A bootflow encapsulates the process used to boot an operating system. It typically has a control file (such as extlinux.conf) and information about which 'bootdev' it came from.
Add the header file for this first, since it is needed by all other files.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v3: - Mention bootflow_state[] in enum bootflow_state_t
MAINTAINERS | 5 + include/bootflow.h | 256 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 261 insertions(+) create mode 100644 include/bootflow.h
diff --git a/MAINTAINERS b/MAINTAINERS index 38c68ee87d4..cfa0dfc77f0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -660,6 +660,11 @@ M: Simon Glass sjg@chromium.org S: Maintained F: tools/binman/
+BOOTDEVICE +M: Simon Glass sjg@chromium.org +S: Maintained +F: include/bootflow.h + BTRFS M: Marek Behun marek.behun@nic.cz R: Qu Wenruo wqu@suse.com diff --git a/include/bootflow.h b/include/bootflow.h new file mode 100644 index 00000000000..ef751179580 --- /dev/null +++ b/include/bootflow.h @@ -0,0 +1,256 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright 2021 Google LLC + * Written by Simon Glass sjg@chromium.org + */ + +#ifndef __bootflow_h +#define __bootflow_h + +#include <linux/list.h> + +/** + * enum bootflow_state_t - states that a particular bootflow can be in + * + * Only bootflows in state BOOTFLOWST_READY can be used to boot. + * + * See bootflow_state[] for the names for each of these + */ +enum bootflow_state_t { + BOOTFLOWST_BASE, /**< Nothing known yet */ + BOOTFLOWST_MEDIA, /**< Media exists */ + BOOTFLOWST_PART, /**< Partition exists */ + BOOTFLOWST_FS, /**< Filesystem exists */ + BOOTFLOWST_FILE, /**< Bootflow file exists */ + BOOTFLOWST_READY, /**< Bootflow file loaded */ + + BOOTFLOWST_COUNT +}; + +/** + * struct bootflow - information about a bootflow + * + * This is connected into two separate linked lists: + * + * bm_sibling - links all bootflows in the same bootdev + * glob_sibling - links all bootflows in all bootdevs + * + * @bm_node: Points to siblings in the same bootdev + * @glob_node: Points to siblings in the global list (all bootdev) + * @dev: Bootdevice device which produced this bootflow + * @blk: Block device which contains this bootflow, NULL if this is a network + * device + * @part: Partition number (0 for whole device) + * @method: Bootmethod device used to perform the boot and read files + * @name: Name of bootflow (allocated) + * @state: Current state (enum bootflow_state_t) + * @subdir: Subdirectory to fetch files from (with trailing /), or NULL if none + * @fname: Filename of bootflow file (allocated) + * @buf: Bootflow file contents (allocated) + * @size: Size of bootflow file in bytes + * @err: Error number received (0 if OK) + */ +struct bootflow { + struct list_head bm_node; + struct list_head glob_node; + struct udevice *dev; + struct udevice *blk; + int part; + struct udevice *method; + char *name; + enum bootflow_state_t state; + char *subdir; + char *fname; + char *buf; + int size; + int err; +}; + +/** + * enum bootflow_flags_t - flags for the bootflow iterator + * + * @BOOTFLOWF_FIXED: Only used fixed/internal media + * @BOOTFLOWF_SHOW: Show each bootdev before scanning it + * @BOOTFLOWF_ALL: Return bootflows with errors as well + * @BOOTFLOWF_SINGLE_DEV: Just scan one bootmeth + */ +enum bootflow_flags_t { + BOOTFLOWF_FIXED = 1 << 0, + BOOTFLOWF_SHOW = 1 << 1, + BOOTFLOWF_ALL = 1 << 2, + BOOTFLOWF_SINGLE_DEV = 1 << 3, +}; + +/** + * struct bootflow_iter - state for iterating through bootflows + * + * This starts at with the first bootdev/partition/bootmeth and can be used to + * iterate through all of them. + * + * Iteration starts with the bootdev. The first partition (0, i.e. whole device) + * is scanned first. For partition 0, it iterates through all the available + * bootmeths to see which one(s) can provide a bootflow. Then it moves to + * parition 1 (if there is one) and the process continues. Once all partitions + * are examined, it moves to the next bootdev. + * + * Initially @max_part is 0, meaning that only the whole device (@part=0) can be + * used. During scanning, if a partition table is found, then @max_part is + * updated to a larger value, no less than the number of available partitions. + * This ensures that iteration works through all partitions on the bootdev. + * + * @flags: Flags to use (see enum bootflow_flags_t) + * @dev: Current bootdev + * @part: Current partition number (0 for whole device) + * @method: Current bootmeth + * @max_part: Maximum hardware partition number in @dev, 0 if there is no + * partition table + * @err: Error obtained from checking the last iteration. This is used to skip + * forward (e.g. to skip the current partition because it is not valid) + * -ESHUTDOWN: try next bootdev + * @num_devs: Number of bootdevs in @dev_order + * @cur_dev: Current