Module drone_cortex_m::sv

The Supervisor module.

Supervisor is an abstraction for the SVC assembly instruction, which means SuperVisor Call, and the SV_CALL exception.

Usage

use drone_cortex_m::{sv, thr};

sv! {
    /// The supervisor.
    pub struct Sv;

    /// Array of services.
    static SERVICES;

    // The list of attached services goes here.
    // SwitchContextService;
    // SwitchBackService;
}

thr::vtable! {
    use Thr;
    pub struct Vtable;
    pub struct Handlers;
    pub struct Thrs;
    static THREADS;

    // Define an external function handler for the SV_CALL exception.
    fn SV_CALL;
}

thr! {
    use THREADS;
    pub struct Thr {}
    pub struct ThrLocal {}
}

#[no_mangle]
pub static VTABLE: Vtable = Vtable::new(Handlers {
    reset,
    // Attach the SV_CALL handler for the supervisor `Sv`.
    sv_call: drone_cortex_m::sv::sv_handler::<Sv>,
});

unsafe extern "C" fn reset() -> ! {
    loop {}
}

Predefined Services

If SwitchContextService and SwitchBackService are defined for the supervisor, switch_context and switch_back functions become available to switch the program stack.

use drone_cortex_m::sv::{Switch, SwitchBackService, SwitchContextService};

use drone_cortex_m::sv;

sv! {
    /// The supervisor.
    pub struct Sv;

    /// Array of services.
    static SERVICES;

    SwitchContextService;
    SwitchBackService;
}

unsafe {
    // Allocate the stack.
    let stack = Box::<[u8]>::new_uninit_slice(0x800).assume_init();
    // `stack_ptr` will store the current stack pointer.
    let mut stack_ptr = stack.as_ptr();
    let mut data = Box::<u32>::new(0);
    let mut data_ptr = &mut *data as *mut u32;
    Sv::switch_context(data_ptr, &mut stack_ptr);
    // -------------------
    // Using the new stack.
    // -------------------
    Sv::switch_back(&mut data_ptr);
}

Structs

SwitchBackService	A service to switch back from a process stack.
SwitchContextService	A service to switch to a process stack.

Traits

Supervisor	Generic supervisor.
SvCall	A supervisor call.
SvService	Generic supervisor service.
Switch	Extends Supervisor types with switch_context and switch_back methods.

Functions

service_handler⚠	This function is called by sv_handler for the supervisor service T. Parameter T is based on the number num in the SVC num instruction.
sv_call⚠	Calls SVC num instruction.
sv_handler⚠	SV_CALL exception handler for the supervisor T.