" then tap n tap, etc. until it shuts off. not sure what i did wrong. I tried initially to go back to 3588 using NVflash. everything seemed to go well, until boot up, then the above loop happened. from there i decided to see if could get back to Clockworkmod so I tried pwr and vol +, to no avail. finally decided cwm must have been deleted, so decided to reflash with new 4339, since nothing else was working (I am sure this was unwise), but it was 1 am and I wanted to try something.

Currently, if i use pwr and vol + i get a different screen and a symbol of a cresent wrench and screwdriver, so i'm guessing cwm is gone. problem is i still get looped on the same screen sequence as before bird, gtab, then tap n tap, then "n", then back to tap n tap, etc.

any help would be greatly appreciated.


jrl

Yes, cwm was wiped with stock (it's designed to do that). You most likely need a data wipe - with 4349, if you run recovery it should run a pop-up menu with some items - don't worry if this failed the first time, as you might have had a recovery folder in there. The second attempt might get you the pop-up menu.

If you JUST see the wrench, click the home button (I think) to toggle the visible screen on and off. You shouldn't have to do that, but maybe your device is messing with you.

This post has been edited by roebeet: 30 April 2011 - 09:38 PM

[ed1field]

Hi Roebeet,

I'm not comfortable with the definitions of ROM and Kernel. When I left the world of programming over a decade ago these words had very different meanings than used here. Now that I'm working to get caught up on what's happening, I'm finding a problem with "new" definitions, and I need some help.

ROM once meant the flash only once memory that came from the manufacturer with no ability to be changed (as used in chips for initial bootstrap routines). Then it became multi-flash, but used as read only memory (making it easier for us to upgrade chips). Next ROM seemed to be defined as anything, anywhere in the system that would only be read and not necessarily directly changed. Until this moment, I was guessing that the current definition of ROM used here was any package of software put together by folks to run on our devices, usually including a lot of programs, and sometimes, but not always a kernel. And now, wanting to call a ROM a "BOOT ROM" and writing that it's "like an operating system" is making a few of my brain's synapses shut down.

Kernel, in the linux world, also had - and appears to still have - a specific meaning that is not the definition here unless taken in a most general way. Wouldn't it be better to talk about core services and the kernel being an abstraction layer (connector) between the hardware and everything else (the stack)? I would consider this more the operating system than the ROM.

I understand that the native libraries and the Java layer have to be put somewhere, and this can confuse the terms ROM and Kernel as being used. I also realize I could be the only one who is having trouble with these definitions. If that's the case I will learn to use them as listed and work to get up to speed in a different programming world than when I left.

Finally, thanks again Roebeet for all you're doing. If you could tell me where I can get more information on the partition setup that would be appreciated. /proc/1/mount* files aren't enough for me to understand what's going on.

Ed1

[Welmoed]

As a new member of the forum, I have to admit it's a little daunting to try and figure out exactly what I should do with my gTablet. I could simply leave it stock, and accept the slower performance, or take the plunge and flash a new ROM. But, while I'm pretty comfortable with technology, this just seems like such a huge step... a real "leap of faith." I really don't want to risk bricking my little toy, but then again, just playing it safe all the time means I won't get to really take advantage of the possibilities.

Is there a "Flashing a New ROM for Dummies" somewhere? With clear, step-by-step instructions on exactly how one goes about the process? Like, will I lose all my current apps? Where does one find these ROMS and how do I know they are safe to install? Is it all done over a USB connection?

Sorry if these are basic idiot questions, but I've been in the PC world up until now, so this is all pretty new to me. Thanks for any pointers!

--Welmoed

[roebeet]

ed1field, on 07 May 2011 - 09:44 AM, said:

Hi Roebeet,

I'm not comfortable with the definitions of ROM and Kernel. When I left the world of programming over a decade ago these words had very different meanings than used here. Now that I'm working to get caught up on what's happening, I'm finding a problem with "new" definitions, and I need some help.

ROM once meant the flash only once memory that came from the manufacturer with no ability to be changed (as used in chips for initial bootstrap routines). Then it became multi-flash, but used as read only memory (making it easier for us to upgrade chips). Next ROM seemed to be defined as anything, anywhere in the system that would only be read and not necessarily directly changed. Until this moment, I was guessing that the current definition of ROM used here was any package of software put together by folks to run on our devices, usually including a lot of programs, and sometimes, but not always a kernel. And now, wanting to call a ROM a "BOOT ROM" and writing that it's "like an operating system" is making a few of my brain's synapses shut down.

Kernel, in the linux world, also had - and appears to still have - a specific meaning that is not the definition here unless taken in a most general way. Wouldn't it be better to talk about core services and the kernel being an abstraction layer (connector) between the hardware and everything else (the stack)? I would consider this more the operating system than the ROM.

I understand that the native libraries and the Java layer have to be put somewhere, and this can confuse the terms ROM and Kernel as being used. I also realize I could be the only one who is having trouble with these definitions. If that's the case I will learn to use them as listed and work to get up to speed in a different programming world than when I left.

Finally, thanks again Roebeet for all you're doing. If you could tell me where I can get more information on the partition setup that would be appreciated. /proc/1/mount* files aren't enough for me to understand what's going on.

Ed1

Same issues, just coming from a PC environment. But since the bootloader and kernel and interlinked, it's hard to really separate the two. For example, as long as a kernel on a PC was x86 compatible, it would load. But here, minor changes to the kernel might require a change to the bootloader, which is exactly what happened with the 1.2 branch. ROM and firmware is almost interchangeable here, also.

Welmoed, on 07 May 2011 - 07:30 PM, said:

As a new member of the forum, I have to admit it's a little daunting to try and figure out exactly what I should do with my gTablet. I could simply leave it stock, and accept the slower performance, or take the plunge and flash a new ROM. But, while I'm pretty comfortable with technology, this just seems like such a huge step... a real "leap of faith." I really don't want to risk bricking my little toy, but then again, just playing it safe all the time means I won't get to really take advantage of the possibilities.

Is there a "Flashing a New ROM for Dummies" somewhere? With clear, step-by-step instructions on exactly how one goes about the process? Like, will I lose all my current apps? Where does one find these ROMS and how do I know they are safe to install? Is it all done over a USB connection?

Sorry if these are basic idiot questions, but I've been in the PC world up until now, so this is all pretty new to me. Thanks for any pointers!

--Welmoed

This post was a first step in trying to do that. Imo, the biggest issues for GTAB users right now is that there IS a transition in place. ROMs should, imo, make it clear which branch you are on and probably have safeguards in place to support both sets of users. It's certainly possible - I should know as I setup these safeguards, myself.

4349 was out for about 24 hours -- not a long time but probably hundreds of stock users got it. And once VS / US Merchants finally releases a new firmware, there will be many more. The modders in XDA should be preparing for this, imo. And if I was moderating over there (which I'm not), I would be pushing that agenda right now. As far as I'm concerned, they caught a break when 4349 was pulled and they should have taken advantage of that window of opportunity.

This post has been edited by roebeet: 09 May 2011 - 11:00 AM