// ......

/* khadas mcu part begin */
#define MCU_I2C_BUS_NUM              2
#define MCU_I2C_CHIP_ADDR            0x18
#define MCU_I2C_REG_BOOT_MODE        0x20
#define MCU_I2C_REG_BOOT_MODE_SPI    0x00
#define MCU_I2C_REG_BOOT_MODE_MMC    0x01
#define MCU_I2C_REG_BOOT_FLAG        0x92
#define MCU_I2C_REG_RESET_MODE       0x91
#define MCU_I2C_REG_BOOT_FLAG_NORMAL 0x00
#define MCU_I2C_REG_BOOT_FLAG_FUNC   0x01
#define MCU_I2C_REG_BOOT_FLAG_OOWOW  0x01
#define MCU_I2C_REG_BOOT_FLAG_SPI    0x02
#define MCU_I2C_REG_BOOT_FLAG_EMMC   0x03
#define MCU_I2C_REG_BOOT_FLAG_RESCUE 0x05
#define MCU_I2C_REG_BOOT_FLAG_PASS   0x50

#define MCU_I2C_REG_LED  0x89
/* khadas mcu part end */

void board_boot_order(u32 *spl_boot_list)
{
	const void *blob = gd->fdt_blob;
	int chosen_node = fdt_path_offset(blob, "/chosen");
	int idx = 0;
	int elem;
	int boot_device;
	int node;
	const char *conf;

/* khadas mcu part begin */
	uchar mcu_boot_mode;
	uchar mcu_boot_flag;
	uchar mcu_led_normal = 8; /* white breath */
	uchar mcu_led_reset  = 1; /* white solid */
	int ret;
	struct udevice *bus;
	struct udevice *dev;

	ret = uclass_first_device(UCLASS_I2C, &bus);
	if (ret) goto mcu_skip;
	ret = i2c_get_chip(bus, MCU_I2C_CHIP_ADDR, 1, &dev);
	if (ret) goto mcu_skip;
	ret = dm_i2c_read(dev, MCU_I2C_REG_BOOT_MODE, &mcu_boot_mode, 1);
	ret = dm_i2c_read(dev, MCU_I2C_REG_BOOT_FLAG, &mcu_boot_flag, 1);
	printf("MCU: boot mode 0x20: %d, flag 0x92: %d\n",
                          mcu_boot_mode, mcu_boot_flag);
	// reset boot flag
	if ( mcu_boot_flag != 0 ) {
		mcu_boot_flag = mcu_boot_flag > 10 ? 0 : mcu_boot_flag ^ MCU_I2C_REG_BOOT_FLAG_PASS;
		dm_i2c_write(dev, MCU_I2C_REG_BOOT_FLAG, &mcu_boot_flag, 1);
		printf("MCU: boot flag < %d\n", mcu_boot_flag);
		if ( mcu_boot_flag != 0 )
		    dm_i2c_write(dev, MCU_I2C_REG_LED, &mcu_led_reset, 1);
	} else {
		dm_i2c_write(dev, MCU_I2C_REG_LED, &mcu_led_normal, 1);
	}
mcu_skip:
/* khadas mcu part end */

	if (chosen_node < 0) {
		debug("%s: /chosen not found, using spl_boot_device()\n",
		      __func__);
		spl_boot_list[0] = spl_boot_device();
		return;
	}

	printf("%s: /chosen found, using spl_boot_device()\n", __func__);

	for (elem = 0;
	     (conf = fdt_stringlist_get(blob, chosen_node,
					"u-boot,spl-boot-order", elem, NULL));
	     elem++) {
		const char *alias;

		printf("!!! %s: \n", conf);

		/* Handle the case of 'same device the SPL was loaded from' */
		if (strncmp(conf, "same-as-spl", 11) == 0) {

			// /mmc@fe2c0000 - SD
			// /mmc@fe2e0000 - EMMC

			mcu_boot_flag &= 0x0F; // restore original flag
			if (mcu_boot_flag == 1 || mcu_boot_flag == 2 || mcu_boot_flag == 5)
			    conf = "/spi@fe2b0000/flash@1";
			else if (mcu_boot_flag == 3)
			    conf = "/mmc@fe2e0000";
			else if (mcu_boot_mode == MCU_I2C_REG_BOOT_MODE_MMC)
			    continue;
			else
			    conf = board_spl_was_booted_from();

			printf("+++ %s: \n", conf);
			if (!conf)
				continue;
		}

		/* First check if the list element is an alias */
		alias = fdt_get_alias(blob, conf);
		if (alias)
			conf = alias;

		/* Try to resolve the config item (or alias) as a path */
		node = fdt_path_offset(blob, conf);
		if (node < 0) {
			debug("%s: could not find %s in FDT", __func__, conf);
			continue;
		}

		/* Try to map this back onto SPL boot devices */
		boot_device = spl_node_to_boot_device(node);
		if (boot_device < 0) {
			debug("%s: could not map node @%x to a boot-device\n",
			      __func__, node);
			continue;
		}

		spl_boot_list[idx++] = boot_device;
	}

	/* If we had no matches, fall back to spl_boot_device */
	if (idx == 0)
		spl_boot_list[0] = spl_boot_device();
}
#endif