Function sys_ipc_send 

pub fn sys_ipc_send(_endpoint: u64, _msg: &[u8]) -> SyscallResult<()>

Send a message to an IPC endpoint.

Transmits a message to the specified IPC endpoint. The endpoint is identified by a capability token that the sender must possess with WRITE rights. The kernel validates the capability before delivering the message.

For small messages (64 bytes or fewer), the kernel uses a fast-path register-based transfer achieving sub-microsecond latency. For larger messages, the kernel uses zero-copy delivery by remapping the sender’s pages into the receiver’s address space, avoiding any data copying.

This call blocks until the receiver has accepted the message or until the endpoint’s send queue has space (for asynchronous endpoints). If the endpoint is a synchronous rendezvous endpoint, the sender blocks until a receiver calls sys_ipc_receive on the same endpoint.

Arguments

• endpoint - Capability token identifying the target IPC endpoint. The caller must hold this capability with at least WRITE rights. The token is a 64-bit value obtained from the capability system.
• msg - Message payload as a byte slice. Must not exceed the endpoint’s maximum message size (default 64 KiB). For optimal performance, keep messages at or below 64 bytes to use the register-based fast path.

Returns

• Ok(()) on successful delivery of the message.

Errors

• SyscallError::InvalidArgument - msg exceeds the endpoint’s maximum message size or is empty.
• SyscallError::PermissionDenied - The caller does not hold the endpoint capability or lacks WRITE rights on it.
• SyscallError::NotFound - The endpoint capability token is invalid or has been revoked.
• SyscallError::WouldBlock - The endpoint’s send queue is full and non-blocking mode was requested.
• SyscallError::Timeout - The operation timed out waiting for the receiver.

Examples

use veridian_kernel::pkg::sdk::syscall_api::sys_ipc_send;

let endpoint: u64 = 0x1234; // capability token for the endpoint
let message = b"hello from sender";
sys_ipc_send(endpoint, message).expect("ipc send failed");