[PATCH v2 21/41] bootstd: Add the bootdev uclass
Simon Glass
sjg at chromium.org
Sun Oct 24 01:26:15 CEST 2021
A 'bootdev' is a device which can be used to boot an operating system.
It is a child of the media device (e.g. MMC) which handles reading files
from that device, such as a bootflow file.
Add a uclass for bootdev and the various helpers needed to make it
work. Also add a binding file, empty for now.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
(no changes since v1)
MAINTAINERS | 4 +-
boot/Makefile | 1 +
boot/bootdev-uclass.c | 431 +++++++++++++++++++++++++++
doc/device-tree-bindings/bootdev.txt | 8 +
include/bootdev.h | 258 ++++++++++++++++
include/dm/uclass-id.h | 1 +
6 files changed, 702 insertions(+), 1 deletion(-)
create mode 100644 boot/bootdev-uclass.c
create mode 100644 doc/device-tree-bindings/bootdev.txt
create mode 100644 include/bootdev.h
diff --git a/MAINTAINERS b/MAINTAINERS
index c928130f94b..d800a3b7acb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -636,9 +636,11 @@ F: tools/binman/
BOOTDEVICE
M: Simon Glass <sjg at chromium.org>
S: Maintained
+F: boot/bootdev*.c
F: boot/bootstd.c
-F: include/bootstd.h
+F: include/bootdev*.h
F: include/bootflow.h
+F: include/bootstd.h
BTRFS
M: Marek Behun <marek.behun at nic.cz>
diff --git a/boot/Makefile b/boot/Makefile
index 48031d1c2b0..35abfd37654 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -23,6 +23,7 @@ obj-y += image.o image-board.o
obj-$(CONFIG_ANDROID_AB) += android_ab.o
obj-$(CONFIG_ANDROID_BOOT_IMAGE) += image-android.o image-android-dt.o
+obj-$(CONFIG_$(SPL_TPL_)BOOTSTD) += bootdev-uclass.o
obj-$(CONFIG_$(SPL_TPL_)BOOTSTD) += bootstd-uclass.o
obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += image-fdt.o
diff --git a/boot/bootdev-uclass.c b/boot/bootdev-uclass.c
new file mode 100644
index 00000000000..c8455ec5159
--- /dev/null
+++ b/boot/bootdev-uclass.c
@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg at chromium.org>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <bootdev.h>
+#include <bootflow.h>
+#include <bootstd.h>
+#include <fs.h>
+#include <log.h>
+#include <malloc.h>
+#include <part.h>
+#include <dm/device-internal.h>
+#include <dm/lists.h>
+#include <dm/uclass-internal.h>
+
+enum {
+ /*
+ * Set some sort of limit on the number of partitions a bootdev can
+ * have. Note that for disks this limits the partitions numbers that
+ * are scanned to 1..MAX_BOOTFLOWS_PER_BOOTDEV
+ */
+ MAX_PART_PER_BOOTDEV = 30,
+};
+
+int bootdev_add_bootflow(struct bootflow *bflow)
+{
+ struct bootdev_uc_plat *ucp = dev_get_uclass_plat(bflow->dev);
+ struct bootstd_priv *std;
