The 'bootstd' device provides the central information about U-Boot standard boot.
Add a uclass for bootstd and the various helpers needed to make it work. Also add a binding file.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v4: - NULL-terminate the default prefix list - Use new Return style in function comments
Changes in v3: - Add CONFIG_BOOTSTD_FULL to enable the full feature set - Support bootdev-order and filename-prefixes only with CONFIG_BOOTSTD_FULL
MAINTAINERS | 2 + boot/Kconfig | 34 ++++++ boot/Makefile | 3 + boot/bootstd-uclass.c | 152 +++++++++++++++++++++++++++ doc/device-tree-bindings/bootstd.txt | 28 +++++ include/bootstd.h | 80 ++++++++++++++ include/dm/uclass-id.h | 1 + 7 files changed, 300 insertions(+) create mode 100644 boot/bootstd-uclass.c create mode 100644 doc/device-tree-bindings/bootstd.txt create mode 100644 include/bootstd.h
diff --git a/MAINTAINERS b/MAINTAINERS index 6e6dcd7e26..9df9812978 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -685,6 +685,8 @@ F: tools/binman/ BOOTDEVICE M: Simon Glass sjg@chromium.org S: Maintained +F: boot/bootstd.c +F: include/bootstd.h F: include/bootflow.h
BTRFS diff --git a/boot/Kconfig b/boot/Kconfig index b83a4e8400..deb2bf386f 100644 --- a/boot/Kconfig +++ b/boot/Kconfig @@ -292,6 +292,40 @@ endif # SPL
endif # FIT
+config BOOTSTD + bool "Standard boot support" + default y + depends on DM && OF_CONTROL && BLK + help + U-Boot supports a standard way of locating something to boot, + typically an Operating System such as Linux, provided by a distro such + as Arch Linux or Debian. Enable this to support iterating through + available bootdevs and using bootmeths to find bootflows suitable for + booting. + + Standard boot is not a standard way of booting, just a framework + within U-Boot for supporting all the different ways that exist. + + Terminology: + + - bootdev - a device which can hold a distro (e.g. MMC) + - bootmeth - a method to scan a bootdev to find bootflows (owned by + U-Boot) + - bootflow - a description of how to boot (owned by the distro) + +config BOOTSTD_FULL + bool "Enhanced features for standard boot" + default y if SANDBOX + help + This enables various useful features for standard boot, which are not + essential for operation: + + - bootdev, bootmeth commands + - extra features in the bootflow command + - support for selecting the ordering of bootmeths ("bootmeth order") + - support for selecting the ordering of bootdevs using the devicetree + as well as the "boot_targets" environment variable + config LEGACY_IMAGE_FORMAT bool "Enable support for the legacy image format" default y if !FIT_SIGNATURE diff --git a/boot/Makefile b/boot/Makefile index 2938c3f145..48031d1c2b 100644 --- a/boot/Makefile +++ b/boot/Makefile @@ -22,6 +22,9 @@ endif 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) += bootstd-uclass.o + obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += image-fdt.o obj-$(CONFIG_$(SPL_TPL_)FIT_SIGNATURE) += fdt_region.o obj-$(CONFIG_$(SPL_TPL_)FIT) += image-fit.o diff --git a/boot/bootstd-uclass.c b/boot/bootstd-uclass.c new file mode 100644 index 0000000000..615cd89bf0 --- /dev/null +++ b/boot/bootstd-uclass.c @@ -0,0 +1,152 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Uclass implementation for standard boot + * + * Copyright 2021 Google LLC + * Written by Simon Glass sjg@chromium.org + */ + +#include <common.h> +#include <bootflow.h> +#include <bootstd.h> +#include <dm.h> +#include <log.h> +#include <malloc.h> +#include <dm/device-internal.h> +#include <dm/lists.h> +#include <dm/read.h> +#include <dm/uclass-internal.h> + +DECLARE_GLOBAL_DATA_PTR; + +/* These are used if filename-prefixes is not present */ +const char *const default_prefixes[] = {"/", "/boot/", NULL}; + +static int bootstd_of_to_plat(struct udevice *dev) +{ + struct bootstd_priv *priv = dev_get_priv(dev); + int ret; + + if (IS_ENABLED(CONFIG_BOOTSTD_FULL)) { + /* Don't check errors since livetree and flattree are different */ + ret = dev_read_string_list(dev, "filename-prefixes", + &priv->prefixes); + dev_read_string_list(dev, "bootdev-order", + &priv->bootdev_order); + } + + return 0; +} + +static void bootstd_clear_glob_(struct bootstd_priv *priv) +{ + while (!list_empty(&priv->glob_head)) { + struct bootflow *bflow; + + bflow = list_first_entry(&priv->glob_head, struct bootflow, + glob_node); + /* add later bootflow_remove(bflow); */ + } +} + +void bootstd_clear_glob(void) +{ + struct bootstd_priv *std; + + if (bootstd_get_priv(&std)) + return; + + bootstd_clear_glob_(std); +} + +static int bootstd_remove(struct udevice *dev) +{ + struct bootstd_priv *priv = dev_get_priv(dev); + + free(priv->prefixes); + free(priv->bootdev_order); + bootstd_clear_glob_(priv); + + return 0; +} + +const char *const *const bootstd_get_bootdev_order(struct udevice *dev) +{ + struct bootstd_priv *std = dev_get_priv(dev); + + return std->bootdev_order; +} + +const char *const *const bootstd_get_prefixes(struct udevice *dev) +{ + struct bootstd_priv *std = dev_get_priv(dev); + + return std->prefixes ? std->prefixes : default_prefixes; +} + +int bootstd_get_priv(struct bootstd_priv **stdp) +{ + struct udevice *dev; + int ret; + + ret = uclass_first_device_err(UCLASS_BOOTSTD, &dev); + if (ret) + return ret; + *stdp = dev_get_priv(dev); + + return 0; +} + +static int bootstd_probe(struct udevice *dev) +{ + struct bootstd_priv *std = dev_get_priv(dev); + + INIT_LIST_HEAD(&std->glob_head); + + return 0; +} + +/* For now, bind the boormethod device if none are found in the devicetree */ +int dm_scan_other(bool pre_reloc_only) +{ + struct udevice *bootstd; + int ret; + + /* These are not needed before relocation */ + if (!