diff --git a/tools/Makefile b/tools/Makefile
index 33e90a8..87d81a3 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -175,6 +175,9 @@
 ifdtool-objs := $(LIBFDT_OBJS) ifdtool.o
 hostprogs-$(CONFIG_X86) += ifdtool
 
+ifwitool-objs := ifwitool.o
+hostprogs-$(CONFIG_X86)$(CONFIG_SANDBOX) += ifwitool
+
 hostprogs-$(CONFIG_MX23) += mxsboot
 hostprogs-$(CONFIG_MX28) += mxsboot
 HOSTCFLAGS_mxsboot.o := -pedantic
diff --git a/tools/ifwitool.c b/tools/ifwitool.c
new file mode 100644
index 0000000..2e020a8
--- /dev/null
+++ b/tools/ifwitool.c
@@ -0,0 +1,2304 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ifwitool, CLI utility for Integrated Firmware Image (IFWI) manipulation
+ *
+ * This is taken from the Coreboot project
+ */
+
+#include <assert.h>
+#include <stdbool.h>
+#include <getopt.h>
+#include "os_support.h"
+
+#define __packed		__attribute__((packed))
+#define KiB			1024
+#define ALIGN(x, a)		__ALIGN_MASK((x), (typeof(x))(a) - 1)
+#define __ALIGN_MASK(x, mask)	(((x) + (mask)) & ~(mask))
+#define ARRAY_SIZE(x)		(sizeof(x) / sizeof((x)[0]))
+
+/*
+ * min()/max()/clamp() macros that also do
+ * strict type-checking.. See the
+ * "unnecessary" pointer comparison.
+ */
+#define min(x, y) ({				\
+	typeof(x) _min1 = (x);			\
+	typeof(y) _min2 = (y);			\
+	(void)&_min1 == &_min2);		\
+	_min1 < _min2 ? _min1 : _min2; })
+
+#define max(x, y) ({				\
+	typeof(x) _max1 = (x);			\
+	typeof(y) _max2 = (y);			\
+	(void)(&_max1 == &_max2);		\
+	_max1 > _max2 ? _max1 : _max2; })
+
+static int verbose = 1;
+
+/* Buffer and file I/O */
+struct buffer {
+	char *name;
+	char *data;
+	size_t offset;
+	size_t size;
+};
+
+#define ERROR(...) { fprintf(stderr, "E: " __VA_ARGS__); }
+#define INFO(...) { if (verbose > 0) fprintf(stderr, "INFO: " __VA_ARGS__); }
+#define DEBUG(...) { if (verbose > 1) fprintf(stderr, "DEBUG: " __VA_ARGS__); }
+
+/*
+ * BPDT is Boot Partition Descriptor Table. It is located at the start of a
+ * logical boot partition(LBP). It stores information about the critical
+ * sub-partitions present within the LBP.
+ *
+ * S-BPDT is Secondary Boot Partition Descriptor Table. It is located after the
+ * critical sub-partitions and contains information about the non-critical
+ * sub-partitions present within the LBP.
+ *
+ * Both tables are identified by BPDT_SIGNATURE stored at the start of the
+ * table.
+ */
+#define BPDT_SIGNATURE				(0x000055AA)
+
+/* Parameters passed in by caller */
+static struct param {
+	const char *file_name;
+	const char *subpart_name;
+	const char *image_name;
+	bool dir_ops;
+	const char *dentry_name;
+} param;
+
+struct bpdt_header {
+	/*
+	 * This is used to identify start of BPDT. It should always be
+	 * BPDT_SIGNATURE.
+	 */
+	uint32_t signature;
+	/* Count of BPDT entries present */
+	uint16_t descriptor_count;
+	/* Version - Currently supported = 1 */
+	uint16_t bpdt_version;
+	/* Unused - Should be 0 */
+	uint32_t xor_redundant_block;
+	/* Version of IFWI build */
+	uint32_t ifwi_version;
+	/* Version of FIT tool used to create IFWI */
+	uint64_t fit_tool_version;
+} __packed;
+#define BPDT_HEADER_SIZE			(sizeof(struct bpdt_header))
+
+struct bpdt_entry {
+	/* Type of sub-partition */
+	uint16_t type;
+	/* Attributes of sub-partition */
+	uint16_t flags;
+	/* Offset of sub-partition from beginning of LBP */
+	uint32_t offset;
+	/* Size in bytes of sub-partition */
+	uint32_t size;
+} __packed;
+#define BPDT_ENTRY_SIZE			(sizeof(struct bpdt_entry))
+
+struct bpdt {
+	struct bpdt_header h;
+	/* In practice, this could be an array of 0 to n entries */
+	struct bpdt_entry e[0];
+} __packed;
+
+static inline size_t get_bpdt_size(struct bpdt_header *h)
+{
+	return (sizeof(*h) + BPDT_ENTRY_SIZE * h->descriptor_count);
+}
+
+/* Minimum size in bytes allocated to BPDT in IFWI */
+#define BPDT_MIN_SIZE			((size_t)512)
+
+/* Header to define directory header for sub-partition */
+struct subpart_dir_header {
+	/* Should be SUBPART_DIR_MARKER */
+	uint32_t marker;
+	/* Number of directory entries in the sub-partition */
+	uint32_t num_entries;
+	/* Currenty supported - 1 */
+	uint8_t header_version;
+	/* Currenty supported - 1 */
+	uint8_t entry_version;
+	/* Length of directory header in bytes */
+	uint8_t header_length;
+	/*
+	 * 2s complement of 8-bit sum from first byte of header to last byte of
+	 * last directory entry.
+	 */
+	uint8_t checksum;
+	/* ASCII short name of sub-partition */
+	uint8_t name[4];
+} __packed;
+#define SUBPART_DIR_HEADER_SIZE			\
+					(sizeof(struct subpart_dir_header))
+#define SUBPART_DIR_MARKER				0x44504324
+#define SUBPART_DIR_HEADER_VERSION_SUPPORTED	1
+#define SUBPART_DIR_ENTRY_VERSION_SUPPORTED	1
+
+/* Structure for each directory entry for sub-partition */
+struct subpart_dir_entry {
+	/* Name of directory entry - Not guaranteed to be NULL-terminated */
+	uint8_t name[12];
+	/* Offset of entry from beginning of sub-partition */
+	uint32_t offset;
+	/* Length in bytes of sub-directory entry */
+	uint32_t length;
+	/* Must be zero */
+	uint32_t rsvd;
+} __packed;
+#define SUBPART_DIR_ENTRY_SIZE			\
+					(sizeof(struct subpart_dir_entry))
+
+struct subpart_dir {
+	struct subpart_dir_header h;
+	/* In practice, this could be an array of 0 to n entries */
+	struct subpart_dir_entry e[0];
+} __packed;
+
+static inline size_t subpart_dir_size(struct subpart_dir_header *h)
+{
+	return (sizeof(*h) + SUBPART_DIR_ENTRY_SIZE * h->num_entries);
+}
+
+struct manifest_header {
+	uint32_t header_type;
+	uint32_t header_length;
+	uint32_t header_version;
+	uint32_t flags;
+	uint32_t vendor;
+	uint32_t date;
+	uint32_t size;
+	uint32_t id;
+	uint32_t rsvd;
+	uint64_t version;
+	uint32_t svn;
+	uint64_t rsvd1;
+	uint8_t rsvd2[64];
+	uint32_t modulus_size;
+	uint32_t exponent_size;
+	uint8_t public_key[256];
+	uint32_t exponent;
+	uint8_t signature[256];
+} __packed;
+
+#define DWORD_SIZE				4
+#define MANIFEST_HDR_SIZE			(sizeof(struct manifest_header))
+#define MANIFEST_ID_MAGIC			(0x324e4d24)
+
+struct module {
+	uint8_t name[12];
+	uint8_t type;
+	uint8_t hash_alg;
+	uint16_t hash_size;
+	uint32_t metadata_size;
+	uint8_t metadata_hash[32];
+} __packed;
+
+#define MODULE_SIZE				(sizeof(struct module))
+
+struct signed_pkg_info_ext {
+	uint32_t ext_type;
+	uint32_t ext_length;
+	uint8_t name[4];
+	uint32_t vcn;
+	uint8_t bitmap[16];
+	uint32_t svn;
+	uint8_t rsvd[16];
+} __packed;
+
+#define SIGNED_PKG_INFO_EXT_TYPE		0x15
+#define SIGNED_PKG_INFO_EXT_SIZE		\
+	(sizeof(struct signed_pkg_info_ext))
+
+/*
+ * Attributes for various IFWI sub-partitions.
