[PATCH] bootcount: clarify documentation

Michael Opdenacker
2022-03-02T15:56:19Z

- 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"
--
2.25.1