9.3.3. Serial ports and multiport cards

The sio driver provides support for NS8250-, NS16450-, NS16550 and NS16550A-based EIA RS-232C (CCITT V.24) communications interfaces. Several multiport cards are supported as well. See the sio(4) manual page for detailed technical documentation.

9.3.3.1. Digiboard PC/8

Contributed by Andrew Webster <awebster@dataradio.com> .
26 August 1995.

Here is a config snippet from a machine with digiboard PC/8 with 16550. It has 8 modems connected to these 8 lines, and they work just great. Do not forget to add options "COM_MULTIPORT" or it will not work very well!

device          sio4    at isa? port 0x100 tty flags 0xb05
device          sio5    at isa? port 0x108 tty flags 0xb05
device          sio6    at isa? port 0x110 tty flags 0xb05
device          sio7    at isa? port 0x118 tty flags 0xb05
device          sio8    at isa? port 0x120 tty flags 0xb05
device          sio9    at isa? port 0x128 tty flags 0xb05
device          sio10   at isa? port 0x130 tty flags 0xb05
device          sio11   at isa? port 0x138 tty flags 0xb05 irq 9 vector siointr

The trick in setting this up is that the MSB of the flags represent the last SIO port, in this case 11 so flags are 0xb05.

9.3.3.2. Boca 16

Contributed by Don Whiteside <whiteside@acm.org> .
26 August 1995.

The procedures to make a Boca 16 pord board with FreeBSD are pretty straighforward, but you will need a couple things to make it work:

1. You either need the kernel sources installed so you can recompile the necessary options or you will need someone else to compile it for you. The 2.0.5 default kernel does not come with multiport support enabled and you will need to add a device entry for each port anyways.

2. Two, you will need to know the interrupt and IO setting for your Boca Board so you can set these options properly in the kernel.

One important note - the actual UART chips for the Boca 16 are in the connector box, not on the internal board itself. So if you have it unplugged, probes of those ports will fail. I have never tested booting with the box unplugged and plugging it back in, and I suggest you do not either.

If you do not already have a custom kernel configuration file set up, refer to Kernel Configuration for general procedurs. The following are the specifics for the Boca 16 board and assume you are using the kernel name MYKERNEL and editing with vi.

1. Add the line

   options "COM_MULTIPORT"
   

   to the config file.

2. Where the current device sio xxx lines are, you will need to add 16 more devices. Only the last device includes the interrupt vector for the board. (See the sio(4) manual page for detail as to why.) The following example is for a Boca Board with an interrupt of 3, and a base IO address 100h. The IO address for Each port is +8 hexidecimal from the previous port, thus the 100h, 108h, 110h... addresses.

   device sio1 at isa? port 0x100 tty flags 0x1005
   device sio2 at isa? port 0x108 tty flags 0x1005
   device sio3 at isa? port 0x110 tty flags 0x1005
   device sio4 at isa? port 0x118 tty flags 0x1005
   [...]
   device sio15 at isa? port 0x170 tty flags 0x1005
   device sio16 at isa? port 0x178 tty flags 0x1005 irq 3 vector siointr
   

   The flags entry must be changed from this example unless you are using the exact same sio assignments. Flags are set according to 0xMYY where M indicates the minor number of the master port (the last port on a Boca 16) and YY indicates if FIFO is enabled or disabled(enabled), IRQ sharing is used(yes) and if there is an AST/4 compatible IRQ control register(no). In this example,

   flags 0x1005
   

   indicates that the master port is sio16. If I added another board and assigned sio17 through sio28, the flags for all 16 ports on that board would be 0x1C05, where 1C indicates the minor number of the master port. Do not change the 05 setting.

3. Save and complete the kernel configuration, recompile, install and reboot. Presuming you have successfully installed the recompiled kernel and have it set to the correct address and IRQ, your boot message should indicate the successful probe of the Boca ports as follows: (obviously the sio numbers, IO and IRQ could be different)

   sio1 at 0x100-0x107 flags 0x1005 on isa
   sio1: type 16550A (multiport)
   sio2 at 0x108-0x10f flags 0x1005 on isa
   sio2: type 16550A (multiport)
   sio3 at 0x110-0x117 flags 0x1005 on isa
   sio3: type 16550A (multiport)
   sio4 at 0x118-0x11f flags 0x1005 on isa
   sio4: type 16550A (multiport)
   sio5 at 0x120-0x127 flags 0x1005 on isa
   sio5: type 16550A (multiport)
   sio6 at 0x128-0x12f flags 0x1005 on isa
   sio6: type 16550A (multiport)
   sio7 at 0x130-0x137 flags 0x1005 on isa
   sio7: type 16550A (multiport)
   sio8 at 0x138-0x13f flags 0x1005 on isa
   sio8: type 16550A (multiport)
   sio9 at 0x140-0x147 flags 0x1005 on isa
   sio9: type 16550A (multiport)
   sio10 at 0x148-0x14f flags 0x1005 on isa
   sio10: type 16550A (multiport)
   sio11 at 0x150-0x157 flags 0x1005 on isa
   sio11: type 16550A (multiport)
   sio12 at 0x158-0x15f flags 0x1005 on isa
   sio12: type 16550A (multiport)
   sio13 at 0x160-0x167 flags 0x1005 on isa
   sio13: type 16550A (multiport)
   sio14 at 0x168-0x16f flags 0x1005 on isa
   sio14: type 16550A (multiport)
   sio15 at 0x170-0x177 flags 0x1005 on isa
   sio15: type 16550A (multiport)
   sio16 at 0x178-0x17f irq 3 flags 0x1005 on isa
   sio16: type 16550A (multiport master)
   

   If the messages go by too fast to see, dmesg > more will show you the boot messages.

4. Next, apprepriate entries in /dev for the devices must be made using the /dev/MAKEDEV script. After becoming root:

   # cd /dev
# ./MAKEDEV tty1
# ./MAKEDEV cua1
(everything in between)
# ./MAKEDEV ttyg
# ./MAKEDEV cuag

   If you do not want or need callout devices for some reason, you can dispense with making the cua* devices.

5. If you want a quick and sloppy way to make sure the devices are working, you can simply plug a modem into each port and (as root) echo at > ttyd* for each device you have made. You should see the RX lights flash for each working port.