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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/devicetree/bindings/reserved-memory/ramoops.txt | |
parent | Initial commit. (diff) | |
download | linux-upstream/5.10.209.tar.xz linux-upstream/5.10.209.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | Documentation/devicetree/bindings/reserved-memory/ramoops.txt | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/reserved-memory/ramoops.txt b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt new file mode 100644 index 000000000..b7886fea3 --- /dev/null +++ b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt @@ -0,0 +1,60 @@ +Ramoops oops/panic logger +========================= + +ramoops provides persistent RAM storage for oops and panics, so they can be +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. + +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" + +- reg: region of memory that is preserved between reboots + + +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 kmsg dump. + (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) + +- max-reason: if present, sets maximum type of kmsg dump reasons to store + (defaults to 2: log Oopses and Panics). This can be set to INT_MAX to + store all kmsg dumps. See include/linux/kmsg_dump.h KMSG_DUMP_* for other + kmsg dump reason values. Setting this to 0 (KMSG_DUMP_UNDEF), means the + reason filtering will be controlled by the printk.always_kmsg_dump boot + param: if unset, it will be KMSG_DUMP_OOPS, otherwise KMSG_DUMP_MAX. + +- no-dump-oops: deprecated, use max_reason instead. If present, and + max_reason is not specified, it is equivalent to max_reason = 1 + (KMSG_DUMP_PANIC). + +- flags: if present, pass ramoops behavioral flags (defaults to 0, + see include/linux/pstore_ram.h RAMOOPS_FLAG_* for flag values). |