bootstd: Add support for bootflows

Add support for bootflows, including maintaining a list of them and
iterating to find them.

Signed-off-by: Simon Glass <sjg@chromium.org>

MAINTAINERS

@@ -696,8 +696,9 @@ F:	tools/binman/
 BOOTDEVICE
 M:	Simon Glass <sjg@chromium.org>
 S:	Maintained
-F:	boot/bootmeth*.c
 F:	boot/bootdev*.c
+F:	boot/bootflow.c
+F:	boot/bootmeth*.c
 F:	boot/bootstd.c
 F:	include/bootdev*.h
 F:	include/bootflow.h

boot/Makefile

@@ -20,6 +20,7 @@ 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) += bootflow.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTSTD) += bootmeth-uclass.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTSTD) += bootstd-uclass.o
 

boot/bootdev-uclass.c

@@ -10,6 +10,7 @@
 #include <dm.h>
 #include <bootdev.h>
 #include <bootflow.h>
+#include <bootmeth.h>
 #include <bootstd.h>
 #include <env.h>
 #include <fs.h>
@@ -130,6 +131,10 @@ int bootdev_find_in_blk(struct udevice *dev, struct udevice *blk,
 
 	bflow->part = iter->part;
 
+	ret = bootmeth_check(bflow->method, iter);
+	if (ret)
+		return log_msg_ret("check", ret);
+
 	/*
 	 * partition numbers start at 0 so this cannot succeed, but it can tell
 	 * us whether there is valid media there
@@ -171,6 +176,10 @@ int bootdev_find_in_blk(struct udevice *dev, struct udevice *blk,
 		bflow->state = BOOTFLOWST_FS;
 	}
 
+	ret = bootmeth_read_bootflow(bflow->method, bflow);
+	if (ret)
+		return log_msg_ret("method", ret);
+
 	return 0;
 }
 
@@ -445,7 +454,7 @@ void bootdev_clear_bootflows(struct udevice *dev)
 
 		bflow = list_first_entry(&ucp->bootflow_head, struct bootflow,
 					 bm_node);
-		/* later bootflow_remove(bflow); */
+		bootflow_remove(bflow);
 	}
 }
 

