[U-Boot] [RFC, PATCH v4 06/16] env: add variable storage attribute support
AKASHI Takahiro
takahiro.akashi at linaro.org
Wed Jul 17 08:25:15 UTC 2019
If U-Boot environment variable is set to ENV_FLAGS_VARSTORAGE_NON_VOLATILE,
it will be saved at env_save[_ext]().
If U-Boot environment variable is set to
ENV_FLAGS_VARSTORAGE_NON_VOLATILE_AUTOSAVE, it will be saved at
env_set_ext() as well as env_save[_ext]().
Otherwise, it is handled as a temporary variable.
Signed-off-by: AKASHI Takahiro <takahiro.akashi at linaro.org>
---
env/flags.c | 130 +++++++++++++++++++++++++++++++++++++++++++-
include/env_flags.h | 36 +++++++++++-
2 files changed, 164 insertions(+), 2 deletions(-)
diff --git a/env/flags.c b/env/flags.c
index 79dccc05fe27..c1db891a2343 100644
--- a/env/flags.c
+++ b/env/flags.c
@@ -29,6 +29,7 @@
static const char env_flags_vartype_rep[] = "sdxb" ENV_FLAGS_NET_VARTYPE_REPS;
static const char env_flags_varaccess_rep[] = "aroc";
+static const char env_flags_varstorage_rep[] = "vna";
static const int env_flags_varaccess_mask[] = {
0,
ENV_FLAGS_VARACCESS_PREVENT_DELETE |
@@ -57,6 +58,12 @@ static const char * const env_flags_varaccess_names[] = {
"change-default",
};
+static const char * const env_flags_varstorage_names[] = {
+ "volatile",
+ "non-volatile",
+ "non-volatile-autosave",
+};
+
/*
* Print the whole list of available type flags.
*/
@@ -85,6 +92,20 @@ void env_flags_print_varaccess(void)
}
}
+/*
+ * Print the whole list of available storage flags.
+ */
+void env_flags_print_varstorage(void)
+{
+ enum env_flags_varstorage curstorage = (enum env_flags_varstorage)0;
+
+ while (curstorage != env_flags_varstorage_end) {
+ printf("\t%c -\t%s\n", env_flags_varstorage_rep[curstorage],
+ env_flags_varstorage_names[curstorage]);
+ curstorage++;
+ }
+}
+
/*
* Return the name of the type.
*/
@@ -100,6 +121,14 @@ const char *env_flags_get_varaccess_name(enum env_flags_varaccess access)
{
return env_flags_varaccess_names[access];
}
+
+/*
+ * Return the name of the storage.
+ */
+const char *env_flags_get_varstorage_name(enum env_flags_varstorage storage)
+{
+ return env_flags_varstorage_names[storage];
+}
#endif /* CONFIG_CMD_ENV_FLAGS */
/*
@@ -146,6 +175,30 @@ enum env_flags_varaccess env_flags_parse_varaccess(const char *flags)
return env_flags_varaccess_any;
}
+/*
+ * Parse the flags string from a .flags attribute list into the varstorage enum.
+ */
+enum env_flags_varstorage env_flags_parse_varstorage(const char *flags)
+{
+ char *storage;
+
+ if (strlen(flags) <= ENV_FLAGS_VARSTORAGE_LOC)
+ /* for compatibility */
+ return env_flags_varstorage_non_volatile;
+
+ storage = strchr(env_flags_varstorage_rep,
+ flags[ENV_FLAGS_VARSTORAGE_LOC]);
+
+ if (storage)
+ return (enum env_flags_varstorage)
+ (storage - &env_flags_varstorage_rep[0]);
+
+ printf("## Warning: Unknown environment variable storage '%c'\n",
+ flags[ENV_FLAGS_VARSTORAGE_LOC]);
+
+ return env_flags_varstorage_non_volatile;
+}
+
/*
* Parse the binary flags from a hash table entry into the varaccess enum.
*/
@@ -164,6 +217,27 @@ enum env_flags_varaccess env_flags_parse_varaccess_from_binflags(int binflags)
return env_flags_varaccess_any;
}
+/*
+ * Parse the binary flags from a hash table entry into the varstorage enum.
