1# SPDX-License-Identifier: GPL-2.0-only 2config PSTORE 3 tristate "Persistent store support" 4 default n 5 help 6 This option enables generic access to platform level 7 persistent storage via "pstore" filesystem that can 8 be mounted as /dev/pstore. Only useful if you have 9 a platform level driver that registers with pstore to 10 provide the data, so you probably should just go say "Y" 11 (or "M") to a platform specific persistent store driver 12 (e.g. ACPI_APEI on X86) which will select this for you. 13 If you don't have a platform persistent store driver, 14 say N. 15 16config PSTORE_DEFAULT_KMSG_BYTES 17 int "Default kernel log storage space" if EXPERT 18 depends on PSTORE 19 default "10240" 20 help 21 Defines default size of pstore kernel log storage. 22 Can be enlarged if needed, not recommended to shrink it. 23 24config PSTORE_COMPRESS 25 bool "Pstore compression (deflate)" 26 depends on PSTORE 27 select ZLIB_INFLATE 28 select ZLIB_DEFLATE 29 default y 30 help 31 Whether pstore records should be compressed before being written to 32 the backing store. This is implemented using the zlib 'deflate' 33 algorithm, using the library implementation instead of using the full 34 blown crypto API. This reduces the risk of secondary oopses or other 35 problems while pstore is recording panic metadata. 36 37config PSTORE_CONSOLE 38 bool "Log kernel console messages" 39 depends on PSTORE 40 help 41 When the option is enabled, pstore will log all kernel 42 messages, even if no oops or panic happened. 43 44config PSTORE_PMSG 45 bool "Log user space messages" 46 depends on PSTORE 47 select RT_MUTEXES 48 help 49 When the option is enabled, pstore will export a character 50 interface /dev/pmsg0 to log user space messages. On reboot 51 data can be retrieved from /sys/fs/pstore/pmsg-ramoops-[ID]. 52 53 If unsure, say N. 54 55config PSTORE_FTRACE 56 bool "Persistent function tracer" 57 depends on PSTORE 58 depends on FUNCTION_TRACER 59 depends on DEBUG_FS 60 help 61 With this option kernel traces function calls into a persistent 62 ram buffer that can be decoded and dumped after reboot through 63 pstore filesystem. It can be used to determine what function 64 was last called before a reset or panic. 65 66 If unsure, say N. 67 68config PSTORE_RAM 69 tristate "Log panic/oops to a RAM buffer" 70 depends on PSTORE 71 depends on HAS_IOMEM 72 select REED_SOLOMON 73 select REED_SOLOMON_ENC8 74 select REED_SOLOMON_DEC8 75 help 76 This enables panic and oops messages to be logged to a circular 77 buffer in RAM where it can be read back at some later point. 78 79 Note that for historical reasons, the module will be named 80 "ramoops.ko". 81 82 For more information, see Documentation/admin-guide/ramoops.rst. 83 84config PSTORE_ZONE 85 tristate 86 depends on PSTORE 87 help 88 The common layer for pstore/blk (and pstore/ram in the future) 89 to manage storage in zones. 90 91config PSTORE_BLK 92 tristate "Log panic/oops to a block device" 93 depends on PSTORE 94 depends on BLOCK 95 select PSTORE_ZONE 96 default n 97 help 98 This enables panic and oops message to be logged to a block dev 99 where it can be read back at some later point. 100 101 For more information, see Documentation/admin-guide/pstore-blk.rst 102 103 If unsure, say N. 104 105config PSTORE_BLK_BLKDEV 106 string "block device identifier" 107 depends on PSTORE_BLK 108 default "" 109 help 110 Which block device should be used for pstore/blk. 111 112 It accepts the following variants: 113 1) <hex_major><hex_minor> device number in hexadecimal representation, 114 with no leading 0x, for example b302. 115 2) /dev/<disk_name> represents the device name of disk 116 3) /dev/<disk_name><decimal> represents the device name and number 117 of partition - device number of disk plus the partition number 118 4) /dev/<disk_name>p<decimal> - same as the above, this form is 119 used when disk name of partitioned disk ends with a digit. 120 5) PARTUUID=00112233-4455-6677-8899-AABBCCDDEEFF representing the 121 unique id of a partition if the partition table provides it. 122 The UUID may be either an EFI/GPT UUID, or refer to an MSDOS 123 partition using the format SSSSSSSS-PP, where SSSSSSSS is a zero- 124 filled hex representation of the 32-bit "NT disk signature", and PP 125 is a zero-filled hex representation of the 1-based partition number. 126 6) PARTUUID=<UUID>/PARTNROFF=<int> to select a partition in relation 127 to a partition with a known unique id. 128 7) <major>:<minor> major and minor number of the device separated by 129 a colon. 130 131 NOTE that, both Kconfig and module parameters can configure 132 pstore/blk, but module parameters have priority over Kconfig. 133 134config PSTORE_BLK_KMSG_SIZE 135 int "Size in Kbytes of kmsg dump log to store" 136 depends on PSTORE_BLK 137 default 64 138 help 139 This just sets size of kmsg dump (oops, panic, etc) log for 140 pstore/blk. The size is in KB and must be a multiple of 4. 141 142 NOTE that, both Kconfig and module parameters can configure 143 pstore/blk, but module parameters have priority over Kconfig. 144 145config PSTORE_BLK_MAX_REASON 146 int "Maximum kmsg dump reason to store" 147 depends on PSTORE_BLK 148 default 2 149 help 150 The maximum reason for kmsg dumps to store. The default is 151 2 (KMSG_DUMP_OOPS), see include/linux/kmsg_dump.h's 152 enum kmsg_dump_reason for more details. 153 154 NOTE that, both Kconfig and module parameters can configure 155 pstore/blk, but module parameters have priority over Kconfig. 156 157config PSTORE_BLK_PMSG_SIZE 158 int "Size in Kbytes of pmsg to store" 159 depends on PSTORE_BLK 160 depends on PSTORE_PMSG 161 default 64 162 help 163 This just sets size of pmsg (pmsg_size) for pstore/blk. The size is 164 in KB and must be a multiple of 4. 165 166 NOTE that, both Kconfig and module parameters can configure 167 pstore/blk, but module parameters have priority over Kconfig. 168 169config PSTORE_BLK_CONSOLE_SIZE 170 int "Size in Kbytes of console log to store" 171 depends on PSTORE_BLK 172 depends on PSTORE_CONSOLE 173 default 64 174 help 175 This just sets size of console log (console_size) to store via 176 pstore/blk. The size is in KB and must be a multiple of 4. 177 178 NOTE that, both Kconfig and module parameters can configure 179 pstore/blk, but module parameters have priority over Kconfig. 180 181config PSTORE_BLK_FTRACE_SIZE 182 int "Size in Kbytes of ftrace log to store" 183 depends on PSTORE_BLK 184 depends on PSTORE_FTRACE 185 default 64 186 help 187 This just sets size of ftrace log (ftrace_size) for pstore/blk. The 188 size is in KB and must be a multiple of 4. 189 190 NOTE that, both Kconfig and module parameters can configure 191 pstore/blk, but module parameters have priority over Kconfig. 192