boot/bootflow.c

@@ -0,0 +1,411 @@
+// 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 <bootdev.h>
+#include <bootflow.h>
+#include <bootmeth.h>
+#include <bootstd.h>
+#include <dm.h>
+#include <malloc.h>
+#include <dm/device-internal.h>
+#include <dm/uclass-internal.h>
+
+/* error codes used to signal running out of things */
+enum {
+	BF_NO_MORE_PARTS	= -ESHUTDOWN,
+	BF_NO_MORE_DEVICES	= -ENODEV,
+};
+
+/**
+ * bootflow_state - name for each state
+ *
+ * See enum bootflow_state_t for what each of these means
+ */
+static const char *const bootflow_state[BOOTFLOWST_COUNT] = {
+	"base",
+	"media",
+	"part",
+	"fs",
+	"file",
+	"ready",
+};
+
+const char *bootflow_state_get_name(enum bootflow_state_t state)
+{
+	/* This doesn't need to be a useful name, since it will never occur */
+	if (state < 0 || state >= BOOTFLOWST_COUNT)
+		return "?";
+
+	return bootflow_state[state];
+}
+
+int bootflow_first_glob(struct bootflow **bflowp)
+{
+	struct bootstd_priv *std;
+	int ret;
+
+	ret = bootstd_get_priv(&std);
+	if (ret)
+		return ret;
+
+	if (list_empty(&std->glob_head))
+		return -ENOENT;
+
+	*bflowp = list_first_entry(&std->glob_head, struct bootflow,
+				   glob_node);
+
+	return 0;
+}
+
+int bootflow_next_glob(struct bootflow **bflowp)
+{
+	struct bootstd_priv *std;
+	struct bootflow *bflow = *bflowp;
+	int ret;
+
+	ret = bootstd_get_priv(&std);
+	if (ret)
+		return ret;
+
+	*bflowp = NULL;
+
+	if (list_is_last(&bflow->glob_node, &std->glob_head))
+		return -ENOENT;
+
+	*bflowp = list_entry(bflow->glob_node.next, struct bootflow, glob_node);
+
+	return 0;
+}
+
+void bootflow_iter_init(struct bootflow_iter *iter, int flags)
+{
+	memset(iter, '\0', sizeof(*iter));
+	iter->flags = flags;
+}
+
+void bootflow_iter_uninit(struct bootflow_iter *iter)
+{
+	free(iter->dev_order);
+	free(iter->method_order);
+}
+
+int bootflow_iter_drop_bootmeth(struct bootflow_iter *iter,
+				const struct udevice *bmeth)
+{
+	/* We only support disabling the current bootmeth */
+	if (bmeth != iter->method || iter->cur_method >= iter->num_methods ||
+	    iter->method_order[iter->cur_method] != bmeth)
+		return -EINVAL;
+
+	memmove(&iter->method_order[iter->cur_method],
+		&iter->method_order[iter->cur_method + 1],
+		(iter->num_methods - iter->cur_method - 1) * sizeof(void *));
+
+	iter->num_methods--;
+
+	return 0;
+}
+
+static void bootflow_iter_set_dev(struct bootflow_iter *iter,
+				  struct udevice *dev)
+{
+	iter->dev = dev;
+	if ((iter->flags & (BOOTFLOWF_SHOW | BOOTFLOWF_SINGLE_DEV)) ==
+	    BOOTFLOWF_SHOW) {
+		if (dev)
+			printf("Scanning bootdev '%s':\n", dev->name);
+		else
+			printf("No more bootdevs\n");
+	}
+}
+
+/**
+ * iter_incr() - Move to the next item (method, part, bootdev)
+ *
+ * Return: 0 if OK, BF_NO_MORE_DEVICES if there are no more bootdevs
+ */
+static int iter_incr(struct bootflow_iter *iter)
+{
+	struct udevice *dev;
+	int ret;
+
+	if (iter->err == BF_NO_MORE_DEVICES)
+		return BF_NO_MORE_DEVICES;
+
+	if (iter->err != BF_NO_MORE_PARTS) {
+		/* Get the next boothmethod */
+		if (++iter->cur_method < iter->num_methods) {
+			iter->method = iter->method_order[iter->cur_method];
+			return 0;
+		}
+	}
+
+	/* No more bootmeths; start at the first one, and... */
+	iter->cur_method = 0;
+	iter->method = iter->method_order[iter->cur_method];
+
+	if (iter->err != BF_NO_MORE_PARTS) {
+		/* ...select next partition  */
+		if (++iter->part <= iter->max_part)
+			return 0;
+	}
+
+	/* No more partitions; start at the first one and...*/
+	iter->part = 0;
+
+	/*
+	 * Note: as far as we know, there is no partition table on the next
+	 * bootdev, so set max_part to 0 until we discover otherwise. See
+	 * bootdev_find_in_blk() for where this is set.
+	 */
+	iter->max_part = 0;
+
+	/* ...select next bootdev */
+	if (iter->flags & BOOTFLOWF_SINGLE_DEV) {
+		ret = -ENOENT;
+	} else if (++iter->cur_dev == iter->num_devs) {
+		ret = -ENOENT;
+		bootflow_iter_set_dev(iter, NULL);
+	} else {
+		dev = iter->dev_order[iter->cur_dev];
+		ret = device_probe(dev);
+		if (!log_msg_ret("probe", ret))
+			bootflow_iter_set_dev(iter, dev);
+	}
+
+	/* if there are no more bootdevs, give up */
+	if (ret)
+		return log_msg_ret("incr", BF_NO_MORE_DEVICES);
+
+	return 0;
+}
+
+/**
+ * bootflow_check() - Check if a bootflow can be obtained
+ *
+ * @iter: Provides part, bootmeth to use
+ * @bflow: Bootflow to update on success
+ * Return: 0 if OK, -ENOSYS if there is no bootflow support on this device,
+ *	BF_NO_MORE_PARTS if there are no more partitions on bootdev
+ */
+static int bootflow_check(struct bootflow_iter *iter, struct bootflow *bflow)
+{
+	struct udevice *dev;
+	int ret;
+
+	dev = iter->dev;
+	ret = bootdev_get_bootflow(dev, iter, bflow);
+
+	/* If we got a valid bootflow, return it */
