include: am654_evm: Establish initial environment for SD card boot

Create a basic U-Boot environment that allows the automatic loading
of a Linux Kernel located at /boot/Image and an associated device tree
blob located at /boot/k3-am654-base-board.dtb from the secondary
partition of an ext4-formatted SD card on the AM654x EVM. Furthermore
the boot.scr and uEnv.txt detection and loading schemes are supported
in a manner already known from other TI platforms.

Note that this is intended to be a starting point to enable initial
board use and will most certainly get extended and refactored as
different boot media become available.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

include/configs/am65x_evm.h

@@ -11,6 +11,7 @@
 
 #include <linux/sizes.h>
 #include <config_distro_bootcmd.h>
+#include <environment/ti/mmc.h>
 
 #define CONFIG_ENV_SIZE			(128 << 10)
 
@@ -28,6 +29,40 @@
 #define CONFIG_SYS_INIT_SP_ADDR         (CONFIG_SPL_TEXT_BASE +	\
 					CONFIG_SYS_K3_NON_SECURE_MSRAM_SIZE - 4)
 
+/* U-Boot general configuration */
+#define EXTRA_ENV_AM65X_BOARD_SETTINGS					\
+	"findfdt="							\
+		"if test $board_name = am65x; then "			\
+			"setenv name_fdt k3-am654-base-board.dtb; "	\
+		"else if test $name_fdt = undefined; then "		\
+			"echo WARNING: Could not determine device tree to use;"\
+		"fi; fi; "						\
+		"setenv fdtfile ${name_fdt}\0"				\
+	"loadaddr=0x80080000\0"						\
+	"fdtaddr=0x82000000\0"						\
+	"name_kern=Image\0"						\
+	"console=ttyS2,115200n8\0"					\
+	"args_all=setenv optargs earlycon=ns16550a,mmio32,0x02800000\0" \
+	"run_kern=booti ${loadaddr} ${rd_spec} ${fdtaddr}\0"
+
+/* U-Boot MMC-specific configuration */
+#define EXTRA_ENV_AM65X_BOARD_SETTINGS_MMC				\
+	"boot=mmc\0"							\
+	"mmcdev=1\0"							\
+	"bootpart=1:2\0"						\
+	"bootdir=/boot\0"						\
+	"rd_spec=-\0"							\
+	"init_mmc=run args_all args_mmc\0"				\
+	"get_fdt_mmc=load mmc ${bootpart} ${fdtaddr} ${bootdir}/${name_fdt}\0" \
+	"get_kern_mmc=load mmc ${bootpart} ${loadaddr} "		\
+		"${bootdir}/${name_kern}\0"
+
+/* Incorporate settings into the U-Boot environment */
+#define CONFIG_EXTRA_ENV_SETTINGS					\
+	DEFAULT_MMC_TI_ARGS						\
+	EXTRA_ENV_AM65X_BOARD_SETTINGS					\
+	EXTRA_ENV_AM65X_BOARD_SETTINGS_MMC
+
 /* Now for the remaining common defines */
 #include <configs/ti_armv7_common.h>