Merge patch series "bootstd: rauc: fix doc and info msg to reflect real flow"

Andreas Pretzsch <[email protected]> says:

For the RAUC bootmethod, newly introduced in U-Boot 2025.10, both code
and documentation contain some incorrect (maybe outdated) statements,
so they do not reflect the real behaviour.
This series corrects both the docs and one log_info in the code, to now
reflect the real flow. Beside being visible in the code, all of it was
tested on a real machine.

Despite the very late time in RC cycle, I suggest inclusion before release
of U-Boot 2025.10, as the current statements are simply incorrect. Also I
do not see any risk in these non-functional changes.
Thanks to Martin Schwan for the review and esp. the initial code!

Link: https://lore.kernel.org/r/[email protected]

2 files changed, 15 insertions, 7 deletions

diff --git a/boot/bootmeth_rauc.c b/boot/bootmeth_rauc.c
index 81a73046e83..f5d5a971e87 100644
--- a/boot/bootmeth_rauc.c
+++ b/boot/bootmeth_rauc.c
@@ -18,6 +18,7 @@
 #include <malloc.h>
 #include <mapmem.h>
 #include <string.h>
+#include <linux/stringify.h>
 #include <asm/cache.h>
 
 /* Length of env var "BOOT_*_LEFT" */
@@ -304,7 +305,7 @@ static int find_active_slot(char **slot_name, ulong *slot_tries)
 	if (!slot_found) {
 		if (IS_ENABLED(CONFIG_BOOTMETH_RAUC_RESET_ALL_ZERO_TRIES)) {
 			log_warning("WARNING: No valid slot found\n");
-			log_info("INFO: Resetting boot order and all slot tries\n");
+			log_info("INFO: Resetting all slot tries to " __stringify(CONFIG_BOOTMETH_RAUC_DEFAULT_TRIES) "\n");
 			boot_order_list = str_to_list(CONFIG_BOOTMETH_RAUC_BOOT_ORDER);
 			for (i = 0; boot_order_list[i]; i++) {
 				sprintf(boot_left, "BOOT_%s_LEFT", boot_order_list[i]);
diff --git a/doc/develop/bootstd/rauc.rst b/doc/develop/bootstd/rauc.rst
index b2661d18da4..5afd705dcb1 100644
--- a/doc/develop/bootstd/rauc.rst
+++ b/doc/develop/bootstd/rauc.rst
@@ -21,14 +21,21 @@ with the left one tried first.
 The default number of boot tries of each slot is set by
 ``CONFIG_BOOTMETH_RAUC_DEFAULT_TRIES``.
 
-In case no valid slot can be found and/or all slots have zero tries left, the
-boot order and slot tries are reset to their default values, if
-``CONFIG_BOOTMETH_RAUC_RESET_ALL_ZERO_TRIES`` is enabled. This prevents a system
-from locking up in the bootloader and tries booting again after a specified
-number of tries.
+If ``BOOT_ORDER`` does not exist in environment, it will be created and set to
+``CONFIG_BOOTMETH_RAUC_BOOT_ORDER``.  If any ``BOOT_x_LEFT`` (for example
+``BOOT_A_LEFT`` and/or ``BOOT_B_LEFT``) does not exist in environment, it will
+be created and set to ``CONFIG_BOOTMETH_RAUC_DEFAULT_TRIES``.
+
+If ``CONFIG_BOOTMETH_RAUC_RESET_ALL_ZERO_TRIES`` is enabled, and no valid slot
+is found (all slots in ``BOOT_ORDER`` have ``BOOT_x_LEFT`` set to 0), *all* slot
+tries are reset to their default values.  This prevents a system from locking up
+in the bootloader and tries booting again after a specified number of tries.
+
+If a valid slot is found, its LEFT value in environment is decremented by 1.
 
 The boot script must be located in each boot partition. The bootmeth searches
-for "boot.scr.uimg" first, then "boot.scr" if not found.
+for ``boot.scr`` first, then ``boot.scr.uimg`` if not found. It will search in
+all directories of the bootstd list of prefixes (``"/", "/boot"`` by default).
 
 When the bootflow is booted, the bootmeth sets these environment variables: