Source Code 1992 March

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Text File | 1990-12-28 | 19.1 KB | 439 lines

release 1.1a Sat Nov 11, 1989 This is an unofficial release as I'm not the original author of this async driver. Uwe Doering Domain : gemini@geminix.in-berlin.de Billstedter Pfad 17 b Bangpath : ...!unido!fub!tmpmbx!geminix!gemini 1000 Berlin 20 Germany New Features: Added a third minor tty device number for every physical port. See description preceding the asyopen function in asy.c. Changed the behavior of ttyxx, too. Added output hardware handshake support for DSR. Now you can do handshake with CTS, DSR or both. Input hardware handshake is on if you use at least one of the output handshake signals. More flexible support of additional interrupt registers on mux boards. This is fully configurable now. Added support for the CREAD flag. If not set, receiver interrupts are still serviced, but the received characters are simply thrown away. This is not as elegant as disabeling the interrupts themselves, but with the already existing driver it was the easiest way, and the most new-bugs-preventing, too. Added a lot of comments to the source so that the curious user can understand why and how things are done. Bug Fixes: The hang-up-on-last-close flag (HUPCL) was ignored. DTR was asserted regardless of this flag. Made the detection of CTS and DCD more bullet-proof. Especially because between a close and the next open of a line, where interrupts are ignored, the software copys of CTS and DCD must be set up propperly in the asyopen function or the tty line would be blocked under certain circum- stances. For similar reasons, there is also a setup in the asyparam function. Rewrote the input character processing function to work according to the TERMIO(7) man page. Changed the behavior of BREAK generation to let the transmitter drain before TX is set to low. Changed line hangup procedure so that the closing process returns immediately and doesn't sleep during the hangup delay/time. Instead, if an other process tries to open the line while hangup is still in progress, this process will sleep until hangup is competed. With DOS Merge, on MicroPort V/386 3.0e the linker was missing the function `init8250'. Reengineered this from a disassembler listing of MicroPort's original driver and modified it to work with the NS16550A 16-byte FIFO. This funktion was added simply to be able to link the kernel. DOS Merge's virtual COM ports are still unusable with this release, though. To include this function, add a `-DMERGE' to the CFLAGS line in your makefile. Made a lot of other corrections and enhancements in both speed and functionallity. As a result of all my effords I think this driver is slightly faster, more versatile and much more stable than the original release. ------------------------------------------------------------ release 1.1b Sat Nov 25, 1989 New Features: Changed the minor device number scheme again. There are now two main groups: The unblocked open and the blocked open. Every group has four sub-modes and an additional hardware handshake flag. All this is coded in the higher four bits of the minor device number. Because of this, the maximum of 32 ports was reduced to 16 ports so that the port number fits into the remaining lower four bits of the minor device number. 32 dumb ports in a single machine would have been overkill anyway. For more details refer to the description in the README file. ------------------------------------------------------------ release 2.00 Mon Nov 27, 1989 As this release differs so much from the original version I got, I now declare this as independant from the original author Jim Murray. This allows me to introduce new release levels without wondering whether they will collide with Jim's releases. Of course many credits to Jim for writing this software in the first place. Without his driver as a base I never would have been able to do such kernel driver development. Bug Fixes: If there were glitches on the hardware handshake lines and the DCD line a getty on this port would sometimes hang and become an immortal process. I think this was because the output buffer wasn't flushed properly on carrier loss. I hope I fixed this now. We'll see. ------------------------------------------------------------ release 2.01 Tue Nov 28, 1989 Did some cleanup in the source code. I splitted the driver into two parts: The driver itself and the file `space.c'. `space.c' contains all data structures necessary to configure the driver and is compiled at kernel link time. Therefore if you change your serial card configuration you simply change `space.c' directly in the link kit directory and relink the kernel. No driver recompilation or installation is necessary for this. But note that whenever you use `make install' your setup in the link kit directory is overwritten by the original `space.c' file. Therefore you should copy your new `space.c' back to the source directory when you are finished with the configuration. Renamed the package to `FAS Final Async Solution'. The following files have been renamed: asy.c -> fas.c asy.h -> fas.h asy_conf-xxxxx -> space-xxxxx ISC 386/ix is supported now. There are separate makefiles for uPort and ISC to cope with the differences in link kit installation. Bug Fixes: `getty' still hung sometimes on a line with hardware handshake. Tried to fix it this time. ------------------------------------------------------------ release 2.02 Thu Nov 30, 1989 Abandoned the distinction between space-xxxxx files with and without hardware flow control