env: Fix env_load_location

Commit 7d714a24d725 ("env: Support multiple environments") added
static variable env_load_location. When saving environmental
variables, this variable is presumed to have the value set before.
In case the value was set before relocation and U-Boot runs from a
NOR flash, this variable wasn't writable. This causes failure when
saving the environment. To save this location, global data must be
used instead.

Signed-off-by: York Sun <york.sun@nxp.com>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>

env/env.c

@@ -62,8 +62,6 @@ static enum env_location env_locations[] = {
 #endif
 };
 
-static enum env_location env_load_location = ENVL_UNKNOWN;
-
 static bool env_has_inited(enum env_location location)
 {
 	return gd->env_has_init & BIT(location);
@@ -108,11 +106,11 @@ __weak enum env_location env_get_location(enum env_operation op, int prio)
 		if (prio >= ARRAY_SIZE(env_locations))
 			return ENVL_UNKNOWN;
 
-		env_load_location = env_locations[prio];
-		return env_load_location;
+		gd->env_load_location = env_locations[prio];
+		return gd->env_load_location;
 
 	case ENVOP_SAVE:
-		return env_load_location;
+		return gd->env_load_location;
 	}
 
 	return ENVL_UNKNOWN;

include/asm-generic/global_data.h

@@ -51,6 +51,7 @@ typedef struct global_data {
 	unsigned long env_addr;		/* Address  of Environment struct */
 	unsigned long env_valid;	/* Environment valid? enum env_valid */
 	unsigned long env_has_init;	/* Bitmask of boolean of struct env_location offsets */
+	int env_load_location;
 
 	unsigned long ram_top;		/* Top address of RAM used by U-Boot */
 	unsigned long relocaddr;	/* Start address of U-Boot in RAM */

include/environment.h

@@ -188,6 +188,7 @@ enum env_valid {
 };
 
 enum env_location {
+	ENVL_UNKNOWN,
 	ENVL_EEPROM,
 	ENVL_EXT4,
 	ENVL_FAT,
@@ -202,7 +203,6 @@ enum env_location {
 	ENVL_NOWHERE,
 
 	ENVL_COUNT,
-	ENVL_UNKNOWN,
 };
 
 /* value for the various operations we want to perform on the env */