bhyve console question

Peter Grehan grehan at
Sun Apr 28 21:35:20 UTC 2013

Hi Dan,

> uart2: <16550 or compatible> port 0x3f8-0x3ff irq 4 at device 31.0 on pci0
> uart2: console (9600,n,8,1)
> which maps to the bhyve argument given: '-S 31,uart,stdio'

  Yes - the '-S' parameter instructs the PCI device to use a 
compatibility address so the console code can still access it. You could 
use any slot number that doesn't conflict (e.g. -S 11,...)

  FreeBSD reserves unit number 0 and 1 for ISA ports. When we have the 
PCI-ISA bridge code in place, it will show up as uart0, requiring ttyu0 
to be edited in /etc/ttys.

> It would be kind of cool to bind a guest's serial port to a named pipe
> on the host system

  You bet. The intent was always to allow different back ends. The third 
parameter is to describe this e.g. in the future, there could be

  -s 10,uart,telnetd:4239   // telnet server on a given port

  -s 12,uart,pty05          // pseudo terminal

  -s 14,uart,exec:"socat UNIX-LISTEN:/tmp/.bhye"  // exec an arbitrary 
program and use it's stdin/stdout

  On the TODO list :)



More information about the freebsd-virtualization mailing list