env: Create a location driver for each location

Set up a location driver for each supported environment location. At
present this just points to the global functions and is not used. A
later patch will switch this over to use private functions in each driver.

There are several special cases here in various drivers to handle
peculiarities of certain boards:

1. Some boards define CONFIG_ENV_IS_IN_FAT and CONFIG_SPL_ENV_SUPPORT but
do not actually load the environment in SPL. The env load code was
optimised out before but with the driver, it is not. Therefore a special
case is added to env/fat.c. The correct fix (depending on board testing
might be to disable CONFIG_SPL_ENV_SUPPORT.

2. A similar situations happens with CONFIG_ENV_IS_IN_FLASH. Some boards
do not actually load the environment in SPL, so to reduce code size we
need to drop that code. A similar fix may be possible with these boards,
or it may be possible to adjust the environment CONFIG settings.

Added to the above is that the CONFIG_SPL_ENV_SUPPORT option does not
apply when the environment is in flash.

Obviously the above has been discovered through painful and time-consuming
trial and error. Hopefully board maintainers can take a look and figure
out what is actually needed.

Signed-off-by: Simon Glass <sjg@chromium.org>

env/dataflash.c

@@ -82,3 +82,11 @@ int env_init(void)
 
 	return 0;
 }
+
+U_BOOT_ENV_LOCATION(dataflash) = {
+	.location	= ENVL_DATAFLASH,
+	.get_char	= env_get_char_spec,
+	.load		= env_relocate_spec,
+	.save		= env_save_ptr(saveenv),
+	.init		= env_init,
+};

env/eeprom.c

@@ -243,3 +243,11 @@ int env_init(void)
 	gd->env_valid = ENV_VALID;
 	return 0;
 }
+
+U_BOOT_ENV_LOCATION(eeprom) = {
+	.location	= ENVL_EEPROM,
+	.get_char	= env_get_char_spec,
+	.load		= env_relocate_spec,
+	.save		= env_save_ptr(saveenv),
+	.init		= env_init,
+};

env/ext4.c

@@ -127,3 +127,11 @@ void env_relocate_spec(void)
 err_env_relocate:
 	set_default_env(NULL);
 }
+
+U_BOOT_ENV_LOCATION(ext4) = {
+	.location	= ENVL_EXT4,
+	.get_char	= env_get_char_spec,
+	.load		= env_relocate_spec,
+	.save		= env_save_ptr(saveenv),
+	.init		= env_init,
+};

env/fat.c

@@ -19,6 +19,18 @@
 #include <fat.h>
 #include <mmc.h>
 
+#ifdef CONFIG_SPL_BUILD
+/* TODO(sjg@chromium.org): Figure out why this is needed */
+# if !defined(CONFIG_TARGET_AM335X_EVM) || defined(CONFIG_SPL_OS_BOOT)
+#  define LOADENV
+# endif
+#else
+# define LOADENV
+# if defined(CONFIG_CMD_SAVEENV)
+#  define CMD_SAVEENV
+# endif
+#endif
+
 char *env_name_spec = "FAT";
 
 env_t *env_ptr;
@@ -34,7 +46,7 @@ int env_init(void)
 	return 0;
 }
 
-#ifdef CONFIG_CMD_SAVEENV
+#ifdef CMD_SAVEENV
 int saveenv(void)
 {
 	env_t	env_new;
@@ -72,8 +84,9 @@ int saveenv(void)
 	puts("done\n");
 	return 0;
 }
-#endif /* CONFIG_CMD_SAVEENV */
+#endif /* CMD_SAVEENV */
 
+#ifdef LOADENV
 void env_relocate_spec(void)
 {
 	ALLOC_CACHE_ALIGN_BUFFER(char, buf, CONFIG_ENV_SIZE);
@@ -108,3 +121,16 @@ void env_relocate_spec(void)
 err_env_relocate:
 	set_default_env(NULL);
 }
+#endif /* LOADENV */
+
+U_BOOT_ENV_LOCATION(fat) = {
+	.location	= ENVL_FAT,
+	.get_char	= env_get_char_spec,
+#ifdef LOADENV
+	.load		= env_relocate_spec,
+#endif
+#ifdef CMD_SAVEENV
+	.save		= env_save_ptr(saveenv),
+#endif
+	.init		= env_init,
+};

env/flash.c

@@ -20,10 +20,12 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-#if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_FLASH)
-#define CMD_SAVEENV
-#elif defined(CONFIG_ENV_ADDR_REDUND)
-#error CONFIG_ENV_ADDR_REDUND must have CONFIG_CMD_SAVEENV & CONFIG_CMD_FLASH
+#ifndef CONFIG_SPL_BUILD
+# if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_FLASH)
+#  define CMD_SAVEENV
+# elif defined(CONFIG_ENV_ADDR_REDUND)
+#  error CONFIG_ENV_ADDR_REDUND must have CONFIG_CMD_SAVEENV & CONFIG_CMD_FLASH
+# endif
 #endif
 
 #if defined(CONFIG_ENV_SIZE_REDUND) &&	\
@@ -31,6 +33,18 @@ DECLARE_GLOBAL_DATA_PTR;
 #error CONFIG_ENV_SIZE_REDUND should not be less then CONFIG_ENV_SIZE
 #endif
 