(gd->flags & GD_FLG_RELOC)) + return 0; + + /* Create a bootstd device if needed */ + uclass_find_first_device(UCLASS_BOOTSTD, &bootstd); + if (!bootstd) { + ret = device_bind_driver(gd->dm_root, "bootstd_drv", "bootstd", + &bootstd); + if (ret) + return log_msg_ret("bootstd", ret); + } + + return 0; +} + +static const struct udevice_id bootstd_ids[] = { + { .compatible = "u-boot,boot-std" }, + { } +}; + +U_BOOT_DRIVER(bootstd_drv) = { + .id = UCLASS_BOOTSTD, + .name = "bootstd_drv", + .of_to_plat = bootstd_of_to_plat, + .probe = bootstd_probe, + .remove = bootstd_remove, + .of_match = bootstd_ids, + .priv_auto = sizeof(struct bootstd_priv), +}; + +UCLASS_DRIVER(bootstd) = { + .id = UCLASS_BOOTSTD, + .name = "bootstd", +#if CONFIG_IS_ENABLED(OF_REAL) + .post_bind = dm_scan_fdt_dev, +#endif +}; diff --git a/doc/device-tree-bindings/bootstd.txt b/doc/device-tree-bindings/bootstd.txt new file mode 100644 index 0000000000..f048b9dd32 --- /dev/null +++ b/doc/device-tree-bindings/bootstd.txt @@ -0,0 +1,28 @@ +U-Boot standard boot device (bootstd) +===================================== + +This is the controlling device for U-Boot standard boot, providing a way to +boot operating systems in a way that can be controlled by distros. + +Required properties: + +compatible: "u-boot,boot-std" + +Optional properties: + +filename-prefixes: + List of strings, each a directory to search for bootflow files + +bootdev-order: + List of bootdevs to check for bootflows, each a bootdev label (the media + uclass followed by the numeric sequence number of the media device) + + +Example: + + bootstd { + compatible = "u-boot,boot-std"; + + filename-prefixes = "/", "/boot/"; + bootdev-order = "mmc2", "mmc1"; + }; diff --git a/include/bootstd.h b/include/bootstd.h new file mode 100644 index 0000000000..b002365f4f --- /dev/null +++ b/include/bootstd.h @@ -0,0 +1,80 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Standard U-Boot boot framework + * + * Copyright 2021 Google LLC + * Written by Simon Glass sjg@chromium.org + */ + +#ifndef __bootstd_h +#define __bootstd_h + +struct udevice; + +/** + * struct bootstd_priv - priv data for the bootstd driver + * + * This is attached to the (only) bootstd device, so there is only one instance + * of this struct. It provides overall information about bootdevs and bootflows. + * + * @prefixes: NULL-terminated list of prefixes to use for bootflow filenames, + * e.g. "/", "/boot/"; NULL if none + * @bootdev_order: Order to use for bootdevs (or NULL if none), with each item + * being a bootdev label, e.g. "mmc2", "mmc1"; + * @cur_bootdev: Currently selected bootdev (for commands) + * @cur_bootflow: Currently selected bootflow (for commands) + * @glob_head: Head for the global list of all bootflows across all bootdevs + * @bootmeth_count: Number of bootmeth devices in @bootmeth_order + * @bootmeth_order: List of bootmeth devices to use, in order, NULL-terminated + */ +struct bootstd_priv { + const char **prefixes; + const char **bootdev_order; + struct udevice *cur_bootdev; + struct bootflow *cur_bootflow; + struct list_head glob_head; + int bootmeth_count; + struct udevice **bootmeth_order; +}; + +/** + * bootstd_get_bootdev_order() - Get the boot-order list + * + * This reads the boot order, e.g. {"mmc0", "mmc2", NULL} + * + * The list is alloced by the bootstd driver so should not be freed. That is the + * reason for all the const stuff in the function signature + * + * Return: list of string points, terminated by NULL; or NULL if no boot order + */ +const char *const *const bootstd_get_bootdev_order(struct udevice *dev); + +/** + * bootstd_get_prefixes() - Get the filename-prefixes list + * + * This reads the prefixes, e.g. {"/", "/bpot", NULL} + * + * The list is alloced by the bootstd driver so should not be freed. That is the + * reason for all the const stuff in the function signature + * + * Return: list of string points, terminated by NULL; or NULL if no boot order + */ +const char *const *const bootstd_get_prefixes(struct udevice *dev); + +/** + * bootstd_get_priv() - Get the (single) state for the bootstd system + * + * The state holds a global list of all bootflows that have been found. + * + * Return: 0 if OK, -ve if the uclass does not exist + */ +int bootstd_get_priv(struct bootstd_priv **stdp); + +/** + * bootstd_clear_glob() - Clear the global list of bootflows + * + * This removes all bootflows globally and across all bootdevs. + */ +void bootstd_clear_glob(void); + +#endif diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h index 0e26e1d138..cece0626a1 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_BOOTSTD, /* Standard boot driver */ UCLASS_BUTTON, /* Button */ UCLASS_CACHE, /* Cache controller */ UCLASS_CLK, /* Clock source, e.g. used by peripherals */