+ */
+enum env_flags_varstorage env_flags_parse_varstorage_from_binflags(int binflags)
+{
+ int bits;
+
+ bits = binflags & ENV_FLAGS_VARSTORAGE_BIN_MASK;
+ if (bits == ENV_FLAGS_VARSTORAGE_VOLATILE)
+ return env_flags_varstorage_volatile;
+ else if (bits == ENV_FLAGS_VARSTORAGE_NON_VOLATILE)
+ return env_flags_varstorage_non_volatile;
+ else if (bits == ENV_FLAGS_VARSTORAGE_NON_VOLATILE_AUTOSAVE)
+ return env_flags_varstorage_non_volatile_autosave;
+
+ printf("Warning: Non-standard storage flags. (0x%x)\n",
+ binflags & ENV_FLAGS_VARSTORAGE_BIN_MASK);
+
+ return env_flags_varstorage_non_volatile;
+}
+
static inline int is_hex_prefix(const char *value)
{
return value[0] == '0' && (value[1] == 'x' || value[1] == 'X');
@@ -336,6 +410,23 @@ enum env_flags_varaccess env_flags_get_varaccess(const char *name)
return env_flags_parse_varaccess(flags);
}
+/*
+ * Look up the storage of a variable directly from the .flags var.
+ */
+enum env_flags_varstorage env_flags_get_storage(const char *name)
+{
+ const char *flags_list = env_get(ENV_FLAGS_VAR);
+ char flags[ENV_FLAGS_ATTR_MAX_LEN + 1];
+
+ if (env_flags_lookup(flags_list, name, flags))
+ return env_flags_varstorage_non_volatile;
+
+ if (strlen(flags) <= ENV_FLAGS_VARSTORAGE_LOC)
+ return env_flags_varstorage_non_volatile;
+
+ return env_flags_parse_varstorage(flags);
+}
+
/*
* Validate that the proposed new value for "name" is valid according to the
* defined flags for that variable, if any.
@@ -402,10 +493,25 @@ int env_flags_validate_env_set_params(char *name, char * const val[], int count)
*/
static int env_parse_flags_to_bin(const char *flags)
{
- int binflags;
+ int binflags = 0;
binflags = env_flags_parse_vartype(flags) & ENV_FLAGS_VARTYPE_BIN_MASK;
binflags |= env_flags_varaccess_mask[env_flags_parse_varaccess(flags)];
+ switch (env_flags_parse_varstorage(flags)) {
+ case env_flags_varstorage_volatile:
+ /* actually no effect */
+ binflags |= ENV_FLAGS_VARSTORAGE_VOLATILE;
+ break;
+ case env_flags_varstorage_non_volatile:
+ binflags |= ENV_FLAGS_VARSTORAGE_NON_VOLATILE;
+ break;
+ case env_flags_varstorage_non_volatile_autosave:
+ binflags |= ENV_FLAGS_VARSTORAGE_NON_VOLATILE_AUTOSAVE;
+ break;
+ case env_flags_varstorage_end:
+ /* makes no sense */
+ break;
+ }
return binflags;
}
@@ -413,6 +519,19 @@ static int env_parse_flags_to_bin(const char *flags)
static int first_call = 1;
static const char *flags_list;
+static int env_flags_default(enum env_context ctx)
+{
+ if (ctx == ENVCTX_UBOOT)
+ return ENV_FLAGS_VARSTORAGE_NON_VOLATILE;
+#ifdef CONFIG_EFI_VARIABLE_USE_ENV
+ else if (ctx == ENVCTX_UEFI)
+ /* explicitly set by caller */
+ return 0;
+#endif
+
+ return 0;
+}
+
/*
* Look for possible flags for a newly added variable
* This is called specifically when the variable did not exist in the hash
@@ -434,6 +553,9 @@ void env_flags_init(ENTRY *var_entry)
/* if any flags were found, set the binary form to the entry */
if (!ret && strlen(flags))
var_entry->flags = env_parse_flags_to_bin(flags);
+ /* TODO: check early? */
+ else if (!var_entry->flags)
+ var_entry->flags = env_flags_default(var_entry->context);
}
/*
@@ -522,6 +644,12 @@ int env_flags_validate(const ENTRY *item, const char *newval, enum env_op op,
}
}
+ /*
+ * TODO: context specific check necessary?