+ * LIES_WITHIN_BPDT_4K = Sub-Partition should lie within the same 4K block as
+ * BPDT.
+ * NON_CRITICAL_SUBPART = Sub-Partition entry should be present in S-BPDT.
+ * CONTAINS_DIR = Sub-Partition contains directory.
+ * AUTO_GENERATED = Sub-Partition is generated by the tool.
+ * MANDATORY_BPDT_ENTRY = Even if sub-partition is deleted, BPDT should contain
+ * an entry for it with size 0 and offset 0.
+ */
+enum subpart_attributes {
+	LIES_WITHIN_BPDT_4K = (1 << 0),
+	NON_CRITICAL_SUBPART = (1 << 1),
+	CONTAINS_DIR = (1 << 2),
+	AUTO_GENERATED = (1 << 3),
+	MANDATORY_BPDT_ENTRY = (1 << 4),
+};
+
+/* Type value for various IFWI sub-partitions */
+enum bpdt_entry_type {
+	SMIP_TYPE		= 0,
+	CSE_RBE_TYPE		= 1,
+	CSE_BUP_TYPE		= 2,
+	UCODE_TYPE		= 3,
+	IBB_TYPE		= 4,
+	S_BPDT_TYPE		= 5,
+	OBB_TYPE		= 6,
+	CSE_MAIN_TYPE		= 7,
+	ISH_TYPE		= 8,
+	CSE_IDLM_TYPE		= 9,
+	IFP_OVERRIDE_TYPE	= 10,
+	DEBUG_TOKENS_TYPE	= 11,
+	UFS_PHY_TYPE		= 12,
+	UFS_GPP_TYPE		= 13,
+	PMC_TYPE		= 14,
+	IUNIT_TYPE		= 15,
+	NVM_CONFIG_TYPE	= 16,
+	UEP_TYPE		= 17,
+	UFS_RATE_B_TYPE	= 18,
+	MAX_SUBPARTS		= 19,
+};
+
+/*
+ * There are two order requirements for an IFWI image:
+ * 1. Order in which the sub-partitions lie within the BPDT entries.
+ * 2. Order in which the sub-partitions lie within the image.
+ *
+ * header_order defines #1 i.e. the order in which the sub-partitions should
+ * appear in the BPDT entries. pack_order defines #2 i.e. the order in which
+ * sub-partitions appear in the IFWI image. pack_order controls the offset and
+ * thus sub-partitions would have increasing offsets as we loop over pack_order.
+ */
+const enum bpdt_entry_type bpdt_header_order[MAX_SUBPARTS] = {
+	/* Order of the following entries is mandatory */
+	CSE_IDLM_TYPE,
+	IFP_OVERRIDE_TYPE,
+	S_BPDT_TYPE,
+	CSE_RBE_TYPE,
+	UFS_PHY_TYPE,
+	UFS_GPP_TYPE,
+	/* Order of the following entries is recommended */
+	UEP_TYPE,
+	NVM_CONFIG_TYPE,
+	UFS_RATE_B_TYPE,
+	IBB_TYPE,
+	SMIP_TYPE,
+	PMC_TYPE,
+	CSE_BUP_TYPE,
+	UCODE_TYPE,
+	DEBUG_TOKENS_TYPE,
+	IUNIT_TYPE,
+	CSE_MAIN_TYPE,
+	ISH_TYPE,
+	OBB_TYPE,
+};
+
+const enum bpdt_entry_type bpdt_pack_order[MAX_SUBPARTS] = {
+	/* Order of the following entries is mandatory */
+	UFS_GPP_TYPE,
+	UFS_PHY_TYPE,
+	IFP_OVERRIDE_TYPE,
+	UEP_TYPE,
+	NVM_CONFIG_TYPE,
+	UFS_RATE_B_TYPE,
+	/* Order of the following entries is recommended */
+	IBB_TYPE,
+	SMIP_TYPE,
+	CSE_RBE_TYPE,
+	PMC_TYPE,
+	CSE_BUP_TYPE,
+	UCODE_TYPE,
+	CSE_IDLM_TYPE,
+	DEBUG_TOKENS_TYPE,
+	S_BPDT_TYPE,
+	IUNIT_TYPE,
+	CSE_MAIN_TYPE,
+	ISH_TYPE,
+	OBB_TYPE,
+};
+
+/* Utility functions */
+enum ifwi_ret {
+	COMMAND_ERR = -1,
+	NO_ACTION_REQUIRED = 0,
+	REPACK_REQUIRED = 1,
+};
+
+struct dir_ops {
+	enum ifwi_ret (*dir_add)(int type);
+};
+
+static enum ifwi_ret ibbp_dir_add(int type);
+
+const struct subpart_info {
+	const char *name;
+	const char *readable_name;
+	uint32_t attr;
+	struct dir_ops dir_ops;
+} subparts[MAX_SUBPARTS] = {
+	/* OEM SMIP */
+	[SMIP_TYPE] = {"SMIP", "SMIP", CONTAINS_DIR, {NULL} },
+	/* CSE RBE */
+	[CSE_RBE_TYPE] = {"RBEP", "CSE_RBE", CONTAINS_DIR |
+			  MANDATORY_BPDT_ENTRY, {NULL} },
+	/* CSE BUP */
+	[CSE_BUP_TYPE] = {"FTPR", "CSE_BUP", CONTAINS_DIR |
+			  MANDATORY_BPDT_ENTRY, {NULL} },
+	/* uCode */
+	[UCODE_TYPE] = {"UCOD", "Microcode", CONTAINS_DIR, {NULL} },
+	/* IBB */
+	[IBB_TYPE] = {"IBBP", "Bootblock", CONTAINS_DIR, {ibbp_dir_add} },
+	/* S-BPDT */
+	[S_BPDT_TYPE] = {"S_BPDT", "S-BPDT", AUTO_GENERATED |
+			 MANDATORY_BPDT_ENTRY, {NULL} },
+	/* OBB */
+	[OBB_TYPE] = {"OBBP", "OEM boot block", CONTAINS_DIR |
+		      NON_CRITICAL_SUBPART, {NULL} },
+	/* CSE Main */
+	[CSE_MAIN_TYPE] = {"NFTP", "CSE_MAIN", CONTAINS_DIR |
+			   NON_CRITICAL_SUBPART, {NULL} },
+	/* ISH */
+	[ISH_TYPE] = {"ISHP", "ISH", NON_CRITICAL_SUBPART, {NULL} },
+	/* CSE IDLM */
+	[CSE_IDLM_TYPE] = {"DLMP", "CSE_IDLM", CONTAINS_DIR |
+			   MANDATORY_BPDT_ENTRY, {NULL} },
+	/* IFP Override */
+	[IFP_OVERRIDE_TYPE] = {"IFP_OVERRIDE", "IFP_OVERRIDE",
+			       LIES_WITHIN_BPDT_4K | MANDATORY_BPDT_ENTRY,
+			       {NULL} },
+	/* Debug Tokens */
+	[DEBUG_TOKENS_TYPE] = {"DEBUG_TOKENS", "Debug Tokens", 0, {NULL} },
+	/* UFS Phy Configuration */
+	[UFS_PHY_TYPE] = {"UFS_PHY", "UFS Phy", LIES_WITHIN_BPDT_4K |
+			  MANDATORY_BPDT_ENTRY, {NULL} },
+	/* UFS GPP LUN ID */
+	[UFS_GPP_TYPE] = {"UFS_GPP", "UFS GPP", LIES_WITHIN_BPDT_4K |
+			  MANDATORY_BPDT_ENTRY, {NULL} },
+	/* PMC */
+	[PMC_TYPE] = {"PMCP", "PMC firmware", CONTAINS_DIR, {NULL} },
+	/* IUNIT */
+	[IUNIT_TYPE] = {"IUNP", "IUNIT", NON_CRITICAL_SUBPART, {NULL} },
+	/* NVM Config */
+	[NVM_CONFIG_TYPE] = {"NVM_CONFIG", "NVM Config", 0, {NULL} },
+	/* UEP */
+	[UEP_TYPE] = {"UEP", "UEP", LIES_WITHIN_BPDT_4K | MANDATORY_BPDT_ENTRY,
+		      {NULL} },
+	/* UFS Rate B Config */
+	[UFS_RATE_B_TYPE] = {"UFS_RATE_B", "UFS Rate B Config", 0, {NULL} },
+};
+
+struct ifwi_image {
+	/* Data read from input file */
+	struct buffer input_buff;
+
+	/* BPDT header and entries */
+	struct buffer bpdt;
+	size_t input_ifwi_start_offset;
+	size_t input_ifwi_end_offset;
+
+	/* Subpartition content */
+	struct buffer subpart_buf[MAX_SUBPARTS];
+} ifwi_image;
+
+/* Buffer and file I/O */
+static off_t get_file_size(FILE *f)
+{
+	off_t fsize;
+
+	fseek(f, 0, SEEK_END);
+	fsize = ftell(f);
+	fseek(f, 0, SEEK_SET);
+	return fsize;
+}
+
+static inline void *buffer_get(const struct buffer *b)
+{
+	return b->data;
+}
+
+static inline size_t buffer_size(const struct buffer *b)
+{
+	return b->size;
+}
+
+static inline size_t buffer_offset(const struct buffer *b)
+{
+	return b->offset;
+}
+
+/*
+ * Shrink a buffer toward the beginning of its previous space.
