riscv-elf-psabi-doc VS FEX

Sure. It's the section here https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/ma...

It's that structs of two simple fields need to be passed in registers. And more specifically that this rule is relevant for mixed integer and floating point fields.

It's a very specific rule that requires a ton of code to implement compared to the integer calling convention. And again like the weird AMD64 convention likely invented to squeeze out a theoretical few cycles that never occur outside microbenchmarks

This one has more info on the ELF output, notably things like how things like relocations and special symbols like %pcrel_hi work: https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-elf.adoc

This is a bit dense but that's what I referred to https://github.com/riscv-non-isa/riscv-elf-psabi-doc/blob/master/riscv-cc.adoc. I'm not sure if there's a RISC-V specific assembly tutorial that talks about calling conventions.

The stack is defined by the ABI and it’s a purely software convention. It’s possible a program could use a different convention. FYI, the EBI is defined here: https://github.com/riscv-non-isa/riscv-elf-psabi-doc

It looks like people are starting to think somewhat along that direction in https://github.com/riscv-non-isa/riscv-elf-psabi-doc etc. but most CPUs that I can think of have basically a monolithic ISA with pretty much an expanding set of instructions as the versions increment and encoded in the -march argument to the linker.

"A fast usermode x86 and x86-64 emulator for Arm64"

Could try this https://github.com/FEX-Emu/FEX + wine/proton. But as always keep in mind that playing on non-supported platforms can lead to bans in future (never happened but who knows).

It's explained in the video, it uses https://github.com/FEX-Emu/FEX

Steam is also funding an x86 tn ARM game emulator, which opens up the potential for it working on Android.

Valve is funding developers working on an x86-to-ARM layer, FEX. I'm assuming that the eventual end goal would be to run Steam on Android, one of the FEX developers was commenting on trying to get FEX to work on an S8 Tab Ultra.

Valve is also funding another translation layer, from x86 to ARM (see FEX).

Additionally, game emulation won't be optimal until someone fixes this issue from FEX-Emu, which will allow that emulator to run on Apple Silicon. QEMU-user is currently your best option though it is dead slow. Box64 is currently pretty capable, however, it will not be able to run any 32-bit libraries (which even modern games ship a few of).