bootstd: Add the bootdev uclass
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@chromium.org>
diff --git a/boot/Makefile b/boot/Makefile
index 21dcf6a..301d75f 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -19,6 +19,7 @@
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 0000000..e0baeb8
--- /dev/null
+++ b/boot/bootdev-uclass.c
@@ -0,0 +1,640 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#define LOG_CATEGORY UCLASS_BOOTSTD
+
+#include <common.h>
+#include <dm.h>
+#include <bootdev.h>
+#include <bootflow.h>
+#include <bootstd.h>
+#include <env.h>
+#include <fs.h>
+#include <log.h>
+#include <malloc.h>
+#include <part.h>
+#include <sort.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,
+
+ /* Maximum supported length of the "boot_targets" env string */
+ BOOT_TARGETS_MAX_LEN = 100,
+};
+
+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->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;
+}
+
+static int bootdev_get_from_blk(struct udevice *blk, struct udevice **bootdevp)
+{
+ struct udevice *parent = dev_get_parent(blk);
+ struct udevice *bootdev;
+ char dev_name[50];
+ int ret;
+
+ if (device_get_uclass_id(blk) != UCLASS_BLK)
+ return -EINVAL;
+
+ /* This should always work if bootdev_setup_sibling_blk() was used */
+ snprintf(dev_name, sizeof(dev_name), "%s.%s", blk->name, "bootdev");
+ ret = device_find_child_by_name(parent, dev_name, &bootdev);
+ if (ret)
+ return log_msg_ret("find", ret);
+ *bootdevp = bootdev;
+
+ 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;
+ const char *end;
+ int seq;
+
+ seq = trailing_strtoln_end(label, NULL, &end);
+ id = uclass_get_by_namelen(label, end - label);
+ log_debug("find %s: seq=%d, id=%d/%s\n", label, seq, id,
+ uclass_get_name(id));
+ if (id == UCLASS_INVALID) {
+ log_warning("Unknown uclass '%s' in label\n", label);
+ return -EINVAL;
+ }
+ if (id == UCLASS_USB)
+ id = UCLASS_MASS_STORAGE;
+
+ /* Iterate through devices in the media uclass (e.g. UCLASS_MMC) */
+ uclass_id_foreach_dev(id, media, uc) {
+ struct udevice *bdev, *blk;
+ int ret;
+
+ /* if there is no seq, match anything */
+ if (seq != -1 && dev_seq(media) != seq) {
+ log_debug("- skip, media seq=%d\n", dev_seq(media));
+ continue;
+ }
+
+ ret = device_find_first_child_by_uclass(media, UCLASS_BOOTDEV,
+ &bdev);
+ if (ret) {
+ log_debug("- looking via blk, seq=%d, id=%d\n", seq,
+ id);
+ ret = blk_find_device(id, seq, &blk);
+ if (!ret) {
+ log_debug("- get from blk %s\n", blk->name);
+ ret = bootdev_get_from_blk(blk, &bdev);
+ }
+ }
+ if (!ret) {
+ log_debug("- found %s\n", bdev->name);
+ *devp = bdev;
+ return 0;
+ }
+ log_debug("- no device in %s\n", media->name);
+ }
+ 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); */
+ }
+}
+
+/**
+ * h_cmp_bootdev() - Compare two bootdevs to find out which should go first
+ *
+ * @v1: struct udevice * of first bootdev device
+ * @v2: struct udevice * of second bootdev device
+ * Return: sort order (<0 if dev1 < dev2, ==0 if equal, >0 if dev1 > dev2)
+ */
+static int h_cmp_bootdev(const void *v1, const void *v2)
+{
+ const struct udevice *dev1 = *(struct udevice **)v1;
+ const struct udevice *dev2 = *(struct udevice **)v2;
+ const struct bootdev_uc_plat *ucp1 = dev_get_uclass_plat(dev1);
+ const struct bootdev_uc_plat *ucp2 = dev_get_uclass_plat(dev2);
+ int diff;
+
+ /* Use priority first */
+ diff = ucp1->prio - ucp2->prio;
+ if (diff)
+ return diff;
+
+ /* Fall back to seq for devices of the same priority */
+ diff = dev_seq(dev1) - dev_seq(dev2);
+
+ return diff;
+}
+
+/**
