LinuxQuestions.org - Problem with old SVR4

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).