adding saveenv-command for bananapi r2

bananapi r2 can be booted from sd-card and emmc
saving the environment have to choose the storage
from which the device has booted

also the offset is set to 1MB to make sure env is written
to block "user data area" between uboot and first partition

https://www.fw-web.de/dokuwiki/lib/exe/fetch.php?cache=&media=bpi-r2:boot-structure.png

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>

board/mediatek/mt7623/mt7623_rfb.c

@@ -14,3 +14,22 @@ int board_init(void)
 
 	return 0;
 }
+
+int mmc_get_boot_dev(void)
+{
+	int g_mmc_devid = -1;
+	char *uflag = (char *)0x81DFFFF0;
+	if (strncmp(uflag,"eMMC",4)==0) {
+		g_mmc_devid = 0;
+		printf("Boot From Emmc(id:%d)\n\n", g_mmc_devid);
+	} else {
+		g_mmc_devid = 1;
+		printf("Boot From SD(id:%d)\n\n", g_mmc_devid);
+	}
+	return g_mmc_devid;
+}
+
+int mmc_get_env_dev(void)
+{
+	return mmc_get_boot_dev();
+}

configs/mt7623n_bpir2_defconfig

@@ -29,6 +29,7 @@ CONFIG_CMD_FS_GENERIC=y
 CONFIG_OF_SEPARATE=y
 CONFIG_DEFAULT_DEVICE_TREE="mt7623n-bananapi-bpi-r2"
 CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_ENV_IS_IN_MMC=y
 CONFIG_REGMAP=y
 CONFIG_SYSCON=y
 # CONFIG_BLOCK_CACHE is not set

include/configs/mt7623.h

@@ -58,4 +58,7 @@
 #define CONFIG_IPADDR			192.168.1.1
 #define CONFIG_SERVERIP			192.168.1.2
 
+#define CONFIG_SYS_MMC_ENV_DEV		0
+#define CONFIG_ENV_OFFSET		0x100000
+
 #endif