efi_serial.cc

bool serial_logger_efi_t::init(int port)
{
    EFI_STATUS status;

    UINTN serial_port_count = 0;
    EFI_HANDLE *serial_ports = nullptr;

    status = efi_systab->BootServices->LocateHandleBuffer(
                ByProtocol,
                &efi_serial_io_guid,
                nullptr,
                &serial_port_count,
                &serial_ports);

    if (EFI_ERROR(status)) {
        DEBUG(TSTR "LocateHandleBuffer SERIAL_IO_PROTOCOL failed");
        return false;
    }

    EFI_SERIAL_IO_PROTOCOL *serial_handles[16];

    for (size_t i = 0; i < serial_port_count && i < 16; ++i) {
        status = efi_systab->BootServices->HandleProtocol(
                serial_ports[i],
                &efi_serial_io_guid,
                (VOID**)&serial_handles[i]);

        if (!EFI_ERROR(status)) {
            char message[] = "Hello";
            UINTN message_len = sizeof(message) - 1;
            status = serial_handles[i]->Write(serial_handles[i],
                &message_len, message);

            if (EFI_ERROR(status)) {
                // To see in debugger
                volatile int it_failed _unused = 1;
            }
        } else {
            DEBUG(TSTR "HandleProtocol SERIAL_IO_PROTOCOL failed");
        }
    }

    return true;
}