+	if (!ret) {
+		log_debug("Bootdevice '%s' part %d method '%s': Found bootflow\n",
+			  dev->name, iter->part, iter->method->name);
+		return 0;
+	}
+
+	/* Unless there is nothing more to try, move to the next device */
+	else if (ret != BF_NO_MORE_PARTS && ret != -ENOSYS) {
+		log_debug("Bootdevice '%s' part %d method '%s': Error %d\n",
+			  dev->name, iter->part, iter->method->name, ret);
+		/*
+		 * For 'all' we return all bootflows, even
+		 * those with errors
+		 */
+		if (iter->flags & BOOTFLOWF_ALL)
+			return log_msg_ret("all", ret);
+	}
+	if (ret)
+		return log_msg_ret("check", ret);
+
+	return 0;
+}
+
+int bootflow_scan_bootdev(struct udevice *dev, struct bootflow_iter *iter,
+			  int flags, struct bootflow *bflow)
+{
+	int ret;
+
+	bootflow_iter_init(iter, flags);
+
+	ret = bootdev_setup_iter_order(iter, &dev);
+	if (ret)
+		return log_msg_ret("obdev", -ENODEV);
+	bootflow_iter_set_dev(iter, dev);
+
+	ret = bootmeth_setup_iter_order(iter);
+	if (ret)
+		return log_msg_ret("obmeth", -ENODEV);
+
+	/* Find the first bootmeth (there must be at least one!) */
+	iter->method = iter->method_order[iter->cur_method];
+
+	ret = bootflow_check(iter, bflow);
+	if (ret) {
+		if (ret != BF_NO_MORE_PARTS && ret != -ENOSYS) {
+			if (iter->flags & BOOTFLOWF_ALL)
+				return log_msg_ret("all", ret);
+		}
+		iter->err = ret;
+		ret = bootflow_scan_next(iter, bflow);
+		if (ret)
+			return log_msg_ret("get", ret);
+	}
+
+	return 0;
+}
+
+int bootflow_scan_first(struct bootflow_iter *iter, int flags,
+			struct bootflow *bflow)
+{
+	int ret;
+
+	ret = bootflow_scan_bootdev(NULL, iter, flags, bflow);
+	if (ret)
+		return log_msg_ret("start", ret);
+
+	return 0;
+}
+
+int bootflow_scan_next(struct bootflow_iter *iter, struct bootflow *bflow)
+{
+	int ret;
+
+	do {
+		ret = iter_incr(iter);
+		if (ret == BF_NO_MORE_DEVICES)
+			return log_msg_ret("done", ret);
+
+		if (!ret) {
+			ret = bootflow_check(iter, bflow);
+			if (!ret)
+				return 0;
+			iter->err = ret;
+			if (ret != BF_NO_MORE_PARTS && ret != -ENOSYS) {
+				if (iter->flags & BOOTFLOWF_ALL)
+					return log_msg_ret("all", ret);
+			}
+		} else {
+			iter->err = ret;
+		}
+
+	} while (1);
+}
+
+void bootflow_free(struct bootflow *bflow)
+{
+	free(bflow->name);
+	free(bflow->subdir);
+	free(bflow->fname);
+	free(bflow->buf);
+}
+
+void bootflow_remove(struct bootflow *bflow)
+{
+	list_del(&bflow->bm_node);
+	list_del(&bflow->glob_node);
+
+	bootflow_free(bflow);
+	free(bflow);
+}
+
+int bootflow_boot(struct bootflow *bflow)
+{
+	int ret;
+
+	if (bflow->state != BOOTFLOWST_READY)
+		return log_msg_ret("load", -EPROTO);
+
+	ret = bootmeth_boot(bflow->method, bflow);
+	if (ret)
+		return log_msg_ret("boot", ret);
+
+	/*
+	 * internal error, should not get here since we should have booted
+	 * something or returned an error
+	 */
+
+	return log_msg_ret("end", -EFAULT);
+}
+
+int bootflow_run_boot(struct bootflow_iter *iter, struct bootflow *bflow)
+{
+	int ret;
+
+	printf("** Booting bootflow '%s' with %s\n", bflow->name,
+	       bflow->method->name);
+	ret = bootflow_boot(bflow);
+	if (!IS_ENABLED(CONFIG_BOOTSTD_FULL)) {
+		printf("Boot failed (err=%d)\n", ret);
+		return ret;
+	}
+
+	switch (ret) {
+	case -EPROTO:
+		printf("Bootflow not loaded (state '%s')\n",
+		       bootflow_state_get_name(bflow->state));
+		break;
+	case -ENOSYS:
+		printf("Boot method '%s' not supported\n", bflow->method->name);
+		break;
+	case -ENOTSUPP:
+		/* Disable this bootflow for this iteration */
+		if (iter) {
+			int ret2;
+
+			ret2 = bootflow_iter_drop_bootmeth(iter, bflow->method);
+			if (!ret2) {
+				printf("Boot method '%s' failed and will not be retried\n",
+				       bflow->method->name);
+			}
+		}
+
+		break;
+	default:
+		printf("Boot failed (err=%d)\n", ret);
+		break;
+	}
+
+	return ret;
+}
+
+int bootflow_iter_uses_blk_dev(const struct bootflow_iter *iter)
+{
+	const struct udevice *media = dev_get_parent(iter->dev);
+	enum uclass_id id = device_get_uclass_id(media);
+
+	log_debug("uclass %d: %s\n", id, uclass_get_name(id));
+	if (id != UCLASS_ETH && id != UCLASS_BOOTSTD)
+		return 0;
+
+	return -ENOTSUPP;
+}
+
+int bootflow_iter_uses_network(const struct bootflow_iter *iter)
+{
+	const struct udevice *media = dev_get_parent(iter->dev);
+	enum uclass_id id = device_get_uclass_id(media);
+
+	log_debug("uclass %d: %s\n", id, uclass_get_name(id));
+	if (id == UCLASS_ETH)
+		return 0;
+
+	return -ENOTSUPP;
+}
+
+int bootflow_iter_uses_system(const struct bootflow_iter *iter)
+{
+	const struct udevice *media = dev_get_parent(iter->dev);
+	enum uclass_id id = device_get_uclass_id(media);
+
+	log_debug("uclass %d: %s\n", id, uclass_get_name(id));
+	if (id == UCLASS_BOOTSTD)
+		return 0;
+
+	return -ENOTSUPP;
+}

