diff --git a/target/linux/generic/files-5.4/include/nmbm/nmbm-os.h b/target/linux/generic/files-5.4/include/nmbm/nmbm-os.h
new file mode 100644
index 0000000..1cae854
--- /dev/null
+++ b/target/linux/generic/files-5.4/include/nmbm/nmbm-os.h
@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 MediaTek Inc. All Rights Reserved.
+ *
+ * OS-dependent definitions for NAND Mapped-block Management (NMBM)
+ *
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#ifndef _NMBM_OS_H_
+#define _NMBM_OS_H_
+
+#include <linux/kernel.h>
+#include <linux/limits.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/crc32.h>
+#include <linux/log2.h>
+#include <asm/div64.h>
+
+static inline uint32_t nmbm_crc32(uint32_t crcval, const void *buf, size_t size)
+{
+	uint chksz;
+	const unsigned char *p = buf;
+
+	while (size) {
+		if (size > UINT_MAX)
+			chksz = UINT_MAX;
+		else
+			chksz = (uint)size;
+
+		crcval = crc32_le(crcval, p, chksz);
+		size -= chksz;
+		p += chksz;
+	}
+
+	return crcval;
+}
+
+static inline uint32_t nmbm_lldiv(uint64_t dividend, uint32_t divisor)
+{
+#if BITS_PER_LONG == 64
+	return dividend / divisor;
+#else
+	do_div(dividend, divisor);
+	return dividend;
+#endif
+}
+
+#define WATCHDOG_RESET()
+
+#ifdef CONFIG_NMBM_LOG_LEVEL_DEBUG
+#define NMBM_DEFAULT_LOG_LEVEL		0
+#elif defined(NMBM_LOG_LEVEL_INFO)
+#define NMBM_DEFAULT_LOG_LEVEL		1
+#elif defined(NMBM_LOG_LEVEL_WARN)
+#define NMBM_DEFAULT_LOG_LEVEL		2
+#elif defined(NMBM_LOG_LEVEL_ERR)
+#define NMBM_DEFAULT_LOG_LEVEL		3
+#elif defined(NMBM_LOG_LEVEL_EMERG)
+#define NMBM_DEFAULT_LOG_LEVEL		4
+#elif defined(NMBM_LOG_LEVEL_NONE)
+#define NMBM_DEFAULT_LOG_LEVEL		5
+#else
+#define NMBM_DEFAULT_LOG_LEVEL		1
+#endif
+
+#endif /* _NMBM_OS_H_ */
diff --git a/target/linux/generic/files-5.4/include/nmbm/nmbm.h b/target/linux/generic/files-5.4/include/nmbm/nmbm.h
new file mode 100644
index 0000000..c1be892
--- /dev/null
+++ b/target/linux/generic/files-5.4/include/nmbm/nmbm.h
@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
+/*
+ * Copyright (C) 2020 MediaTek Inc. All Rights Reserved.
+ *
+ * Definitions for NAND Mapped-block Management (NMBM)
+ *
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#ifndef _NMBM_H_
+#define _NMBM_H_
+
+#include <nmbm/nmbm-os.h>
+
+enum nmbm_log_category {
+	NMBM_LOG_DEBUG,
+	NMBM_LOG_INFO,
+	NMBM_LOG_WARN,
+	NMBM_LOG_ERR,
+	NMBM_LOG_EMERG,
+
+	__NMBM_LOG_MAX
+};
+
+enum nmbm_oob_mode {
+	NMBM_MODE_PLACE_OOB,
+	NMBM_MODE_AUTO_OOB,
+	NMBM_MODE_RAW,
+
+	__NMBM_MODE_MAX
+};
+
+struct nmbm_lower_device {
+	uint32_t max_ratio;
+	uint32_t max_reserved_blocks;
+	int flags;
+
+	uint64_t size;
+	uint32_t erasesize;
+	uint32_t writesize;
+	uint32_t oobsize;
+	uint32_t oobavail;
+
+	void *arg;
+	int (*reset_chip)(void *arg);
+
+	/*
+	 * read_page:
+	 *    return 0 if succeeds
+	 *    return positive number for ecc error
+	 *    return negative number for other errors
+	 */
+	int (*read_page)(void *arg, uint64_t addr, void *buf, void *oob, enum nmbm_oob_mode mode);
+	int (*write_page)(void *arg, uint64_t addr, const void *buf, const void *oob, enum nmbm_oob_mode mode);
+	int (*erase_block)(void *arg, uint64_t addr);
+
+	int (*is_bad_block)(void *arg, uint64_t addr);
+	int (*mark_bad_block)(void *arg, uint64_t addr);
+
+	/* OS-dependent logging function */
+	void (*logprint)(void *arg, enum nmbm_log_category level, const char *fmt, va_list ap);
+};
+
+struct nmbm_instance;
+
+/* Create NMBM if management area not found, or not complete */
+#define NMBM_F_CREATE			0x01
+
+size_t nmbm_calc_structure_size(struct nmbm_lower_device *nld);
+int nmbm_attach(struct nmbm_lower_device *nld, struct nmbm_instance *ni);
+int nmbm_detach(struct nmbm_instance *ni);
+
+enum nmbm_log_category nmbm_set_log_level(struct nmbm_instance *ni,
+					  enum nmbm_log_category level);
+
+int nmbm_erase_block_range(struct nmbm_instance *ni, uint64_t addr,
+			   uint64_t size, uint64_t *failed_addr);
+int nmbm_read_single_page(struct nmbm_instance *ni, uint64_t addr, void *data,
+			  void *oob, enum nmbm_oob_mode mode);
+int nmbm_read_range(struct nmbm_instance *ni, uint64_t addr, size_t size,
+		    void *data, enum nmbm_oob_mode mode, size_t *retlen);
+int nmbm_write_single_page(struct nmbm_instance *ni, uint64_t addr,
+			   const void *data, const void *oob,
+			   enum nmbm_oob_mode mode);
+int nmbm_write_range(struct nmbm_instance *ni, uint64_t addr, size_t size,
+		     const void *data, enum nmbm_oob_mode mode,
+		     size_t *retlen);
+
+int nmbm_check_bad_block(struct nmbm_instance *ni, uint64_t addr);
+int nmbm_mark_bad_block(struct nmbm_instance *ni, uint64_t addr);
+
+uint64_t nmbm_get_avail_size(struct nmbm_instance *ni);
+
+int nmbm_get_lower_device(struct nmbm_instance *ni, struct nmbm_lower_device *nld);
+
+#endif /* _NMBM_H_ */