+ * Afterward, buffer_delete() remains the means of cleaning it up
+ */
+static inline void buffer_set_size(struct buffer *b, size_t size)
+{
+	b->size = size;
+}
+
+/* Splice a buffer into another buffer. Note that it's up to the caller to
+ * bounds check the offset and size. The resulting buffer is backed by the same
+ * storage as the original, so although it is valid to buffer_delete() either
+ * one of them, doing so releases both simultaneously
+ */
+static void buffer_splice(struct buffer *dest, const struct buffer *src,
+			  size_t offset, size_t size)
+{
+	dest->name = src->name;
+	dest->data = src->data + offset;
+	dest->offset = src->offset + offset;
+	dest->size = size;
+}
+
+/*
+ * Shrink a buffer toward the end of its previous space.
+ * Afterward, buffer_delete() remains the means of cleaning it up
+ */
+static inline void buffer_seek(struct buffer *b, size_t size)
+{
+	b->offset += size;
+	b->size -= size;
+	b->data += size;
+}
+
+/* Returns the start of the underlying buffer, with the offset undone */
+static inline void *buffer_get_original_backing(const struct buffer *b)
+{
+	if (!b)
+		return NULL;
+	return buffer_get(b) - buffer_offset(b);
+}
+
+int buffer_create(struct buffer *buffer, size_t size, const char *name)
+{
+	buffer->name = strdup(name);
+	buffer->offset = 0;
+	buffer->size = size;
+	buffer->data = (char *)malloc(buffer->size);
+	if (!buffer->data) {
+		fprintf(stderr, "%s: Insufficient memory (0x%zx).\n", __func__,
+			size);
+	}
+
+	return !buffer->data;
+}
+
+int buffer_write_file(struct buffer *buffer, const char *filename)
+{
+	FILE *fp = fopen(filename, "wb");
+
+	if (!fp) {
+		perror(filename);
+		return -1;
+	}
+	assert(buffer && buffer->data);
+	if (fwrite(buffer->data, 1, buffer->size, fp) != buffer->size) {
+		fprintf(stderr, "incomplete write: %s\n", filename);
+		fclose(fp);
+		return -1;
+	}
+	fclose(fp);
+	return 0;
+}
+
+void buffer_delete(struct buffer *buffer)
+{
+	assert(buffer);
+	if (buffer->name) {
+		free(buffer->name);
+		buffer->name = NULL;
+	}
+	if (buffer->data) {
+		free(buffer_get_original_backing(buffer));
+		buffer->data = NULL;
+	}
+	buffer->offset = 0;
+	buffer->size = 0;
+}
+
+int buffer_from_file(struct buffer *buffer, const char *filename)
+{
+	FILE *fp = fopen(filename, "rb");
+
+	if (!fp) {
+		perror(filename);
+		return -1;
+	}
+	buffer->offset = 0;
+	off_t file_size = get_file_size(fp);
+
+	if (file_size < 0) {
+		fprintf(stderr, "could not determine size of %s\n", filename);
+		fclose(fp);
+		return -1;
+	}
+	buffer->size = file_size;
+	buffer->name = strdup(filename);
+	buffer->data = (char *)malloc(buffer->size);
+	assert(buffer->data);
+	if (fread(buffer->data, 1, buffer->size, fp) != buffer->size) {
+		fprintf(stderr, "incomplete read: %s\n", filename);
+		fclose(fp);
+		buffer_delete(buffer);
+		return -1;
+	}
+	fclose(fp);
+	return 0;
+}
+
+static void alloc_buffer(struct buffer *b, size_t s, const char *n)
+{
+	if (buffer_create(b, s, n) == 0)
+		return;
+
+	ERROR("Buffer allocation failure for %s (size = %zx).\n", n, s);
+	exit(-1);
+}
+
+/* Little-Endian functions */
+static inline uint8_t read_ble8(const void *src)
+{
+	const uint8_t *s = src;
+	return *s;
+}
+
+static inline uint8_t read_at_ble8(const void *src, size_t offset)
+{
+	const uint8_t *s = src;
+
+	s += offset;
+	return read_ble8(s);
+}
+
+static inline void write_ble8(void *dest, uint8_t val)
+{
+	*(uint8_t *)dest = val;
+}
+
+static inline void write_at_ble8(void *dest, uint8_t val, size_t offset)
+{
+	uint8_t *d = dest;
+
+	d += offset;
+	write_ble8(d, val);
+}
+
+static inline uint8_t read_at_le8(const void *src, size_t offset)
+{
+	return read_at_ble8(src, offset);
+}
+
+static inline void write_le8(void *dest, uint8_t val)
+{
+	write_ble8(dest, val);
+}
+
+static inline void write_at_le8(void *dest, uint8_t val, size_t offset)
+{
+	write_at_ble8(dest, val, offset);
+}
+
+static inline uint16_t read_le16(const void *src)
+{
+	const uint8_t *s = src;
+
+	return (((uint16_t)s[1]) << 8) | (((uint16_t)s[0]) << 0);
+}
+
+static inline uint16_t read_at_le16(const void *src, size_t offset)
+{
+	const uint8_t *s = src;
+
+	s += offset;
+	return read_le16(s);
+}
+
+static inline void write_le16(void *dest, uint16_t val)
+{
+	write_le8(dest, val >> 0);
+	write_at_le8(dest, val >> 8, sizeof(uint8_t));
+}
+
+static inline void write_at_le16(void *dest, uint16_t val, size_t offset)
+{
+	uint8_t *d = dest;
+
+	d += offset;
+	write_le16(d, val);
+}
+
+static inline uint32_t read_le32(const void *src)
+{
+	const uint8_t *s = src;
+
+	return (((uint32_t)s[3]) << 24) | (((uint32_t)s[2]) << 16) |
+		(((uint32_t)s[1]) << 8) | (((uint32_t)s[0]) << 0);
+}
+
+static inline uint32_t read_at_le32(const void *src, size_t offset)
+{
+	const uint8_t *s = src;
+
+	s += offset;
+	return read_le32(s);
+}
+
+static inline void write_le32(void *dest, uint32_t val)
+{
+	write_le16(dest, val >> 0);
+	write_at_le16(dest, val >> 16, sizeof(uint16_t));
+}
+
+static inline void write_at_le32(void *dest, uint32_t val, size_t offset)
+{
+	uint8_t *d = dest;
+
+	d += offset;
+	write_le32(d, val);
+}
+
+static inline uint64_t read_le64(const void *src)
+{
+	uint64_t val;
+
+	val = read_at_le32(src, sizeof(uint32_t));
+	val <<= 32;
+	val |= read_le32(src);
+	return val;
+}
+
+static inline uint64_t read_at_le64(const void *src, size_t offset)
+{
+	const uint8_t *s = src;
+
+	s += offset;
+	return read_le64(s);
+}
+
+static inline void write_le64(void *dest, uint64_t val)
+{
+	write_le32(dest, val >> 0);
+	write_at_le32(dest, val >> 32, sizeof(uint32_t));
+}
+
+static inline void write_at_le64(void *dest, uint64_t val, size_t offset)
+{
+	uint8_t *d = dest;
+
+	d += offset;
+	write_le64(d, val);
+}
+
+/*
+ * Read header/entry members in little-endian format.
