6e9007e144
This is the same change as in commit c5caa3b but for the instances I
noticed in the rest of the chapters.
Before this change, clicking on the icon to copy the code snippet to
the clipboard would result in:
```rust
fn main() {
// Exception handler for the SysTick (System Timer) exception
fn SysTick() {
// ..
}
}
```
After this change, the following is copied to the clipboard instead:
```rust
// Exception handler for the SysTick (System Timer) exception
fn SysTick() {
// ..
}
```
2.1 KiB
Interoperability
Interoperability between Rust and C code is always dependent
on transforming data between the two languages.
For this purposes there are two dedicated modules
in the stdlib called
std::ffi and
std::os::raw.
std::os::raw deals with low-level primitive types that can
be converted implicitly by the compiler
because the memory layout between Rust and C
is similar enough or the same.
std::ffi provides some utility for converting more complex
types such as Strings, mapping both &str and String
to C-types that are easier and safer to handle.
Neither of these modules are available in core, but you can find a #![no_std]
compatible version of std::ffi::{CStr,CString} in the cstr_core crate, and
most of the std::os::raw types in the cty crate.
| Rust type | Intermediate | C type |
|---|---|---|
| String | CString | *char |
| &str | CStr | *const char |
| () | c_void | void |
| u32 or u64 | c_uint | unsigned int |
| etc | ... | ... |
As mentioned above, primitive types can be converted by the compiler implicitly.
unsafe fn foo(num: u32) {
let c_num: c_uint = num;
let r_num: u32 = c_num;
}
Interoperability with other build systems
A common requirement for including Rust in your embedded project is combining Cargo with your existing build system, such as make or cmake.
We are collecting examples and use cases for this on our issue tracker in issue #61.
Interoperability with RTOSs
Integrating Rust with an RTOS such as FreeRTOS or ChibiOS is still a work in progress; especially calling RTOS functions from Rust can be tricky.
We are collecting examples and use cases for this on our issue tracker in issue #62.