Add a boot device driver for MTD (Memory Technology Devices) that enables bootstd to scan MTD partitions for FIT images.
Add a mtd_bootdev_hunt() callback that: - Calls mtd_probe_devices() once to probe all MTD devices (both UCLASS_MTD and UCLASS_SPI_FLASH) and parse their partitions - Iterates the MTD subsystem device list and binds an mtd_bootdev for any top-level MTD device that has partitions but is not in UCLASS_MTD (those already get their bootdev from mtd_post_bind) - Uses bootdev_bind() directly since sf_bootdev may already occupy the standard bootdev child slot The MTD bootdev calls bootmeth_check() at the start of get_bootflow() so that only compatible bootmeths (those that accept MTD bootdevs) produce bootflows. Until bootmeth_openwrt's check() is extended to accept MTD bootdevs, this driver is inert — each commit compiles and introduces no regressions independently. Signed-off-by: Daniel Golle <[email protected]> --- boot/Kconfig | 9 +++ boot/Makefile | 1 + boot/mtd_bootdev.c | 150 +++++++++++++++++++++++++++++++++++++++ drivers/mtd/mtd-uclass.c | 15 ++++ 4 files changed, 175 insertions(+) create mode 100644 boot/mtd_bootdev.c diff --git a/boot/Kconfig b/boot/Kconfig index d8c7b8360ac..63e373cc62d 100644 --- a/boot/Kconfig +++ b/boot/Kconfig @@ -585,6 +585,15 @@ config BOOTMETH_CROS Note that only x86 devices are supported at present. +config BOOTDEV_MTD + bool "MTD bootdev support" + depends on DM_MTD + depends on BOOTSTD + help + Enable a boot device for MTD (Memory Technology Devices). + This scans MTD partitions for uImage.FIT firmware images, + enabling raw-flash boot via the OpenWrt boot method. + config BOOTMETH_OPENWRT bool "Bootdev support for OpenWrt" depends on FIT diff --git a/boot/Makefile b/boot/Makefile index 7b42358eb0c..feeed4924dd 100644 --- a/boot/Makefile +++ b/boot/Makefile @@ -72,6 +72,7 @@ obj-$(CONFIG_$(PHASE_)BOOTMETH_VBE_SIMPLE_FW) += vbe_simple_fw.o obj-$(CONFIG_$(PHASE_)BOOTMETH_VBE_SIMPLE_OS) += vbe_simple_os.o obj-$(CONFIG_$(PHASE_)BOOTMETH_ANDROID) += bootmeth_android.o +obj-$(CONFIG_$(PHASE_)BOOTDEV_MTD) += mtd_bootdev.o obj-$(CONFIG_$(PHASE_)BOOTMETH_OPENWRT) += bootmeth_openwrt.o obj-$(CONFIG_IMAGE_LOADER) += image-loader.o diff --git a/boot/mtd_bootdev.c b/boot/mtd_bootdev.c new file mode 100644 index 00000000000..8a3304be988 --- /dev/null +++ b/boot/mtd_bootdev.c @@ -0,0 +1,150 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * MTD boot device + * + * Copyright (C) 2026 Daniel Golle <[email protected]> + */ + +#define LOG_CATEGORY UCLASS_BOOTSTD + +#include <bootdev.h> +#include <bootflow.h> +#include <bootmeth.h> +#include <dm.h> +#include <malloc.h> +#include <mtd.h> +#include <linux/libfdt.h> + +static int mtd_bootdev_get_bootflow(struct udevice *dev, + struct bootflow_iter *iter, + struct bootflow *bflow) +{ + struct udevice *parent = dev_get_parent(dev); + struct mtd_info *mtd, *part; + u8 buf[40]; + size_t retlen; + char dname[60]; + int n = 0; + int ret; + + ret = bootmeth_check(bflow->method, iter); + if (ret) + return log_msg_ret("chk", ret); + + /* Find the top-level MTD device matching our parent */ + mtd_for_each_device(mtd) { + if (!mtd_is_partition(mtd) && mtd->dev == parent) + break; + } + if (!mtd || mtd->dev != parent) + return log_msg_ret("mtd", -ESHUTDOWN); + + /* Count partitions so the scanning framework knows the bound */ + list_for_each_entry(part, &mtd->partitions, node) + n++; + if (n) + iter->max_part = n - 1; + + n = 0; + + /* Walk to the