[PATCH v2] spl: Add generic SPL MTD loader support
Fabio Estevam
festevam at gmail.com
Fri Feb 20 04:12:32 CET 2026
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>
---
Changes since v1:
- Use uclass_get_device_by_seq().
- Use puts() instead of debug() for error.
- Include the new loader to include/spl_load.h.
- Introduce SPL_MTD_SPI_NAND.
common/spl/Kconfig | 30 ++++++++++++++
common/spl/Makefile | 1 +
common/spl/spl_mtd.c | 83 +++++++++++++++++++++++++++++++++++++++
drivers/mtd/Makefile | 1 +
drivers/mtd/nand/Makefile | 4 +-
include/spl_load.h | 1 +
6 files changed, 119 insertions(+), 1 deletion(-)
create mode 100644 common/spl/spl_mtd.c
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index 2998b7acb75f..16dbc5b54324 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -933,6 +933,12 @@ config SYS_MMCSD_FS_BOOT_PARTITION
used in fs mode.
Use -1 as a special value to use the first bootable partition.
+config SYS_SPL_MTD_SEQ
+ int "MTD device number for the SPL load"
+ default 0
+ help
+ MTD device number used for the SPL load.
+
config SPL_MMC_TINY
bool "Tiny MMC framework in SPL"
depends on SPL_MMC
@@ -1578,6 +1584,30 @@ config SPL_SPI_LOAD
endif # SPL_SPI_FLASH_SUPPORT
+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 the next stage from an MTD device
+ using the MTD subsystem in SPL.
+
+ This supports raw NAND and SPI NAND devices.
+
+config SPL_MTD_SPI_NAND
+ bool "Enable SPI NAND support in SPL"
+ depends on SPL_MTD_LOAD
+ select MTD_SPI_NAND
+ help
+ Build SPI NAND support for SPL.
+
+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..67fc1cd1b396 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-$(CONFIG_SPL_MTD_LOAD) += spl_mtd.o
obj-$(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..904f1fbad834
--- /dev/null
+++ b/common/spl/spl_mtd.c
@@ -0,0 +1,83 @@
+// 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;
+
+ ret = uclass_get_device_by_seq(UCLASS_MTD, CONFIG_SYS_SPL_MTD_SEQ, &dev);
+ if (ret)
+ return NULL;
+
+ return dev_get_uclass_priv(dev);
+}
+
+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) {
+ puts("SPL: No MTD device found\n");
+ 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/
obj-$(CONFIG_$(PHASE_)NAND_SUPPORT) += nand/
obj-$(CONFIG_SPL_ONENAND_SUPPORT) += onenand/
obj-$(CONFIG_$(PHASE_)SPI_FLASH_SUPPORT) += spi/
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index c8169cf73902..4bc11054ad74 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -1,10 +1,12 @@
# SPDX-License-Identifier: GPL-2.0+
-ifeq ($(CONFIG_XPL_BUILD)$(CONFIG_TPL_BUILD),)
nandcore-objs := core.o bbt.o
+ifeq ($(CONFIG_XPL_BUILD)$(CONFIG_TPL_BUILD),)
obj-$(CONFIG_MTD_NAND_CORE) += nandcore.o
obj-$(CONFIG_MTD_RAW_NAND) += raw/
obj-$(CONFIG_MTD_SPI_NAND) += spi/
else
+obj-$(CONFIG_SPL_MTD_LOAD) += nandcore.o
+obj-$(CONFIG_SPL_MTD_SPI_NAND) += spi/
obj-$(CONFIG_$(PHASE_)NAND_SUPPORT) += raw/
endif
diff --git a/include/spl_load.h b/include/spl_load.h
index 525e0c9e86c6..5b06fa419dbf 100644
--- a/include/spl_load.h
+++ b/include/spl_load.h
@@ -113,6 +113,7 @@ static inline int _spl_load(struct spl_image_info *spl_image,
IS_ENABLED(CONFIG_SPL_NOR_SUPPORT) + \
IS_ENABLED(CONFIG_SPL_SEMIHOSTING) + \
IS_ENABLED(CONFIG_SPL_SPI_LOAD) + \
+ IS_ENABLED(CONFIG_SPL_MTD_LOAD) + \
0
#if SPL_LOAD_USERS > 1
--
2.34.1
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