Rust embedded dual core programming

Question

Greetings everyone I hope you all are doing great!

The problem I'm facing is that all the crates I add as dependency, get as unresolved imports, albeit I've made sure to properly set the dependencies in the corresponding Cargo.toml file.

error[E0432]: unresolved import `panic_halt`
 --> cortex-m7/src/main.rs:5:5
  |
5 | use panic_halt as _; // you can put a breakpoint on `rust_begin_unwind` to catch p...
  |     ^^^^^^^^^^^^^^^ no `panic_halt` in the root

error[E0432]: unresolved import `cortex_m`
  --> cortex-m7/src/main.rs:10:5
   |
10 | use cortex_m::asm;
   |     ^^^^^^^^ maybe a missing crate `cortex_m`?
   |
   = help: consider adding `extern crate cortex_m` to use the `cortex_m` crate

error[E0432]: unresolved import `cortex_m_rt`
  --> cortex-m7/src/main.rs:11:5
   |
11 | use cortex_m_rt::entry;
   |     ^^^^^^^^^^^ maybe a missing crate `cortex_m_rt`?
   |
   = help: consider adding `extern crate cortex_m_rt` to use the `cortex_m_rt` crate

error[E0432]: unresolved import `greeter`
  --> cortex-m7/src/main.rs:12:5
   |
12 | use greeter;
   |     ^^^^^^^ no `greeter` in the root

error: cannot determine resolution for the attribute macro `entry`
  --> cortex-m7/src/main.rs:14:3
   |
14 | #[entry]
   |   ^^^^^
   |
   = note: import resolution is stuck, try simplifying macro imports

error: `#[panic_handler]` function required, but not found

For more information about this error, try `rustc --explain E0432`.
error: could not compile `cortex-m7` (bin "cortex-m7") due to 6 previous errors

As the title says, I'm trying to setup an environment for dual core programming in Rust, I've already successfully setup another environment for a single core MCU, so I don't really see it quite clear where might I be failing.

Here is my detailed setup:

1.Project structure:

.
|-- Cargo.lock
|-- Cargo.toml
|-- cortex-m4
|   |-- Cargo.toml
|   |-- build.rs
|   |-- memory.x
|   |-- openocd.cfg
|   |-- openocd.dbg
|   `-- src
|       `-- main.rs
|-- cortex-m7
|   |-- Cargo.toml
|   |-- build.rs
|   |-- memory.x
|   |-- openocd.cfg
|   |-- openocd.dbg
|   `-- src
|       `-- main.rs
`-- shared
    `-- greeter
        |-- Cargo.toml
        `-- src
            `-- lib.rs

2. main.rs:

The code within cortex-m7/src/main.rs is actually quite simple and is exactly the same in cortex-m4/src/main.rs

#![no_std]
#![no_main]

// pick a panicking behavior
use panic_halt as _; // you can put a breakpoint on `rust_begin_unwind` to catch panics
// use panic_abort as _; // requires nightly
// use panic_itm as _; // logs messages over ITM; requires ITM support
// use panic_semihosting as _; // logs messages to the host stderr; requires a debugger

use cortex_m::asm;
use cortex_m_rt::entry;

#[entry]
fn main() -> ! {
    asm::nop(); // To not have main optimize to abort in release mode, remove when you add code

    loop {
        // your code goes here
    }
}

3. Cargo.toml:

This is the Cargo.toml file within each of the cores directories. (NOT the global Cargo.toml)

//cortex-m7/Cargo.toml
[package]
name = "cortex-m7"
version.workspace = true
authors.workspace = true
description.workspace = true

# Dependencis for bare metal dev
[dependencies]
cortex-m.workspace = true 
cortex-m-rt.workspace = true 
panic-halt.workspace = true 
#cortex-m-semihosting.workspace = true #un-comment to enable semihosting

### cortex-m7 bin config
[[bin]]
name = "cortex-m7"
path = "src/main.rs"
    

4.Cargo.toml (root of the project)

### Workspaces
[workspace]
members = [ 
    "cortex-m7",
    "cortex-m4",
    "shared/greeter", 
]
default-members = ["cortex-m7"]
resolver = "2"

[workspace.package]
version = "0.1.0"
authors = ["Juan David Tangarife Hernandez <[email protected]>"]
description = "Dual core project for STM32H755ZI"

[workspace.dependencies]
cortex-m = "0.6.0"
cortex-m-rt = "0.6.10"
panic-halt = "0.2.0"
cortex-m-semihosting = "0.3.3" # un-comment to enable semihosting

### Debug build config
[profile.dev]
opt-level = 0  # No optimizations, full debug info

### Release build config
[profile.release]
codegen-units = 1 # better optimizations
debug = true # symbols are nice and they don't increase the size on Flash
lto = true # better optimizations

When I go into either of the cortex-m7 or cortex-m4 directories and run cargo build, I get errors related to the crates not being found:

error[E0432]: unresolved import `panic_halt`
 --> cortex-m7/src/main.rs:5:5
  |
5 | use panic_halt as _; // you can put a breakpoint on `rust_begin_unwind` to catch p...
  |     ^^^^^^^^^^^^^^^ no `panic_halt` in the root

error[E0432]: unresolved import `cortex_m`
  --> cortex-m7/src/main.rs:10:5
   |
10 | use cortex_m::asm;
   |     ^^^^^^^^ maybe a missing crate `cortex_m`?
   |
   = help: consider adding `extern crate cortex_m` to use the `cortex_m` crate

error[E0432]: unresolved import `cortex_m_rt`
  --> cortex-m7/src/main.rs:11:5
   |
11 | use cortex_m_rt::entry;
   |     ^^^^^^^^^^^ maybe a missing crate `cortex_m_rt`?
   |
   = help: consider adding `extern crate cortex_m_rt` to use the `cortex_m_rt` crate

error[E0432]: unresolved import `greeter`
  --> cortex-m7/src/main.rs:12:5
   |
12 | use greeter;
   |     ^^^^^^^ no `greeter` in the root

error: cannot determine resolution for the attribute macro `entry`
  --> cortex-m7/src/main.rs:14:3
   |
14 | #[entry]
   |   ^^^^^
   |
   = note: import resolution is stuck, try simplifying macro imports

error: `#[panic_handler]` function required, but not found

For more information about this error, try `rustc --explain E0432`.
error: could not compile `cortex-m7` (bin "cortex-m7") due to 6 previous errors

I followed exactly the same approach for my single core setup (with a few changes, obviously) and it worked just great.

It might be obvious the answer, but I don't really see it. Help would be appreciated, I want to start programming my stm32h755zi haha.