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authorMichael Opdenacker <michael.opdenacker@bootlin.com>2022-03-02 18:56:02 +0300
committerHeiko Schocher <hs@denx.de>2022-03-23 09:27:38 +0300
commitfc1383ae2b5ca69e51bee68e4047589a5ee7b386 (patch)
tree131b94ca8a39c5bb58b2b0f34e0ba4654d4df8e2 /doc/README.bootcount
parente3c2042ae7d188e00e48d984e373a2de505d8b77 (diff)
downloadu-boot-fc1383ae2b5ca69e51bee68e4047589a5ee7b386.tar.xz
bootcount: clarify documentation
- Grammar fixes - Clarify explanations Signed-off-by: Michael Opdenacker <michael.opdenacker@bootlin.com> Reviewed-by: Heiko Schocher <hs@denx.de>
Diffstat (limited to 'doc/README.bootcount')
-rw-r--r--doc/README.bootcount34
1 files changed, 18 insertions, 16 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.