+ struct bootflow *new;
+ int ret;
+
+ assert(bflow->dev);
+ ret = bootstd_get_priv(&std);
+ if (ret)
+ return ret;
+
+ new = malloc(sizeof(*bflow));
+ if (!new)
+ return log_msg_ret("bflow", -ENOMEM);
+ memcpy(new, bflow, sizeof(*bflow));
+
+ list_add_tail(&new->glob_node, &std->glob_head);
+ list_add_tail(&new->bm_node, &ucp->bootflow_head);
+
+ return 0;
+}
+
+int bootdev_first_bootflow(struct udevice *dev, struct bootflow **bflowp)
+{
+ struct bootdev_uc_plat *ucp = dev_get_uclass_plat(dev);
+
+ if (list_empty(&ucp->bootflow_head))
+ return -ENOENT;
+
+ *bflowp = list_first_entry(&ucp->bootflow_head, struct bootflow,
+ bm_node);
+
+ return 0;
+}
+
+int bootdev_next_bootflow(struct bootflow **bflowp)
+{
+ struct bootflow *bflow = *bflowp;
+ struct bootdev_uc_plat *ucp = dev_get_uclass_plat(bflow->dev);
+
+ *bflowp = NULL;
+
+ if (list_is_last(&bflow->bm_node, &ucp->bootflow_head))
+ return -ENOENT;
+
+ *bflowp = list_entry(bflow->bm_node.next, struct bootflow, bm_node);
+
+ return 0;
+}
+
+int bootdev_bind(struct udevice *parent, const char *drv_name, const char *name,
+ struct udevice **devp)
+{
+ struct udevice *dev;
+ char dev_name[30];
+ char *str;
+ int ret;
+
+ snprintf(dev_name, sizeof(dev_name), "%s.%s", parent->name, name);
+ str = strdup(dev_name);
+ if (!str)
+ return -ENOMEM;
+ ret = device_bind_driver(parent, drv_name, str, &dev);
+ if (ret)
+ return ret;
+ device_set_name_alloced(dev);
+ *devp = dev;
+
+ return 0;
+}
+
+int bootdev_find_in_blk(struct udevice *dev, struct udevice *blk,
+ struct bootflow_iter *iter, struct bootflow *bflow)
+{
+ struct blk_desc *desc = dev_get_uclass_plat(blk);
+ struct disk_partition info;
+ char partstr[20];
+ char name[60];
+ int ret;
+
+ /* Sanity check */
+ if (iter->part >= MAX_PART_PER_BOOTDEV)
+ return log_msg_ret("max", -ESHUTDOWN);
+
+ bflow->blk = blk;
+ if (iter->part)
+ snprintf(partstr, sizeof(partstr), "part_%x", iter->part);
+ else
+ strcpy(partstr, "whole");
+ snprintf(name, sizeof(name), "%s.%s", dev->name, partstr);
+ bflow->name = strdup(name);
+ if (!bflow->name)
+ return log_msg_ret("name", -ENOMEM);
+
+ bflow->state = BOOTFLOWST_BASE;
+ bflow->part = iter->part;
+
+ /*
+ * partition numbers start at 0 so this cannot succeed, but it can tell
+ * us whether there is valid media there
+ */
+ ret = part_get_info(desc, iter->part, &info);
+ if (!iter->part && ret == -ENOENT)
+ ret = 0;
+
+ /*
+ * This error indicates the media is not present. Otherwise we just
+ * blindly scan the next partition. We could be more intelligent here
+ * and check which partition numbers actually exist.
+ */
+ if (ret == -EOPNOTSUPP)
+ ret = -ESHUTDOWN;
+ else
+ bflow->state = BOOTFLOWST_MEDIA;
+ if (ret)
+ return log_msg_ret("part", ret);
+
+ /*
+ * Currently we don't get the number of partitions, so just
+ * assume a large number
+ */
+ iter->max_part = MAX_PART_PER_BOOTDEV;
+
+ if (iter->part) {
+ ret = fs_set_blk_dev_with_part(desc, bflow->part);
+ bflow->state = BOOTFLOWST_PART;
+
+ /* Use an #ifdef due to info.sys_ind */
+#ifdef CONFIG_DOS_PARTITION
+ log_debug("%s: Found partition %x type %x fstype %d\n",
+ blk->name, bflow->part, info.sys_ind,
+ ret ? -1 : fs_get_type());
+#endif
+ if (ret)
+ return log_msg_ret("fs", ret);
+ bflow->state = BOOTFLOWST_FS;
+ }
+
+ return 0;
+}
+
+void bootdev_list(bool probe)
+{
+ struct udevice *dev;
+ int ret;
+ int i;
+
+ printf("Seq Probed Status Uclass Name\n");
+ printf("--- ------ ------ -------- ------------------\n");
+ if (probe)
+ ret = uclass_first_device_err(UCLASS_BOOTDEV, &dev);
+ else
+ ret = uclass_find_first_device(UCLASS_BOOTDEV, &dev);
+ for (i = 0; dev; i++) {
+ printf("%3x [ %c ] %6s %-9.9s %s\n", dev_seq(dev),
+ device_active(dev) ? '+' : ' ',
+ ret ? simple_itoa(ret) : "OK",
+ dev_get_uclass_name(dev_get_parent(dev)), dev->name);
+ if (probe)
+ ret = uclass_next_device_err(&dev);
+ else
+ ret = uclass_find_next_device(&dev);
+ }
+ printf("--- ------ ------ -------- ------------------\n");
+ printf("(%d bootdev%s)\n", i, i != 1 ? "s" : "");
+}
+
+int bootdev_setup_for_dev(struct udevice *parent, const char *drv_name)
+{
+ struct udevice *bdev;
+ int ret;
+
+ ret = device_find_first_child_by_uclass(parent, UCLASS_BOOTDEV,
+ &bdev);
+ if (ret) {
+ if (ret != -ENODEV) {
+ log_debug("Cannot access bootdev device\n");
+ return ret;
+ }
+
+ ret = bootdev_bind(parent, drv_name, "bootdev", &bdev);
+ if (ret) {
+ log_debug("Cannot create bootdev device\n");
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+int bootdev_setup_sibling_blk(struct udevice *blk, const char *drv_name)
+{
+ struct udevice *parent, *dev;
+ char dev_name[50];
+ int ret;
+
+ snprintf(dev_name, sizeof(dev_name), "%s.%s", blk->name, "bootdev");
+
+ parent = dev_get_parent(blk);
+ ret = device_find_child_by_name(parent, dev_name, &dev);
+ if (ret) {
+ char *str;
+
+ if (ret != -ENODEV) {
+ log_debug("Cannot access bootdev device\n");
+ return ret;
+ }
+ str = strdup(dev_name);
+ if (!str)
+ return -ENOMEM;
+
+ ret = device_bind_driver(parent, drv_name, str, &dev);
+ if (ret) {
+ log_debug("Cannot create bootdev device\n");
+ return ret;
+ }
+ device_set_name_alloced(dev);
+ }
+
+ return 0;
+}
+
+int bootdev_get_sibling_blk(struct udevice *dev, struct udevice **blkp)
+{
+ struct udevice *parent = dev_get_parent(dev);
+ struct udevice *blk;
+ int ret, len;
+ char *p;
+
+ if (device_get_uclass_id(dev) != UCLASS_BOOTDEV)
+ return -EINVAL;
+
+ /* This should always work if bootdev_setup_sibling_blk() was used */
+ p = strstr(dev->name, ".bootdev");
+ if (!p)
+ return log_msg_ret("str", -EINVAL);
+
+ len = p - dev->name;
+ ret = device_find_child_by_namelen(parent, dev->name, len, &blk);
+ if (ret)
+ return log_msg_ret("find", ret);
+ *blkp = blk;
+
+ return 0;
+}
+
+int bootdev_unbind_dev(struct udevice *parent)
+{
+ struct udevice *dev;
+ int ret;
+
+ ret = device_find_first_child_by_uclass(parent, UCLASS_BOOTDEV, &dev);
+ if (!ret) {
+ ret = device_remove(dev, DM_REMOVE_NORMAL);
+ if (ret)
+ return log_msg_ret("rem", ret);
+ ret = device_unbind(dev);
+ if (ret)
+ return log_msg_ret("unb", ret);
+ }
+
+ return 0;
+}
+
+/**
+ * bootdev_find_by_label() - Convert a label string to a bootdev device
+ *
+ * Looks up a label name to find the associated bootdev. For example, if the
+ * label name is "mmc2", this will find a bootdev for an mmc device whose
+ * sequence number is 2.
