Tag: EFIDroid

EFIDroid’s Qt port working on Intel now

~ hucktech ~ Leave a comment

The author of EFIDroid posted a comment, in reply to another EFIDroid query comment.  Previously, UEFI Qt of EFIDroid was ARM-centric, now:

“I’ve even recently started adding X64 support so it can be used on regular computers – I only have to add X64 support to UEFIThreads to complete that(which is required by QML).”

Looking forward to seeing UEFITool GUI app working as a UEFI app. 🙂

Qtbase: EFIDroid port of Qt to UEFI!

https://github.com/efidroid/qtbase

UEFIThreads: EFIDroid’s port of LittleKernel’s thread library for UEFI

~ hucktech ~ Leave a comment

UEFI is event-based, not thread-based. Earlier this month, Michael Zimmermann of the EFIDroid project posted a message on the EDK2-devel list about EFIDroid’s thread library support for UEFI, which is based on the Little Kernel threads implementation, and comparing it to the GreenThreads-UEFI project. Edited (footnotified) version of Michael’s message below.

IMO this [GreenThreads-UEFI] library[0] has some crucial problems like changing the TPL during context switching. For my project “EFIDroid” I’ve invested many months analyzing, testing and implementing my own threading implementation based on LK(LittleKernel, a MIT licensed project) threads and get/set -context. The result is a pretty stable implementation which can even be used in UEFI drivers[1]. I’m currently using this lib for my LKL(LinuxKernelLibrary) port to be able to use linux touchscreen drivers in UEFI – so you could say it has been well tested. The only “problem” is that it only supports ARM right now and that the get/set context implementation was copied (and simplified) from glibc which means that this part is GPL code.

From the Little Kernel web site:

Who is using LK?
* LK is the Android bootloader and is also used in Android Trusted Execution Environment – “Trusty TEE” Operating System.
* Newer Android phones have some chance of LK running all the time alongside Linux.
* A few ARM SoC manufacturers use LK as their default bootloader such as DragonBoard 410c based on Qualcomm Snapdragon 410 processor.
* The Fuchsia Operating System’s microkernel, Zircon is based on LK.

[0] https://github.com/Openwide-Ingenierie/GreenThreads-UEFI
[1] https://github.com/efidroid/uefi_edk2packages_EFIDroidLKLPkg/tree/master/UEFIThreads
http://efidroid.org/

https://github.com/littlekernel
https://github.com/littlekernel/lk/wiki/Introduction
https://github.com/littlekernel/lk/blob/master/kernel/thread.c

Click to access lm80-p0436-1_little_kernel_boot_loader_overview.pdf

https://android.googlesource.com/kernel/lk/

Full message: 2017-11-02 post on EDK2-devel.

LibC library musl ported to UEFI

~ hucktech ~ Leave a comment

Michael Zimmerman, one of the main developers behind EFIDroid, also has another interesting UEFI side project: uefi-musl-toolchain, a port of the LibC library musl to UEFI!

Quoting Wikipedia, musl is “a C standard library intended for operating systems based on the Linux kernel, released under the MIT License. It was developed by Rich Felker with the goal to write a clean, efficient and standards-conformant libc implementation. It is designed from scratch to allow efficient static linking and to have realtime-quality robustness by avoiding races, internal failures on resource exhaustion and various other bad worst-case behaviours present in existing implementations. The dynamic runtime is a single file with stable ABI allowing race-free updates and the static linking support allows an application to be deployed as a single portable binary without significant size overhead. It claims compatibility with the POSIX 2008 specification and the C11 standard. It also implements most of the widely used non-standard Linux, BSD, and glibc functions.

On his musl port to UEFI, Michael says:

I ported the libc alternative musl to UEFI by replacing the syscalls with simple function calls to library and wrote a GCC wrapper. The system call table is still incomplete but this way I can compile any (single-threaded) application for UEFI. This currently works on ARM only, but just because this is the platform I am interested in, not because it wouldn’t be possible.

This is fresh code, the project is only 2 days old. 🙂

https://github.com/M1cha/uefi-musl-toolchain

Example of busybox on UEFI compiled using musl: http://pastebin.com/MRXdBjyN

https://www.musl-libc.org/

 

EFIDroid

~ hucktech ~ Leave a comment

I just learned about EFIDroid, “a multiboot solution for mobile devices”. It is not new, EFIDroid was announced Feburary 2014 on the Xiaomi.eu mailing lists:

“Opensource (multiboot) Bootloader: Efidroid (formerly Grub4android):
This is the successor of GRUB4Android – a project to bring multiboot to Android. Even though most people hate UEFI on computers(users because of secureboot and devs because it doesn’t change many problems of BIOS afaik), Intel’s implementation (“EDKII”) actually is quite good and perfectly fits our needs. Also, it still allows you to boot GRUB – just in case you wanna do that.”

It is a Google+-based community, with over a hundred members. There’s been a lot of recent Github activity for the project, including an interesting Linux kernel module.

https://github.com/efidroid
https://plus.google.com/communities/114053643671219382368
http://xiaomi.eu/community/threads/dev-opensource-multiboot-bootloader-efidroid-formerly-grub4android.23615/

https://plus.google.com/u/0/MichaelZimmermann
http://mzimmermann.info/