ARMv7 support

[alanhoff]

Hello there, I'm trying to compile may but it looks like generator doesn't likes my Raspberry Pi v2.

I used this command to try to build it:

git clone https://github.com/Xudong-Huang/may
cd may && cargo run --example echo --release

This is the error log:

error[E0432]: unresolved import `self::asm`
  --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/generator-0.6.1/src/detail/mod.rs:33:15
   |
33 | pub use self::asm::{Registers, swap_registers, initialize_call_frame, prefetch};
   |               ^^^ Could not find `asm` in `self`

error[E0433]: failed to resolve. Use of undeclared type or module `Registers`
  --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/generator-0.6.1/src/reg_context.rs:15:28
   |
15 |         RegContext { regs: Registers::new() }
   |                            ^^^^^^^^^ Use of undeclared type or module `Registers`

error[E0433]: failed to resolve. Use of undeclared type or module `Registers`
  --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/generator-0.6.1/src/reg_context.rs:63:23
   |
63 |         let mut cur = Registers::new();
   |                       ^^^^^^^^^ Use of undeclared type or module `Registers`

error[E0412]: cannot find type `Registers` in this scope
 --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/generator-0.6.1/src/reg_context.rs:7:11
  |
7 |     regs: Registers,
  |           ^^^^^^^^^ not found in this scope

error[E0425]: cannot find function `initialize_call_frame` in this scope
  --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/generator-0.6.1/src/reg_context.rs:36:9
   |
36 |         initialize_call_frame(&mut self.regs, init, arg, start, stack);
   |         ^^^^^^^^^^^^^^^^^^^^^ not found in this scope

error[E0412]: cannot find type `Registers` in this scope
  --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/generator-0.6.1/src/reg_context.rs:47:28
   |
47 |         let out_regs: &mut Registers = match *out_context {
   |                            ^^^^^^^^^ not found in this scope

error[E0412]: cannot find type `Registers` in this scope
  --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/generator-0.6.1/src/reg_context.rs:50:23
   |
50 |         let in_regs: &Registers = match *in_context {
   |                       ^^^^^^^^^ not found in this scope

error[E0425]: cannot find function `swap_registers` in this scope
  --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/generator-0.6.1/src/reg_context.rs:56:18
   |
56 |         unsafe { swap_registers(out_regs, in_regs) }
   |                  ^^^^^^^^^^^^^^ not found in this scope

error[E0412]: cannot find type `Registers` in this scope
  --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/generator-0.6.1/src/reg_context.rs:64:20
   |
64 |         let regs: &Registers = &to_context.regs;
   |                    ^^^^^^^^^ not found in this scope

error[E0425]: cannot find function `swap_registers` in this scope
  --> /root/.cargo/registry/src/github.com-1ecc6299db9ec823/generator-0.6.1/src/reg_context.rs:66:18
   |
66 |         unsafe { swap_registers(&mut cur, regs) }
   |                  ^^^^^^^^^^^^^^ not found in this scope
error: aborting due to 10 previous errors

error: Could not compile `generator`.
warning: build failed, waiting for other jobs to finish...

This is my /proc/cpu/info

processor       : 0
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

processor       : 1
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

processor       : 2
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

processor       : 3
model name      : ARMv7 Processor rev 5 (v7l)
BogoMIPS        : 38.40
Features        : half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm
CPU implementer : 0x41
CPU architecture: 7
CPU variant     : 0x0
CPU part        : 0xc07
CPU revision    : 5

Hardware        : BCM2835
Revision        : a21041
Serial          : 0000000095c87563

Kernel, distro, toolchain and Rust info:

root@rust:~/may# lsb_release -a && uname -a && cargo --version && rustc --version && rustup toolchain list
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 9.3 (stretch)
Release:        9.3
Codename:       stretch
Linux rust 4.9.59-v7+ #1047 SMP Sun Oct 29 12:19:23 GMT 2017 armv7l GNU/Linux
cargo 0.25.0-nightly (930f9d949 2017-12-05)
rustc 1.24.0-nightly (250b49205 2017-12-21)
nightly-armv7-unknown-linux-gnueabihf (default)

[Xudong-Huang]

thanks for reporting.
currently this project only supports x64_86 platforms. I don't have ARM based platforms for testing. I hope somebody could help to contribute on other platforms. 😄

[alanhoff]

I would gladly help you if I didn't lack ASM skills :-(

Even if you don't have an ARM device you can still cross compile and execute/test using qemu:

$ rustc \
    --target=arm-unknown-linux-gnueabihf \
    -C linker=arm-linux-gnueabihf-gcc \
    hello.rs

Then try to run it:

qemu-arm -L /usr/arm-linux-gnueabihf/ ./hello

• https://gist.github.com/Liryna/10710751
• https://github.com/japaric/rust-cross

[Xudong-Huang]

the libfringe branch should be an easier porting for ARM, we can just reuse the asm code from libfringe.

ref #4

[crabdancing]

If it helps, I can confirm as of 2023-02 that this library is compiling & working on aarch64, with all tests passing.

[Xudong-Huang]

Now armv7 linux is supported. Thanks you all!