This section answers common questions about serial communications with FreeBSD.
14.1. | How do I get the boot: prompt to show on the serial console? |
14.2. | How do I tell if FreeBSD found my serial ports or modem cards? |
As the FreeBSD kernel boots, it will probe for the serial ports for which the kernel is configured. Either watch the boot messages closely or run this command after the system is up and running:
This example shows two serial ports. The first is on
IRQ4, port address
The | |
14.3. | How do I access the serial ports on FreeBSD? (x86-specific) |
The third serial port, When
opening | |
14.4. | How do I enable support for a multi-port serial card? |
The section on kernel configuration provides information about configuring the kernel. For a multi-port serial card, place an sio(4) line for each serial port on the card in the device.hints(5) file. But place the IRQ specifiers on only one of the entries. All of the ports on the card should share one IRQ. For consistency, use the last serial port to specify the IRQ. Also, specify the following option in the kernel configuration file: options COM_MULTIPORT The following hint.sio.4.at="isa" hint.sio.4.port="0x2a0" hint.sio.4.flags="0x701" hint.sio.5.at="isa" hint.sio.5.port="0x2a8" hint.sio.5.flags="0x701" hint.sio.6.at="isa" hint.sio.6.port="0x2b0" hint.sio.6.flags="0x701" hint.sio.7.at="isa" hint.sio.7.port="0x2b8" hint.sio.7.flags="0x701" hint.sio.7.irq="12" The flags indicate that the master port has minor
number | |
14.5. | Can I set the default serial parameters for a port? |
See the Serial Communications section in the FreeBSD Handbook. | |
14.6. | Why can I not run |
The built-in tip(1) and
cu(1) utilities can only access the
Alternatively, everyone can be configured to run tip(1) and cu(1) by typing:
|
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