Ryan Houdek
063841f491
This comes in the form of a new define and a new function. Assuming assert doesn't quite cover 100% of our asserting logging use cases so we need to break this out. If the compiler can't see through side effects at compile time for the predicate then it'll throw a warning. This gives us a nice behaviour. In the case that asserts are enabled, we fall down the assert checking path. So if an assert fails to predicate we will do an assert log like normal. The change comes when we build release without asserts, we use the `__builtin_assume` definition to allow the compiler to optimize around assumptions. Since these aren't runtime asserts in release build, this gives us some small optimizations in various locations. Clang will very specifically do additional optimizations when you provide it `__builtin_assume` directives that can really be worth it.
FEX - Fast x86 emulation frontend
FEX allows you to run x86 and x86-64 binaries on an AArch64 host, similar to qemu-user and box86. It has native support for a rootfs overlay, so you don't need to chroot, as well as some thunklibs so it can forward things like GL to the host. FEX presents a Linux 5.0 interface to the guest, and supports both AArch64 and x86-64 as hosts. FEX is very much work in progress, so expect things to change.
Quick start guide
For Ubuntu 20.04, 21.04, 21.10, 22.04
Execute the following command in the terminal to install FEX through a PPA.
curl --silent https://raw.githubusercontent.com/FEX-Emu/FEX/main/Scripts/InstallFEX.py --output /tmp/InstallFEX.py && python3 /tmp/InstallFEX.py && rm /tmp/InstallFEX.py
This command will walk you through installing FEX through a PPA, and downloading a RootFS for use with FEX.
Ubuntu PPA is updated with our monthly releases.
For everyone else
Please see Building FEX.
Getting Started
FEX has been tested to build and run on ARMv8.0, ARMv8.1+, and x86-64(AVX or newer) hardware. ARMv7 and older x86 hardware will not work. Expected operating system usage is Linux. FEX has been tested with Ubuntu 20.04, 20.10, and 21.04. Also Arch Linux.
On AArch64 hosts the user MUST have an x86-64 RootFS Creating a RootFS.
Navigating the Source
See the Source Outline for more information.
Building FEX
Follow the guide on the official FEX-Emu Wiki here.
RootFS generation
AArch64 hosts require a rootfs for running applications. Follow the guide on the wiki page for seeing how to set up the rootfs from scratch https://wiki.fex-emu.org/index.php/Development:Setting_up_RootFS