+ * For example, STORAGE_NON_VOLATILE and STORAGE_NON_VOLATILE_AUTOSAVE
+ * must not be mixed in one context.
+ */
+
/* check for access permission */
#ifndef CONFIG_ENV_ACCESS_IGNORE_FORCE
if (flag & H_FORCE)
diff --git a/include/env_flags.h b/include/env_flags.h
index 23744e395c8a..f46528691889 100644
--- a/include/env_flags.h
+++ b/include/env_flags.h
@@ -27,10 +27,18 @@ enum env_flags_varaccess {
env_flags_varaccess_end
};
+enum env_flags_varstorage {
+ env_flags_varstorage_volatile, /* 'v' */
+ env_flags_varstorage_non_volatile, /* 'n' */
+ env_flags_varstorage_non_volatile_autosave, /* 'a' */
+ env_flags_varstorage_end
+};
+
#define ENV_FLAGS_VAR ".flags"
-#define ENV_FLAGS_ATTR_MAX_LEN 2
+#define ENV_FLAGS_ATTR_MAX_LEN 3
#define ENV_FLAGS_VARTYPE_LOC 0
#define ENV_FLAGS_VARACCESS_LOC 1
+#define ENV_FLAGS_VARSTORAGE_LOC 2
#ifndef CONFIG_ENV_FLAGS_LIST_STATIC
#define CONFIG_ENV_FLAGS_LIST_STATIC ""
@@ -85,6 +93,10 @@ void env_flags_print_vartypes(void);
* Print the whole list of available access flags.
*/
void env_flags_print_varaccess(void);
+/*
+ * Print the whole list of available storage flags.
+ */
+void env_flags_print_varstorage(void);
/*
* Return the name of the type.
*/
@@ -93,6 +105,10 @@ const char *env_flags_get_vartype_name(enum env_flags_vartype type);
* Return the name of the access.
*/
const char *env_flags_get_varaccess_name(enum env_flags_varaccess access);
+/*
+ * Return the name of the storage.
+ */
+const char *env_flags_get_varstorage_name(enum env_flags_varstorage storage);
#endif
/*
@@ -103,10 +119,19 @@ enum env_flags_vartype env_flags_parse_vartype(const char *flags);
* Parse the flags string from a .flags attribute list into the varaccess enum.
*/
enum env_flags_varaccess env_flags_parse_varaccess(const char *flags);
+/*
+ * Parse the flags string from a .flags attribute list into the varstorage enum.
+ */
+enum env_flags_varstorage env_flags_parse_varstorage(const char *flags);
/*
* Parse the binary flags from a hash table entry into the varaccess enum.
*/
enum env_flags_varaccess env_flags_parse_varaccess_from_binflags(int binflags);
+/*
+ * Parse the binary flags from a hash table entry into the varstorage enum.
+ */
+enum env_flags_varstorage
+env_flags_parse_varstorage_from_binflags(int binflags);
#ifdef CONFIG_CMD_NET
/*
@@ -124,6 +149,10 @@ enum env_flags_vartype env_flags_get_type(const char *name);
* Look up the access of a variable directly from the .flags var.
*/
enum env_flags_varaccess env_flags_get_access(const char *name);
+/*
+ * Look up the storage of a variable directly from the .flags var.
+ */
+enum env_flags_varstorage env_flags_get_storage(const char *name);
/*
* Validate the newval for its type to conform with the requirements defined by
* its flags (directly looked at the .flags var).
@@ -173,5 +202,10 @@ int env_flags_validate(const ENTRY *item, const char *newval, enum env_op op,
#define ENV_FLAGS_VARACCESS_PREVENT_OVERWR 0x00000020
#define ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR 0x00000040
#define ENV_FLAGS_VARACCESS_BIN_MASK 0x00000078
+#define ENV_FLAGS_VARSTORAGE_VOLATILE 0x00000000
+#define ENV_FLAGS_VARSTORAGE_NON_VOLATILE 0x00000080
+#define ENV_FLAGS_VARSTORAGE_NON_VOLATILE_AUTOSAVE 0x00000100
+#define ENV_FLAGS_VARSTORAGE_RESERVED 0x00000180
+#define ENV_FLAGS_VARSTORAGE_BIN_MASK 0x00000180
#endif /* __ENV_FLAGS_H__ */
--
2.21.0
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