console driver which dumps all printk messages to stderr.
The User-Mode Linux environment allows you to create virtual serial lines on the UML that are usually made to show up on the host as ttys or ptys. See <http://user-mode-linux.sourceforge.net/old/input.html> for more information and command line examples of how to use this facility. Unless you have a specific reason for disabling this, say Y.
This option enables support for attaching UML consoles and serial lines to a device similar to /dev/null. Data written to it disappears and there is never any data to be read.
This option enables support for attaching UML consoles and serial lines to host portals. They may be accessed with 'telnet <host> <port number>'. Any number of consoles and serial lines may be attached to a single portal, although what UML device you get when you telnet to that portal will be unpredictable. It is safe to say 'Y' here.
This option enables support for attaching UML consoles and serial lines to host pseudo-terminals. Access to both traditional pseudo-terminals (/dev/pty*) and pts pseudo-terminals are controlled with this option. The assignment of UML devices to host devices will be announced in the kernel message log. It is safe to say 'Y' here.
This option enables support for attaching UML consoles and serial lines to host terminals. Access to both virtual consoles (/dev/tty*) and the slave side of pseudo-terminals (/dev/ttyp* and /dev/pts/*) are controlled by this option. It is safe to say 'Y' here.
This option enables support for attaching UML consoles and serial lines to xterms. Each UML device so assigned will be brought up in its own xterm. It is safe to say 'Y' here.
This is the string describing the channel to which the main console will be attached by default. This value can be overridden from the command line. The default value is "fd:0,fd:1", which attaches the main console to stdin and stdout. It is safe to leave this unchanged.
This is the string describing the channel to which all consoles except the main console will be attached by default. This value can be overridden from the command line. The default value is "xterm", which brings them up in xterms. It is safe to leave this unchanged, although you may wish to change this if you expect the UML that you build to be run in environments which don't have X or xterm available.
This is the string describing the channel to which the serial lines will be attached by default. This value can be overridden from the command line. The default value is "pty", which attaches them to traditional pseudo-terminals. It is safe to leave this unchanged, although you may wish to change this if you expect the UML that you build to be run in environments which don't have a set of /dev/pty* devices.
This option enables UML sound support. If enabled, it will pull in soundcore and the UML hostaudio relay, which acts as a intermediary between the host's dsp and mixer devices and the UML sound system. It is safe to say 'Y' here.
While the User-Mode port cannot directly talk to any physical hardware devices, this choice and the following transport options provide one or more virtual network devices through which the UML kernels can talk to each other, the host, and with the host's help, machines on the outside world. For more information, including explanations of the networking and sample configurations, see <http://user-mode-linux.sourceforge.net/old/networking.html>. If you'd like to be able to enable networking in the User-Mode linux environment, say Y; otherwise say N. Note that you must enable at least one of the following transport options to actually make use of UML networking.
The Ethertap User-Mode Linux network transport allows a single running UML to exchange packets with its host over one of the host's Ethertap devices, such as /dev/tap0. Additional running UMLs can use additional Ethertap devices, one per running UML. While the UML believes it's on a (multi-device, broadcast) virtual Ethernet network, it's in fact communicating over a point-to-point link with the host. To use this, your host kernel must have support for Ethertap devices. Also, if your host kernel is 2.4.x, it must have CONFIG_NETLINK_DEV configured as Y or M. For more information, see <http://user-mode-linux.sourceforge.net/old/networking.html> That site has examples of the UML command line to use to enable Ethertap networking. NOTE: THIS TRANSPORT IS DEPRECATED AND WILL BE REMOVED SOON!!! Please migrate to UML_NET_VECTOR. If unsure, say N.
The UML TUN/TAP network transport allows a UML instance to exchange packets with the host over a TUN/TAP device. This option will only work with a 2.4 host, unless you've applied the TUN/TAP patch to your 2.2 host kernel. To use this transport, your host kernel must have support for TUN/TAP devices, either built-in or as a module. NOTE: THIS TRANSPORT IS DEPRECATED AND WILL BE REMOVED SOON!!! Please migrate to UML_NET_VECTOR. If unsure, say N.