+ * Returns the offset upto which the read was performed.
+ */
+static size_t read_member(void *src, size_t offset, size_t size_bytes,
+			  void *dst)
+{
+	switch (size_bytes) {
+	case 1:
+		*(uint8_t *)dst = read_at_le8(src, offset);
+		break;
+	case 2:
+		*(uint16_t *)dst = read_at_le16(src, offset);
+		break;
+	case 4:
+		*(uint32_t *)dst = read_at_le32(src, offset);
+		break;
+	case 8:
+		*(uint64_t *)dst = read_at_le64(src, offset);
+		break;
+	default:
+		ERROR("Read size not supported %zd\n", size_bytes);
+		exit(-1);
+	}
+
+	return (offset + size_bytes);
+}
+
+/*
+ * Convert to little endian format.
+ * Returns the offset upto which the fixup was performed.
+ */
+static size_t fix_member(void *data, size_t offset, size_t size_bytes)
+{
+	uint8_t *src = (uint8_t *)data + offset;
+
+	switch (size_bytes) {
+	case 1:
+		write_at_le8(data, *(uint8_t *)src, offset);
+		break;
+	case 2:
+		write_at_le16(data, *(uint16_t *)src, offset);
+		break;
+	case 4:
+		write_at_le32(data, *(uint32_t *)src, offset);
+		break;
+	case 8:
+		write_at_le64(data, *(uint64_t *)src, offset);
+		break;
+	default:
+		ERROR("Write size not supported %zd\n", size_bytes);
+		exit(-1);
+	}
+	return (offset + size_bytes);
+}
+
+static void print_subpart_dir(struct subpart_dir *s)
+{
+	if (verbose == 0)
+		return;
+
+	size_t i;
+
+	printf("%-25s 0x%-23.8x\n", "Marker", s->h.marker);
+	printf("%-25s %-25d\n", "Num entries", s->h.num_entries);
+	printf("%-25s %-25d\n", "Header Version", s->h.header_version);
+	printf("%-25s %-25d\n", "Entry Version", s->h.entry_version);
+	printf("%-25s 0x%-23x\n", "Header Length", s->h.header_length);
+	printf("%-25s 0x%-23x\n", "Checksum", s->h.checksum);
+	printf("%-25s ", "Name");
+	for (i = 0; i < sizeof(s->h.name); i++)
+		printf("%c", s->h.name[i]);
+
+	printf("\n");
+
+	printf("%-25s%-25s%-25s%-25s%-25s\n", "Entry #", "Name", "Offset",
+	       "Length", "Rsvd");
+
+	printf("=========================================================================================================================\n");
+
+	for (i = 0; i < s->h.num_entries; i++) {
+		printf("%-25zd%-25.12s0x%-23x0x%-23x0x%-23x\n", i + 1,
+		       s->e[i].name, s->e[i].offset, s->e[i].length,
+		       s->e[i].rsvd);
+	}
+
+	printf("=========================================================================================================================\n");
+}
+
+static void bpdt_print_header(struct bpdt_header *h, const char *name)
+{
+	if (verbose == 0)
+		return;
+
+	printf("%-25s %-25s\n", "Header", name);
+	printf("%-25s 0x%-23.8x\n", "Signature", h->signature);
+	printf("%-25s %-25d\n", "Descriptor count", h->descriptor_count);
+	printf("%-25s %-25d\n", "BPDT Version", h->bpdt_version);
+	printf("%-25s 0x%-23x\n", "XOR checksum", h->xor_redundant_block);
+	printf("%-25s 0x%-23x\n", "IFWI Version", h->ifwi_version);
+	printf("%-25s 0x%-23llx\n", "FIT Tool Version",
+	       (long long)h->fit_tool_version);
+}
+
+static void bpdt_print_entries(struct bpdt_entry *e, size_t count,
+			       const char *name)
+{
+	size_t i;
+
+	if (verbose == 0)
+		return;
+
+	printf("%s entries\n", name);
+
+	printf("%-25s%-25s%-25s%-25s%-25s%-25s%-25s%-25s\n", "Entry #",
+	       "Sub-Partition", "Name", "Type", "Flags", "Offset", "Size",
+	       "File Offset");
+
+	printf("=========================================================================================================================================================================================================\n");
+
+	for (i = 0; i < count; i++) {
+		printf("%-25zd%-25s%-25s%-25d0x%-23.08x0x%-23x0x%-23x0x%-23zx\n",
+		       i + 1, subparts[e[i].type].name,
+		       subparts[e[i].type].readable_name, e[i].type, e[i].flags,
+		       e[i].offset, e[i].size,
+		       e[i].offset + ifwi_image.input_ifwi_start_offset);
+	}
+
+	printf("=========================================================================================================================================================================================================\n");
+}
+
+static void bpdt_validate_header(struct bpdt_header *h, const char *name)
+{
+	assert(h->signature == BPDT_SIGNATURE);
+
+	if (h->bpdt_version != 1) {
+		ERROR("Invalid header : %s\n", name);
+		exit(-1);
+	}
+
+	DEBUG("Validated header : %s\n", name);
+}
+
+static void bpdt_read_header(void *data, struct bpdt_header *h,
+			     const char *name)
+{
+	size_t offset = 0;
+
+	offset = read_member(data, offset, sizeof(h->signature), &h->signature);
+	offset = read_member(data, offset, sizeof(h->descriptor_count),
+			     &h->descriptor_count);
+	offset = read_member(data, offset, sizeof(h->bpdt_version),
+			     &h->bpdt_version);
+	offset = read_member(data, offset, sizeof(h->xor_redundant_block),
+			     &h->xor_redundant_block);
+	offset = read_member(data, offset, sizeof(h->ifwi_version),
+			     &h->ifwi_version);
+	read_member(data, offset, sizeof(h->fit_tool_version),
+		    &h->fit_tool_version);
+
+	bpdt_validate_header(h, name);
+	bpdt_print_header(h, name);
+}
+
+static void bpdt_read_entries(void *data, struct bpdt *bpdt, const char *name)
+{
+	size_t i, offset = 0;
+	struct bpdt_entry *e = &bpdt->e[0];
+	size_t count = bpdt->h.descriptor_count;
+
+	for (i = 0; i < count; i++) {
+		offset = read_member(data, offset, sizeof(e[i].type),
+				     &e[i].type);
+		offset = read_member(data, offset, sizeof(e[i].flags),
+				     &e[i].flags);
+		offset = read_member(data, offset, sizeof(e[i].offset),
+				     &e[i].offset);
+		offset = read_member(data, offset, sizeof(e[i].size),
+				     &e[i].size);
+	}
+
+	bpdt_print_entries(e, count, name);
+}
+
+/*
+ * Given type of sub-partition, identify BPDT entry for it.
+ * Sub-Partition could lie either within BPDT or S-BPDT.
+ */
+static struct bpdt_entry *__find_entry_by_type(struct bpdt_entry *e,
+					       size_t count, int type)
+{
+	size_t i;
+
+	for (i = 0; i < count; i++) {
+		if (e[i].type == type)
+			break;
+	}
+
+	if (i == count)
+		return NULL;
+
+	return &e[i];
+}
+
+static struct bpdt_entry *find_entry_by_type(int type)
+{
+	struct bpdt *b = buffer_get(&ifwi_image.bpdt);
+
+	if (!b)
+		return NULL;
+
+	struct bpdt_entry *curr = __find_entry_by_type(&b->e[0],
+						       b->h.descriptor_count,
+						       type);
+
+	if (curr)
+		return curr;
+
+	b = buffer_get(&ifwi_image.subpart_buf[S_BPDT_TYPE]);
+	if (!b)
+		return NULL;
+
+	return __find_entry_by_type(&b->e[0], b->h.descriptor_count, type);
+}
+
+/*
+ * Find sub-partition type given its name. If the name does not exist, returns
+ * -1.
+ */
+static int find_type_by_name(const char *name)
+{
+	int i;
+
+	for (i = 0; i < MAX_SUBPARTS; i++) {
+		if ((strlen(subparts[i].name) == strlen(name)) &&
+		    (!strcmp(subparts[i].name, name)))
+			break;
+	}
+
+	if (i == MAX_SUBPARTS) {
+		ERROR("Invalid sub-partition name %s.\n", name);
+		return -1;
+	}
+
+	return i;
+}
+
+/*
+ * Read the content of a sub-partition from input file and store it in
+ * ifwi_image.subpart_buf[SUB-PARTITION_TYPE].
