Android Daily Superthread (Dec 21 2021) - Your daily thread for questions, device recommendations and general discussions! |
- Daily Superthread (Dec 21 2021) - Your daily thread for questions, device recommendations and general discussions!
- This is the OSOM OV1, the new phone from the team behind the Essential Phone
- The next front in Google's war on fragmentation is virtualization. Here's what Google plans to do about it for the Android 13 release.
- Xiaomi 12 to be Xiaomi's First Compact Flagship in years, Xiaomi 12 Pro will be its bigger sibling
- Someone just turned the LG Wing's secondary screen into a standalone phone
- There is a definite answer about the rear cover material of Galaxy S22 series: S22, S22 +, S22 ultra are all made of glass!
- Foldable phone hinge solution comparison between Oppo, Huawei, and Samsung (Summary in comment and Chinese caption can be auto-translated into English)
- The Amazon Appstore is finally up and running on Android 12
- Chinese review of the Dimensity Mediatek 9000 - Reference Benchmarks + Power Figures
- Daily Superthread (Dec 20 2021) - Your daily thread for questions, device recommendations and general discussions!
- Flashback: Samsung Galaxy S6 got a lot of hate, but it also got many things right - GSMArena.com news
- Sunday Rant/Rage (Dec 19 2021) - Your weekly complaint thread!
- Daily Superthread (Dec 19 2021) - Your daily thread for questions, device recommendations and general discussions!
| Posted: 21 Dec 2021 04:00 AM PST Note 1. Check MoronicMondayAndroid, which serves as a repository for our retired weekly threads. Just pick any thread and Ctrl-F your way to wisdom! Note 2. Join our IRC and Telegram chat-rooms! Please see our wiki for instructions. Please post your questions here. Feel free to use this thread for general questions/discussion as well. The /r/Android wiki now has a list of recommended phones and covers most areas, the links have been added below. Any suggestions or changes are welcome. Please contact us if you would like to help maintain this section. Flagship section, containing the most expensive devices with the highest end specifications [link] [comments] | ||
| This is the OSOM OV1, the new phone from the team behind the Essential Phone Posted: 21 Dec 2021 06:10 AM PST
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| Posted: 20 Dec 2021 10:01 AM PST Ah, fragmentation: a word that has tainted the Android platform since its inception. The way Google architected and licensed Android was designed to promote early adoption by OEMs, but those early design choices led to years of accrued technical debt that require major technical undertakings to address. Slowly but surely, Google is clawing back control over Android to address fragmentation. First, it addressed the core Android framework with Project Treble and the Generic System Image (GSI). Then it targeted core Android system components with Project Mainline. More recently, it tackled kernel fragmentation with the Generic Kernel Image (GKI). The next front in Google's multi-year war on fragmentation is virtualization. Virtualization on Android is a topic that you won't find much discussion on because it's esoteric and the work is quietly ongoing, but if you've followed my work, you'll know that it doesn't matter how niche it is—if it's Android-related, it's right up my alley. That's why this post is dedicated to virtualization on Android and what Google plans to do with it. Bringing KVM to AndroidVirtualization on Android today is "the Wild West of fragmentation," according to Will Deacon on the Android Systems team. This is because hypervisors may or may not be present on a device, and when they are, they're often not even used for their intended purpose, which is to run an operating system in a virtual machine! Instead, they're used for things like enhancing the security of the kernel (or at least trying to) and running miscellaneous code (such as third-party code for DRM, cryptography, and other closed-source binaries) outside of the Android OS. To understand why the latter is particularly problematic, consider that in the Armv8/v9 exception model, the hypervisor runs at exception level 2 (EL2). In Arm's nomenclature, the higher the number, the higher the privilege level, which means that code running at EL0 (eg. userspace applications) is least privileged, code running at EL1 (eg. the Android OS and Linux kernel) is more privileged, and so on. Thus, a lot of opaque third-party binary blobs run with higher privileges than even the OS and kernel! This is harmful for security, as it increases the attack surface of privileged code that