Function handleProtocol [src]

Returns a pointer to the Protocol interface if it's supported by the handle. Note that UEFI implementations are no longer required to implement this function, so it's implemented using openProtocol instead.

Prototype

pub fn handleProtocol( self: *BootServices, Protocol: type, handle: Handle, ) HandleProtocolError!?*Protocol

Parameters

self: *BootServicesProtocol: typehandle: Handle

Possible Errors

Unexpected UnexpectedError

Unsupported

Source

  pub fn handleProtocol(
    self: *BootServices,
    Protocol: type,
    handle: Handle,
) HandleProtocolError!?*Protocol {
    // per https://uefi.org/specs/UEFI/2.10/07_Services_Boot_Services.html#efi-boot-services-handleprotocol
    // handleProtocol is basically `openProtocol` where:
    // 1. agent_handle is `uefi.handle` (aka handle passed to `EfiMain`)
    // 2. controller_handle is `null`
    // 3. attributes is `EFI_OPEN_PROTOCOL_BY_HANDLE_PROTOCOL`

    return self.openProtocol(
        Protocol,
        handle,
        .{ .by_handle_protocol = .{ .agent = uefi.handle } },
    ) catch |err| switch (err) {
        error.AlreadyStarted => return uefi.unexpectedStatus(.already_started),
        error.AccessDenied => return uefi.unexpectedStatus(.access_denied),
        error.InvalidParameter => return uefi.unexpectedStatus(.invalid_parameter),
        else => return @errorCast(err),
    };
}  