mtd: Make mtdparts work with pre-reloc env

The env in UBI needs to look up the mtd partition as part of relocation,
which happens before relocation.  Make the mtdparts code capable of
working on the default env to start with.

The code tries to set values in the env as well, but again, the env
isn't there yet, so add a check to setenv to not allow sets before the
env is relocated.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>

common/cmd_mtdparts.c

@@ -106,6 +106,8 @@
 #include <onenand_uboot.h>
 #endif
 
+DECLARE_GLOBAL_DATA_PTR;
+
 /* special size referring to all the remaining space in a partition */
 #define SIZE_REMAINING		0xFFFFFFFF
 
@@ -1537,6 +1539,7 @@ static int parse_mtdparts(const char *const mtdparts)
 	const char *p = mtdparts;
 	struct mtd_device *dev;
 	int err = 1;
+	char tmp_parts[MTDPARTS_MAXLEN];
 
 	debug("\n---parse_mtdparts---\nmtdparts = %s\n\n", p);
 
@@ -1547,7 +1550,12 @@ static int parse_mtdparts(const char *const mtdparts)
 	}
 
 	/* re-read 'mtdparts' variable, mtd_devices_init may be updating env */
-	p = getenv("mtdparts");
+	if (gd->flags & GD_FLG_ENV_READY) {
+		p = getenv("mtdparts");
+	} else {
+		p = tmp_parts;
+		getenv_f("mtdparts", tmp_parts, MTDPARTS_MAXLEN);
+	}
 
 	if (strncmp(p, "mtdparts=", 9) != 0) {
 		printf("mtdparts variable doesn't start with 'mtdparts='\n");
@@ -1705,6 +1713,7 @@ int mtdparts_init(void)
 	const char *current_partition;
 	int ids_changed;
 	char tmp_ep[PARTITION_MAXLEN];
+	char tmp_parts[MTDPARTS_MAXLEN];
 
 	debug("\n---mtdparts_init---\n");
 	if (!initialized) {
@@ -1718,7 +1727,17 @@ int mtdparts_init(void)
 
 	/* get variables */
 	ids = getenv("mtdids");
-	parts = getenv("mtdparts");
+	/*
+	 * The mtdparts variable tends to be long. If we need to access it
+	 * before the env is relocated, then we need to use our own stack
+	 * buffer.  gd->env_buf will be too small.
+	 */
+	if (gd->flags & GD_FLG_ENV_READY) {
+		parts = getenv("mtdparts");
+	} else {
+		parts = tmp_parts;
+		getenv_f("mtdparts", tmp_parts, MTDPARTS_MAXLEN);
+	}
 	current_partition = getenv("partition");
 
 	/* save it for later parsing, cannot rely on current partition pointer

common/cmd_nvedit.c

@@ -273,6 +273,10 @@ int setenv(const char *varname, const char *varvalue)
 {
 	const char * const argv[4] = { "setenv", varname, varvalue, NULL };
 
+	/* before import into hashtable */
+	if (!(gd->flags & GD_FLG_ENV_READY))
+		return 1;
+
 	if (varvalue == NULL || varvalue[0] == '\0')
 		return _do_env_set(0, 2, (char * const *)argv);
 	else