+ *
+ * Returns the maximum offset occupied by the sub-partitions.
+ */
+static size_t read_subpart_buf(void *data, size_t size, struct bpdt_entry *e,
+			       size_t count)
+{
+	size_t i, type;
+	struct buffer *buf;
+	size_t max_offset = 0;
+
+	for (i = 0; i < count; i++) {
+		type = e[i].type;
+
+		if (type >= MAX_SUBPARTS) {
+			ERROR("Invalid sub-partition type %zd.\n", type);
+			exit(-1);
+		}
+
+		if (buffer_size(&ifwi_image.subpart_buf[type])) {
+			ERROR("Multiple sub-partitions of type %zd(%s).\n",
+			      type, subparts[type].name);
+			exit(-1);
+		}
+
+		if (e[i].size == 0) {
+			INFO("Dummy sub-partition %zd(%s). Skipping.\n", type,
+			     subparts[type].name);
+			continue;
+		}
+
+		assert((e[i].offset + e[i].size) <= size);
+
+		/*
+		 * Sub-partitions in IFWI image are not in the same order as
+		 * in BPDT entries. BPDT entires are in header_order whereas
+		 * sub-partition offsets in the image are in pack_order.
+		 */
+		if ((e[i].offset + e[i].size) > max_offset)
+			max_offset = e[i].offset + e[i].size;
+
+		/*
+		 * S-BPDT sub-partition contains information about all the
+		 * non-critical sub-partitions. Thus, size of S-BPDT
+		 * sub-partition equals size of S-BPDT plus size of all the
+		 * non-critical sub-partitions. Thus, reading whole of S-BPDT
+		 * here would be redundant as the non-critical partitions are
+		 * read and allocated buffers separately. Also, S-BPDT requires
+		 * special handling for reading header and entries.
+		 */
+		if (type == S_BPDT_TYPE)
+			continue;
+
+		buf = &ifwi_image.subpart_buf[type];
+
+		alloc_buffer(buf, e[i].size, subparts[type].name);
+		memcpy(buffer_get(buf), (uint8_t *)data + e[i].offset,
+		       e[i].size);
+	}
+
+	assert(max_offset);
+	return max_offset;
+}
+
+/*
+ * Allocate buffer for bpdt header, entries and all sub-partition content.
+ * Returns offset in data where BPDT ends.
+ */
+static size_t alloc_bpdt_buffer(void *data, size_t size, size_t offset,
+				struct buffer *b, const char *name)
+{
+	struct bpdt_header bpdt_header;
+
+	assert((offset + BPDT_HEADER_SIZE) < size);
+	bpdt_read_header((uint8_t *)data + offset, &bpdt_header, name);
+
+	/* Buffer to read BPDT header and entries */
+	alloc_buffer(b, get_bpdt_size(&bpdt_header), name);
+
+	struct bpdt *bpdt = buffer_get(b);
+
+	memcpy(&bpdt->h, &bpdt_header, BPDT_HEADER_SIZE);
+
+	/*
+	 * If no entries are present, maximum offset occupied is (offset +
+	 * BPDT_HEADER_SIZE).
+	 */
+	if (bpdt->h.descriptor_count == 0)
+		return (offset + BPDT_HEADER_SIZE);
+
+	/* Read all entries */
+	assert((offset + get_bpdt_size(&bpdt->h)) < size);
+	bpdt_read_entries((uint8_t *)data + offset + BPDT_HEADER_SIZE, bpdt,
+			  name);
+
+	/* Read all sub-partition content in subpart_buf */
+	return read_subpart_buf(data, size, &bpdt->e[0],
+				bpdt->h.descriptor_count);
+}
+
+static void parse_sbpdt(void *data, size_t size)
+{
+	struct bpdt_entry *s;
+
+	s  = find_entry_by_type(S_BPDT_TYPE);
+	if (!s)
+		return;
+
+	assert(size > s->offset);
+
+	alloc_bpdt_buffer(data, size, s->offset,
+			  &ifwi_image.subpart_buf[S_BPDT_TYPE],
+			  "S-BPDT");
+}
+
+static uint8_t calc_checksum(struct subpart_dir *s)
+{
+	size_t size = subpart_dir_size(&s->h);
+	uint8_t *data = (uint8_t *)s;
+	uint8_t checksum = 0;
+	size_t i;
+	uint8_t old_checksum = s->h.checksum;
+
+	s->h.checksum = 0;
+
+	for (i = 0; i < size; i++)
+		checksum += data[i];
+
+	s->h.checksum = old_checksum;
+
+	/* 2s complement */
+	return -checksum;
+}
+
+static void validate_subpart_dir(struct subpart_dir *s, const char *name,
+				 bool checksum_check)
+{
+	if (s->h.marker != SUBPART_DIR_MARKER ||
+	    s->h.header_version != SUBPART_DIR_HEADER_VERSION_SUPPORTED ||
+	    s->h.entry_version != SUBPART_DIR_ENTRY_VERSION_SUPPORTED ||
+	    s->h.header_length != SUBPART_DIR_HEADER_SIZE) {
+		ERROR("Invalid subpart_dir for %s.\n", name);
+		exit(-1);
+	}
+
+	if (!checksum_check)
+		return;
+
+	uint8_t checksum = calc_checksum(s);
+
+	if (checksum != s->h.checksum)
+		ERROR("Invalid checksum for %s (Expected=0x%x, Actual=0x%x).\n",
+		      name, checksum, s->h.checksum);
+}
+
+static void validate_subpart_dir_without_checksum(struct subpart_dir *s,
+						  const char *name)
+{
+	validate_subpart_dir(s, name, 0);
+}
+
+static void validate_subpart_dir_with_checksum(struct subpart_dir *s,
+					       const char *name)
+{
+	validate_subpart_dir(s, name, 1);
+}
+
+static void parse_subpart_dir(struct buffer *subpart_dir_buf,
+			      struct buffer *input_buf, const char *name)
+{
+	struct subpart_dir_header hdr;
+	size_t offset = 0;
+	uint8_t *data = buffer_get(input_buf);
+	size_t size = buffer_size(input_buf);
+
+	/* Read Subpart_Dir header */
+	assert(size >= SUBPART_DIR_HEADER_SIZE);
+	offset = read_member(data, offset, sizeof(hdr.marker), &hdr.marker);
+	offset = read_member(data, offset, sizeof(hdr.num_entries),
+			     &hdr.num_entries);
+	offset = read_member(data, offset, sizeof(hdr.header_version),
+			     &hdr.header_version);
+	offset = read_member(data, offset, sizeof(hdr.entry_version),
+			     &hdr.entry_version);
+	offset = read_member(data, offset, sizeof(hdr.header_length),
+			     &hdr.header_length);
+	offset = read_member(data, offset, sizeof(hdr.checksum), &hdr.checksum);
+	memcpy(hdr.name, data + offset, sizeof(hdr.name));
+	offset += sizeof(hdr.name);
+
+	validate_subpart_dir_without_checksum((struct subpart_dir *)&hdr, name);
+
+	assert(size > subpart_dir_size(&hdr));
+	alloc_buffer(subpart_dir_buf, subpart_dir_size(&hdr), "Subpart Dir");
+	memcpy(buffer_get(subpart_dir_buf), &hdr, SUBPART_DIR_HEADER_SIZE);
+
+	/* Read Subpart Dir entries */
+	struct subpart_dir *subpart_dir = buffer_get(subpart_dir_buf);
+	struct subpart_dir_entry *e = &subpart_dir->e[0];
+	uint32_t i;
+
+	for (i = 0; i < hdr.num_entries; i++) {
+		memcpy(e[i].name, data + offset, sizeof(e[i].name));
+		offset += sizeof(e[i].name);
+		offset = read_member(data, offset, sizeof(e[i].offset),
+				     &e[i].offset);
+		offset = read_member(data, offset, sizeof(e[i].length),
+				     &e[i].length);
+		offset = read_member(data, offset, sizeof(e[i].rsvd),
+				     &e[i].rsvd);
+	}
+
+	validate_subpart_dir_with_checksum(subpart_dir, name);
+
+	print_subpart_dir(subpart_dir);
+}
+
+/* Parse input image file to identify different sub-partitions */
+static int ifwi_parse(void)
+{
+	struct buffer *buff = &ifwi_image.input_buff;
+	const char *image_name = param.image_name;
+
+	DEBUG("Parsing IFWI image...\n");
+
+	/* Read input file */
+	if (buffer_from_file(buff, image_name)) {
+		ERROR("Failed to read input file %s.\n", image_name);
+		return -1;
+	}
+
+	INFO("Buffer %p size 0x%zx\n", buff->data, buff->size);
+
+	/* Look for BPDT signature at 4K intervals */
+	size_t offset = 0;
+	void *data = buffer_get(buff);
+
+	while (offset < buffer_size(buff)) {
+		if (read_at_le32(data, offset) == BPDT_SIGNATURE)
+			break;
+		offset += 4 * KiB;
+	}
+
+	if (offset >= buffer_size(buff)) {
+		ERROR("Image does not contain BPDT!!\n");
+		return -1;
+	}
+
+	ifwi_image.input_ifwi_start_offset = offset;
+	INFO("BPDT starts at offset 0x%zx.\n", offset);
+
+	data = (uint8_t *)data + offset;
+	size_t ifwi_size = buffer_size(buff) - offset;
+
+	/* Read BPDT and sub-partitions */
+	uintptr_t end_offset;
+
+	end_offset = ifwi_image.input_ifwi_start_offset +
+		alloc_bpdt_buffer(data, ifwi_size, 0, &ifwi_image.bpdt, "BPDT");
+
+	/* Parse S-BPDT, if any */
+	parse_sbpdt(data, ifwi_size);
+
+	/*
+	 * Store end offset of IFWI. Required for copying any trailing non-IFWI
+	 * part of the image.