+ *
+ * @label: Label string to convert, e.g. "mmc2"
+ * @devp: Returns bootdev device corresponding to that boot label
+ * @return 0 if OK, -EINVAL if the label name (e.g. "mmc") does not refer to a
+ * uclass, -ENOENT if no bootdev for that media has the sequence number
+ * (e.g. 2)
+ */
+int bootdev_find_by_label(const char *label, struct udevice **devp)
+{
+ struct udevice *media;
+ struct uclass *uc;
+ enum uclass_id id;
+ int seq, len;
+
+ seq = trailing_strtoln_len(label, NULL, &len);
+ id = uclass_get_by_name_len(label, len);
+ if (id == UCLASS_INVALID) {
+ log_warning("Unknown uclass '%s' in label\n", label);
+ return -EINVAL;
+ }
+
+ /* Iterate through devices in the media uclass (e.g. UCLASS_MMC) */
+ uclass_id_foreach_dev(id, media, uc) {
+ struct udevice *bdev;
+ int ret;
+
+ /* if there is no seq, match anything */
+ if (seq != -1 && dev_seq(media) != seq)
+ continue;
+
+ ret = device_find_first_child_by_uclass(media, UCLASS_BOOTDEV,
+ &bdev);
+ if (!ret) {
+ *devp = bdev;
+ return 0;
+ }
+ }
+ log_warning("Unknown seq %d for label '%s'\n", seq, label);
+
+ return -ENOENT;
+}
+
+int bootdev_find_by_any(const char *name, struct udevice **devp)
+{
+ struct udevice *dev;
+ int ret, seq;
+ char *endp;
+
+ seq = simple_strtol(name, &endp, 16);
+
+ /* Select by name, label or number */
+ if (*endp) {
+ ret = uclass_get_device_by_name(UCLASS_BOOTDEV, name, &dev);
+ if (ret == -ENODEV) {
+ ret = bootdev_find_by_label(name, &dev);
+ if (ret) {
+ printf("Cannot find bootdev '%s' (err=%d)\n",
+ name, ret);
+ return ret;
+ }
+ ret = device_probe(dev);
+ }
+ if (ret) {
+ printf("Cannot probe bootdev '%s' (err=%d)\n", name,
+ ret);
+ return ret;
+ }
+ } else {
+ ret = uclass_get_device_by_seq(UCLASS_BOOTDEV, seq, &dev);
+ }
+ if (ret) {
+ printf("Cannot find '%s' (err=%d)\n", name, ret);
+ return ret;
+ }
+
+ *devp = dev;
+
+ return 0;
+}
+
+int bootdev_get_bootflow(struct udevice *dev, struct bootflow_iter *iter,
+ struct bootflow *bflow)
+{
+ const struct bootdev_ops *ops = bootdev_get_ops(dev);
+
+ if (!ops->get_bootflow)
+ return -ENOSYS;
+ memset(bflow, '\0', sizeof(*bflow));
+ bflow->dev = dev;
+ bflow->method = iter->method;
+ bflow->state = BOOTFLOWST_BASE;
+
+ return ops->get_bootflow(dev, iter, bflow);
+}
+
+void bootdev_clear_bootflows(struct udevice *dev)
+{
+ struct bootdev_uc_plat *ucp = dev_get_uclass_plat(dev);
+
+ while (!list_empty(&ucp->bootflow_head)) {
+ struct bootflow *bflow;
+
+ bflow = list_first_entry(&ucp->bootflow_head, struct bootflow,
+ bm_node);
+ /* later bootflow_remove(bflow); */
+ }
+}
+
+static int bootdev_post_bind(struct udevice *dev)
+{
+ struct bootdev_uc_plat *ucp = dev_get_uclass_plat(dev);
+
+ INIT_LIST_HEAD(&ucp->bootflow_head);
+
+ return 0;
+}
+
+static int bootdev_pre_unbind(struct udevice *dev)
+{
+ bootdev_clear_bootflows(dev);
+
+ return 0;
+}
+
+UCLASS_DRIVER(bootdev) = {
+ .id = UCLASS_BOOTDEV,
+ .name = "bootdev",
+ .flags = DM_UC_FLAG_SEQ_ALIAS,
+ .per_device_plat_auto = sizeof(struct bootdev_uc_plat),
+ .post_bind = bootdev_post_bind,
+ .pre_unbind = bootdev_pre_unbind,