bootdev number, an index into @dev_order[] + * @dev_order: List of bootdevs to scan, in order of priority. The scan starts + * with the first one on the list + * @num_methods: Number of bootmeth devices in @method_order + * @cur_method: Current method number, an index into @method_order + * @method_order: List of bootmeth devices to use, in order + */ +struct bootflow_iter { + int flags; + struct udevice *dev; + int part; + struct udevice *method; + int max_part; + int err; + int num_devs; + int cur_dev; + struct udevice **dev_order; + int num_methods; + int cur_method; + struct udevice **method_order; +}; + +/** + * bootflow_iter_init() - Reset a bootflow iterator + * + * This sets everything to the starting point, ready for use. + * + * @iter: Place to store private info (inited by this call) + * @flags: Flags to use (see enum bootflow_flags_t) + */ +void bootflow_iter_init(struct bootflow_iter *iter, int flags); + +/** + * bootflow_iter_uninit() - Free memory used by an interator + * + * @iter: Iterator to free + */ +void bootflow_iter_uninit(struct bootflow_iter *iter); + +/** + * bootflow_scan_bootdev() - find the first bootflow in a bootdev + * + * If @flags includes BOOTFLOWF_ALL then bootflows with errors are returned too + * + * @dev: Boot device to scan, NULL to work through all of them until it + * finds one that * can supply a bootflow + * @iter: Place to store private info (inited by this call) + * @flags: Flags for bootdev (enum bootflow_flags_t) + * @bflow: Place to put the bootflow if found + * @return 0 if found, -ENODEV if no device, other -ve on other error + * (iteration can continue) + */ +int bootflow_scan_bootdev(struct udevice *dev, struct bootflow_iter *iter, + int flags, struct bootflow *bflow); + +/** + * bootflow_scan_first() - find the first bootflow + * + * This works through the available bootdev devices until it finds one that + * can supply a bootflow. It then returns that + * + * If @flags includes BOOTFLOWF_ALL then bootflows with errors are returned too + * + * @iter: Place to store private info (inited by this call), with + * @flags: Flags for bootdev (enum bootflow_flags_t) + * @bflow: Place to put the bootflow if found + * @return 0 if found, -ENODEV if no device, other -ve on other error (iteration + * can continue) + */ +int bootflow_scan_first(struct bootflow_iter *iter, int flags, + struct bootflow *bflow); + +/** + * bootflow_scan_next() - find the next bootflow + * + * This works through the available bootdev devices until it finds one that + * can supply a bootflow. It then returns that bootflow + * + * @iter: Private info (as set up by bootflow_scan_first()) + * @bflow: Place to put the bootflow if found + * @return 0 if found, -ENODEV if no device, -ESHUTDOWN if no more bootflows, + * other -ve on other error (iteration can continue) + */ +int bootflow_scan_next(struct bootflow_iter *iter, struct bootflow *bflow); + +/** + * bootflow_first_glob() - Get the first bootflow from the global list + * + * Returns the first bootflow in the global list, no matter what bootflow it is + * attached to + * + * @bflowp: Returns a pointer to the bootflow + * @return 0 if found, -ENOENT if there are no bootflows + */ +int bootflow_first_glob(struct bootflow **bflowp); + +/** + * bootflow_next_glob() - Get the next bootflow from the global list + * + * Returns the next bootflow in the global list, no matter what bootflow it is + * attached to + * + * @bflowp: On entry, the last bootflow returned , e.g. from + * bootflow_first_glob() + * @return 0 if found, -ENOENT if there are no more bootflows + */ +int bootflow_next_glob(struct bootflow **bflowp); + +/** + * bootflow_free() - Free memory used by a bootflow + * + * This frees fields within @bflow, but not the @bflow pointer itself + */ +void bootflow_free(struct bootflow *bflow); + +/** + * bootflow_boot() - boot a bootflow + * + * @bflow: Bootflow to boot + * @return -EPROTO if bootflow has not been loaded, -ENOSYS if the bootflow + * type is not supported, -EFAULT if the boot returned without an error + * when we are expecting it to boot, -ENOTSUPP if trying method resulted in + * finding out that is not actually supported for this boot and should not + * be tried again unless something changes + */ +int bootflow_boot(struct bootflow *bflow); + +/** + * bootflow_run_boot() - Try to boot a bootflow + * + * @iter: Current iteration (or NULL if none). Used to disable a bootmeth if the + * boot returns -ENOTSUPP + * @bflow: Bootflow to boot + * @return result of trying to boot + */ +int bootflow_run_boot(struct bootflow_iter *iter, struct bootflow *bflow); + +/** + * bootflow_state_get_name() - Get the name of a bootflow state + * + * @state: State to check + * @return name, or "?" if invalid + */ +const char *bootflow_state_get_name(enum bootflow_state_t state); + +#endif