On Mon, Nov 16, 2015 at 04:13:25PM -0800, Greg Hackmann wrote: > ramoops is one of the remaining places where ARM vendors still rely on > board-specific shims. Device Tree lets us replace those shims with > generic code. > > These bindings mirror the ramoops module parameters, with two small > differences: > > (1) dump_oops becomes an optional "no-dump-oops" property, since ramoops > sets dump_oops=1 by default. > > (2) mem_type=1 becomes the more self-explanatory "unbuffered" property. > > Signed-off-by: Greg Hackmann <ghackmann@xxxxxxxxxx> > --- > Changes in V2: > - make DT binding documentation more generic > Documentation/devicetree/bindings/misc/ramoops.txt | 40 ++++++++ > Documentation/ramoops.txt | 6 +- > fs/pstore/ram.c | 110 ++++++++++++++++++++- > 3 files changed, 152 insertions(+), 4 deletions(-) > create mode 100644 Documentation/devicetree/bindings/misc/ramoops.txt > > diff --git a/Documentation/devicetree/bindings/misc/ramoops.txt b/Documentation/devicetree/bindings/misc/ramoops.txt > new file mode 100644 > index 0000000..96c082b > --- /dev/null > +++ b/Documentation/devicetree/bindings/misc/ramoops.txt > @@ -0,0 +1,40 @@ > +Ramoops oops/panic logger > +========================= > + > +ramoops provides persistent RAM storage for oops and panics, so they can be > +recovered after a reboot. > + > +Parts of this storage may be set aside for other persistent log buffers, such > +as kernel log messages, or for optional ECC error-correction data. The total > +size of these optional buffers must fit in the reserved region. Any remaining > +space will be used for oops and panics. If record-size is not set, I don't think this last statement is true. > + > + > +Required properties: > + > +- compatible: must be "ramoops" > + > +- memory-region: phandle to a region of memory that is preserved between reboots > + > + > +Optional properties: > + > +- ecc-size: enables ECC support and specifies ECC buffer size in bytes > + (defaults to no ECC) > + > +- record-size: maximum size in bytes of each dump done on oops/panic > + (defaults to 0) Perhaps the default should be something useful. > + > +- console-size: size in bytes of log buffer reserved for kernel messages > + (defaults to 0) > + > +- ftrace-size: size in bytes of log buffer reserved for function tracing and > + profiling (defaults to 0) > + > +- pmsg-size: size in bytes of log buffer reserved for userspace messages > + (defaults to 0) > + > +- unbuffered: if present, use uncached mappings to map the reserved region > + (defaults to cached mappings) It defaults to write-combined or buffered which is not really cached. > + > +- no-dump-oops: if present, only dump panics (defaults to panics and oops) Rob -- 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
