Problem with old SVR4

camerabambai · 03-26-2023, 10:26 PM

Usually one serial port is sufficient to control via minicom the old SVR4 on Qemu (I know is a very old system, is unsafe, etc..). But I need two serials (one for login, the other to try pppd).

I have set those two ports on configuration of vm

Code:

    <serial type="pty">
      <source path="/dev/pts/1"/>
      <target type="isa-serial" port="0">
        <model name="isa-serial"/>
      </target>
      <alias name="serial0"/>
    </serial>
    
    serial type="pty">
      <source path="/dev/pts/2"/>
      <target type="isa-serial" port="1">
        <model name="isa-serial"/>
      </target>
      <alias name="serial1"/>
    </serial>

But on start, only one port is enabled

Code:

find /dev/ -name *tty* -print
    /dev/systty
    /dev/tty00
    /dev/tty
    /dev/tty00s
    /dev/tty00h

So I try to rebuild the kernel. On SVR4 to rebuild the kernel first I make the changes in
the file /etc/conf/sdevice.d/asy

Code:

    asy     Y       1       7       1       4       3f8     3ff     0       0
    asy     Y       1       7       1       3       2f8     2ff     0       0

the syntax is simple: asy is the driver Y enable it, 1 7 1 I don't know, 3 is the interrupt (on all my system irq 3 is used by the second serial port, 4 by the first). 3f8-3ff and 2f8-2ff are the port interval, 0 0 I don't know

Then I rebuild the kernel with idbuild.
After reboot, same situation.
If I edit the file /etc/conf/node.d/asy

Code:

    asy     tty00   c       0
    asy     term/00 c       0
    asy     tty00s  c       0
    asy     tty00h  c       128
    asy     term/00s        c       0
    asy     term/00h        c       128
    
    asy     tty01   c       1
    asy     term/01 c       1
    asy     tty01s  c       1
    asy     tty01h  c       128
    asy     term/01s        c       1
    asy     term/01h        c       128

and recreate the nodes

Code:

    idmknod -s

I have this strange situation

ls -ld /dev/tty*

Code:

 crw-rw-rw-   1 bin      bin       16,  0 Dec 25 19:31 /dev/tty
    crw--w----   1 myuser   tty        3,  0 Mar 27 05:20 /dev/tty00
    crw-rw-rw-   1 root     root       3,128 Mar 27 04:26 /dev/tty00h
    crw-rw-rw-   1 root     root       3,  0 Mar 27 04:26 /dev/tty00s
    crw--w----   1 root     root       3,  0 Mar 27 05:20 /dev/tty01
    crw-rw-rw-   1 root     root       3,128 Mar 27 04:26 /dev/tty01h
    crw-rw-rw-   1 root     root       3,  0 Mar 27 04:26 /dev/tty01s

All files use the major number 3.
Why the 4 is complete ignored? What I miss? Probably a bug in the kernel or what else?
On all my system the two serials are recognized, modern (Linux) and old (Sco Unix).

smallpond · 04-05-2023, 09:44 AM

major number is the driver, minor number is the device. So com1 (3f8) should be minor 0 and com2 (2f8) should be minor 1.