iter->part'th sub-partition */ + list_for_each_entry(part, &mtd->partitions, node) { + if (n == iter->part) + goto found; + n++; + } + return -ESHUTDOWN; + +found: + ret = mtd_read(part, 0, sizeof(buf), &retlen, buf); + if (ret || retlen < sizeof(buf)) + return log_msg_ret("rd", -EIO); + + if (fdt_check_header(buf)) + return log_msg_ret("fdt", -ENOENT); + + /* Device-style name and partition index for bootflow list display */ + snprintf(dname, sizeof(dname), "%s.part_%x", dev->name, iter->part); + bflow->name = strdup(dname); + bflow->part = iter->part; + bflow->fname = strdup(part->name); + bflow->bootmeth_priv = strdup(part->name); + bflow->state = BOOTFLOWST_MEDIA; + + return bootmeth_read_bootflow(bflow->method, bflow); +} + +static int mtd_bootdev_bind(struct udevice *dev) +{ + struct bootdev_uc_plat *ucp = dev_get_uclass_plat(dev); + + ucp->prio = BOOTDEVP_4_SCAN_FAST; + + return 0; +} + +struct bootdev_ops mtd_bootdev_ops = { + .get_bootflow = mtd_bootdev_get_bootflow, +}; + +static const struct udevice_id mtd_bootdev_ids[] = { + { .compatible = "u-boot,bootdev-mtd" }, + { } +}; + +U_BOOT_DRIVER(mtd_bootdev) = { + .name = "mtd_bootdev", + .id = UCLASS_BOOTDEV, + .ops = &mtd_bootdev_ops, + .bind = mtd_bootdev_bind, + .of_match = mtd_bootdev_ids, +}; + +/** + * mtd_bootdev_hunt() - probe MTD devices and bind bootdevs + * + * Call mtd_probe_devices() to ensure all MTD devices (including SPI NOR + * flash via CONFIG_SPI_FLASH_MTD) are probed and their partitions parsed. + * + * UCLASS_MTD devices already get an mtd_bootdev via mtd_post_bind(). + * This creates mtd_bootdev instances for other MTD devices (e.g. SPI NOR + * in UCLASS_SPI_FLASH) that have partitions but would otherwise lack one. + * bootdev_bind() is used directly because sf_bootdev may already occupy + * the standard bootdev child slot. + */ +static int mtd_bootdev_hunt(struct bootdev_hunter *info, bool show) +{ + struct mtd_info *mtd; + struct udevice *bdev; + + mtd_probe_devices(); + + mtd_for_each_device(mtd) { + /* Only top-level MTD devices, not partitions */ + if (mtd_is_partition(mtd)) + continue; + + /* Must have a DM device */ + if (!mtd->dev) + continue; + + /* UCLASS_MTD devices already have mtd_bootdev from post_bind */ + if (device_get_uclass_id(mtd->dev) == UCLASS_MTD) + continue; + + /* Only interested in MTD devices that have partitions */ + if (list_empty(&mtd->partitions)) + continue; + + bootdev_bind(mtd->dev, "mtd_bootdev", "mtdbootdev", &bdev); + } + + return 0; +} + +BOOTDEV_HUNTER(mtd_bootdev_hunter) = { + .prio = BOOTDEVP_4_SCAN_FAST, + .uclass = UCLASS_MTD, + .drv = DM_DRIVER_REF(mtd_bootdev), + .hunt = mtd_bootdev_hunt, +}; diff --git a/drivers/mtd/mtd-uclass.c b/drivers/mtd/mtd-uclass.c index 720bd824c4d..0c637d3f5ec 100644 --- a/drivers/mtd/mtd-uclass.c +++ b/drivers/mtd/mtd-uclass.c @@ -5,11 +5,25 @@ #define LOG_CATEGORY UCLASS_MTD +#include <bootdev.h> #include <dm.h> #include <dm/device-internal.h> #include <errno.h> #include <mtd.h> +static int mtd_post_bind(struct udevice *dev) +{ + if (CONFIG_IS_ENABLED(BOOTDEV_MTD)) { + int ret; + + ret = bootdev_setup_for_dev(dev, "mtd_bootdev"); + if (ret) + return log_msg_ret("bd", ret); + } + + return 0; +} + /* * Implement a MTD uclass which should include most flash drivers. * The uclass private is pointed to mtd_info. @@ -18,5 +32,6 @@ UCLASS_DRIVER(mtd) = { .id = UCLASS_MTD, .name = "mtd", + .post_bind = mtd_post_bind, .per_device_auto = sizeof(struct mtd_info), }; -- 2.53.0