+	 * ASSUMPTION: IFWI image always ends on a 4K boundary.
+	 */
+	ifwi_image.input_ifwi_end_offset = ALIGN(end_offset, 4 * KiB);
+	DEBUG("Parsing done.\n");
+
+	return 0;
+}
+
+/*
+ * This function is used by repack to count the number of BPDT and S-BPDT
+ * entries that are present. It frees the current buffers used by the entries
+ * and allocates fresh buffers that can be used for repacking. Returns BPDT
+ * entries which are empty and need to be filled in.
+ */
+static void __bpdt_reset(struct buffer *b, size_t count, size_t size)
+{
+	size_t bpdt_size = BPDT_HEADER_SIZE + count * BPDT_ENTRY_SIZE;
+
+	assert(size >= bpdt_size);
+
+	/*
+	 * If buffer does not have the required size, allocate a fresh buffer.
+	 */
+	if (buffer_size(b) != size) {
+		struct buffer temp;
+
+		alloc_buffer(&temp, size, b->name);
+		memcpy(buffer_get(&temp), buffer_get(b), buffer_size(b));
+		buffer_delete(b);
+		*b = temp;
+	}
+
+	struct bpdt *bpdt = buffer_get(b);
+	uint8_t *ptr = (uint8_t *)&bpdt->e[0];
+	size_t entries_size = BPDT_ENTRY_SIZE * count;
+
+	/* Zero out BPDT entries */
+	memset(ptr, 0, entries_size);
+	/* Fill any pad-space with FF */
+	memset(ptr + entries_size, 0xFF, size - bpdt_size);
+
+	bpdt->h.descriptor_count = count;
+}
+
+static void bpdt_reset(void)
+{
+	size_t i;
+	size_t bpdt_count = 0, sbpdt_count = 0, dummy_bpdt_count = 0;
+
+	/* Count number of BPDT and S-BPDT entries */
+	for (i = 0; i < MAX_SUBPARTS; i++) {
+		if (buffer_size(&ifwi_image.subpart_buf[i]) == 0) {
+			if (subparts[i].attr & MANDATORY_BPDT_ENTRY) {
+				bpdt_count++;
+				dummy_bpdt_count++;
+			}
+			continue;
+		}
+
+		if (subparts[i].attr & NON_CRITICAL_SUBPART)
+			sbpdt_count++;
+		else
+			bpdt_count++;
+	}
+
+	DEBUG("Count: BPDT = %zd, Dummy BPDT = %zd, S-BPDT = %zd\n", bpdt_count,
+	      dummy_bpdt_count, sbpdt_count);
+
+	/* Update BPDT if required */
+	size_t bpdt_size = max(BPDT_MIN_SIZE,
+			       BPDT_HEADER_SIZE + bpdt_count * BPDT_ENTRY_SIZE);
+	__bpdt_reset(&ifwi_image.bpdt, bpdt_count, bpdt_size);
+
+	/* Update S-BPDT if required */
+	bpdt_size = ALIGN(BPDT_HEADER_SIZE + sbpdt_count * BPDT_ENTRY_SIZE,
+			  4 * KiB);
+	__bpdt_reset(&ifwi_image.subpart_buf[S_BPDT_TYPE], sbpdt_count,
+		     bpdt_size);
+}
+
+/* Initialize BPDT entries in header order */
+static void bpdt_entries_init_header_order(void)
+{
+	int i, type;
+	size_t size;
+
+	struct bpdt *bpdt, *sbpdt, *curr;
+	size_t bpdt_curr = 0, sbpdt_curr = 0, *count_ptr;
+
+	bpdt = buffer_get(&ifwi_image.bpdt);
+	sbpdt = buffer_get(&ifwi_image.subpart_buf[S_BPDT_TYPE]);
+
+	for (i = 0; i < MAX_SUBPARTS; i++) {
+		type = bpdt_header_order[i];
+		size = buffer_size(&ifwi_image.subpart_buf[type]);
+
+		if (size == 0 && !(subparts[type].attr & MANDATORY_BPDT_ENTRY))
+			continue;
+
+		if (subparts[type].attr & NON_CRITICAL_SUBPART) {
+			curr = sbpdt;
+			count_ptr = &sbpdt_curr;
+		} else {
+			curr = bpdt;
+			count_ptr = &bpdt_curr;
+		}
+
+		assert(*count_ptr < curr->h.descriptor_count);
+		curr->e[*count_ptr].type = type;
+		curr->e[*count_ptr].flags = 0;
+		curr->e[*count_ptr].offset = 0;
+		curr->e[*count_ptr].size = size;
+
+		(*count_ptr)++;
+	}
+}
+
+static void pad_buffer(struct buffer *b, size_t size)
+{
+	size_t buff_size = buffer_size(b);
+
+	assert(buff_size <= size);
+
+	if (buff_size == size)
+		return;
+
+	struct buffer temp;
+
+	alloc_buffer(&temp, size, b->name);
+	uint8_t *data = buffer_get(&temp);
+
+	memcpy(data, buffer_get(b), buff_size);
+	memset(data + buff_size, 0xFF, size - buff_size);
+
+	*b = temp;
+}
+
+/* Initialize offsets of entries using pack order */
+static void bpdt_entries_init_pack_order(void)
+{
+	int i, type;
+	struct bpdt_entry *curr;
+	size_t curr_offset, curr_end;
+
+	curr_offset = max(BPDT_MIN_SIZE, buffer_size(&ifwi_image.bpdt));
+
+	/*
+	 * There are two types of sub-partitions that need to be handled here:
+	 *   1. Sub-partitions that lie within the same 4K as BPDT
+	 *   2. Sub-partitions that lie outside the 4K of BPDT
+	 *
+	 * For sub-partitions of type # 1, there is no requirement on the start
+	 * or end of the sub-partition. They need to be packed in without any
+	 * holes left in between. If there is any empty space left after the end
+	 * of the last sub-partition in 4K of BPDT, then that space needs to be
+	 * padded with FF bytes, but the size of the last sub-partition remains
+	 * unchanged.
+	 *
+	 * For sub-partitions of type # 2, both the start and end should be a
+	 * multiple of 4K. If not, then it needs to be padded with FF bytes and
+	 * size adjusted such that the sub-partition ends on 4K boundary.
