u-boot/common/spl/spl_usb.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2014
 * Texas Instruments, <www.ti.com>
 *
 * Dan Murphy <dmurphy@ti.com>
 *
 * Derived work from spl_mmc.c
 */

#include <common.h>
#include <spl.h>
#include <asm/u-boot.h>
#include <errno.h>
#include <usb.h>
#include <fat.h>

static int usb_stor_curr_dev = -1; /* current device */

static int spl_usb_load_image(struct spl_image_info *spl_image,
			      struct spl_boot_device *bootdev)
{
	int err;
	struct blk_desc *stor_dev;

	usb_stop();
	err = usb_init();
	if (err) {
#ifdef CONFIG_SPL_LIBCOMMON_SUPPORT
		printf("%s: usb init failed: err - %d\n", __func__, err);
#endif
		return err;
	}

	/* try to recognize storage devices immediately */
	usb_stor_curr_dev = usb_stor_scan(1);
	stor_dev = blk_get_devnum_by_type(IF_TYPE_USB, usb_stor_curr_dev);
	if (!stor_dev)
		return -ENODEV;

	debug("boot mode - FAT\n");

#ifdef CONFIG_SPL_OS_BOOT
	if (spl_start_uboot() ||
	    spl_load_image_fat_os(spl_image, stor_dev,
				  CONFIG_SYS_USB_FAT_BOOT_PARTITION))
#endif
	{
		err = spl_load_image_fat(spl_image, stor_dev,
					CONFIG_SYS_USB_FAT_BOOT_PARTITION,
					CONFIG_SPL_FS_LOAD_PAYLOAD_NAME);
	}

	if (err) {
		puts("Error loading from USB device\n");
		return err;
	}

	return 0;
}
SPL_LOAD_IMAGE_METHOD("USB", 0, BOOT_DEVICE_USB, spl_usb_load_image);