+/* TODO(sjg@chromium.org): Figure out all these special cases */
+#if (!defined(CONFIG_MICROBLAZE) && !defined(CONFIG_ARCH_ZYNQ) && \
+	!defined(CONFIG_TARGET_MCCMON6) && !defined(CONFIG_TARGET_X600) && \
+	!defined(CONFIG_TARGET_EDMINIV2)) || \
+	!defined(CONFIG_SPL_BUILD)
+#define LOADENV
+#endif
+
+#if !defined(CONFIG_TARGET_X600) || !defined(CONFIG_SPL_BUILD)
+#define INITENV
+#endif
+
 char *env_name_spec = "Flash";
 
 #ifdef ENV_IS_EMBEDDED
@@ -58,6 +72,7 @@ static ulong end_addr_new = CONFIG_ENV_ADDR_REDUND + CONFIG_ENV_SECT_SIZE - 1;
 
 
 #ifdef CONFIG_ENV_ADDR_REDUND
+#ifdef INITENV
 int env_init(void)
 {
 	int crc1_ok = 0, crc2_ok = 0;
@@ -101,6 +116,7 @@ int env_init(void)
 
 	return 0;
 }
+#endif
 
 #ifdef CMD_SAVEENV
 int saveenv(void)
@@ -207,6 +223,7 @@ done:
 
 #else /* ! CONFIG_ENV_ADDR_REDUND */
 
+#ifdef INITENV
 int env_init(void)
 {
 	if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
@@ -219,6 +236,7 @@ int env_init(void)
 	gd->env_valid	= 0;
 	return 0;
 }
+#endif
 
 #ifdef CMD_SAVEENV
 int saveenv(void)
@@ -336,3 +354,16 @@ void env_relocate_spec(void)
 
 	env_import((char *)flash_addr, 1);
 }
+
+U_BOOT_ENV_LOCATION(flash) = {
+	.location	= ENVL_FLASH,
+#ifdef LOADENV
+	.load		= env_relocate_spec,
+#endif
+#ifdef CMD_SAVEENV
+	.save		= env_save_ptr(saveenv),
+#endif
+#ifdef INITENV
+	.init		= env_init,
+#endif
+};

env/mmc.c

@@ -324,3 +324,13 @@ err:
 #endif
 }
 #endif /* CONFIG_ENV_OFFSET_REDUND */
+
+U_BOOT_ENV_LOCATION(mmc) = {
+	.location	= ENVL_MMC,
+	.get_char	= env_get_char_spec,
+	.load		= env_relocate_spec,
+#ifndef CONFIG_SPL_BUILD
+	.save		= env_save_ptr(saveenv),
+#endif
+	.init		= env_init,
+};

env/nand.c

@@ -24,7 +24,8 @@
 #include <search.h>
 #include <errno.h>
 
-#if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_NAND)
+#if defined(CONFIG_CMD_SAVEENV) && defined(CONFIG_CMD_NAND) && \
+		!defined(CONFIG_SPL_BUILD)
 #define CMD_SAVEENV
 #elif defined(CONFIG_ENV_OFFSET_REDUND)
 #error CONFIG_ENV_OFFSET_REDUND must have CONFIG_CMD_SAVEENV & CONFIG_CMD_NAND
@@ -394,3 +395,12 @@ void env_relocate_spec(void)
 #endif /* ! ENV_IS_EMBEDDED */
 }
 #endif /* CONFIG_ENV_OFFSET_REDUND */
+
+U_BOOT_ENV_LOCATION(nand) = {
+	.location	= ENVL_NAND,
+	.load		= env_relocate_spec,
+#if defined(CMD_SAVEENV)
+	.save		= env_save_ptr(saveenv),
+#endif
+	.init		= env_init,
+};

env/nowhere.c

@@ -33,3 +33,9 @@ int env_init(void)
 
 	return 0;
 }
+
+U_BOOT_ENV_LOCATION(nowhere) = {
+	.location	= ENVL_NOWHERE,
+	.load		= env_relocate_spec,
+	.init		= env_init,
+};

env/nvram.c

@@ -112,3 +112,13 @@ int env_init(void)
 
 	return 0;
 }
+
+U_BOOT_ENV_LOCATION(nvram) = {
+	.location	= ENVL_NVRAM,
+#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
+	.get_char	= env_get_char_spec,
+#endif
+	.load		= env_relocate_spec,
+	.save		= env_save_ptr(saveenv),
+	.init		= env_init,
+};

env/onenand.c

@@ -114,3 +114,11 @@ int env_init(void)
 
 	return 0;
 }
+
+U_BOOT_ENV_LOCATION(onenand) = {
+	.location	= ENVL_ONENAND,
+	.get_char	= env_get_char_spec,
+	.load		= env_relocate_spec,
+	.save		= env_save_ptr(saveenv),
+	.init		= env_init,
+};