because this is selected by the minor device number now. Bug Fixes: Set the high and low water marks for hardware input flow control to higher values than software flow control. This gives precedence to software flow control if both methods are used. These marks are self-adjusting and don't need to be changed if some flavor of UNIX has a different buffer size than the standard 256 characters. Before this change concurrent use of both flow controls could cause trouble with some high-speed modems. This is fixed now. A flush read or write buffer request now also clears the receiver or transmitter FIFO, respectively. An ioctl call with a TCSETA* command clears the FIFOs, too. ------------------------------------------------------------ release 2.03 Fri Dec 01, 1989 Wrote an installation guide. The driver should be quite easy to install now. Added tty node configuration files for ISC. Hardware input flow control is bound now to the level of the receiver ring buffer instead of the UNIX input buffer. This has the advantage that buffer size and trigger levels are defined in the driver and therefore can be varied as needed. New Features: Added a boot time status message that shows the init state of each port. This tells you immediately what ports are found and initted by the driver. Useful to determine hardware configuration problems. Look at the description in the README file. Thanks to Kritt Gierlewsen (kritt@einoed.UUCP) for this proposal. ------------------------------------------------------------ release 2.04 Thu Dec 07, 1989 Did some cleanup in the source. Removed the FIFO clear from the ioctl function. We don't want to do things there that aren't in the book. An ioctl call that switches off the CLOCAL flag will create a SIGHUP signal if the carrier is actually missing at this time. Every device is tested now quite thoroughly during initialization. If the test fails the corresponding device keeps unconfigured. ------------------------------------------------------------ release 2.05 Sat Jan 13, 1990 This is the first public release of the FAS driver. Special thanks to the sysops of my test sites, Axel Fischer (fischer@utower.UUCP) and Kritt Gierlewsen (kritt@einoed.UUCP). FAS is now an independant driver with its own driver name (`fas'), major device number, link kit directory and other things necessary for a driver. The original asy driver may or may not be linked with the kernel. You only need it if you want to access some serial devices via the virtual COM ports of the DOS emulator (DosMerge or VP/ix) because the FAS driver doesn't have this (really vendor dependant) feature. The default prefix for tty device node names is `ttyF' now. This prevents mix-ups with the device names of the original asy driver. Dropped the SYSV/AT support. I couldn't test the driver for several release generations on uPort SYSV/AT, and because there are not very much systems left with that flavor of UNIX it doesn't make sense to try to maintain compatibility with it. If someone really wants to use this driver on a 286 he has to port it himself. Improved the transmitter FIFO fill procedure. Now it will try harder to fill the FIFO as much as possible to cut down on transmitter interrupts. Software input flow control (XON/XOFF) is controlled by the driver now. It is bound to the level of the receiver ring buffer (as is hardware flow control). As usual, it can be switched on and off by the IXOFF flag in the termio(7) structure. Changed and speeded up the ring buffer -> unix buffer processing. For ISC, the getty lines for the inittab file are installed by the makefile now. The conditional compilation of the function `init8250' (for DosMerge) is now controlled by a define in `fas.h'. The compiler switch `-DMERGE' is not used any more. Improved the documentation. The signals used for modem control and hardware flow control are fully configurable in the `space.c' file now. Look at `fas.h' for possible macros and combinations. There are some new modes for hardware flow control, for instance HO_CTS_ON_DSR. This means that CTS is only looked at if DSR is on. If DSR is off output is possible regardless of CTS. The underlying assumption here is that we can expect proper handshake handling only from devices that are in the ready state (indicated by DSR). As a spin-off the problem with the hanging getty on lines with turned-off terminals (mentioned in earlier releases) should be gone if you use this new mode. If the XCLUDE-Flag is availabe (SYSV 3.2 because of Xenix compatibility) exclusive open of a device is possible. The default size of the input ring buffer is now 5000 bytes. This makes streaming input more likely even on loaded systems. Bug Fixes: The task state busy flag wasn't reset in some rare cases. This could cause processes to become immortal while waiting for the busy flag. Under some special conditions an ioctl call with a TCSETA? command could corrupt the last character in the transmitter shift register. This is fixed now. More fixing of the busy flag handling was necessary. Co-ordinating several delayed tasks controlling this flag is kind of tricky. After a TCSETA* ioctl command we disable the transmitter for 2 sec (measured from the last transmitted character) if the character format and/or speed has changed. This gives the receiving side some time to do the same changes. This is kind of experimental. There may be applications that suffer from this delay. You may change the #define ADAPT_TIME in `fas.h' to a smaller value. ------------------------------------------------------------ release 2.06 Fri Mar 