+ * build_order() - Build the ordered list of bootdevs to use
+ *
+ * This builds an ordered list of devices by one of three methods:
+ * - using the boot_targets environment variable, if non-empty
+ * - using the bootdev-order devicetree property, if present
+ * - sorted by priority and sequence number
+ *
+ * @bootstd: BOOTSTD device to use
+ * @order: Bootdevs listed in default order
+ * @max_count: Number of entries in @order
+ * Return: number of bootdevs found in the ordering, or -E2BIG if the
+ * boot_targets string is too long, or -EXDEV if the ordering produced 0 results
+ */
+static int build_order(struct udevice *bootstd, struct udevice **order,
+ int max_count)
+{
+ const char *overflow_target = NULL;
+ const char *const *labels;
+ struct udevice *dev;
+ const char *targets;
+ int i, ret, count;
+
+ targets = env_get("boot_targets");
+ labels = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
+ bootstd_get_bootdev_order(bootstd) : NULL;
+ if (targets) {
+ char str[BOOT_TARGETS_MAX_LEN];
+ char *target;
+
+ if (strlen(targets) >= BOOT_TARGETS_MAX_LEN)
+ return log_msg_ret("len", -E2BIG);
+
+ /* make a copy of the string, since strok() will change it */
+ strcpy(str, targets);
+ for (i = 0, target = strtok(str, " "); target;
+ target = strtok(NULL, " ")) {
+ ret = bootdev_find_by_label(target, &dev);
+ if (!ret) {
+ if (i == max_count) {
+ overflow_target = target;
+ break;
+ }
+ order[i++] = dev;
+ }
+ }
+ count = i;
+ } else if (labels) {
+ int upto;
+
+ upto = 0;
+ for (i = 0; labels[i]; i++) {
+ ret = bootdev_find_by_label(labels[i], &dev);
+ if (!ret) {
+ if (upto == max_count) {
+ overflow_target = labels[i];
+ break;
+ }
+ order[upto++] = dev;
+ }
+ }
+ count = upto;
+ } else {
+ /* sort them into priority order */
+ count = max_count;
+ qsort(order, count, sizeof(struct udevice *), h_cmp_bootdev);
+ }
+
+ if (overflow_target) {
+ log_warning("Expected at most %d bootdevs, but overflowed with boot_target '%s'\n",
+ max_count, overflow_target);
+ }
+
+ if (!count)
+ return log_msg_ret("targ", -EXDEV);
+
+ return count;
+}
+
+int bootdev_setup_iter_order(struct bootflow_iter *iter, struct udevice **devp)
+{
+ struct udevice *bootstd, *dev = *devp, **order;
+ int upto, i;
+ int count;
+ int ret;
+
+ ret = uclass_first_device_err(UCLASS_BOOTSTD, &bootstd);
+ if (ret) {
+ log_err("Missing bootstd device\n");
+ return log_msg_ret("std", ret);
+ }
+
+ /* Handle scanning a single device */
+ if (dev) {
+ iter->flags |= BOOTFLOWF_SINGLE_DEV;
+ return 0;
+ }
+
+ count = uclass_id_count(UCLASS_BOOTDEV);
+ if (!count)
+ return log_msg_ret("count", -ENOENT);
+
+ order = calloc(count, sizeof(struct udevice *));
+ if (!order)
+ return log_msg_ret("order", -ENOMEM);
+
+ /*
+ * Get a list of bootdevs, in seq order (i.e. using aliases). There may
+ * be gaps so try to count up high enough to find them all.
+ */
+ for (i = 0, upto = 0; upto < count && i < 20 + count * 2; i++) {
+ ret = uclass_find_device_by_seq(UCLASS_BOOTDEV, i, &dev);
+ if (!ret)
+ order[upto++] = dev;
+ }
+ log_debug("Found %d bootdevs\n", count);
+ if (upto != count)
+ log_debug("Expected %d bootdevs, found %d using aliases\n",
+ count, upto);
+
+ count = build_order(bootstd, order, upto);
+ if (count < 0) {
+ free(order);
+ return log_msg_ret("build", count);
+ }
+
+ iter->dev_order = order;
+ iter->num_devs = count;
+ iter->cur_dev = 0;
+
+ dev = *order;
+ ret = device_probe(dev);
+ if (ret)
+ return log_msg_ret("probe", ret);
+ *devp = dev;
+
+ return 0;
+}
+
+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,
+};