Sergiu Iordache <sergiu@chromium.org>
-Updated: 8 August 2011
+Updated: 17 November 2011
0. Introduction
The module uses a counter to record multiple dumps but the counter gets reset
on restart (i.e. new dumps after the restart will overwrite old ones).
+Ramoops also supports software ECC protection of persistent memory regions.
+This might be useful when a hardware reset was used to bring the machine back
+to life (i.e. a watchdog triggered). In such cases, RAM may be somewhat
+corrupt, but usually it is restorable.
+
2. Setting the parameters
Setting the ramoops parameters can be done in 2 different manners:
2. Use a platform device and set the platform data. The parameters can then
be set through that platform data. An example of doing that is:
-#include <linux/ramoops.h>
+#include <linux/pstore_ram.h>
[...]
static struct ramoops_platform_data ramoops_data = {
.mem_address = <...>,
.record_size = <...>,
.dump_oops = <...>,
+ .ecc = <...>,
};
static struct platform_device ramoops_dev = {
4. Reading the data
-The dump data can be read from memory (through /dev/mem or other means).
-Getting the module parameters, which are needed in order to parse the data, can
-be done through /sys/module/ramoops/parameters/* .
+The dump data can be read from the pstore filesystem. The format for these
+files is "dmesg-ramoops-N", where N is the record number in memory. To delete
+a stored record from RAM, simply unlink the respective pstore file.