boot/bootstd-uclass.c

@@ -45,7 +45,7 @@ static void bootstd_clear_glob_(struct bootstd_priv *priv)
 
 		bflow = list_first_entry(&priv->glob_head, struct bootflow,
 					 glob_node);
-		/* add later bootflow_remove(bflow); */
+		bootflow_remove(bflow);
 	}
 }
 

include/bootflow.h

@@ -151,6 +151,18 @@ void bootflow_iter_init(struct bootflow_iter *iter, int flags);
  */
 void bootflow_iter_uninit(struct bootflow_iter *iter);
 
+/**
+ * bootflow_iter_drop_bootmeth() - Remove a bootmeth from an iterator
+ *
+ * Update the iterator so that the bootmeth will not be used again while this
+ * iterator is in use
+ *
+ * @iter: Iterator to update
+ * @bmeth: Boot method to remove
+ */
+int bootflow_iter_drop_bootmeth(struct bootflow_iter *iter,
+				const struct udevice *bmeth);
+
 /**
  * bootflow_scan_bootdev() - find the first bootflow in a bootdev
  *
@@ -257,4 +269,42 @@ int bootflow_run_boot(struct bootflow_iter *iter, struct bootflow *bflow);
  */
 const char *bootflow_state_get_name(enum bootflow_state_t state);
 
+/**
+ * bootflow_remove() - Remove a bootflow and free its memory
+ *
+ * This updates the linked lists containing the bootflow then frees it.
+ *
+ * @bflow: Bootflow to remove
+ */
+void bootflow_remove(struct bootflow *bflow);
+
+/**
+ * bootflow_iter_uses_blk_dev() - Check that a bootflow uses a block device
+ *
+ * This checks the bootdev in the bootflow to make sure it uses a block device
+ *
+ * Return: 0 if OK, -ENOTSUPP if some other device is used (e.g. ethernet)
+ */
+int bootflow_iter_uses_blk_dev(const struct bootflow_iter *iter);
+
+/**
+ * bootflow_iter_uses_network() - Check that a bootflow uses a network device
+ *
+ * This checks the bootdev in the bootflow to make sure it uses a network
+ * device
+ *
+ * Return: 0 if OK, -ENOTSUPP if some other device is used (e.g. MMC)
+ */
+int bootflow_iter_uses_network(const struct bootflow_iter *iter);
+
+/**
+ * bootflow_iter_uses_system() - Check that a bootflow uses the bootstd device
+ *
+ * This checks the bootdev in the bootflow to make sure it uses the bootstd
+ * device
+ *
+ * Return: 0 if OK, -ENOTSUPP if some other device is used (e.g. MMC)
+ */
+int bootflow_iter_uses_system(const struct bootflow_iter *iter);
+
 #endif