[PATCH] spl: Add generic SPL MTD loader support
Sean Anderson
seanga2 at gmail.com
Tue Feb 17 16:11:23 CET 2026
On 2/11/26 17:25, Fabio Estevam wrote:
> From: Fabio Estevam <festevam at nabladev.com>
>
> Add support for loading the next stage from an MTD device in SPL.
>
> Introduce CONFIG_SPL_MTD_LOAD and a generic SPL MTD loader
> implementation that uses the MTD subsystem to read the U-Boot payload.
>
> The loader works with any MTD-backed storage, including raw NAND and
> SPI NAND, without being tied to a specific NAND type.
>
> The payload offset defaults to CONFIG_SYS_MTD_U_BOOT_OFFS and can be
> overridden via the device tree property:
>
> u-boot,spl-payload-offset
>
> To support both raw NAND and SPI NAND boot flows, the loader is
> registered for BOOT_DEVICE_NAND and BOOT_DEVICE_SPI. This allows it
> to operate correctly on platforms where the ROM reports either NAND
> or SPI as the boot source while using the same MTD-based loading
> infrastructure.
>
> The required NAND core and SPI NAND drivers are built for SPL when
> CONFIG_SPL_MTD_LOAD is enabled.
>
> This provides reusable infrastructure for boards that boot from MTD
> devices without relying on SPI-specific or NAND-specific SPL loaders.
>
> Signed-off-by: Fabio Estevam <festevam at nabladev.com>
Thanks for putting this together. For platforms that have the space this
is definitely the way to go.
> ---
> Dinesh,
>
> Could you please test this approach on your boards?
>
> Thanks
>
> common/spl/Kconfig | 15 +++++++
> common/spl/Makefile | 1 +
> common/spl/spl_mtd.c | 88 +++++++++++++++++++++++++++++++++++++++
> drivers/mtd/Makefile | 1 +
> drivers/mtd/nand/Makefile | 12 +++++-
> 5 files changed, 116 insertions(+), 1 deletion(-)
> create mode 100644 common/spl/spl_mtd.c
>
> diff --git a/common/spl/Kconfig b/common/spl/Kconfig
> index 2998b7acb75f..2aba6da73c10 100644
> --- a/common/spl/Kconfig
> +++ b/common/spl/Kconfig
> @@ -1576,8 +1576,23 @@ config SPL_SPI_LOAD
> Enable support for loading next stage, U-Boot or otherwise, from
> SPI NOR in U-Boot SPL.
>
> +config SPL_MTD_LOAD
> + bool "Support loading from a generic MTD device"
> + depends on SPL
> + depends on MTD && DM_MTD
> + help
> + Enable support for loading next stage, U-Boot or otherwise, from
> + a generic MTD device (raw NAND, SPI NAND) in U-Boot SPL.
> +
> endif # SPL_SPI_FLASH_SUPPORT
>
> +config SYS_MTD_U_BOOT_OFFS
> + hex "address of u-boot payload in the MTD device"
> + default 0x0
> + help
> + Address within the MTD device where the u-boot payload is fetched
> + from.
> +
> config SYS_SPI_U_BOOT_OFFS
> hex "address of u-boot payload in SPI flash"
> default 0x8000 if ARCH_SUNXI
> diff --git a/common/spl/Makefile b/common/spl/Makefile
> index 4c9482bd3096..9f5ddcad17af 100644
> --- a/common/spl/Makefile
> +++ b/common/spl/Makefile
> @@ -35,6 +35,7 @@ obj-$(CONFIG_$(PHASE_)NVME) += spl_nvme.o
> obj-$(CONFIG_$(PHASE_)SEMIHOSTING) += spl_semihosting.o
> obj-$(CONFIG_$(PHASE_)DFU) += spl_dfu.o
> obj-$(CONFIG_$(PHASE_)SPI_LOAD) += spl_spi.o
> +obj-$(CONFIG_$(PHASE_)MTD_LOAD) += spl_mtd.o
> obj-$(CONFIG_$(PHASE_)RAM_SUPPORT) += spl_ram.o
> obj-$(CONFIG_$(PHASE_)USB_SDP_SUPPORT) += spl_sdp.o
> endif
> diff --git a/common/spl/spl_mtd.c b/common/spl/spl_mtd.c
> new file mode 100644
> index 000000000000..8c6c94e592d0
> --- /dev/null
> +++ b/common/spl/spl_mtd.c
> @@ -0,0 +1,88 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +
> +/*
> + * Generic SPL loader for MTD devices.
> + *
> + * Based on spl_spi.c, which is:
> + *
> + * Copyright (C) 2011 OMICRON electronics GmbH
> + *
> + * based on drivers/mtd/nand/raw/nand_spl_load.c
> + *
> + * Copyright (C) 2011
> + * Heiko Schocher, DENX Software Engineering, hs at denx.de.