+};
diff --git a/doc/device-tree-bindings/bootdev.txt b/doc/device-tree-bindings/bootdev.txt
new file mode 100644
index 00000000000..95b7fec8212
--- /dev/null
+++ b/doc/device-tree-bindings/bootdev.txt
@@ -0,0 +1,8 @@
+U-Boot boot device (bootdev)
+============================
+
+A bootdev provides a way to obtain a bootflow file from a device. It is a
+child of the media device (UCLASS_MMC, UCLASS_SPI_FLASH, etc.)
+
+The bootdev driver is provided by the media devices. The bindings for each
+are described in this file (to come).
diff --git a/include/bootdev.h b/include/bootdev.h
new file mode 100644
index 00000000000..3068cf309b9
--- /dev/null
+++ b/include/bootdev.h
@@ -0,0 +1,258 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg at chromium.org>
+ */
+
+#ifndef __bootdev_h
+#define __bootdev_h
+
+#include <linux/list.h>
+
+struct bootflow;
+struct bootflow_iter;
+struct udevice;
+
+/**
+ * enum bootdev_prio_t - priority of each bootdev
+ *
+ * These values are associated with each bootdev and set up by the driver.
+ *
+ * Smallest value is the highest priority. By default, bootdevs are scanned from
+ * highest to lowest priority
+ */
+enum bootdev_prio_t {
+ BOOTDEVP_0_INTERNAL_FAST = 10,
+ BOOTDEVP_1_INTERNAL_SLOW = 20,
+ BOOTDEVP_2_SCAN_FAST = 30,
+ BOOTDEVP_3_SCAN_SLOW = 40,
+ BOOTDEVP_4_NET_BASE = 50,
+ BOOTDEVP_5_NET_FALLBACK = 60,
+ BOOTDEVP_6_SYSTEM = 70,
+
+ BOOTDEVP_COUNT,
+};
+
+/**
+ * struct bootdev_uc_plat - uclass information about a bootdev
+ *
+ * This is attached to each device in the bootdev uclass and accessible via
+ * dev_get_uclass_plat(dev)
+ *
+ * @bootflows: List of available bootflows for this bootdev
+ * @piro: Priority of this bootdev
+ */
+struct bootdev_uc_plat {
+ struct list_head bootflow_head;
+ enum bootdev_prio_t prio;
+};
+
+/** struct bootdev_ops - Operations for the bootdev uclass */
+struct bootdev_ops {
+ /**
+ * get_bootflow() - get a bootflow
+ *
+ * @dev: Bootflow device to check
+ * @iter: Provides current dev, part, method to get. Should update
+ * max_part if there is a partition table. Should update state,
+ * subdir, fname, buf, size according to progress
+ * @bflow: Updated bootflow if found
+ * @return 0 if OK, -ESHUTDOWN if there are no more bootflows on this
+ * device, -ENOSYS if this device doesn't support bootflows,
+ * other -ve value on other error
+ */
+ int (*get_bootflow)(struct udevice *dev, struct bootflow_iter *iter,
+ struct bootflow *bflow);
+};
+
+#define bootdev_get_ops(dev) ((struct bootdev_ops *)(dev)->driver->ops)
+
+/**
+ * bootdev_get_bootflow() - get a bootflow
+ *
+ * @dev: Bootflow device to check
+ * @iter: Provides current part, method to get
+ * @bflow: Returns bootflow if found
+ * @return 0 if OK, -ESHUTDOWN if there are no more bootflows on this device,
+ * -ENOSYS if this device doesn't support bootflows, other -ve value on
+ * other error
+ */
+int bootdev_get_bootflow(struct udevice *dev, struct bootflow_iter *iter,
+ struct bootflow *bflow);
+
+/**
+ * bootdev_bind() - Bind a new named bootdev device
+ *
+ * @parent: Parent of the new device
