[U-Boot] [PATCH v4 2/7] env: unify logic to check and apply changes
Gerlando Falauto
gerlando.falauto at keymile.com
Fri Aug 24 12:11:37 CEST 2012
The logic of checking special parameters (e.g. baudrate, stdin, stdout,
for a valid value and/or whether can be overwritten) and applying the
new value to the running system is now all within a single function
env_check_apply() which can be called whenever changes are made
to the environment, no matter if by set, default or import.
With this patch env_check_apply() is only called by "env set",
retaining previous behavior.
Signed-off-by: Gerlando Falauto <gerlando.falauto at keymile.com>
---
common/cmd_nvedit.c | 141 +++++++++++++++++++++++++++++++++------------------
include/search.h | 3 +-
2 files changed, 94 insertions(+), 50 deletions(-)
diff --git a/common/cmd_nvedit.c b/common/cmd_nvedit.c
index b8c7676..2f5dcbc 100644
--- a/common/cmd_nvedit.c
+++ b/common/cmd_nvedit.c
@@ -198,31 +198,19 @@ static int do_env_grep(cmd_tbl_t *cmdtp, int flag,
#endif
/*
- * Set a new environment variable,
- * or replace or delete an existing one.
+ * Perform consistency checking before setting, replacing, or deleting an
+ * environment variable, then (if successful) apply the changes to internals so
+ * to make them effective. Code for this function was taken out of
+ * _do_env_set(), which now calls it instead.
+ * Returns 0 in case of success, 1 in case of failure.
+ * When (flag & H_FORCE) is set, do not print out any error message and force
+ * overwriting of write-once variables.
*/
-int _do_env_set(int flag, int argc, char * const argv[])
+
+int env_check_apply(const char *name, const char *oldval,
+ const char *newval, int flag)
{
- int i, len;
int console = -1;
- char *name, *value, *s;
- ENTRY e, *ep;
-
- name = argv[1];
-
- if (strchr(name, '=')) {
- printf("## Error: illegal character '=' in variable name"
- "\"%s\"\n", name);
- return 1;
- }
-
- env_id++;
- /*
- * search if variable with this name already exists
- */
- e.key = name;
- e.data = NULL;
- hsearch_r(e, FIND, &ep, &env_htab);
/* Check for console redirection */
if (strcmp(name, "stdin") == 0)
@@ -233,59 +221,75 @@ int _do_env_set(int flag, int argc, char * const argv[])
console = stderr;
if (console != -1) {
- if (argc < 3) { /* Cannot delete it! */
- printf("Can't delete \"%s\"\n", name);
+ if ((newval == NULL) || (*newval == '\0')) {
+ /* We cannot delete stdin/stdout/stderr */
+ if ((flag & H_FORCE) == 0)
+ printf("Can't delete \"%s\"\n", name);
return 1;
}
#ifdef CONFIG_CONSOLE_MUX
- if (iomux_doenv(console, argv[2]))
+ if (iomux_doenv(console, newval))
return 1;
#else
/* Try assigning specified device */
- if (console_assign(console, argv[2]) < 0)
+ if (console_assign(console, newval) < 0)
return 1;
#ifdef CONFIG_SERIAL_MULTI
- if (serial_assign(argv[2]) < 0)
+ if (serial_assign(newval) < 0)
return 1;
#endif
#endif /* CONFIG_CONSOLE_MUX */
}
/*
- * Some variables like "ethaddr" and "serial#" can be set only
- * once and cannot be deleted; also, "ver" is readonly.
+ * Some variables like "ethaddr" and "serial#" can be set only once and
+ * cannot be deleted, unless CONFIG_ENV_OVERWRITE is defined.
*/
- if (ep) { /* variable exists */
#ifndef CONFIG_ENV_OVERWRITE
+ if (oldval != NULL && /* variable exists */
+ (flag & H_FORCE) == 0) { /* and we are not forced */
if (strcmp(name, "serial#") == 0 ||
(strcmp(name, "ethaddr") == 0
#if defined(CONFIG_OVERWRITE_ETHADDR_ONCE) && defined(CONFIG_ETHADDR)
- && strcmp(ep->data, MK_STR(CONFIG_ETHADDR)) != 0
+ && strcmp(oldval, MK_STR(CONFIG_ETHADDR)) != 0
#endif /* CONFIG_OVERWRITE_ETHADDR_ONCE && CONFIG_ETHADDR */
)) {
printf("Can't overwrite \"%s\"\n", name);
return 1;
}
+ }
#endif
+ /*
+ * When we change baudrate, or we are doing an env default -a
+ * (which will erase all variables prior to calling this),
+ * we want the baudrate to actually change - for real.
