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Diffstat (limited to 'Documentation/virt/uml/user_mode_linux_howto_v2.rst')
-rw-r--r-- | Documentation/virt/uml/user_mode_linux_howto_v2.rst | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/Documentation/virt/uml/user_mode_linux_howto_v2.rst b/Documentation/virt/uml/user_mode_linux_howto_v2.rst index 2cafd3c3c6cb..863f67b72c05 100644 --- a/Documentation/virt/uml/user_mode_linux_howto_v2.rst +++ b/Documentation/virt/uml/user_mode_linux_howto_v2.rst @@ -664,7 +664,11 @@ one is input, the second one output. * The fd channel - use file descriptor numbers for input/output. Example: ``con1=fd:0,fd:1.`` -* The port channel - listen on TCP port number. Example: ``con1=port:4321`` +* The port channel - start a telnet server on TCP port number. Example: + ``con1=port:4321``. The host must have /usr/sbin/in.telnetd (usually part of + a telnetd package) and the port-helper from the UML utilities (see the + information for the xterm channel below). UML will not boot until a client + connects. * The pty and pts channels - use system pty/pts. @@ -1189,6 +1193,26 @@ E.g. ``os_close_file()`` is just a wrapper around ``close()`` which ensures that the userspace function close does not clash with similarly named function(s) in the kernel part. +Using UML as a Test Platform +============================ + +UML is an excellent test platform for device driver development. As +with most things UML, "some user assembly may be required". It is +up to the user to build their emulation environment. UML at present +provides only the kernel infrastructure. + +Part of this infrastructure is the ability to load and parse fdt +device tree blobs as used in Arm or Open Firmware platforms. These +are supplied as an optional extra argument to the kernel command +line:: + + dtb=filename + +The device tree is loaded and parsed at boottime and is accessible by +drivers which query it. At this moment in time this facility is +intended solely for development purposes. UML's own devices do not +query the device tree. + Security Considerations ----------------------- |