+ * @drv_name: Driver name to use for the bootdev device
+ * @name: Name for the device (parent name is prepended)
+ * @devp: the new device (which has not been probed)
+ */
+int bootdev_bind(struct udevice *parent, const char *drv_name, const char *name,
+ struct udevice **devp);
+
+/**
+ * bootdev_find_in_blk() - Find a bootdev in a block device
+ *
+ * @dev: Bootflow device associated with this block device
+ * @blk: Block device to search
+ * @iter: Provides current dev, part, method to get. Should update
+ * max_part if there is a partition table
+ * @bflow: On entry, provides information about the partition and device to
+ * check. On exit, returns bootflow if found
+ * @return 0 if found, -ESHUTDOWN if no more bootflows, other -ve on error
+ */
+int bootdev_find_in_blk(struct udevice *dev, struct udevice *blk,
+ struct bootflow_iter *iter, struct bootflow *bflow);
+
+/**
+ * bootdev_list() - List all available bootdevs
+ *
+ * @probe: true to probe devices, false to leave them as is
+ */
+void bootdev_list(bool probe);
+
+/**
+ * bootdev_clear_bootflows() - Clear bootflows from a bootdev
+ *
+ * Each bootdev maintains a list of discovered bootflows. This provides a
+ * way to clear it. These bootflows are removed from the global list too.
+ *
+ * @dev: bootdev device to update
+ */
+void bootdev_clear_bootflows(struct udevice *dev);
+
+/**
+ * bootdev_add_bootflow() - Add a bootflow to the bootdev's list
+ *
+ * All fields in @bflow must be set up. Note that @bflow->dev is used to add the
+ * bootflow to that device.
+ *
+ * @dev: Bootdevice device to add to
+ * @bflow: Bootflow to add. Note that fields within bflow must be allocated
+ * since this function takes over ownership of these. This functions makes
+ * a copy of @bflow itself (without allocating its fields again), so the
+ * caller must dispose of the memory used by the @bflow pointer itself
+ * @return 0 if OK, -ENOMEM if out of memory
+ */
+int bootdev_add_bootflow(struct bootflow *bflow);
+
+/**
+ * bootdev_first_bootflow() - Get the first bootflow from a bootdev
+ *
+ * Returns the first bootflow attached to a bootdev
+ *
+ * @dev: bootdev device
+ * @bflowp: Returns a pointer to the bootflow
+ * @return 0 if found, -ENOENT if there are no bootflows
+ */
+int bootdev_first_bootflow(struct udevice *dev, struct bootflow **bflowp);
+
+/**
+ * bootdev_next_bootflow() - Get the next bootflow from a bootdev
+ *
+ * Returns the next bootflow attached to a bootdev
+ *
+ * @bflowp: On entry, the last bootflow returned , e.g. from
+ * bootdev_first_bootflow()
+ * @return 0 if found, -ENOENT if there are no more bootflows
+ */
+int bootdev_next_bootflow(struct bootflow **bflowp);
+
+/**
+ * bootdev_find_by_label() - Look up a bootdev by label
+ *
+ * Each bootdev has a label which contains the media-uclass name and a number,
+ * e.g. 'mmc2'. This looks up the label and returns the associated bootdev
+ *
+ * The lookup is performed based on the media device's sequence number. So for
+ * 'mmc2' this looks for a device in UCLASS_MMC with a dev_seq() of 2.
