arm-trusted-firmware VS gccrs

I have a PinePhone Pro, and I'm trying to figure out a reasonable way to get more than one half of ten minutes of battery life out of it, while still receiving notifications. I figure the best route to go will be to create a service that holds ports open, while the CPU is completely asleep, and either run it on the modem's processor or, as an possibility for the PinePhone Pro, but not the original Pinephone, run it on the m0 core used for power management.

Arm v7 was a Wild West, but with v8, Arm tried to standardize a lot. The Arm Trusted Firmware is the reference boot firmware implementation for v8+ CPUs: https://github.com/ARM-software/arm-trusted-firmware.

I'd think most of the referece documents can be discovered from that code base.

Relatedly, from the perspective of hands-on programming, the System Programmer's guide is the manual to start with.

I assure you that there is no lack of skill; that is just what happens over the course of ten years in a 300,000 line code-base and multiple hundreds of contributors: https://github.com/ARM-software/arm-trusted-firmware/blob/master/Makefile

The ARM Trusted Firmware is what typically runs in the secure world, and it is indeed open source: https://github.com/ARM-software/arm-trusted-firmware

ROM code generally speaking is not open source, but has been dumped on occasion.

The reference Trustzone implementation for ARM is open source https://github.com/ARM-software/arm-trusted-firmware , so I really can't think of some reason the ARM license would have to do with it.

SMP support (at least as far as CPU suspend and hotplug goes) is usually handled by TrustZone firmware on aarch64, not by the kernel (see PSCI). If you write your own OS on a bare-metal platform you can of course do what you want, but if you're looking for existing sources that's where you'd have to look. https://github.com/ARM-software/arm-trusted-firmware is a common reference implementation that supports a bunch of platforms, but many others (e.g. all Samsung and Qualcomm phones) also use their own proprietary stuff which is not publicly available.

Come again? https://github.com/ARM-software/arm-trusted-firmware

There is a Rust front-end for GCC that is under active development [1]. If the chip vendors are not willing to develop and upstream a LLVM back-end then they can feel free to start contributing to it.

[1] https://rust-gcc.github.io/

That's why gccrs doesn't even consider lifetime checking a part of the language (they plan to use Polonius, too).

There's ongoing work on a Rust front-end for GCC (https://github.com/Rust-GCC/gccrs). Bit barebones right now -- ie, even core doesn't compile -- but there's funding, demand, and regular progress, so it'll only get better from there. Once gccrs can compile core, it should be ready to compile most of Rust, and thus if you've taught the calling conventions for C to GCC, you're golden.

I recommend checking out the GCC Rust frontend project.

That is what theyre refering to, yes. The GitHub is named https://github.com/Rust-GCC/gccrs

- But this misses so much extra context information

3. Macro invocations there are really subtle rules on how you treat macro invocations such as this which is not documented at all https://github.com/Rust-GCC/gccrs/blob/master/gcc/rust/expan...

Some day I personally want to write a blog post about how complicated and under spec'd Rust is, then write one about the stuff i do like it such as iterators being part of libcore so i don't need reactive extensions.

(Speaking of which, Rust-GCC (or gcc-rs or gccrs or whichever other of their names they decide is the primary one) isn't even going to be a complete C++ implementation. Their plan is to implement enough to compile Polonius (the NLL 2.0 borrow checker being developed in Rust for rustc) and then share that since borrow-checking isn't necessary for codegen... only to identify and reject invalid programs... making the C++ portion of it not that different in scope from mrustc.)

That bridge will be crossed with gccrs (compiling Rust with gcc directly, coming next month with GCC 13) and rust_codegen_gcc (rustc frontend, GCC backend, works now but just doesn’t yet have an “easy” setup)