16, 1990 This should have been patch #3 for release 2.05, but there are so many changes now that I decided to make it a new release. Therefor some of the changes are described in the 2.05 release notes above but were never released to the public. New Features: There is a transmitter ring buffer now to make the output less system load dependent. This really speeds things up because the transmitter FIFO gets filled with more characters at once. The buffer size depends on the actual baud rate to prevent long output buffer drains at low speeds. There are also bigger input buffers to make FAS more competitive against "intelligent" cards. Lots of speed improvements and many small changes. Bug Fixes: Fixed input/output buffer flush on carrier loss while close is waiting for the output to drain. ------------------------------------------------------------ release 2.07 Tue Sep 18, 1990 This is a major redesign of the previous release. I put most of the time consuming tasks in one function that is invoked asynchronously by timeout calls. Inside this function most of the code runs at a lower system priority level (spl5) than the interrupts. That means that during character processing tty interrupts are allowed. This is the main key to operation at 38400 bps on multiple ports at the same time which is possible now with this release. New Features: FAS supports the VP/ix DOS emulator! Now you can throw out the vendor's original driver even if you like to have a serial mouse or modem access in DOS. Read the paragraph about VP/ix in the README file. The Intel i82510 port chip is supported. It has separate 4-character FIFOs for input and output. Although the NS16550A is much better this chip is your second choice if you can't get your hands on the National chips. Thanks to Christian Seyb (cs@gold.UUCP) for sending me patches and the necessary documentation for the Intel chips. There is an init sequence in `space.c'. You can put any number of address-data pairs in a null terminated array to program your serial card or other hardware before FAS makes the first access to the ports. AST 4-port cards, for instance, have an additional port that needs to be written to with a certain bit pattern to allow shared interrupts. If you need to read a port to achieve the setting or resetting of flags as a side effect, this is possible, too. ESIX is officially supported now. SCO UNIX is officially supported, too. FAS needs to be compiled with the command line flag `-DSCO'. The makefile for SCO takes care of that. Thanks to Walter Mecky (walter@mecky.systemware.de) and Frank Simon (terra@sol.north.de) for helping me in making the necessary changes for SCO UNIX. SCO Xenix 386 is also officially supported. FAS needs to be compiled with the command line flag `-DXENIX'. The makefile for SCO Xenix takes care of that. Thanks to Andreas Steinmetzler (andreas@oil.UUCP) for doing the port. If you have the RTSFLOW and CTSFLOW termio(7) flags, hardware handshake can be controlled by them. Note that enabling handware flow control via the minor device number overrides these flags. If you like to use them you need to create tty device nodes with minor device numbers in which the bit for hardware handshake is set to 0. Look at the description in the README file for more details. Note also that if you choose to use RTSFLOW and CTSFLOW all your programs that do initial access to tty devices (getty, uucico, cu, SLIP dialup program etc.) need to know about these flags or hardware handshake will not be used. The `O_EXCL' flag for the open(2) call is honored now. This allowes exclusive access to an FAS device without suffering from race conditions which could occure with the termio(7) XCLUDE flag method. The `fas_test_device' function returns a digit now that indicates at which phase the test exited due to an error. This error digit is displayed in the boot message. Thanks to Brian Beattie (beattie@visenix.UUCP) for sending me the necessary patches. Bug Fixes: Automatic input FIFO flush after unblocking the getty open by the carrier or the unblock signal. This makes sure that there is no chance that there are characters in the FIFO that were received before the open got unblocked. The sdevice entry for the AST 4-port card had a wrong I/O address range (`s_fas-mux4'). This didn't affect FAS but is checked by the kernel config program. The gcc (GNU cc) support was removed because gcc's object file wants to link in some "helpful" functions that aren't contained in the kernel. But anyway, FAS is tuned so carefully and depends on the optimization behaviour of the AT&T standard C compiler that gcc won't have any advantages. I changed the method with which the `fas_test_device' function waits for certain events. The `delay' function was used for that purpose but it turned out that with some flavors of UNIX it is prohibited to use this function during the xxinit phase of the boot process. Now a simple timeout loop is used instead. Removed the ADAPT_TIME mechanismn introduced in release 2.05. The open() call now returns an `EBUSY' error number if the device is already open and can't be opened in the desired mode at this time. The handling of the RING signal needed fixing. Unlike the other three modem status lines RING generates an interrupt only at the trailing edge. No SIGHUP signal is sent any more if an ioctl call clears the CLOCAL termio(7) flag while there is no carrier present. SIGHUP is only sent if the actual DCD modem line drops. The files *-mux4 were renamed to *-ast4 because this type of card was originally developed by AST (AST 4-port card).