Enum kernel::syscall::SyscallReturn

pub enum SyscallReturn {
    Failure(ErrorCode),
    FailureU32(ErrorCode, u32),
    FailureU32U32(ErrorCode, u32, u32),
    FailureU64(ErrorCode, u64),
    Success,
    SuccessU32(u32),
    SuccessU32U32(u32, u32),
    SuccessU32U32U32(u32, u32, u32),
    SuccessU64(u64),
    SuccessU64U32(u64, u32),
    AllowReadWriteSuccess(*mut u8, usize),
    AllowReadWriteFailure(ErrorCode, *mut u8, usize),
    UserspaceReadableAllowSuccess(*mut u8, usize),
    UserspaceReadableAllowFailure(ErrorCode, *mut u8, usize),
    AllowReadOnlySuccess(*const u8, usize),
    AllowReadOnlyFailure(ErrorCode, *const u8, usize),
    SubscribeSuccess(*const (), usize),
    SubscribeFailure(ErrorCode, *const (), usize),
}

Enumeration of the possible system call return variants specified in TRD104.

This struct operates over primitive types such as integers of fixed length and pointers. It is constructed by the scheduler and passed down to the architecture to be encoded into registers, using the provided encode_syscall_return method.

Capsules do not use this struct. Capsules use higher level Rust types (e.g. ReadWriteProcessBuffer and GrantKernelData) or wrappers around this struct (CommandReturn) which limit the available constructors to safely constructable variants.

Variants

Failure(ErrorCode)

Generic error case

FailureU32(ErrorCode, u32)

Generic error case, with an additional 32-bit data field

FailureU32U32(ErrorCode, u32, u32)

Generic error case, with two additional 32-bit data fields

FailureU64(ErrorCode, u64)

Generic error case, with an additional 64-bit data field

Success

Generic success case

SuccessU32(u32)

Generic success case, with an additional 32-bit data field

SuccessU32U32(u32, u32)

Generic success case, with two additional 32-bit data fields

SuccessU32U32U32(u32, u32, u32)

Generic success case, with three additional 32-bit data fields

SuccessU64(u64)

Generic success case, with an additional 64-bit data field

SuccessU64U32(u64, u32)

Generic success case, with an additional 32-bit and 64-bit data field

AllowReadWriteSuccess(*mut u8, usize)

Read/Write allow success case, returns the previous allowed buffer and size to the process.

AllowReadWriteFailure(ErrorCode, *mut u8, usize)

Read/Write allow failure case, returns the passed allowed buffer and size to the process.

UserspaceReadableAllowSuccess(*mut u8, usize)

Shared Read/Write allow success case, returns the previous allowed buffer and size to the process.

UserspaceReadableAllowFailure(ErrorCode, *mut u8, usize)

Shared Read/Write allow failure case, returns the passed allowed buffer and size to the process.

AllowReadOnlySuccess(*const u8, usize)

Read only allow success case, returns the previous allowed buffer and size to the process.

AllowReadOnlyFailure(ErrorCode, *const u8, usize)

Read only allow failure case, returns the passed allowed buffer and size to the process.

SubscribeSuccess(*const (), usize)

Subscribe success case, returns the previous upcall function pointer and application data.

SubscribeFailure(ErrorCode, *const (), usize)

Subscribe failure case, returns the passed upcall function pointer and application data.

Implementations

impl SyscallReturn

pub fn encode_syscall_return(
    &self,
    a0: &mut u32,
    a1: &mut u32,
    a2: &mut u32,
    a3: &mut u32
)

Encode the system call return value into 4 registers, following the encoding specified in TRD104. Architectures which do not follow TRD104 are free to define their own encoding.

Trait Implementations

impl Clone for SyscallReturn

fn clone(&self) -> SyscallReturn

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SyscallReturn

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for SyscallReturn