- Grammar fixes - Clarify explanations
Signed-off-by: Michael Opdenacker michael.opdenacker@bootlin.com --- doc/README.bootcount | 34 ++++++++++++++++++---------------- drivers/bootcount/Kconfig | 10 +++++----- 2 files changed, 23 insertions(+), 21 deletions(-)
diff --git a/doc/README.bootcount b/doc/README.bootcount index b1c22905c6..f6c5f82f98 100644 --- a/doc/README.bootcount +++ b/doc/README.bootcount @@ -3,14 +3,16 @@ Boot Count Limit ================
+This is enabled by CONFIG_BOOTCOUNT_LIMIT. + This allows to detect multiple failed attempts to boot Linux.
-After a power-on reset, "bootcount" variable will be initialized with 1, and +After a power-on reset, the "bootcount" variable will be initialized to 1, and each reboot will increment the value by 1.
If, after a reboot, the new value of "bootcount" exceeds the value of "bootlimit", then instead of the standard boot action (executing the contents of -"bootcmd") an alternate boot action will be performed, and the contents of +"bootcmd"), an alternate boot action will be performed, and the contents of "altbootcmd" will be executed.
If the variable "bootlimit" is not defined in the environment, the Boot Count @@ -18,18 +20,18 @@ Limit feature is disabled. If it is enabled, but "altbootcmd" is not defined, then U-Boot will drop into interactive mode and remain there.
It is the responsibility of some application code (typically a Linux -application) to reset the variable "bootcount", thus allowing for more boot -cycles. +application) to reset the variable "bootcount" to 0 when the system booted +successfully, thus allowing for more boot cycles.
-BOOTCOUNT_EXT -------------- +CONFIG_BOOTCOUNT_EXT +--------------------
This adds support for maintaining boot count in a file on an EXT filesystem. -The file to use is define by: +The file to use is defined by:
-SYS_BOOTCOUNT_EXT_INTERFACE -SYS_BOOTCOUNT_EXT_DEVPART -SYS_BOOTCOUNT_EXT_NAME +CONFIG_SYS_BOOTCOUNT_EXT_INTERFACE +CONFIG_SYS_BOOTCOUNT_EXT_DEVPART +CONFIG_SYS_BOOTCOUNT_EXT_NAME
The format of the file is:
@@ -42,10 +44,10 @@ u8 bootcount u8 upgrade_available ==== =================
-To prevent unattended usage of "altbootcmd" the "upgrade_available" variable is +To prevent unattended usage of "altbootcmd", the "upgrade_available" variable is used. -If "upgrade_available" is 0, "bootcount" is not saved, if "upgrade_available" is -1 "bootcount" is save. -So the Userspace Application must set the "upgrade_available" and "bootcount" -variables to 0, if a boot was successfully. -This also prevents writes on all reboots. +If "upgrade_available" is 0, "bootcount" is not saved. +If "upgrade_available" is 1, "bootcount" is saved. +So a userspace application should take care of setting the "upgrade_available" +and "bootcount" variables to 0, if the system boots successfully. +This also avoids writing the "bootcount" information on all reboots. diff --git a/drivers/bootcount/Kconfig b/drivers/bootcount/Kconfig index 607027c968..65c052fc2e 100644 --- a/drivers/bootcount/Kconfig +++ b/drivers/bootcount/Kconfig @@ -68,15 +68,15 @@ config BOOTCOUNT_ENV "bootcount" is stored in the environment. To prevent a saveenv on all reboots, the environment variable "upgrade_available" is used. If "upgrade_available" is - 0, "bootcount" is always 0, if "upgrade_available" is - 1 "bootcount" is incremented in the environment. + 0, "bootcount" is always 0. If "upgrade_available" is 1, + "bootcount" is incremented in the environment. So the Userspace Application must set the "upgrade_available" - and "bootcount" variable to 0, if a boot was successfully. + and "bootcount" variables to 0, if the system booted successfully.
config BOOTCOUNT_RAM bool "Boot counter in RAM" help - Store the bootcount in DRAM protected against against bit errors + Store the bootcount in DRAM protected against bit errors due to short power loss or holding a system in RESET.
config BOOTCOUNT_I2C @@ -166,7 +166,7 @@ config BOOTCOUNT_BOOTLIMIT help Set the Maximum number of reboot cycles allowed without the boot counter being cleared. - If set to 0 do not set a boot limit in the environment. + If set to 0, do not set a boot limit in the environment.
config BOOTCOUNT_ALEN int "I2C address length"