> + */
> +
> +#include <config.h>
> +#include <errno.h>
> +#include <image.h>
> +#include <log.h>
> +#include <spl.h>
> +#include <spl_load.h>
> +
> +#include <dm.h>
> +#include <dm/ofnode.h>
> +#include <dm/uclass.h>
> +#include <mtd.h>
> +
> +static struct mtd_info *spl_mtd_get_device(void)
> +{
> + struct udevice *dev;
> + int ret;
> +
> + for (ret = uclass_first_device_err(UCLASS_MTD, &dev);
> + dev;
> + ret = uclass_next_device_err(&dev)) {
> + if (ret)
> + continue;
> +
> + return dev_get_uclass_priv(dev);
> + }
I think this should be uclass_get_device_by_seq(UCLASS_MTD,
CONFIG_SYS_MTD_SEQ) or use the above method if e.g.
CONFIG_SYS_MTD_U_BOOT_OFFS is -1.
> +
> + return NULL;
> +}
> +
> +static ulong spl_mtd_read(struct spl_load_info *load,
> + ulong offs, ulong size, void *buf)
> +{
> + struct mtd_info *mtd = load->priv;
> + size_t retlen;
> + int ret;
> +
> + ret = mtd_read(mtd, offs, size, &retlen, buf);
> + if (ret && !mtd_is_bitflip(ret))
> + return 0;
> +
> + if (retlen != size)
> + return 0;
> +
> + return retlen;
> +}
> +
> +static int spl_mtd_load_image(struct spl_image_info *spl_image,
> + struct spl_boot_device *bootdev)
> +{
> + struct spl_load_info load;
> + struct mtd_info *mtd;
> + ulong offset;
> +
> + mtd = spl_mtd_get_device();
> + if (!mtd) {
> + debug("No MTD device found\n");
This should be a puts, as otherwise there will be no error printed at all.
> + return -ENODEV;
> + }
> +
> + spl_load_init(&load, spl_mtd_read, mtd, mtd->writesize);
> +
> + offset = CONFIG_SYS_MTD_U_BOOT_OFFS;
> +
> + if (CONFIG_IS_ENABLED(OF_REAL))
> + offset = ofnode_conf_read_int("u-boot,spl-payload-offset",
> + offset);
> +
> + return spl_load(spl_image, bootdev, &load, 0, offset);
> +}
> +
> +/* Priority 1 so boards may override */
> +SPL_LOAD_IMAGE_METHOD("MTD-NAND", 1, BOOT_DEVICE_NAND, spl_mtd_load_image);
> +SPL_LOAD_IMAGE_METHOD("MTD-SPI-NAND", 1, BOOT_DEVICE_SPI, spl_mtd_load_image);
> diff --git a/drivers/mtd/Makefile b/drivers/mtd/Makefile
> index ce05e206073d..0856a8f68732 100644
> --- a/drivers/mtd/Makefile
> +++ b/drivers/mtd/Makefile
> @@ -34,6 +34,7 @@ else
> ifneq ($(mtd-y),)
> obj-$(CONFIG_SPL_MTD) += mtd.o
> endif
> +obj-$(CONFIG_SPL_MTD_LOAD) += nand/
You should add this to the list in include/spl_load.h.
> obj-$(CONFIG_$(PHASE_)NAND_SUPPORT) += nand/
> obj-$(CONFIG_SPL_ONENAND_SUPPORT) += onenand/
> obj-$(CONFIG_$(PHASE_)SPI_FLASH_SUPPORT) += spi/
> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
> index c8169cf73902..cd6eaa87739c 100644
> --- a/drivers/mtd/nand/Makefile
> +++ b/drivers/mtd/nand/Makefile
> @@ -1,10 +1,20 @@
> # SPDX-License-Identifier: GPL-2.0+
>
> -ifeq ($(CONFIG_XPL_BUILD)$(CONFIG_TPL_BUILD),)
> nandcore-objs := core.o bbt.o
> +
> +ifeq ($(CONFIG_XPL_BUILD),)
> +
> +# U-Boot proper
> obj-$(CONFIG_MTD_NAND_CORE) += nandcore.o
> obj-$(CONFIG_MTD_RAW_NAND) += raw/
> obj-$(CONFIG_MTD_SPI_NAND) += spi/
> +
> else
> +
> +# XPL
> +obj-$(CONFIG_SPL_MTD_LOAD) += nandcore.o
> +obj-$(CONFIG_SPL_MTD_LOAD) += spi/
This should be done in Kconfig. Some platforms may want to load from different
MTD combinations, e.g. SPI nand and SPI nor.
> +
> +# raw NAND still follows the normal SPL rule
> obj-$(CONFIG_$(PHASE_)NAND_SUPPORT) += raw/
> endif
Please add a test for this. You should be able to extend test/image/spl_load_spi.c
and test/image/spl_load_nand.c
--Sean
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