env/remote.c

@@ -56,3 +56,11 @@ void env_relocate_spec(void)
 	env_import((char *)env_ptr, 1);
 #endif
 }
+
+U_BOOT_ENV_LOCATION(remote) = {
+	.location	= ENVL_REMOTE,
+	.get_char	= env_get_char_spec,
+	.load		= env_relocate_spec,
+	.save		= env_save_ptr(saveenv),
+	.init		= env_init,
+};

env/sata.c

@@ -125,3 +125,11 @@ void env_relocate_spec(void)
 
 	env_import(buf, 1);
 }
+
+U_BOOT_ENV_LOCATION(sata) = {
+	.location	= ENVL_ESATA,
+	.get_char	= env_get_char_spec,
+	.load		= env_relocate_spec,
+	.save		= env_save_ptr(saveenv),
+	.init		= env_init,
+};

env/sf.c

@@ -32,9 +32,15 @@
 # define CONFIG_ENV_SPI_MODE	CONFIG_SF_DEFAULT_MODE
 #endif
 
+#ifndef CONFIG_SPL_BUILD
+#define CMD_SAVEENV
+#endif
+
 #ifdef CONFIG_ENV_OFFSET_REDUND
+#ifdef CMD_SAVEENV
 static ulong env_offset		= CONFIG_ENV_OFFSET;
 static ulong env_new_offset	= CONFIG_ENV_OFFSET_REDUND;
+#endif
 
 #define ACTIVE_FLAG	1
 #define OBSOLETE_FLAG	0
@@ -77,6 +83,7 @@ static int setup_flash_device(void)
 }
 
 #if defined(CONFIG_ENV_OFFSET_REDUND)
+#ifdef CMD_SAVEENV
 int saveenv(void)
 {
 	env_t	env_new;
@@ -155,6 +162,7 @@ int saveenv(void)
 
 	return ret;
 }
+#endif /* CMD_SAVEENV */
 
 void env_relocate_spec(void)
 {
@@ -240,6 +248,7 @@ out:
 	free(tmp_env2);
 }
 #else
+#ifdef CMD_SAVEENV
 int saveenv(void)
 {
 	u32	saved_size, saved_offset, sector;
@@ -299,6 +308,7 @@ int saveenv(void)
 
 	return ret;
 }
+#endif /* CMD_SAVEENV */
 
 void env_relocate_spec(void)
 {
@@ -342,3 +352,13 @@ int env_init(void)
 
 	return 0;
 }
+
+U_BOOT_ENV_LOCATION(sf) = {
+	.location	= ENVL_SPI_FLASH,
+	.get_char	= env_get_char_spec,
+	.load		= env_relocate_spec,
+#ifdef CMD_SAVEENV
+	.save		= env_save_ptr(saveenv),
+#endif
+	.init		= env_init,
+};

env/ubi.c

@@ -177,3 +177,11 @@ void env_relocate_spec(void)
 	env_import(buf, 1);
 }
 #endif /* CONFIG_SYS_REDUNDAND_ENVIRONMENT */
+
+U_BOOT_ENV_LOCATION(ubi) = {
+	.location	= ENVL_UBI,
+	.get_char	= env_get_char_spec,
+	.load		= env_relocate_spec,
+	.save		= env_save_ptr(saveenv),
+	.init		= env_init,
+};

include/environment.h

@@ -204,6 +204,76 @@ enum env_valid {
 	ENV_REDUND,	/* Redundant environment is valid */
 };
 
+enum env_location {
+	ENVL_DATAFLASH,
+	ENVL_EEPROM,
+	ENVL_EXT4,
+	ENVL_FAT,
+	ENVL_FLASH,
+	ENVL_MMC,
+	ENVL_NAND,
+	ENVL_NVRAM,
+	ENVL_ONENAND,
+	ENVL_REMOTE,
+	ENVL_SPI_FLASH,
+	ENVL_UBI,
+	ENVL_NOWHERE,
+
+	ENVL_COUNT,
+	ENVL_UNKNOWN,
+};
+
+struct env_driver {
+	enum env_location location;
+
+	/**
+	 * get_char() - Read a character from the environment
+	 *
+	 * This method is optional. If not provided, a default implementation
+	 * will read from gd->env_addr.
+	 *
+	 * @index: Index of character to read (0=first)
+	 * @return character read
+	 */
+	unsigned char (*get_char)(int index);
+
+	/**
+	 * load() - Load the environment from storage
+	 *
+	 * This method is optional. If not provided, no environment will be
+	 * loaded.
+	 */
+	void (*load)(void);
+
+	/**
+	 * save() - Save the environment to storage
+	 *
+	 * This method is required for 'saveenv' to work.
+	 *
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*save)(void);
+
+	/**
+	 * init() - Set up the initial pre-relocation environment
+	 *
+	 * This method is optional.
+	 *
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*init)(void);
+};
+
+/* Declare a new environment location driver */
+#define U_BOOT_ENV_LOCATION(__name)					\
+	ll_entry_declare(struct env_driver, __name, env_driver)
+
+#ifdef CONFIG_CMD_SAVEENV
+#define env_save_ptr(x) x
+#else
+#define env_save_ptr(x) NULL
+#endif
+
 extern struct hsearch_data env_htab;
 
 /* Function that returns a character from the environment */