Rockbox Technical Forums

Support and General Use => Theming and Appearance Customization => Topic started by: mcc01 on December 25, 2015, 07:11:26 AM

Title: Rockbox on Android 5.0 (ASUS Me176CX 1280x800)
Post by: mcc01 on December 25, 2015, 07:11:26 AM
Hi,

hopefully I have choosen the correct part of this forum... :)

I installed the curent build of rashers build of Rockbox for Android
on my tablet - a ASUS ME176cx with x86 processor and a screen
resolution of 1280x800.
The application starts and I can see, there is "something" and I can
select the "something" but it is by far too tiny for my eyes. Finger pinch
zoom does not work with Rockbox(Android) it seems.

I downloaded a 1280x800 theme from the internet.

The only thing is: I dont know how to install and configure this
theme manually since I cannot read anything from the rockbox
ui itsself.

Where can I find a howto or tutorial, which explains what files
I have to copy where and what cfg-files I have to tweak to
get a readable ui to start with?

Thank you very much in advance for any help!
Best regards,
mcc

Title: Re: Rockbox on Android 5.0 (ASUS Me176CX 1280x800)
Post by: [Saint] on December 25, 2015, 10:14:04 PM
The theme isn't the issue here I am afraid. Rockbox can actually cope with a missing theme for any given resolution remarkably well.

The issue is the ART runtime engine in Android 5.0+ (actually optionally available since Android 4.4, but this version of ART was rather different to that in current deployment). Sadly there is nothing you can do on your end to negate this. 5.0+ does not ship with the Dalvik runtime engine.


[Saint]
Title: Re: Rockbox on Android 5.0 (ASUS Me176CX 1280x800)
Post by: mcc01 on December 26, 2015, 03:09:21 AM
Hi Saint,

MERRY CHRISTMAS AND A HAPPY NEW YEAR! :)

Thanks for your reply!!!

It "feels" that rockbox is already running...the problem seems
that only the fonts are far too tiny.

I checked the system a little. I found a deavlik cache...so...
But what is the technical problem here...?
(NO OFFENSE INTENDED!!! ...I am no native english speaker)
For example changing a java engine should not make java-
code defunct as changing a C-compiler doesn´t render
C-code useless...
And where is the repository for the Android port?
Best regards,
mcc
Title: Re: Rockbox on Android 5.0 (ASUS Me176CX 1280x800)
Post by: wodz on December 26, 2015, 04:30:50 AM
Google acknowlege there are known corner cases when switching from dalvik to ART. W just happen to be in one of this corners. We are bitten by new stack protection scheme. JNI calls are allowed only from main thread now and thats the issue. I inspected the case and without heavy rework of our threading code running on ART is not feasible unfortunately.
Title: Re: Rockbox on Android 5.0 (ASUS Me176CX 1280x800)
Post by: mcc01 on December 26, 2015, 04:43:52 AM
Hi Saint,

ok...I begin to understand that I am not understanding... ;)

Interesting side-effect:
My tablet (ASUS ME176CX) is based on a Bay Trail CPU, which is of the x86 family.
This CPU is capable of "interpreting" ARM-code.
When installing and starting rashers daily build (res.:1280x800) for x86 it crashes
instantly.
Using the ARM build...it runs...with a supertiny ui which is impossible to use with
the stick which I use as touch screen stylus.

Next I will check, what happens if I use a build for a smaller screen size...

Best regards,
mcc

Post edit:
...builds with smaller resolutions crash in both cases (x86/arm)
Title: Re: Rockbox on Android 5.0 (ASUS Me176CX 1280x800)
Post by: [Saint] on December 26, 2015, 03:57:39 PM
We do not run on Android 5.0+, period.

Regarding the "Dalvik Cache" you found, I assure you you did not. Several places in the Android codebase still refer to the Dalvik Cache despite the fact that the runtime changed from Dalvik to ART, this isn't unusual at all (nothing with 5.)+ ships with both runtime engines, and definitely not with two forward facing runtime engines - 4.4 was a corner case to allow developers to test the water with the ART runtime engine, and ART had to be specifically enabled in developer options).

There really isn't any point in continuing on your end, unless you want to go through the Rockbox codebase and fix up our threading - which is a truly monumental task for very little gain - because I assure you even if it is "running" on your end, you'll literally never be able to actually initiate playback without the runtime engine kicking us to the curb.

Also, yes, indeed, as you discovered, builds for smaller (or larger) resolutions will not work either. The resolution of the compiled binary must match the framebuffer exactly.


[Saint]
Title: Re: Rockbox on Android 5.0 (ASUS Me176CX 1280x800)
Post by: g2geo94 on March 20, 2016, 12:32:59 PM
Saint,

Please pardon the thread resurrection, but are you suggesting that Android 5.0+ is a lost cause? If so, that's a real shame. I would be willing to learn to code for the sake of Rockbox simply because, in my findings, I've not been able to find another media application to match the power I had using RB on my Sansa e280. I wish I could continue using it, but its charge port has died so that is regrettably no longer an option. I however have many Android devices that I would want to run RB on that still function properly.

I would love to work with someone if there's a chance this is feasible.
Title: Re: Rockbox on Android 5.0 (ASUS Me176CX 1280x800)
Post by: Kevorex on February 12, 2018, 07:31:25 PM
Rockbox app with Android 5.0 or up compatibility was out there a long time ago, but it is developed by a user in Rockbox Chinese community. The download process required a good Chinese reading ability, so it is almost impossible for a non-Chinese person to find it out. I only distributed it by extracted it, set the default language to English, did some translating jobs on the file name, made a instruction file then recompressed it. The app and additional files belong to the author "迈戈" from Rockbox Chinese community.
Original post in Rockbox Chinese community:
https://forum.open-embedded.org/rockbox/t/20160823-mgamp6-8-7-0/746/3 (https://forum.open-embedded.org/rockbox/t/20160823-mgamp6-8-7-0/746/3)
Link to the zip file I distributed:
https://drive.google.com/file/d/1MUfYeDqTsksLT_mRyyZbz6NHmkScUgEM/view?usp=sharing (https://drive.google.com/file/d/1MUfYeDqTsksLT_mRyyZbz6NHmkScUgEM/view?usp=sharing)

If you encounter any problem, please use Google Translate to view the original post in Rockbox Chinese community. Oh... and don't thank me! (^o^)