JXD S7800b Offical Rom Android 4.4.4

[lexluthermiester]

I will look into it...but my go to launcher is Apex.

Haven't used that one in a while, I'll give it a try.

[lexluthermiester]

Riley, Out of curiosity, the parameters files, when opened there are very clear differences but I'm having a problem interpreting them. Could you post a list of what each one does?

[rrileypm]

The parameter files specify the size of each of the partitions...in hex format. Here's the 4gb parameter for example:

mtdparts=rk29xxnand:0x00002000@0x00002000(misc),0x00006000@0x00004000(kernel),0x00006000@0x0000a000(boot),0x00010000@0x00010000(recovery),0x00020000@0x00020000(backup),0x00040000@0x00040000(cache),0x00800000@0x00080000(userdata),0x00002000@0x00980000(metadata),0x00002000@0x00982000(kpanic),0x00180000@0x00984000(system),-@0x00B04000(user)

And here is the 6gb parameter:

mtdparts=rk29xxnand:0x00002000@0x00002000(misc),0x00006000@0x00004000(kernel),0x00006000@0x0000a000(boot),0x00010000@0x00010000(recovery),0x00020000@0x00020000(backup),0x00040000@0x00040000(cache),0x00C00000@0x00080000(userdata),0x00002000@0x00D80000(metadata),0x00002000@0x00D82000(kpanic),0x00180000@0x00D84000(system),-@0x00F04000(user)

By adjusting the numbers, the size of each partition can be changed. Each partition has two numbers...the size is the number on the left of the @...and the start location is indicated to the right of the @. For example...in the 4gb parameter (userdata) partition the size is 800000 (hex) which is 4gb. In the 6gb parameter (userdata) partition the size is C00000 (hex) which is 6gb. Not only must I change the size of the partition, I have to adjust the start location for each of the remaining partitions.

The same can be done if you need a bigger kernel.img, or a bigger recovery.img....each of those files is saved in a partition in NAND. But you are limited to the amount of space provided in the parameter file.

I have a little tool that helps me do the math. I just plug in the numbers in the parameter file after I've calculated the required settings.

So in this ROM, I've grown the system.img to take up the entire space allocated in the stock parameter file. The stock ROM only used half of this space, which was wasted.

Then, I change the size of the userdata partition...that's the user app space (the amount of space set aside for installing apps). The default was only 2gb. But on a device that was designed to play games...you need more room to install those apps...so I give you choices of how much space you want to devote to apps in 1gb increments...all the way up to 12gb. You decide how big you want the userdata partition to be when you choose the parameter file to flash.

Notice the last partition...(user). That is the internal SD card space. It starts at the end of the system partition and fills the remainder of what's left over.

The trick is that each 1gb of space you add to the userdata partition, it takes away 1gb from the internal SD partition. So for a 16gb device, you are left with only 4gb if you select the 12gb parameter...but really you only have 2.5gb internal SD because the other system partitions take up about 1.5gb. I'm talking about all of those other partitions listed in the above examples...misc, kernel, boot, recovery, backup, cache, userdata, metadata, kpanic and system...added together.

You must have some internal SD space for apps to save data to....larger games require more space to save external data, so 3gb isn't enough.

That's where the alternate boot.img comes in. If you swap the internal and external SD drives, you can put a 32gb micro SD card in....and you have 32gb of space for game data. It won't really matter how much leftover NAND you have because it becomes external SD space that apps don't depend on for data storage.

I hope that answers your question.

[lexluthermiester]

Ok, kinda thought it was something along those lines, but wanted to be sure. Thank you for the info. Very insightful!

[lexluthermiester]

Riley,

Been having a lot of fun playing around with your roms[not just this one] today. Found the power button/sleep crash bug that happen with the 3188T models of which mine belongs and have discovered several things that seemed to work well. So question for you, how difficult would it be to take this new rom you put together and replace the JXD launcher with the AOSP, with the app launch buttons along the bottom of the screen and restore the soft buttons[back/home/app]? Kind of like Maetel's Prometheum AOSP version mixed with Exucaveira V2. Would you be interested in trying such? I'd give it a go myself but lack the knowledge, though I'd be more than willing to beta test such an effort. After watching more than a few reviews on youtube the general opinion is that the above suggested options would be well loved. What do you think?

[rrileypm]

I'm not familiar with those other ROM's, but I can do some testing.

What I do is install Apex launcher and switch it to the default launcher on my own device. There are plenty of settings options for that launcher.

I will do some more testing and see what I can do with ASOP.

[lexluthermiester]

That would be very cool of you! Not sure if it was mentioned but I've discovered I have the 3188T version. Have read that can cause a bit of a hangup. So I'm totally willing to test anything you want me to. Have learned how to recover from a brick so no worries.

[lexluthermiester]

Just encountered a unique problem. Went to make a full backup so that the current config could be restored after trying things out. Used the "Reboot" app found in the apps list, and hit "Reboot to Recovery". After rebooting it showed "Android bot" laying on his back door open showing a red caution sign. Thinking maybe you didn't have time to full test the recovery partition, I tried installing varying versions of CWM & TWRP. And while I found versions of both that loaded and displayed properly, neither found or mounted any of the partitions.

You wouldn't happen to have a working recovery partition that can do full backups do you?

[rrileypm]

Did you try this one from Abdul_pt?

http://www.freak-tab.de/abdul_pt/TWRP/Generic/TWRP_1280x800_rk31xx_KK.img

[lexluthermiester]

Did you try this one from Abdul_pt?

http://www.freak-tab.de/abdul_pt/TWR..._rk31xx_KK.img

That seems to be the same one included in your package. I downloaded this one from the link and tried it just now and with the same results. See the attached picture. Is this problem my device or the img file?

FYI, I used the patching tool you provided and selected only the parameter[2] and recovery[6] then clicked flash rom button. Did I do it correctly?

[rrileypm]

That's correct...except you don't need to check the parameter if you are only flashing recovery.

Look on Abdul's page and select a lower resolution version. I'm not sure if there's a portrait version...which is what we need.

He is working on some that are auto adjustable to screen formats.

[lexluthermiester]

That's correct...except you don't need to check the parameter if you are only flashing recovery.

Look on Abdul's page and select a lower resolution version. I'm not sure if there's a portrait version...which is what we need.

He is working on some that are auto adjustable to screen formats.

Hadn't seen that page, very useful. The 1024x600 kitkat[ http://www.freak-tab.de/abdul_pt/TWR..._rk31xx_KK.img ] version is the only one working and backing up but it's still sideways[see picture. The 800x1280 would be cool, but it just shows the TWRP logo and reboots the system. Not sure what those details say. I did find the new 2.8.5.0's [ http://www.freaktab.com/showthread.p...light=abdul_pt ] and the both versions work but the landscape is still in portrait and all squished in, but all buttons are visible. Maybe include the 2.8.5.0 sdcard portrait version in with your rom. It works perfectly. What do you think?

[rrileypm]

I think we might ask Abdul to make us a portrait version.

[lexluthermiester]

I think we might ask Abdul to make us a portrait version.

Did you mean landscape version? LOL! The portrait version already works perfectly.

[rrileypm]

That's the crazy thing about this ROM. The graphics default to portrait. I had to rotate the graphics in the boot animation for it to work right.

What we need is a portrait TWRP that rotates to landscape so it will take up the whole screen.

So it needs to be 800x1280 with the screens rotated.

Edit: Sorry, that statement wasn't totally accurate. Let me do some testing.