Function openProtocol [src]

Opens a protocol with a structure as the loaded image for a UEFI application If flag is .test_protocol, then the only valid return value is null, and Status.unsupported is returned. Otherwise, if _openProtocol returns Status.unsupported, then null is returned.

Prototype

 pub fn openProtocol( self: *BootServices, Protocol: type, handle: Handle, attributes: OpenProtocolArgs, ) OpenProtocolError!?*Protocol

Parameters

self: *BootServicesProtocol: typehandle: Handleattributes: OpenProtocolArgs

Possible Errors

AccessDenied

AlreadyStarted

InvalidParameter

Unexpected UnexpectedError

Unsupported

Source

  pub fn openProtocol(
    self: *BootServices,
    Protocol: type,
    handle: Handle,
    attributes: OpenProtocolArgs,
) OpenProtocolError!?*Protocol {
    if (!@hasDecl(Protocol, "guid"))
        @compileError("Protocol is missing guid: " ++ @typeName(Protocol));

    const agent_handle: ?Handle, const controller_handle: ?Handle = switch (attributes) {
        inline else => |arg| .{ arg.agent, arg.controller },
    };

    var ptr: ?*Protocol = undefined;

    switch (self._openProtocol(
        handle,
        &Protocol.guid,
        @as(*?*anyopaque, @ptrCast(&ptr)),
        agent_handle,
        controller_handle,
        std.meta.activeTag(attributes),
    )) {
        .success => return if (attributes == .test_protocol) null else ptr,
        .unsupported => return if (attributes == .test_protocol) error.Unsupported else null,
        .access_denied => return error.AccessDenied,
        .already_started => return error.AlreadyStarted,
        else => |status| return uefi.unexpectedStatus(status),
    }
}  