[BRLTTY] BRLTTY in GRUB2

[Vladimir 'φ-coder/phcoder' Serbinenko]

On 30.03.2012 01:51, Dave Mielke wrote:
> What's the danger of losing a serial device character if the device isn't 
> polled for a while?
Relatively high unfortunately if UART buffer (16 characters AFAIR) is
overflown it starts discarding characters. If polling speed isn't enough
in practice we could start using interrupts but only to extend buffer,
not to have a complete interrupt handler.
>
> Am I correct that fetching from a serial port returns an unsigned byte (0-255), 
> and that no preprocesisng (like UTF-8) is done?
Right, just whatever is on serial 0-255 or -1 if nothing.
GRUB itself doesn't parse the input as UTF-8 but as ASCII + C1 codes
since using 0x9b instead of \e[ is somewhat common and conflicts with UTF-8.
>
> Is any kind of flow control (like RTS/CTS) supported? If so, how is it set?
Currently it's hardwired based on machine but can be made configurable.


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko


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