# SPDX-License-Identifier: GPL-2.0-only 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_DEFAULT_KMSG_BYTES int "Default kernel log storage space" if EXPERT depends on PSTORE default "10240" help Defines default size of pstore kernel log storage. Can be enlarged if needed, not recommended to shrink it. config PSTORE_COMPRESS bool "Pstore compression (deflate)" depends on PSTORE select ZLIB_INFLATE select ZLIB_DEFLATE default y help Whether pstore records should be compressed before being written to the backing store. This is implemented using the zlib 'deflate' algorithm, using the library implementation instead of using the full blown crypto API. This reduces the risk of secondary oopses or other problems while pstore is recording panic metadata. 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 select RT_MUTEXES 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 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. config PSTORE_ZONE tristate depends on PSTORE help The common layer for pstore/blk (and pstore/ram in the future) to manage storage in zones. config PSTORE_BLK tristate "Log panic/oops to a block device" depends on PSTORE depends on BLOCK select PSTORE_ZONE default n help This enables panic and oops message to be logged to a block dev where it can be read back at some later point. For more information, see Documentation/admin-guide/pstore-blk.rst If unsure, say N. config PSTORE_BLK_BLKDEV string "block device identifier" depends on PSTORE_BLK default "" help Which block device should be used for pstore/blk. It accepts the following variants: 1) device number in hexadecimal representation, with no leading 0x, for example b302. 2) /dev/ represents the device name of disk 3) /dev/ represents the device name and number of partition - device number of disk plus the partition number 4) /dev/p - same as the above, this form is used when disk name of partitioned disk ends with a digit. 5) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the unique id of a partition if the partition table provides it. The UUID may be either an EFI/GPT UUID, or refer to an MSDOS partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero- filled hex representation of the 32-bit "NT disk signature", and PP is a zero-filled hex representation of the 1-based partition number. 6) PARTUUID=/PARTNROFF= to select a partition in relation to a partition with a known unique id. 7) : major and minor number of the device separated by a colon. NOTE that, both Kconfig and module parameters can configure pstore/blk, but module parameters have priority over Kconfig. config PSTORE_BLK_KMSG_SIZE int "Size in Kbytes of kmsg dump log to store" depends on PSTORE_BLK default 64 help This just sets size of kmsg dump (oops, panic, etc) log for pstore/blk. The size is in KB and must be a multiple of 4. NOTE that, both Kconfig and module parameters can configure pstore/blk, but module parameters have priority over Kconfig. config PSTORE_BLK_MAX_REASON int "Maximum kmsg dump reason to store" depends on PSTORE_BLK default 2 help The maximum reason for kmsg dumps to store. The default is 2 (KMSG_DUMP_OOPS), see include/linux/kmsg_dump.h's enum kmsg_dump_reason for more details. NOTE that, both Kconfig and module parameters can configure pstore/blk, but module parameters have priority over Kconfig. config PSTORE_BLK_PMSG_SIZE int "Size in Kbytes of pmsg to store" depends on PSTORE_BLK depends on PSTORE_PMSG default 64 help This just sets size of pmsg (pmsg_size) for pstore/blk. The size is in KB and must be a multiple of 4. NOTE that, both Kconfig and module parameters can configure pstore/blk, but module parameters have priority over Kconfig. config PSTORE_BLK_CONSOLE_SIZE int "Size in Kbytes of console log to store" depends on PSTORE_BLK depends on PSTORE_CONSOLE default 64 help This just sets size of console log (console_size) to store via pstore/blk. The size is in KB and must be a multiple of 4. NOTE that, both Kconfig and module parameters can configure pstore/blk, but module parameters have priority over Kconfig. config PSTORE_BLK_FTRACE_SIZE int "Size in Kbytes of ftrace log to store" depends on PSTORE_BLK depends on PSTORE_FTRACE default 64 help This just sets size of ftrace log (ftrace_size) for pstore/blk. The size is in KB and must be a multiple of 4. NOTE that, both Kconfig and module parameters can configure pstore/blk, but module parameters have priority over Kconfig.