Ryan Houdek
a11566012d
Fixes #3675 This was the first time I've ever actually dived in to this code and this function melted my brain a bit while reading it. It was trying to be too smart in tracking VMA splits, but if it split right at the end of a VMA range it would then add a new range at the end where one already existed. This then caused us to have overlapping VMA ranges and it would completely break our SMC tracking since all tracking in the map must not overlap. Instead of being too smart, just break it down in to 4 merge strategies, three of which are one shot. This is significantly easier to reason about and each strategy is mostly self-contained. The fourth strategy in the list is the most complex since it requires multiple steps since it needs to walk multiple VMAs. To help test this I added some sanity checking code that proved invaluable to ensure everything was correct. That's not getting merged since the overhead is too much to run, but good to have available. Diff for this is at https://gist.github.com/Sonicadvance1/1ee60101ed0742b971a476fadbb51083
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 only AArch64 as a host. 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+ hardware. ARMv7 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.com/index.php/Development:Setting_up_RootFS
