Symbol: EFI_SERIAL_REQUEST_TO_SEND
usr/src/boot/efi/libefi/efiserialio.c
1130
new_control &= ~(EFI_SERIAL_REQUEST_TO_SEND |
usr/src/boot/efi/libefi/efiserialio.c
1133
new_control |= EFI_SERIAL_REQUEST_TO_SEND;