config PSTORE tristate "Persistent store support" default n help This option enables generic access to platform level persistent storage via "pstore" filesystem that can be mounted as /dev/pstore. Only useful if you have a platform level driver that registers with pstore to provide the data, so you probably should just go say "Y" (or "M") to a platform specific persistent store driver (e.g. ACPI_APEI on X86) which will select this for you. If you don't have a platform persistent store driver, say N. config PSTORE_ZLIB_COMPRESS bool "ZLIB compression" default y depends on PSTORE select ZLIB_DEFLATE select ZLIB_INFLATE help This option enables ZLIB compression algorithm support. config PSTORE_LZO_COMPRESS bool "LZO compression" depends on PSTORE select LZO_COMPRESS select LZO_DECOMPRESS help This option enables LZO compression algorithm support. config PSTORE_LZ4_COMPRESS bool "LZ4 compression" depends on PSTORE select LZ4_COMPRESS select LZ4_DECOMPRESS help This option enables LZ4 compression algorithm support. config PSTORE_LZ4HC_COMPRESS bool "LZ4HC compression" depends on PSTORE select LZ4HC_COMPRESS select LZ4_DECOMPRESS help This option enables LZ4HC (high compression) mode algorithm. config PSTORE_842_COMPRESS bool "842 compression" depends on PSTORE select 842_COMPRESS select 842_DECOMPRESS help This option enables 842 compression algorithm support. config PSTORE_COMPRESS def_bool y depends on PSTORE depends on PSTORE_ZLIB_COMPRESS || PSTORE_LZO_COMPRESS || \ PSTORE_LZ4_COMPRESS || PSTORE_LZ4HC_COMPRESS || \ PSTORE_842_COMPRESS choice prompt "Default pstore compression algorithm" depends on PSTORE_COMPRESS help This option chooses the default active compression algorithm. This change be changed at boot with "pstore.compress=..." on the kernel command line. Currently, pstore has support for 5 compression algorithms: zlib, lzo, lz4, lz4hc and 842. The default compression algorithm is zlib. config PSTORE_ZLIB_COMPRESS_DEFAULT bool "zlib" if PSTORE_ZLIB_COMPRESS=y config PSTORE_LZO_COMPRESS_DEFAULT bool "lzo" if PSTORE_LZO_COMPRESS=y config PSTORE_LZ4_COMPRESS_DEFAULT bool "lz4" if PSTORE_LZ4_COMPRESS=y config PSTORE_LZ4HC_COMPRESS_DEFAULT bool "lz4hc" if PSTORE_LZ4HC_COMPRESS=y config PSTORE_842_COMPRESS_DEFAULT bool "842" if PSTORE_842_COMPRESS=y endchoice config PSTORE_COMPRESS_DEFAULT string depends on PSTORE_COMPRESS default "zlib" if PSTORE_ZLIB_COMPRESS_DEFAULT default "lzo" if PSTORE_LZO_COMPRESS_DEFAULT default "lz4" if PSTORE_LZ4_COMPRESS_DEFAULT default "lz4hc" if PSTORE_LZ4HC_COMPRESS_DEFAULT default "842" if PSTORE_842_COMPRESS_DEFAULT config PSTORE_CONSOLE bool "Log kernel console messages" depends on PSTORE help When the option is enabled, pstore will log all kernel messages, even if no oops or panic happened. config PSTORE_PMSG bool "Log user space messages" depends on PSTORE help When the option is enabled, pstore will export a character interface /dev/pmsg0 to log user space messages. On reboot data can be retrieved from /sys/fs/pstore/pmsg-ramoops-[ID]. If unsure, say N. config PSTORE_FTRACE bool "Persistent function tracer" depends on PSTORE depends on FUNCTION_TRACER depends on DEBUG_FS help With this option kernel traces function calls into a persistent ram buffer that can be decoded and dumped after reboot through pstore filesystem. It can be used to determine what function was last called before a reset or panic. If unsure, say N. config PSTORE_RAM tristate "Log panic/oops to a RAM buffer" depends on PSTORE depends on HAS_IOMEM depends on HAVE_MEMBLOCK select REED_SOLOMON select REED_SOLOMON_ENC8 select REED_SOLOMON_DEC8 help This enables panic and oops messages to be logged to a circular buffer in RAM where it can be read back at some later point. Note that for historical reasons, the module will be named "ramoops.ko". For more information, see Documentation/admin-guide/ramoops.rst.