diff --git a/target/linux/generic/files-5.4/drivers/mtd/nmbm/nmbm-private.h b/target/linux/generic/files-5.4/drivers/mtd/nmbm/nmbm-private.h
new file mode 100644
index 0000000..c285aeb
--- /dev/null
+++ b/target/linux/generic/files-5.4/drivers/mtd/nmbm/nmbm-private.h
@@ -0,0 +1,137 @@
+/* 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_PRIVATE_H_
+#define _NMBM_PRIVATE_H_
+
+#include <nmbm/nmbm.h>
+
+#define NMBM_MAGIC_SIGNATURE			0x304d4d4e	/* NMM0 */
+#define NMBM_MAGIC_INFO_TABLE			0x314d4d4e	/* NMM1 */
+
+#define NMBM_VERSION_MAJOR_S			0
+#define NMBM_VERSION_MAJOR_M			0xffff
+#define NMBM_VERSION_MINOR_S			16
+#define NMBM_VERSION_MINOR_M			0xffff
+#define NMBM_VERSION_MAKE(major, minor)		(((major) & NMBM_VERSION_MAJOR_M) | \
+						(((minor) & NMBM_VERSION_MINOR_M) << \
+						NMBM_VERSION_MINOR_S))
+#define NMBM_VERSION_MAJOR_GET(ver)		(((ver) >> NMBM_VERSION_MAJOR_S) & \
+						NMBM_VERSION_MAJOR_M)
+#define NMBM_VERSION_MINOR_GET(ver)		(((ver) >> NMBM_VERSION_MINOR_S) & \
+						NMBM_VERSION_MINOR_M)
+
+typedef uint32_t				nmbm_bitmap_t;
+#define NMBM_BITMAP_UNIT_SIZE			(sizeof(nmbm_bitmap_t))
+#define NMBM_BITMAP_BITS_PER_BLOCK		2
+#define NMBM_BITMAP_BITS_PER_UNIT		(8 * sizeof(nmbm_bitmap_t))
+#define NMBM_BITMAP_BLOCKS_PER_UNIT		(NMBM_BITMAP_BITS_PER_UNIT / \
+						 NMBM_BITMAP_BITS_PER_BLOCK)
+
+#define NMBM_SPARE_BLOCK_MULTI			1
+#define NMBM_SPARE_BLOCK_DIV			2
+#define NMBM_SPARE_BLOCK_MIN			2
+
+#define NMBM_MGMT_DIV				16
+#define NMBM_MGMT_BLOCKS_MIN			32
+
+#define NMBM_TRY_COUNT				3
+
+#define BLOCK_ST_BAD				0
+#define BLOCK_ST_NEED_REMAP			2
+#define BLOCK_ST_GOOD				3
+#define BLOCK_ST_MASK				3
+
+struct nmbm_header {
+	uint32_t magic;
+	uint32_t version;
+	uint32_t size;
+	uint32_t checksum;
+};
+
+struct nmbm_signature {
+	struct nmbm_header header;
+	uint64_t nand_size;
+	uint32_t block_size;
+	uint32_t page_size;
+	uint32_t spare_size;
+	uint32_t mgmt_start_pb;
+	uint8_t max_try_count;
+	uint8_t padding[3];
+};
+
+struct nmbm_info_table_header {
+	struct nmbm_header header;
+	uint32_t write_count;
+	uint32_t state_table_off;
+	uint32_t mapping_table_off;
+	uint32_t padding;
+};
+
+struct nmbm_instance {
+	struct nmbm_lower_device lower;
+
+	uint32_t rawpage_size;
+	uint32_t rawblock_size;
+	uint32_t rawchip_size;
+
+	uint32_t writesize_mask;
+	uint32_t erasesize_mask;
+	uint16_t writesize_shift;
+	uint16_t erasesize_shift;
+
+	struct nmbm_signature signature;
+
+	uint8_t *info_table_cache;
+	uint32_t info_table_size;
+	uint32_t info_table_spare_blocks;
+	struct nmbm_info_table_header info_table;
+
+	nmbm_bitmap_t *block_state;
+	uint32_t block_state_changed;
+	uint32_t state_table_size;
+
+	int32_t *block_mapping;
+	uint32_t block_mapping_changed;
+	uint32_t mapping_table_size;
+
+	uint8_t *page_cache;
+
+	int protected;
+
+	uint32_t block_count;
+	uint32_t data_block_count;
+
+	uint32_t mgmt_start_ba;
+	uint32_t main_table_ba;
+	uint32_t backup_table_ba;
+	uint32_t mapping_blocks_ba;
+	uint32_t mapping_blocks_top_ba;
+	uint32_t signature_ba;
+
+	enum nmbm_log_category log_display_level;
+};
+
+/* Log utilities */
+#define nlog_debug(ni, fmt, ...) \
+	nmbm_log(ni, NMBM_LOG_DEBUG, fmt, ##__VA_ARGS__)
+
+#define nlog_info(ni, fmt, ...) \
+	nmbm_log(ni, NMBM_LOG_INFO, fmt, ##__VA_ARGS__)
+
+#define nlog_warn(ni, fmt, ...) \
+	nmbm_log(ni, NMBM_LOG_WARN, fmt, ##__VA_ARGS__)
+
+#define nlog_err(ni, fmt, ...) \
+	nmbm_log(ni, NMBM_LOG_ERR, fmt, ##__VA_ARGS__)
+
+#define nlog_emerg(ni, fmt, ...) \
+	nmbm_log(ni, NMBM_LOG_EMERG, fmt, ##__VA_ARGS__)
+
+#endif /* _NMBM_PRIVATE_H_ */