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authorTom Rini <[email protected]>2020-04-24 13:04:38 -0400
committerTom Rini <[email protected]>2020-04-24 13:04:38 -0400
commit18b9c98024ec89e00a57707f07ff6ada06089d26 (patch)
tree60b4659a673d7a9dff309ee0d0b324c242a53cfc /doc
parentb897306341024695d17296efc1f9d83d06368209 (diff)
parent08140dba0f539842d4836afb56fe43a33d8ba045 (diff)
Merge branch '2020-04-24-master-imports'
- Assorted minor bugfixes. - Resync fixdep with Linux v5.7-rc1 - Numerous changes to reduce SPL in various cases including when we have read-only env support. - Allow mkimage to align the header on FIT images to a specific size.
Diffstat (limited to 'doc')
-rw-r--r--doc/README.bootcount51
-rw-r--r--doc/conf.py2
-rwxr-xr-xdoc/sphinx/rstFlatTable.py2
-rw-r--r--doc/uImage.FIT/source_file_format.txt5
4 files changed, 57 insertions, 3 deletions
diff --git a/doc/README.bootcount b/doc/README.bootcount
new file mode 100644
index 00000000000..b1c22905c66
--- /dev/null
+++ b/doc/README.bootcount
@@ -0,0 +1,51 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Boot Count Limit
+================
+
+This allows to detect multiple failed attempts to boot Linux.
+
+After a power-on reset, "bootcount" variable will be initialized with 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
+"altbootcmd" will be executed.
+
+If the variable "bootlimit" is not defined in the environment, the Boot Count
+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.
+
+BOOTCOUNT_EXT
+-------------
+
+This adds support for maintaining boot count in a file on an EXT filesystem.
+The file to use is define by:
+
+SYS_BOOTCOUNT_EXT_INTERFACE
+SYS_BOOTCOUNT_EXT_DEVPART
+SYS_BOOTCOUNT_EXT_NAME
+
+The format of the file is:
+
+==== =================
+type entry
+==== =================
+u8 magic
+u8 version
+u8 bootcount
+u8 upgrade_available
+==== =================
+
+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.
diff --git a/doc/conf.py b/doc/conf.py
index 0772fb6f0c8..8bb27ad9e25 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -37,7 +37,7 @@ needs_sphinx = '1.3'
extensions = ['kerneldoc', 'rstFlatTable', 'kernel_include', 'cdomain', 'kfigure']
# The name of the math extension changed on Sphinx 1.4
-if major == 1 and minor > 3:
+if (major == 1 and minor > 3) or (major > 1):
extensions.append("sphinx.ext.imgmath")
else:
extensions.append("sphinx.ext.pngmath")
diff --git a/doc/sphinx/rstFlatTable.py b/doc/sphinx/rstFlatTable.py
index f9a4b46dbe2..2019a55f6b1 100755
--- a/doc/sphinx/rstFlatTable.py
+++ b/doc/sphinx/rstFlatTable.py
@@ -53,8 +53,6 @@ from docutils.utils import SystemMessagePropagation
# common globals
# ==============================================================================
-# The version numbering follows numbering of the specification
-# (doc/books/kernel-doc-HOWTO).
__version__ = '1.0'
PY3 = sys.version_info[0] == 3
diff --git a/doc/uImage.FIT/source_file_format.txt b/doc/uImage.FIT/source_file_format.txt
index 18d2aedcb73..884a58456f7 100644
--- a/doc/uImage.FIT/source_file_format.txt
+++ b/doc/uImage.FIT/source_file_format.txt
@@ -304,6 +304,11 @@ Normal kernel FIT image has data embedded within FIT structure. U-Boot image
for SPL boot has external data. Existence of 'data-offset' can be used to
identify which format is used.
+For FIT image with external data, it would be better to align each blob of data
+to block(512 byte) for block device, so that we don't need to do the copy when
+read the image data in SPL. Pass '-B 0x200' to mkimage to align the FIT
+structure and data to 512 byte, other values available for other align size.
+
9) Examples
-----------