The slip User-Mode Linux network transport allows a running UML to network with its host over a point-to-point link. Unlike Ethertap, which can carry any Ethernet frame (and hence even non-IP packets), the slip transport can only carry IP packets. To use this, your host must support slip devices. For more information, see <http://user-mode-linux.sourceforge.net/old/networking.html>. has examples of the UML command line to use to enable slip networking, and details of a few quirks with it. NOTE: THIS TRANSPORT IS DEPRECATED AND WILL BE REMOVED SOON!!! Please migrate to UML_NET_VECTOR. If unsure, say N.
This User-Mode Linux network transport allows one or more running UMLs on a single host to communicate with each other, but not to the host. To use this form of networking, you'll need to run the UML networking daemon on the host. For more information, see <http://user-mode-linux.sourceforge.net/old/networking.html> That site has examples of the UML command line to use to enable Daemon networking. NOTE: THIS TRANSPORT IS DEPRECATED AND WILL BE REMOVED SOON!!! Please migrate to UML_NET_VECTOR. If unsure, say N.
This User-Mode Linux network driver uses multi-message send and receive functions. The host running the UML guest must have a linux kernel version above 3.0 and a libc version > 2.13. This driver provides tap, raw, gre and l2tpv3 network transports with up to 4 times higher network throughput than the UML network drivers.
This User-Mode Linux network transport allows one or more running UMLs on a single host to communicate with each other and also with the rest of the world using Virtual Distributed Ethernet, an improved fork of uml_switch. You must have libvdeplug installed in order to build the vde transport into UML. To use this form of networking, you will need to run vde_switch on the host. For more information, see <http://wiki.virtualsquare.org/> That site has a good overview of what VDE is and also examples of the UML command line to use to enable VDE networking. NOTE: THIS TRANSPORT IS DEPRECATED AND WILL BE REMOVED SOON!!! Please migrate to UML_NET_VECTOR. If unsure, say N.
This Multicast User-Mode Linux network transport allows multiple UMLs (even ones running on different host machines!) to talk to each other over a virtual ethernet network. However, it requires at least one UML with one of the other transports to act as a bridge if any of them need to be able to talk to their hosts or any other IP machines. To use this, your host kernel(s) must support IP Multicasting. For more information, see <http://user-mode-linux.sourceforge.net/old/networking.html> That site has examples of the UML command line to use to enable Multicast networking, and notes about the security of this approach. NOTE: THIS TRANSPORT IS DEPRECATED AND WILL BE REMOVED SOON!!! Please migrate to UML_NET_VECTOR. If unsure, say N.
The pcap transport makes a pcap packet stream on the host look like an ethernet device inside UML. This is useful for making UML act as a network monitor for the host. You must have libcap installed in order to build the pcap transport into UML. For more information, see <http://user-mode-linux.sourceforge.net/old/networking.html> That site has examples of the UML command line to use to enable this option. NOTE: THIS TRANSPORT IS DEPRECATED AND WILL BE REMOVED SOON!!! Please migrate to UML_NET_VECTOR. If unsure, say N.
The SLiRP User-Mode Linux network transport allows a running UML to network by invoking a program that can handle SLIP encapsulated packets. This is commonly (but not limited to) the application known as SLiRP, a program that can re-socket IP packets back onto he host on which it is run. Only IP packets are supported, unlike other network transports that can handle all Ethernet frames. In general, slirp allows the UML the same IP connectivity to the outside world that the host user is permitted, and unlike other transports, SLiRP works without the need of root level privileges, setuid binaries, or SLIP devices on the host. This also means not every type of connection is possible, but most situations can be accommodated with carefully crafted slirp commands that can be passed along as part of the network device's setup string. The effect of this transport on the UML is similar that of a host behind a firewall that masquerades all network connections passing through it (but is less secure). NOTE: THIS TRANSPORT IS DEPRECATED AND WILL BE REMOVED SOON!!! Please migrate to UML_NET_VECTOR. If unsure, say N. Startup example: "eth0=slirp,FE:FD:01:02:03:04,/usr/local/bin/slirp"
This driver provides support for virtio based paravirtual device drivers over vhost-user sockets.
When PM_SLEEP is configured, it may be desirable to wake up using rtcwake, especially in time-travel mode. This driver enables that by providing a fake RTC clock that causes a wakeup at the right time.