> I am planning to improve, if possible, the serial units for both Linux
> and Windows, but have a few questions before I proceed any further:
>
> 1- I guess the unit rtl\win\wininc\struct.inc has 2 bugs:
> a- bm_DCB_fRtsControl = $3000. It should be $2000.
> b- bm_DCB_fDtrControl = $30. It should be $20.
> Can anybody confirm this?
No, they are correct. If you look into the headers you'll see:
DWORD DCBlength; /* sizeof(DCB) */
DWORD BaudRate; /* Baudrate at which running */
DWORD fBinary: 1; /* Binary Mode (skip EOF check) */
DWORD fParity: 1; /* Enable parity checking */
DWORD fOutxCtsFlow:1; /* CTS handshaking on output */
DWORD fOutxDsrFlow:1; /* DSR handshaking on output */
DWORD fDtrControl:2; /* DTR Flow control */
DWORD fDsrSensitivity:1; /* DSR Sensitivity */
DWORD fTXContinueOnXoff: 1; /* Continue TX when Xoff sent */
DWORD fOutX: 1; /* Enable output X-ON/X-OFF */
DWORD fInX: 1; /* Enable input X-ON/X-OFF */
DWORD fErrorChar: 1; /* Enable Err Replacement */
DWORD fNull: 1; /* Enable Null stripping */
DWORD fRtsControl:2; /* Rts Flow control */
DWORD fAbortOnError:1; /* Abort all reads and writes on Error */
DWORD fDummy2:17; /* Reserved */
WORD wReserved; /* Not currently used */
WORD XonLim; /* Transmit X-ON threshold */
WORD XoffLim; /* Transmit X-OFF threshold */
BYTE ByteSize; /* Number of bits/byte, 4-8 */
BYTE Parity; /* 0-4=None,Odd,Even,Mark,Space */
BYTE StopBits; /* 0,1,2 = 1, 1.5, 2 */
char XonChar; /* Tx and Rx X-ON character */
char XoffChar; /* Tx and Rx X-OFF character */
char ErrorChar; /* Error replacement char */
char EofChar; /* End of Input character */
char EvtChar; /* Received Event character */
WORD wReserved1; /* Fill for now. */
} DCB, *LPDCB;
Note the :2 with frts and fdtr. These are two bit values, not one bit, so a
mask that masks 2 bits makes sense
> 2- I will define TSerialFlags = set of (XOnXOffFlowControl,
> RtsCtsFlowControl);
> What flags do we have to set in Linux to have XOnXOff handshaking? The
> number of parameters in tios is mind boggling.
Well the existance of flags are named "IXON", "IXOFF" and "IXANY" might
provide a clue when googled.
> 3- The Linux SerOpen function (based on fpopen) claims to return 0 if
> the device could not be found. Shouldn't it be -1?
Probably. In 1.0.x times FPC unix functions had own error conventions.
> 4- Windows SerOpen function (based on CreateFile) returns an
> INVALID_HANDLE_VALUE if the device could not be found. How to unify for
> both Linux & Windows? Is it safe to return instead -1 (as in the Linux
> case)?
See Tomas, it is define
>
> 5- Is it OK to designate serial ports by COMx fow Windows and /dev/ttySx
> for Linux?
No, since e.g a serial port on some other device might have a different
state. And strictly, this is even possible for Windows. Always keep naming
configurable and overridable. Those series are extremely common, but not
that
Also note that serial.pp is a general unix unit, not just linux. So it needs
to work on FreeBSD too. (and maybe Mac, but I have no serial on my mac
anymore)
I've acquired a serial device suitable for testing with FreeBSD if needed.
> 6- Is it OK for TSerialState to include DCB for Windows and tios for Linux?
I don't understand what you mean with this.
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