can be exploited, as code running at a higher EL can access all the registers of the lower levels. Armv8/v9 exception levels. Credits: Arm In order to both de-privilege this third-party code and isolate that code from Android and other third-party programs, Google is working to bring a common hypervisor solution on top of which a virtual machine running at the same privilege level as the OS and the kernel will execute that code. There exists a mature kernel virtualization mechanism called KVM which is already supported by Linux, so naturally Google is choosing to deploy it as the common hypervisor. And thanks to Google's ongoing efforts to reduce kernel fragmentation, KVM can be enabled on a broad spectrum of Android devices shipping a recent version of the GKI. (Sidenote: Google is actually extending KVM with additional security features and calling it pKVM, or "protected KVM". pKVM is designed to enable data confidentiality in a virtual machine, even if the OS is compromised. The implementation is available in the mainline, android13-5.10, and android13-5.15 Android Common Kernel branches.) To manage these virtual machines, Google is porting crosvm, the Rust-based Virtual Machine Manager (VMM) used to run Linux apps on Chrome OS, to Android, and it will be delivered to devices through a new Mainline module called "Virtualization" (com.android.virt). Currently, no Android devices on the market ship with the Virtualization module — not even Google's own Pixel 6 — but this is set to change with the upcoming Android 13 release. In fact, Google is currently testing its new virtualization tools on the Pixel 6; if you build AOSP with the target aosp_oriole_pkvm, you'll find that com.android.virt will be automatically inherited. I don't know if Google will enable pKVM on the Pixel 6 series with the Android 13 update, but there is evidence that Google plans for Android 13 to include the first release of the pKVM hypervisor and virtual machine framework. (If you're interested in the full history of Google's efforts to bring KVM to Android devices, watch Will Deacon's talk from last year's KVM Forum or this excellent summary by Jake Edge for LWN.) Isolated compilation in a virtual machine running CompOSWith the groundwork laid to run virtual machines on a hypervisor, the question then becomes: What feature(s) does Google itself plan to use this for? Thanks to a series of code changes submitted to the AOSP Gerrit, I have learned about one way that Google plans to demo Android's new virtualization support: isolated compilation. Earlier this year, I shared that Google is working on a new build of Android called "microdroid". Google describes microdroid as "a (very) lightweight version of Android that is intended to run on on-device virtual machines" and host headless (ie. without a GUI) and native workloads. It is built "from the same source code as regular Android, but it is much smaller" as it lacks the system_server process, HALs, or a GUI. Microdroid is included in the Virtualization module with its payload of APEX modules and APKs defined in one JSON file and its partitions and allocated memory defined in another. Interestingly, it seems that microdroid is just the default name of the OS in the VM — it can be configured to be called something else. This is what I believe "CompOS" is — an instance of microdroid that's dedicated to performing isolated compilation. (CompOS is short for "Compilation OS," in case you're wondering.) You may be wondering at this point what isolated compilation means. According to Google, isolated compilation is the compilation of boot and system_server classpath JARs in a protected VM. When configuring the system ROM, device makers typically ship precompiled code for core services like system_server and other classes that zygote initializes on startup. Whenever the Android Runtime (ART) is updated, which can now happen out-of-band as it was made a Mainline module in Android 12, it's possible that compilation artifacts for boot class path extensions and system_server need to be regenerated using the odrefresh tool (which is why ART APEX updates sometimes show a progress bar during boot up). In Android 12, this all happens on the host OS because there's no virtualization support, but in Android 13, this could happen in CompOS. To be perfectly honest, I am not entirely sure why it's advantageous to move this compilation to an isolated VM, but I've heard a few theories. First, moving this functionality to a VM makes the process overall more secure. Any exploits during the process would need to chain into an exploit of the hypervisor to escape the