Root [CDMA] 3D on custom ROMs... possible?

[ndh777]

Just curious...do you think that some ROMs will not be able to use the 3D function?

I just was thinking about this as we had already seen with the original Evo that we lost 4G, HDMI, and front camera on many ROMs.

I love ROMs and I love 3D...or at least the sound of it. I know the phone hasn't officially launched yet but does anyone have a clue as to whether it will not work on some and others?

 

[novox77]

The reason why 4G and HDMI came so late is because these aren't standard hardware functions supported by Android. They require custom code in the kernel to interface with Android.

HTC obviously wrote kernel code to support these features. So if you have a Sense-based ROM, you're likely using a kernel that's based on HTC's, which already includes the interface for 4G and HDMI. If you go with an AOSP ROM, the kernel doesn't have the interface and has to be created. That requires intimate knowledge of the hardware responsible for these features.

The same will be true for 3D. The screen used on the 3D is whatever HTC decided to use. They worked with the manufacturer of the screen to write the kernel code to allow Android to work with the screen. I would expect Sense-based ROMs to be able to utilize 3D, while AOSP will have a while before they get the 3D screen working.

As for 4G, I believe HTC is using the same exact radio as the Evo 4G, so hopefully a lot of the AOSP ROM's 4G kernel code can be reused. MHL port might be a different story though.

So I'm predicting that 3D won't be available on AOSP ROMs for a while....

 

[jerofld]

What about the htcdev.com thing? Wouldn't 3D capabilities be apart of the SDK? Or, at least, a reasonable expectation?

 

[novox77]

What about the htcdev.com thing? Wouldn't 3D capabilities be apart of the SDK? Or, at least, a reasonable expectation?

I thought of that. But I think it's too high-level. The htcdev.com (as I understand it) is an API to program for Sense. Sense runs on top of Android, which runs on top of Linux and the kernel. So... we're talking about really low level kernel code, and I think htcdev is way too high level to be of use.

So... htcdev.com may allow programmers to write an app to use the 3D camera in creative ways, but these apps would only work on Sense-based ROMs. The issue here is that AOSP doesn't have the code to even get the 3D hardware (dual cameras + parallax barrier LCD) to communicate with the software. So any layers you add to the software isn't going to help.

Now, if HTC decides to release the source code to their kernel, that'd be a different story. They aren't obligated to release that code, but if they wanted to be really really cool, they would.

 

[jerofld]

I can see your point. I doubt HTC would concede source code on their kernel. But, you never know. Sammy straight up handed the GS2 to various ROM devs. HTC knows they have to step it up to compete. Unlocking the bootloader was the first step and htcdev.com seemed to be the second step in that.

And I really, really need to start learning Linux and Unix. For being the OSes that are "left out in the cold", they certainly are everywhere. Damn you, Microsoft. Damn you for being successful so I never learned the OSes that ran the rest of the world.

 

[novox77]

See here:

HTC - Developer Center


HTC does release kernel source code. Though they don't coincide with the OTA. I remember people getting pissed at how long it took for them to release the kernel code when Froto OTA was made available on Evo, probably because people were impatient to get 4G working on AOSP, heh.

Even with the source, it's not as simple as copy/paste. I would think you'd be better off rewriting it. But at least the source tells you how to interface with the hardware. In the end, it's still a big task, and the devs do it all via donations.

 

[ndh777]

The reason why 4G and HDMI came so late is because these aren't standard hardware functions supported by Android. They require custom code in the kernel to interface with Android.

HTC obviously wrote kernel code to support these features. So if you have a Sense-based ROM, you're likely using a kernel that's based on HTC's, which already includes the interface for 4G and HDMI. If you go with an AOSP ROM, the kernel doesn't have the interface and has to be created. That requires intimate knowledge of the hardware responsible for these features.

The same will be true for 3D. The screen used on the 3D is whatever HTC decided to use. They worked with the manufacturer of the screen to write the kernel code to allow Android to work with the screen. I would expect Sense-based ROMs to be able to utilize 3D, while AOSP will have a while before they get the 3D screen working.

As for 4G, I believe HTC is using the same exact radio as the Evo 4G, so hopefully a lot of the AOSP ROM's 4G kernel code can be reused. MHL port might be a different story though.

So I'm predicting that 3D won't be available on AOSP ROMs for a while....

That's what I was assuming.

I knew there was a huge difference between ASOP and Sense ROMs and had a feeling it was due to how you explained it. Well that makes all the more sense.

I was simply curious cause I love these ROMs but I think I'm going to miss 3D if I flash some of my favorite ROMs so I wanted to double check for future reference.

I understood that the reason they couldn't add features like 4G and front camera is that they were so new and very little information was on them to help build ROMs. That makes sense and I should've guessed that since 3D is also a brand new feature.

And thanks for fixing my thread's name for clarification, I'm still learning all this

 

[afazel]

One thing missing from novox77's explanation is that a lot of times the extra, non-standard features are built into the framework of the ROM.

For example: with the Evo 4G, kernel support for WiMax was developed fairly early on. It was much later when TeamWin really got to work on it that they were able to integrate the implementation into the Android framework and have actual apps that could run on the phone to tie into the kernel support and make use of the sequans chip to run the WiMax.

I imagine that the same will be true with the Evo 3D, maybe even more so. I would suspect that there won't be much kernel-level activity going on to make the 3D image, and that part of it will be all in the Android, not the underlying Linux, software.

 

[ndh777]

One thing missing from novox77's explanation is that a lot of times the extra, non-standard features are built into the framework of the ROM.

For example: with the Evo 4G, kernel support for WiMax was developed fairly early on. It was much later when TeamWin really got to work on it that they were able to integrate the implementation into the Android framework and have actual apps that could run on the phone to tie into the kernel support and make use of the sequans chip to run the WiMax.

I imagine that the same will be true with the Evo 3D, maybe even more so. I would suspect that there won't be much kernel-level activity going on to make the 3D image, and that part of it will be all in the Android, not the underlying Linux, software.

You had me then you lost me lol but thanks for the explanation.

While we're on the topic, so if someone were to make a kernel for say MIUI which currently does not support 4G, they could make a kernel that could enable 4G on the ROM? Is that what you are saying about the Evo 3D? Maybe I completely lost you.

 

[Android 17]

It's likely that the camera will also be broken initially on AOSP roms, or at the very least, the 3D-capture function as well.

 

[afazel]

You had me then you lost me lol but thanks for the explanation.

While we're on the topic, so if someone were to make a kernel for say MIUI which currently does not support 4G, they could make a kernel that could enable 4G on the ROM? Is that what you are saying about the Evo 3D? Maybe I completely lost you.

In short, just because the kernel supports a feature doesn't mean the phone can do it yet. It's like having webcam drivers installed on your new laptop. You have the webcam, you have the drivers, but you haven't installed an app yet that can use the webcam.

 

[ndh777]

In short, just because the kernel supports a feature doesn't mean the phone can do it yet. It's like having webcam drivers installed on your new laptop. You have the webcam, you have the drivers, but you haven't installed an app yet that can use the webcam.

I understand now, thank you.