Hi Rob, > On Jun 15, 2015, at 16:24 , Rob Herring <robherring2@xxxxxxxxx> wrote: > > On Fri, Jun 12, 2015 at 2:38 PM, Pantelis Antoniou > <pantelis.antoniou@xxxxxxxxxxxx> wrote: >> Documentation ABI entry for overlays sysfs entries. >> >> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx> >> --- >> .../ABI/testing/sysfs-firmware-devicetree-overlays | 35 ++++++++++++++++++++++ >> 1 file changed, 35 insertions(+) >> create mode 100644 Documentation/ABI/testing/sysfs-firmware-devicetree-overlays >> >> diff --git a/Documentation/ABI/testing/sysfs-firmware-devicetree-overlays b/Documentation/ABI/testing/sysfs-firmware-devicetree-overlays >> new file mode 100644 >> index 0000000..be2d28b >> --- /dev/null >> +++ b/Documentation/ABI/testing/sysfs-firmware-devicetree-overlays >> @@ -0,0 +1,35 @@ >> +What: /sys/firmware/devicetree/overlays/ >> +Date: March 2015 >> +Contact: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx> >> +Description: >> + This directory contains the applied device tree overlays of >> + the running system, as directories of the overlay id. >> + >> + enable: The master enable switch, by default is 1, and when >> + set to 0 it cannot be re-enabled for security reasons. >> + >> +What: /sys/firmware/devicetree/overlays/<id> >> +Date: March 2015 >> +Contact: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx> >> +Description: >> + Each directory represents an applied overlay, containing >> + the following attribute files. >> + >> + The discussion about this switch takes place in: >> + http://comments.gmane.org/gmane.linux.drivers.devicetree/101871 >> + >> + Kees Cook: >> + "Coming from the perspective of drawing a bright line between >> + kernel and the root user (which tends to start with disabling >> + kernel module loading), I would say that there at least needs >> + to be a high-level one-way "off" switch for the interface so >> + that systems that have this interface can choose to turn it off >> + during initial boot, etc." > > Doesn't this below up above with "enable”? Ugh I guess so. > >> + >> + targets: A file containing the list of targets of each overlay >> + with each line containing a target. > > We have OF nodes in sysfs now. Would it be more useful if we created > links to the target nodes instead of having a list of names? > Probably, this interface is merely informational; things get complicated by the fact that there can be more than one target in each overlay. >> + >> + can_remove: The attribute set to 1 means that the overlay can >> + be removed, while 0 means that the overlay is being >> + overlapped therefore removal is prohibited. >> + >> -- >> 1.7.12 >> Regards — Pantelis -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