+ *
+ * @label: Label to look up (e.g. "mmc1" or "mmc0")
+ * @devp: Returns the bootdev device found, or NULL if none (note it does not
+ * return the media device, but its bootdev child)
+ * @return 0 if OK, -EINVAL if the uclass is not supported by this board,
+ * -ENOENT if there is no device with that number
+ */
+int bootdev_find_by_label(const char *label, struct udevice **devp);
+
+/**
+ * bootdev_find_by_any() - Find a bootdev by name, label or sequence
+ *
+ * @name: name (e.g. "mmc2.bootdev"), label ("mmc2"), or sequence ("2") to find
+ * @devp: returns the device found, on success
+ * @return 0 if OK, -ve on error
+ */
+int bootdev_find_by_any(const char *name, struct udevice **devp);
+
+#if CONFIG_IS_ENABLED(BOOTSTD)
+/**
+ * bootdev_setup_for_dev() - Bind a new bootdev device
+ *
+ * Creates a bootdev device as a child of @parent. This should be called from
+ * the driver's bind() method or its uclass' post_bind() method.
+ *
+ * If a child bootdev already exists, this function does nothing
+ *
+ * @parent: Parent device (e.g. MMC or Ethernet)
+ * @drv_name: Name of bootdev driver to bind
+ * @return 0 if OK, -ve on error
+ */
+int bootdev_setup_for_dev(struct udevice *parent, const char *drv_name);
+
+/**
+ * bootdev_setup_for_blk() - Bind a new bootdev device for a blk device
+ *
+ * Creates a bootdev device as a sibling of @blk. This should be called from
+ * the driver's bind() method or its uclass' post_bind() method, at the same
+ * time as the bould device is bound
+ *
+ * If a device of the same name already exists, this function does nothing
+ *
+ * @parent: Parent device (e.g. MMC or Ethernet)
+ * @drv_name: Name of bootdev driver to bind
+ * @return 0 if OK, -ve on error
+ */
+int bootdev_setup_sibling_blk(struct udevice *blk, const char *drv_name);
+
+/**
+ * bootdev_get_sibling_blk() - Locate the block device for a bootdev
+ *
+ * @dev: bootdev to check
+ * @blkp: returns associated block device
+ * @return 0 if OK, -EINVAL if @dev is not a bootdev device, other -ve on other
+ * error
+ */
+int bootdev_get_sibling_blk(struct udevice *dev, struct udevice **blkp);
+
+/**
+ * bootdev_unbind_dev() - Unbind a bootdev device
+ *
+ * Remove and unbind a bootdev device which is a child of @parent. This should
+ * be called from the driver's unbind() method or its uclass' post_bind()
+ * method.
+ *
+ * @parent: Parent device (e.g. MMC or Ethernet)
+ * @return 0 if OK, -ve on error
+ */
+int bootdev_unbind_dev(struct udevice *parent);
+#else
+static inline int bootdev_setup_for_dev(struct udevice *parent,
+ const char *drv_name)
+{
+ return 0;
+}
+
+static inline int bootdev_setup_sibling_blk(struct udevice *blk,
+ const char *drv_name)
+{
+ return 0;
+}
+
+static inline int bootdev_unbind_dev(struct udevice *parent)
+{
+ return 0;
+}
+#endif
+
+#endif
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 17383fc38c1..03912cb0db8 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -38,6 +38,7 @@ enum uclass_id {
UCLASS_AXI, /* AXI bus */
UCLASS_BLK, /* Block device */
UCLASS_BOOTCOUNT, /* Bootcount backing store */
+ UCLASS_BOOTDEV, /* Boot device for locating an OS to boot */
UCLASS_BOOTSTD, /* Standard boot driver */
UCLASS_BUTTON, /* Button */
UCLASS_CACHE, /* Cache controller */
--
2.33.0.1079.g6e70778dc9-goog
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