+	 */
+
+	/* #1 Sub-partitions that lie within same 4K as BPDT */
+	struct buffer *last_bpdt_buff = &ifwi_image.bpdt;
+
+	for (i = 0; i < MAX_SUBPARTS; i++) {
+		type = bpdt_pack_order[i];
+		curr = find_entry_by_type(type);
+
+		if (!curr || curr->size == 0)
+			continue;
+
+		if (!(subparts[type].attr & LIES_WITHIN_BPDT_4K))
+			continue;
+
+		curr->offset = curr_offset;
+		curr_offset = curr->offset + curr->size;
+		last_bpdt_buff = &ifwi_image.subpart_buf[type];
+		DEBUG("type=%d, curr_offset=0x%zx, curr->offset=0x%x, curr->size=0x%x, buff_size=0x%zx\n",
+		      type, curr_offset, curr->offset, curr->size,
+		      buffer_size(&ifwi_image.subpart_buf[type]));
+	}
+
+	/* Pad ff bytes if there is any empty space left in BPDT 4K */
+	curr_end = ALIGN(curr_offset, 4 * KiB);
+	pad_buffer(last_bpdt_buff,
+		   buffer_size(last_bpdt_buff) + (curr_end - curr_offset));
+	curr_offset = curr_end;
+
+	/* #2 Sub-partitions that lie outside of BPDT 4K */
+	for (i = 0; i < MAX_SUBPARTS; i++) {
+		type = bpdt_pack_order[i];
+		curr = find_entry_by_type(type);
+
+		if (!curr || curr->size == 0)
+			continue;
+
+		if (subparts[type].attr & LIES_WITHIN_BPDT_4K)
+			continue;
+
+		assert(curr_offset == ALIGN(curr_offset, 4 * KiB));
+		curr->offset = curr_offset;
+		curr_end = ALIGN(curr->offset + curr->size, 4 * KiB);
+		curr->size = curr_end - curr->offset;
+
+		pad_buffer(&ifwi_image.subpart_buf[type], curr->size);
+
+		curr_offset = curr_end;
+		DEBUG("type=%d, curr_offset=0x%zx, curr->offset=0x%x, curr->size=0x%x, buff_size=0x%zx\n",
+		      type, curr_offset, curr->offset, curr->size,
+		      buffer_size(&ifwi_image.subpart_buf[type]));
+	}
+
+	/*
+	 * Update size of S-BPDT to include size of all non-critical
+	 * sub-partitions.
+	 *
+	 * Assumption: S-BPDT always lies at the end of IFWI image.
+	 */
+	curr = find_entry_by_type(S_BPDT_TYPE);
+	assert(curr);
+
+	assert(curr_offset == ALIGN(curr_offset, 4 * KiB));
+	curr->size = curr_offset - curr->offset;
+}
+
+/* Convert all members of BPDT to little-endian format */
+static void bpdt_fixup_write_buffer(struct buffer *buf)
+{
+	struct bpdt *s = buffer_get(buf);
+
+	struct bpdt_header *h = &s->h;
+	struct bpdt_entry *e = &s->e[0];
+
+	size_t count = h->descriptor_count;
+
+	size_t offset = 0;
+
+	offset = fix_member(&h->signature, offset, sizeof(h->signature));
+	offset = fix_member(&h->descriptor_count, offset,
+			    sizeof(h->descriptor_count));
+	offset = fix_member(&h->bpdt_version, offset, sizeof(h->bpdt_version));
+	offset = fix_member(&h->xor_redundant_block, offset,
+			    sizeof(h->xor_redundant_block));
+	offset = fix_member(&h->ifwi_version, offset, sizeof(h->ifwi_version));
+	offset = fix_member(&h->fit_tool_version, offset,
+			    sizeof(h->fit_tool_version));
+
+	uint32_t i;
+
+	for (i = 0; i < count; i++) {
+		offset = fix_member(&e[i].type, offset, sizeof(e[i].type));
+		offset = fix_member(&e[i].flags, offset, sizeof(e[i].flags));
+		offset = fix_member(&e[i].offset, offset, sizeof(e[i].offset));
+		offset = fix_member(&e[i].size, offset, sizeof(e[i].size));
+	}
+}
+
+/* Write BPDT to output buffer after fixup */
+static void bpdt_write(struct buffer *dst, size_t offset, struct buffer *src)
+{
+	bpdt_fixup_write_buffer(src);
+	memcpy(buffer_get(dst) + offset, buffer_get(src), buffer_size(src));
+}
+
+/*
+ * Follows these steps to re-create image:
+ * 1. Write any non-IFWI prefix.
+ * 2. Write out BPDT header and entries.
+ * 3. Write sub-partition buffers to respective offsets.
+ * 4. Write any non-IFWI suffix.
+ *
+ * While performing the above steps, make sure that any empty holes are filled
+ * with FF.
+ */
+static void ifwi_write(const char *image_name)
+{
+	struct bpdt_entry *s = find_entry_by_type(S_BPDT_TYPE);
+
+	assert(s);
+
+	size_t ifwi_start, ifwi_end, file_end;
+
+	ifwi_start = ifwi_image.input_ifwi_start_offset;
+	ifwi_end = ifwi_start + ALIGN(s->offset + s->size, 4 * KiB);
+	file_end = ifwi_end + (buffer_size(&ifwi_image.input_buff) -
+			       ifwi_image.input_ifwi_end_offset);
+
+	struct buffer b;
+
+	alloc_buffer(&b, file_end, "Final-IFWI");
+
+	uint8_t *input_data = buffer_get(&ifwi_image.input_buff);
+	uint8_t *output_data = buffer_get(&b);
+
+	DEBUG("ifwi_start:0x%zx, ifwi_end:0x%zx, file_end:0x%zx\n", ifwi_start,
+	      ifwi_end, file_end);
+
+	/* Copy non-IFWI prefix, if any */
+	memcpy(output_data, input_data, ifwi_start);
+
+	DEBUG("Copied non-IFWI prefix (offset=0x0, size=0x%zx).\n", ifwi_start);
+
+	struct buffer ifwi;
+
+	buffer_splice(&ifwi, &b, ifwi_start, ifwi_end - ifwi_start);
+	uint8_t *ifwi_data = buffer_get(&ifwi);
+
+	/* Copy sub-partitions using pack_order */
+	struct bpdt_entry *curr;
+	struct buffer *subpart_buf;
+	int i, type;
+
+	for (i = 0; i < MAX_SUBPARTS; i++) {
+		type = bpdt_pack_order[i];
+
+		if (type == S_BPDT_TYPE)
+			continue;
+
+		curr = find_entry_by_type(type);
+
+		if (!curr || !curr->size)
+			continue;
+
+		subpart_buf = &ifwi_image.subpart_buf[type];
+
+		DEBUG("curr->offset=0x%x, curr->size=0x%x, type=%d, write_size=0x%zx\n",
+		      curr->offset, curr->size, type, buffer_size(subpart_buf));
+
+		assert((curr->offset + buffer_size(subpart_buf)) <=
+		       buffer_size(&ifwi));
+
+		memcpy(ifwi_data + curr->offset, buffer_get(subpart_buf),
+		       buffer_size(subpart_buf));
+	}
+
+	/* Copy non-IFWI suffix, if any */
+	if (ifwi_end != file_end) {
+		memcpy(output_data + ifwi_end,
+		       input_data + ifwi_image.input_ifwi_end_offset,
+		       file_end - ifwi_end);
+		DEBUG("Copied non-IFWI suffix (offset=0x%zx,size=0x%zx).\n",
+		      ifwi_end, file_end - ifwi_end);
+	}
+
+	/*
+	 * Convert BPDT to little-endian format and write it to output buffer.
+	 * S-BPDT is written first and then BPDT.
+	 */
+	bpdt_write(&ifwi, s->offset, &ifwi_image.subpart_buf[S_BPDT_TYPE]);
+	bpdt_write(&ifwi, 0, &ifwi_image.bpdt);
+
+	if (buffer_write_file(&b, image_name)) {
+		ERROR("File write error\n");
+		exit(-1);
+	}
+
+	buffer_delete(&b);
+	printf("Image written successfully to %s.\n", image_name);
+}
+
+/*
+ * Calculate size and offset of each sub-partition again since it might have
+ * changed because of add/delete operation. Also, re-create BPDT and S-BPDT
+ * entries and write back the new IFWI image to file.