VM and access data in the host OS. Keep in mind that many parts of the virtual machine framework are written in Rust, a programming language designed with the security of memory management in mind, so this is not trivial to do. Second, a compromised system_server process could be used to accept modified OAT files. By running dex2oat in a VM that's verified by the hypervisor, the compiled OAT file can be cryptographically verified. Those are just theories, though. Only Google knows the exact reason behind this feature, but I'm not privy to the internal discussions that led to the development of CompOS. Isolated compilation doesn't sound like a particularly interesting use of virtualization on Android, but it's most likely not the only use case that Google is working on. It just happens to be the one use case that's developed mostly in public. There are a number of other things that Google can do with a virtualized Android build, but we'll have to wait for the release of Android 13 to find out what those are. In the meantime, if you're interested in playing with virtualization on Android yourself, Google has a guide on how to get started with protected virtual machines and microdroid. shameless plug Thanks for reading this post! If you enjoyed it, I actually post this kind of content on a weekly basis for The Android Edge newsletter. Check it out! I'll continue to share posts here, of course, but signing up will mean you won't miss them plus it supports me! [link] [comments] | ||
| Xiaomi 12 to be Xiaomi's First Compact Flagship in years, Xiaomi 12 Pro will be its bigger sibling Posted: 21 Dec 2021 06:25 AM PST | ||
| Someone just turned the LG Wing's secondary screen into a standalone phone Posted: 20 Dec 2021 02:23 AM PST
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| Posted: 20 Dec 2021 02:27 AM PST
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| Posted: 20 Dec 2021 04:47 AM PST
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| The Amazon Appstore is finally up and running on Android 12 Posted: 19 Dec 2021 10:26 AM PST
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| Chinese review of the Dimensity Mediatek 9000 - Reference Benchmarks + Power Figures Posted: 19 Dec 2021 05:53 PM PST
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| Posted: 20 Dec 2021 04:00 AM PST Note 1. Check MoronicMondayAndroid, which serves as a repository for our retired weekly threads. Just pick any thread and Ctrl-F your way to wisdom! Note 2. Join our IRC and Telegram chat-rooms! Please see our wiki for instructions. Please post your questions here. Feel free to use this thread for general questions/discussion as well. The /r/Android wiki now has a list of recommended phones and covers most areas, the links have been added below. Any suggestions or changes are welcome. Please contact us if you would like to help maintain this section. Flagship section, containing the most expensive devices with the highest end specifications [link] [comments] | ||
| Posted: 19 Dec 2021 01:50 AM PST
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| Sunday Rant/Rage (Dec 19 2021) - Your weekly complaint thread! Posted: 19 Dec 2021 04:00 AM PST Note 1. Join our IRC and Telegram chat-rooms This weekly Sunday thread is for you to let off some steam and speak out about whatever complaint you might have about:
Rules 1) Please do not target any individuals or try to name/shame any individual. If you hate Google/Samsung/HTC etc. for one thing that is fine, but do not be rude to an individual app developer. 2) If you have a suggestion to solve another user's issue, please leave a comment but be sure it's constructive! We do not want any flame-wars. 3) Be respectful of other's opinions. Even if you feel that somebody is "wrong" you don't have to go out of your way to prove them wrong. Disagree politely, and move on. [link] [comments] | ||
| Posted: 19 Dec 2021 04:15 AM PST Note 1. Check MoronicMondayAndroid, which serves as a repository for our retired weekly threads. Just pick any thread and Ctrl-F your way to wisdom! Note 2. Join our IRC and Telegram chat-rooms! Please see our wiki for instructions. Please post your questions here. Feel free to use this thread for general questions/discussion as well. The /r/Android wiki now has a list of recommended phones and covers most areas, the links have been added below. Any suggestions or changes are welcome. Please contact us if you would like to help maintain this section. Flagship section, containing the most expensive devices with the highest end specifications [link] [comments] |
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