am335x_evm: Add CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG support

We add CONFIG_ENV_VARS_UBOOT_CONFIG,
CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG and CONFIG_BOARD_LATE_INIT to set
the variables and then fdtfile and findfdt to make us of this.  It is
now possible to do 'run findfdt' to have fdtfile be set to the value of
the dtb file to load for the board we are running on.

Signed-off-by: Tom Rini <trini@ti.com>

board/ti/am335x/board.c

@@ -299,6 +299,26 @@ int board_init(void)
 	return 0;
 }
 
+#ifdef CONFIG_BOARD_LATE_INIT
+int board_late_init(void)
+{
+#ifdef CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
+	char safe_string[HDR_NAME_LEN + 1];
+
+	/* Now set variables based on the header. */
+	strncpy(safe_string, (char *)header.name, sizeof(header.name));
+	safe_string[sizeof(header.name)] = 0;
+	setenv("board_name", safe_string);
+
+	strncpy(safe_string, (char *)header.version, sizeof(header.version));
+	safe_string[sizeof(header.version)] = 0;
+	setenv("board_rev", safe_string);
+#endif
+
+	return 0;
+}
+#endif
+
 #ifdef CONFIG_DRIVER_TI_CPSW
 static void cpsw_control(int enabled)
 {

include/configs/am335x_evm.h

@@ -29,6 +29,7 @@
 #define CONFIG_SYS_LONGHELP		/* undef to save memory */
 #define CONFIG_SYS_HUSH_PARSER		/* use "hush" command parser */
 #define CONFIG_SYS_PROMPT		"U-Boot# "
+#define CONFIG_BOARD_LATE_INIT
 #define CONFIG_SYS_NO_FLASH
 #define MACH_TYPE_TIAM335EVM		3589	/* Until the next sync */
 #define CONFIG_MACH_TYPE		MACH_TYPE_TIAM335EVM
@@ -46,11 +47,14 @@
 
 /* set to negative value for no autoboot */
 #define CONFIG_BOOTDELAY		1
+#define CONFIG_ENV_VARS_UBOOT_CONFIG
+#define CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
 #define CONFIG_EXTRA_ENV_SETTINGS \
 	"loadaddr=0x80200000\0" \
 	"fdtaddr=0x80F80000\0" \
 	"rdaddr=0x81000000\0" \
 	"bootfile=/boot/uImage\0" \
+	"fdtfile=\0" \
 	"console=ttyO0,115200n8\0" \
 	"optargs=\0" \
 	"mmcdev=0\0" \
@@ -79,6 +83,13 @@
 	"ramboot=echo Booting from ramdisk ...; " \
 		"run ramargs; " \
 		"bootm ${loadaddr}\0" \
+	"findfdt="\
+		"if test $board_name = A335BONE; then " \
+			"setenv fdtfile am335x-bone.dtb; fi; " \
+		"if test $board_name = A33515BB; then " \
+			"setenv fdtfile am335x-evm.dtb; fi; " \
+		"if test $board_name = A335X_SK; then " \
+			"setenv fdtfile am335x-evmsk.dtb; fi\0" \
 
 #define CONFIG_BOOTCOMMAND \
 	"mmc dev ${mmcdev}; if mmc rescan; then " \