+ */
+ if (oldval != NULL || /* variable exists */
+ (flag & H_NOCLEAR) == 0) { /* or env is clear */
/*
* Switch to new baudrate if new baudrate is supported
*/
if (strcmp(name, "baudrate") == 0) {
- int baudrate = simple_strtoul(argv[2], NULL, 10);
+ int baudrate = simple_strtoul(newval, NULL, 10);
int i;
for (i = 0; i < N_BAUDRATES; ++i) {
if (baudrate == baudrate_table[i])
break;
}
if (i == N_BAUDRATES) {
- printf("## Baudrate %d bps not supported\n",
- baudrate);
+ if ((flag & H_FORCE) == 0)
+ printf("## Baudrate %d bps not "
+ "supported\n", baudrate);
return 1;
}
+ if (gd->baudrate == baudrate) {
+ /* If unchanged, we just say it's OK */
+ return 0;
+ }
printf("## Switch baudrate to %d bps and"
- "press ENTER ...\n", baudrate);
+ "press ENTER ...\n", baudrate);
udelay(50000);
gd->baudrate = baudrate;
#if defined(CONFIG_PPC) || defined(CONFIG_MCF52x2)
@@ -299,6 +303,59 @@ int _do_env_set(int flag, int argc, char * const argv[])
}
}
+ /*
+ * Some variables should be updated when the corresponding
+ * entry in the environment is changed
+ */
+ if (strcmp(name, "loadaddr") == 0) {
+ load_addr = simple_strtoul(newval, NULL, 16);
+ return 0;
+ }
+#if defined(CONFIG_CMD_NET)
+ else if (strcmp(name, "bootfile") == 0) {
+ copy_filename(BootFile, newval, sizeof(BootFile));
+ return 0;
+ }
+#endif
+ return 0;
+}
+
+/*
+ * Set a new environment variable,
+ * or replace or delete an existing one.
+*/
+int _do_env_set(int flag, int argc, char * const argv[])
+{
+ int i, len;
+ char *name, *value, *s;
+ ENTRY e, *ep;
+
+ name = argv[1];
+ value = argv[2];
+
+ if (strchr(name, '=')) {
+ printf("## Error: illegal character '='"
+ "in variable name \"%s\"\n", name);
+ return 1;
+ }
+
+ env_id++;
+ /*
+ * search if variable with this name already exists
+ */
+ e.key = name;
+ e.data = NULL;
+ hsearch_r(e, FIND, &ep, &env_htab);
+
+ /*
+ * Perform requested checks. Notice how since we are overwriting
+ * a single variable, we need to set H_NOCLEAR
+ */
+ if (env_check_apply(name, ep ? ep->data : NULL, value, H_NOCLEAR)) {
+ debug("check function did not approve, refusing\n");
+ return 1;
+ }
+
/* Delete only ? */
if (argc < 3 || argv[2] == NULL) {
int rc = hdelete_r(name, &env_htab);
@@ -336,20 +393,6 @@ int _do_env_set(int flag, int argc, char * const argv[])
return 1;
}
- /*
- * Some variables should be updated when the corresponding
- * entry in the environment is changed
- */
- if (strcmp(argv[1], "loadaddr") == 0) {
- load_addr = simple_strtoul(argv[2], NULL, 16);
- return 0;
- }
-#if defined(CONFIG_CMD_NET)
- else if (strcmp(argv[1], "bootfile") == 0) {
- copy_filename(BootFile, argv[2], sizeof(BootFile));
- return 0;
- }
-#endif
return 0;
}
diff --git a/include/search.h b/include/search.h
index ef53edb..a4a5ef4 100644
--- a/include/search.h
+++ b/include/search.h
@@ -99,6 +99,7 @@ extern int himport_r(struct hsearch_data *__htab,
int __flag);
/* Flags for himport_r() */
-#define H_NOCLEAR 1 /* do not clear hash table before importing */
+#define H_NOCLEAR (1 << 0) /* do not clear hash table before importing */
+#define H_FORCE (1 << 1) /* overwrite read-only/write-once variables */
#endif /* search.h */
--
1.7.10.4
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