ramoops.txt 1.64 KB
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Ramoops oops/panic logger
=========================

ramoops provides persistent RAM storage for oops and panics, so they can be
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recovered after a reboot. This is a child-node of "/reserved-memory", and
is named "ramoops" after the backend, rather than "pstore" which is the
subsystem.
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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 a circular buffer of oops and panic
records.  These records have a configurable size, with a size of 0 indicating
that they should be disabled.

At least one of "record-size", "console-size", "ftrace-size", or "pmsg-size"
must be set non-zero, but are otherwise optional as listed below.


Required properties:

- compatible: must be "ramoops"

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- reg: region of memory that is preserved between reboots
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Optional properties:

- ecc-size: enables ECC support and specifies ECC buffer size in bytes
  (defaults to 0: no ECC)

- record-size: maximum size in bytes of each dump done on oops/panic
  (defaults to 0: disabled)

- console-size: size in bytes of log buffer reserved for kernel messages
  (defaults to 0: disabled)

- ftrace-size: size in bytes of log buffer reserved for function tracing and
  profiling (defaults to 0: disabled)

- pmsg-size: size in bytes of log buffer reserved for userspace messages
  (defaults to 0: disabled)

- unbuffered: if present, use unbuffered mappings to map the reserved region
  (defaults to buffered mappings)

- no-dump-oops: if present, only dump panics (defaults to panics and oops)