[U-Boot] [PATCH 2/2] nand_spl: read environment early, when booting from NAND using nand_spl

[Guennadi Liakhovetski]

Currently, when booting from NAND using nand_spl, in the beginning the default
environment is used until later in boot process the dynamic environment is read
out. This way environment variables that must be interpreted early, like the
baudrate or "silent", cannot be modified dynamically and remain at their
default values. Fix this problem by reading out main and redundand (if used)
copies of the environment in the nand_spl code.

Signed-off-by: Guennadi Liakhovetski <lg at denx.de>
---
 README                     |    6 ++++++
 common/env_nand.c          |   43 ++++++++++++++++++++++++++++++-------------
 include/configs/smdk6400.h |    3 +++
 nand_spl/nand_boot.c       |   10 ++++++++++
 4 files changed, 49 insertions(+), 13 deletions(-)

diff --git a/README b/README
index 142dbcc..060b676 100644
--- a/README
+++ b/README
@@ -2422,6 +2422,12 @@ to save the current settings.
 	to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
 	the NAND devices block size.
 
+- CONFIG_NAND_ENV_DST
+
+	Defines address in RAM to which the nand_spl code should copy the
+	environment. If redundant environment is used, it will be copied to
+	CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
+
 - CONFIG_SYS_SPI_INIT_OFFSET
 
 	Defines offset to the initial SPI buffer area in DPRAM. The
diff --git a/common/env_nand.c b/common/env_nand.c
index 21bce25..90a1c45 100644
--- a/common/env_nand.c
+++ b/common/env_nand.c
@@ -68,9 +68,11 @@ extern int default_environment_size;
 char * env_name_spec = "NAND";
 
 
-#ifdef ENV_IS_EMBEDDED
+#if defined(ENV_IS_EMBEDDED)
 extern uchar environment[];
 env_t *env_ptr = (env_t *)(&environment[0]);
+#elif defined(CONFIG_NAND_ENV_DST)
+env_t *env_ptr = (env_t *)CONFIG_NAND_ENV_DST;
 #else /* ! ENV_IS_EMBEDDED */
 env_t *env_ptr = 0;
 #endif /* ENV_IS_EMBEDDED */
@@ -102,23 +104,33 @@ uchar env_get_char_spec (int index)
  */
 int env_init(void)
 {
-#if defined(ENV_IS_EMBEDDED)
+#if defined(ENV_IS_EMBEDDED) || defined(CONFIG_NAND_ENV_DST)
 	int crc1_ok = 0, crc2_ok = 0;
-	env_t *tmp_env1, *tmp_env2;
+	env_t *tmp_env1;
+
+#ifdef CONFIG_ENV_OFFSET_REDUND
+	env_t *tmp_env2;
 
-	tmp_env1 = env_ptr;
 	tmp_env2 = (env_t *)((ulong)env_ptr + CONFIG_ENV_SIZE);
+	crc2_ok = (crc32(0, tmp_env2->data, ENV_SIZE) == tmp_env2->crc);
+#endif
+
+	tmp_env1 = env_ptr;
 
 	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)
+	if (!crc1_ok && !crc2_ok) {
+		gd->env_addr  = 0;
 		gd->env_valid = 0;
-	else if(crc1_ok && !crc2_ok)
+
+		return 0;
+	} else if (crc1_ok && !crc2_ok) {
 		gd->env_valid = 1;
-	else if(!crc1_ok && crc2_ok)
+	}
+#ifdef CONFIG_ENV_OFFSET_REDUND
+	else if (!crc1_ok && crc2_ok) {
 		gd->env_valid = 2;
-	else {
+	} else {
 		/* both ok - check serial */
 		if(tmp_env1->flags == 255 && tmp_env2->flags == 0)
 			gd->env_valid = 2;
@@ -132,14 +144,19 @@ int env_init(void)
 			gd->env_valid = 1;
 	}
 
+	if (gd->env_valid == 2)
+		env_ptr = tmp_env2;
+	else
+#endif
 	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)env_ptr->data;
+
+#else /* ENV_IS_EMBEDDED || CONFIG_NAND_ENV_DST */
 	gd->env_addr  = (ulong)&default_environment[0];
 	gd->env_valid = 1;
-#endif /* ENV_IS_EMBEDDED */
+#endif /* ENV_IS_EMBEDDED || CONFIG_NAND_ENV_DST */
 
 	return (0);
 }
diff --git a/include/configs/smdk6400.h b/include/configs/smdk6400.h
index cac58cf..018f576 100644
--- a/include/configs/smdk6400.h
+++ b/include/configs/smdk6400.h
@@ -209,6 +209,9 @@
 /* total memory available to uboot */
 #define CONFIG_SYS_UBOOT_SIZE		(1024 * 1024)
 
+/* Put environment copies after the end of U-Boot owned RAM */
+#define CONFIG_NAND_ENV_DST	(CONFIG_SYS_UBOOT_BASE + CONFIG_SYS_UBOOT_SIZE)
+
 #ifdef CONFIG_ENABLE_MMU
 #define CONFIG_SYS_MAPPED_RAM_BASE	0xc0000000
 #define CONFIG_BOOTCOMMAND	"nand read 0xc0018000 0x60000 0x1c0000;" \
diff --git a/nand_spl/nand_boot.c b/nand_spl/nand_boot.c
index c7eadad..be2e69c 100644
--- a/nand_spl/nand_boot.c
+++ b/nand_spl/nand_boot.c
@@ -246,6 +246,16 @@ void nand_boot(void)
 	ret = nand_load(&nand_info, CONFIG_SYS_NAND_U_BOOT_OFFS, CONFIG_SYS_NAND_U_BOOT_SIZE,
 			(uchar *)CONFIG_SYS_NAND_U_BOOT_DST);
 
+#ifdef CONFIG_NAND_ENV_DST
+	nand_load(&nand_info, CONFIG_ENV_OFFSET, CONFIG_ENV_SIZE,
+		  (uchar *)CONFIG_NAND_ENV_DST);
+
+#ifdef CONFIG_ENV_OFFSET_REDUND
+	nand_load(&nand_info, CONFIG_ENV_OFFSET_REDUND, CONFIG_ENV_SIZE,
+		  (uchar *)CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE);
+#endif
+#endif
+
 	if (nand_chip.select_chip)
 		nand_chip.select_chip(&nand_info, -1);
 
-- 
1.6.2.4