Hi,
Am 05.10.2022 um 10:33 schrieb Jan Kiszka:
From: Jan Kiszka <jan.kis...@siemens.com>
This completes what 890feecaab72 started by selecting ENV_APPEND and
ENV_IS_NOWHERE and by moving this driver to top if the list. This
ensures that load operations pick up both the default env and the
permitted parts of the next-prio location. When writing though, we must
use the regular ordering.
With this change, boards only need to define the list of writable
variables but no longer have to provide a custom env_get_location
implementation.
CC: Joe Hershberger <joe.hershber...@ni.com>
CC: Marek Vasut <ma...@denx.de>
Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
---
env/Kconfig | 2 ++
env/env.c | 22 ++++++++++++++++++++++
2 files changed, 24 insertions(+)
diff --git a/env/Kconfig b/env/Kconfig
index 24111dfaf47..05b5fbf17d1 100644
--- a/env/Kconfig
+++ b/env/Kconfig
@@ -715,6 +715,8 @@ config ENV_APPEND
config ENV_WRITEABLE_LIST
bool "Permit write access only to listed variables"
+ select ENV_IS_NOWHERE
+ select ENV_APPEND
help
If defined, only environment variables which explicitly set the 'w'
writeable flag can be written and modified at runtime. No variables
diff --git a/env/env.c b/env/env.c
index 69848fb0608..d0649f9540d 100644
--- a/env/env.c
+++ b/env/env.c
@@ -133,6 +133,28 @@ __weak enum env_location arch_env_get_location(enum
env_operation op, int prio)
if (prio >= ARRAY_SIZE(env_locations))
return ENVL_UNKNOWN;
+ if (IS_ENABLED(CONFIG_ENV_WRITEABLE_LIST)) {
+ /*
+ * In writeable-list mode, ENVL_NOWHERE gains highest prio by
+ * virtually injecting it at prio 0.
+ */
+ if (prio == 0) {
+ /*
+ * Avoid the injection for write operations as that
+ * would block it.
+ */
+ if (op != ENVOP_SAVE && op != ENVOP_ERASE)
+ return ENVL_NOWHERE;
Is it consensus now to use ENVL_NOWHERE as synonym for default
environment? If I remember correct this was rejected in the past and
ENVL_NOWHERE should only be used if no enviroment is available.
Why don't you call env_set_default(NULL, 0) in env_load() before
env_driver_lookup()?
+ } else {
+ /*
+ * always subtract 1, also for writing because
+ * env_load_prio, which is used for writing, was
+ * initialized with that offset.
+ */
+ prio--;
+ }
+ }
+
return env_locations[prio];
}
Regards
Stefan
