Add NAND environment support for PPC440EPx Sequoia NAND boot config
Patch by Stefan Roese, 12 Sep 2006
diff --git a/common/env_nand.c b/common/env_nand.c
index 0a05b09..67c4a4e 100644
--- a/common/env_nand.c
+++ b/common/env_nand.c
@@ -2,7 +2,7 @@
  * (C) Copyright 2004
  * Jian Zhang, Texas Instruments, jzhang@ti.com.
 
- * (C) Copyright 2000-2004
+ * (C) Copyright 2000-2006
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
  * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
@@ -76,7 +76,9 @@
 
 
 /* local functions */
+#if !defined(ENV_IS_EMBEDDED)
 static void use_default(void);
+#endif
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -91,11 +93,55 @@
  * Mark it OK for now. env_relocate() in env_common.c
  * will call our relocate function which will does
  * the real validation.
+ *
+ * When using a NAND boot image (like sequoia_nand), the environment
+ * can be embedded or attached to the U-Boot image in NAND flash. This way
+ * the SPL loads not only the U-Boot image from NAND but also the
+ * environment.
  */
 int env_init(void)
 {
+#if defined(ENV_IS_EMBEDDED)
+	ulong total;
+	int crc1_ok = 0, crc2_ok = 0;
+	env_t *tmp_env1, *tmp_env2;
+
+	total = CFG_ENV_SIZE;
+
+	tmp_env1 = env_ptr;
+	tmp_env2 = (env_t *)((ulong)env_ptr + CFG_ENV_SIZE);
+
+	crc1_ok = (crc32(0, tmp_env1->data, ENV_SIZE) == tmp_env1->crc);
+	crc2_ok = (crc32(0, tmp_env2->data, ENV_SIZE) == tmp_env2->crc);
+
+	if (!crc1_ok && !crc2_ok)
+		gd->env_valid = 0;
+	else if(crc1_ok && !crc2_ok)
+		gd->env_valid = 1;
+	else if(!crc1_ok && crc2_ok)
+		gd->env_valid = 2;
+	else {
+		/* both ok - check serial */
+		if(tmp_env1->flags == 255 && tmp_env2->flags == 0)
+			gd->env_valid = 2;
+		else if(tmp_env2->flags == 255 && tmp_env1->flags == 0)
+			gd->env_valid = 1;
+		else if(tmp_env1->flags > tmp_env2->flags)
+			gd->env_valid = 1;
+		else if(tmp_env2->flags > tmp_env1->flags)
+			gd->env_valid = 2;
+		else /* flags are equal - almost impossible */
+			gd->env_valid = 1;
+	}
+
+	if (gd->env_valid == 1)
+		env_ptr = tmp_env1;
+	else if (gd->env_valid == 2)
+		env_ptr = tmp_env2;
+#else /* ENV_IS_EMBEDDED */
 	gd->env_addr  = (ulong)&default_environment[0];
 	gd->env_valid = 1;
+#endif /* ENV_IS_EMBEDDED */
 
 	return (0);
 }
@@ -236,6 +282,7 @@
 }
 #endif /* CFG_ENV_OFFSET_REDUND */
 
+#if !defined(ENV_IS_EMBEDDED)
 static void use_default()
 {
 	puts ("*** Warning - bad CRC or NAND, using default environment\n\n");
@@ -253,5 +300,6 @@
 	gd->env_valid = 1;
 
 }
+#endif
 
 #endif /* CFG_ENV_IS_IN_NAND */
diff --git a/common/environment.c b/common/environment.c
index 81471ce..19bdeb0 100644
--- a/common/environment.c
+++ b/common/environment.c
@@ -60,7 +60,8 @@
      defined(CONFIG_RRVISION)	|| \
      defined(CONFIG_TRAB)   	|| \
      defined(CONFIG_PPCHAMELEONEVB) || \
-     defined(CONFIG_M5271EVB))	&& \
+     defined(CONFIG_M5271EVB)	|| \
+     defined(CONFIG_NAND_U_BOOT))	&& \
      defined(ENV_CRC) /* Environment embedded in U-Boot .ppcenv section */
 /* XXX - This only works with GNU C */
 #  define __PPCENV__ __attribute__ ((section(".ppcenv")))