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authorMartyn Welch <[email protected]>2024-10-09 14:15:40 +0100
committerTom Rini <[email protected]>2024-10-15 10:24:27 -0600
commit3809fd35a5dbdbd62043ba0a72c3f37f58e69f9d (patch)
treeb7a3cbf6da74d598d2e8529aaf18a30ce3ccba57 /doc/usage/cmd
parent8ba82a91b3aa615fb6148ecfa2af4e91a28659ae (diff)
bootstd: Add command to enable setting of bootmeth specific properties
We have previously added logic to allow a "fallback" option to be specified in the extlinux configuration. Provide a command that allows us to set this as the preferred default option when booting. Combined with the bootcount functionality, this allows the "altbootcmd" to provide a means of falling back to a previously known good state after a failed update. For example, if "bootcmd" is set to: bootflow scan -lb We would set "altbootcmd" to: bootmeth set extlinux fallback 1; bootflow scan -lb Causing the boot process to boot from the fallback option. Reviewed-by: Simon Glass <[email protected]> Signed-off-by: Martyn Welch <[email protected]>
Diffstat (limited to 'doc/usage/cmd')
-rw-r--r--doc/usage/cmd/bootmeth.rst38
1 files changed, 37 insertions, 1 deletions
diff --git a/doc/usage/cmd/bootmeth.rst b/doc/usage/cmd/bootmeth.rst
index c3d2ec1574b..4f899d92b2e 100644
--- a/doc/usage/cmd/bootmeth.rst
+++ b/doc/usage/cmd/bootmeth.rst
@@ -12,7 +12,8 @@ Synopsis
::
bootmeth list [-a] - list selected bootmeths (-a for all)
- bootmeth order "[<bm> ...]" - select the order of bootmeths\n"
+ bootmeth order "[<bm> ...]" - select the order of bootmeths
+ bootmeth set <bootmeth> <property> <value> - set optional property
Description
@@ -112,3 +113,38 @@ which are not::
- 4 efi_mgr EFI bootmgr flow
----- --- ------------------ ------------------
(5 bootmeths)
+
+
+bootmeth set
+~~~~~~~~~~~~
+
+Allows setting of bootmeth specific configuration. This allows finer grain
+control over the boot process in specific instances.
+
+
+Supported Configuration Options
+-------------------------------
+
+The following configuration options are currently supported:
+
+======== =================== ====== ===============================
+Property Supported Bootmeths Values Description
+======== =================== ====== ===============================
+fallback extlinux 0 | 1 Enable or disable fallback path
+======== =================== ====== ===============================
+
+
+Bootmeth set Example
+--------------------
+
+With the bootcount functionality enabled, when the bootlimit is reached, the
+`altbootcmd` environment variable lists the command used for booting rather
+than `bootcmd`. We can set the fallback configuration to cause the fallback
+boot option to be preferred, to revert to a previous known working boot option
+after a failed update for example. So if `bootcmd` is set to::
+
+ bootflow scan -lb
+
+We would set "altbootcmd" to::
+
+ bootmeth set extlinux fallback 1; bootflow scan -lb