+ */
+static void ifwi_repack(void)
+{
+	bpdt_reset();
+	bpdt_entries_init_header_order();
+	bpdt_entries_init_pack_order();
+
+	struct bpdt *b = buffer_get(&ifwi_image.bpdt);
+
+	bpdt_print_entries(&b->e[0], b->h.descriptor_count, "BPDT");
+
+	b = buffer_get(&ifwi_image.subpart_buf[S_BPDT_TYPE]);
+	bpdt_print_entries(&b->e[0], b->h.descriptor_count, "S-BPDT");
+
+	DEBUG("Repack done.. writing image.\n");
+	ifwi_write(param.image_name);
+}
+
+static void init_subpart_dir_header(struct subpart_dir_header *hdr,
+				    size_t count, const char *name)
+{
+	memset(hdr, 0, sizeof(*hdr));
+
+	hdr->marker = SUBPART_DIR_MARKER;
+	hdr->num_entries = count;
+	hdr->header_version = SUBPART_DIR_HEADER_VERSION_SUPPORTED;
+	hdr->entry_version = SUBPART_DIR_ENTRY_VERSION_SUPPORTED;
+	hdr->header_length = SUBPART_DIR_HEADER_SIZE;
+	memcpy(hdr->name, name, sizeof(hdr->name));
+}
+
+static size_t init_subpart_dir_entry(struct subpart_dir_entry *e,
+				     struct buffer *b, size_t offset)
+{
+	memset(e, 0, sizeof(*e));
+
+	assert(strlen(b->name) <= sizeof(e->name));
+	strncpy((char *)e->name, (char *)b->name, sizeof(e->name));
+	e->offset = offset;
+	e->length = buffer_size(b);
+
+	return (offset + buffer_size(b));
+}
+
+static void init_manifest_header(struct manifest_header *hdr, size_t size)
+{
+	memset(hdr, 0, sizeof(*hdr));
+
+	hdr->header_type = 0x4;
+	assert((MANIFEST_HDR_SIZE % DWORD_SIZE) == 0);
+	hdr->header_length = MANIFEST_HDR_SIZE / DWORD_SIZE;
+	hdr->header_version = 0x10000;
+	hdr->vendor = 0x8086;
+
+	struct tm *local_time;
+	time_t curr_time;
+	char buffer[11];
+
+	curr_time = time(NULL);
+	local_time = localtime(&curr_time);
+	strftime(buffer, sizeof(buffer), "0x%Y%m%d", local_time);
+	hdr->date = strtoul(buffer, NULL, 16);
+
+	assert((size % DWORD_SIZE) == 0);
+	hdr->size = size / DWORD_SIZE;
+	hdr->id = MANIFEST_ID_MAGIC;
+}
+
+static void init_signed_pkg_info_ext(struct signed_pkg_info_ext *ext,
+				     size_t count, const char *name)
+{
+	memset(ext, 0, sizeof(*ext));
+
+	ext->ext_type = SIGNED_PKG_INFO_EXT_TYPE;
+	ext->ext_length = SIGNED_PKG_INFO_EXT_SIZE + count * MODULE_SIZE;
+	memcpy(ext->name, name, sizeof(ext->name));
+}
+
+static void subpart_dir_fixup_write_buffer(struct buffer *buf)
+{
+	struct subpart_dir *s = buffer_get(buf);
+	struct subpart_dir_header *h = &s->h;
+	struct subpart_dir_entry *e = &s->e[0];
+
+	size_t count = h->num_entries;
+	size_t offset = 0;
+
+	offset = fix_member(&h->marker, offset, sizeof(h->marker));
+	offset = fix_member(&h->num_entries, offset, sizeof(h->num_entries));
+	offset = fix_member(&h->header_version, offset,
+			    sizeof(h->header_version));
+	offset = fix_member(&h->entry_version, offset,
+			    sizeof(h->entry_version));
+	offset = fix_member(&h->header_length, offset,
+			    sizeof(h->header_length));
+	offset = fix_member(&h->checksum, offset, sizeof(h->checksum));
+	offset += sizeof(h->name);
+
+	uint32_t i;
+
+	for (i = 0; i < count; i++) {
+		offset += sizeof(e[i].name);
+		offset = fix_member(&e[i].offset, offset, sizeof(e[i].offset));
+		offset = fix_member(&e[i].length, offset, sizeof(e[i].length));
+		offset = fix_member(&e[i].rsvd, offset, sizeof(e[i].rsvd));
+	}
+}
+
+static void create_subpart(struct buffer *dst, struct buffer *info[],
+			   size_t count, const char *name)
+{
+	struct buffer subpart_dir_buff;
+	size_t size = SUBPART_DIR_HEADER_SIZE + count * SUBPART_DIR_ENTRY_SIZE;
+
+	alloc_buffer(&subpart_dir_buff, size, "subpart-dir");
+
+	struct subpart_dir_header *h = buffer_get(&subpart_dir_buff);
+	struct subpart_dir_entry *e = (struct subpart_dir_entry *)(h + 1);
+
+	init_subpart_dir_header(h, count, name);
+
+	size_t curr_offset = size;
+	size_t i;
+
+	for (i = 0; i < count; i++) {
+		curr_offset = init_subpart_dir_entry(&e[i], info[i],
+						     curr_offset);
+	}
+
+	alloc_buffer(dst, curr_offset, name);
+	uint8_t *data = buffer_get(dst);
+
+	for (i = 0; i < count; i++) {
+		memcpy(data + e[i].offset, buffer_get(info[i]),
+		       buffer_size(info[i]));
+	}
+
+	h->checksum = calc_checksum(buffer_get(&subpart_dir_buff));
+
+	struct subpart_dir *dir = buffer_get(&subpart_dir_buff);
+
+	print_subpart_dir(dir);
+
+	subpart_dir_fixup_write_buffer(&subpart_dir_buff);
+	memcpy(data, dir, buffer_size(&subpart_dir_buff));
+
+	buffer_delete(&subpart_dir_buff);
+}
+
+static enum ifwi_ret ibbp_dir_add(int type)
+{
+	struct buffer manifest;
+	struct signed_pkg_info_ext *ext;
+	struct buffer ibbl;
+	struct buffer ibb;
+
+#define DUMMY_IBB_SIZE			(4 * KiB)
+
+	assert(type == IBB_TYPE);
+
+	/*
+	 * Entry # 1 - IBBP.man
+	 * Contains manifest header and signed pkg info extension.
+	 */
+	size_t size = MANIFEST_HDR_SIZE + SIGNED_PKG_INFO_EXT_SIZE;
+
+	alloc_buffer(&manifest, size, "IBBP.man");
+
+	struct manifest_header *man_hdr = buffer_get(&manifest);
+
+	init_manifest_header(man_hdr, size);
+
+	ext = (struct signed_pkg_info_ext *)(man_hdr + 1);
+
+	init_signed_pkg_info_ext(ext, 0, subparts[type].name);
+
+	/* Entry # 2 - IBBL */
+	if (buffer_from_file(&ibbl, param.file_name))
+		return COMMAND_ERR;
+
+	/* Entry # 3 - IBB */
+	alloc_buffer(&ibb, DUMMY_IBB_SIZE, "IBB");
+	memset(buffer_get(&ibb), 0xFF, DUMMY_IBB_SIZE);
+
+	/* Create subpartition */
+	struct buffer *info[] = {
+		&manifest, &ibbl, &ibb,
+	};
+	create_subpart(&ifwi_image.subpart_buf[type], &info[0],
+		       ARRAY_SIZE(info), subparts[type].name);
+
+	return REPACK_REQUIRED;
+}
+
+static enum ifwi_ret ifwi_raw_add(int type)
+{
+	if (buffer_from_file(&ifwi_image.subpart_buf[type], param.file_name))
+		return COMMAND_ERR;
+
+	printf("Sub-partition %s(%d) added from file %s.\n", param.subpart_name,
+	       type, param.file_name);
+	return REPACK_REQUIRED;
+}
+
+static enum ifwi_ret ifwi_dir_add(int type)
+{
+	if (!(subparts[type].attr & CONTAINS_DIR) ||
+	    !subparts[type].dir_ops.dir_add) {
+		ERROR("Sub-Partition %s(%d) does not support dir ops.\n",
+		      subparts[type].name, type);
+		return COMMAND_ERR;
+	}
+
+	if (!param.dentry_name) {
+		ERROR("%s: -e option required\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	enum ifwi_ret ret = subparts[type].dir_ops.dir_add(type);
+
+	if (ret != COMMAND_ERR)
+		printf("Sub-partition %s(%d) entry %s added from file %s.\n",
+		       param.subpart_name, type, param.dentry_name,
+		       param.file_name);
+	else
+		ERROR("Sub-partition dir operation failed.\n");
+
+	return ret;
+}
+
+static enum ifwi_ret ifwi_add(void)
+{
+	if (!param.file_name) {
+		ERROR("%s: -f option required\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	if (!param.subpart_name) {
+		ERROR("%s: -n option required\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	int type = find_type_by_name(param.subpart_name);
+
+	if (type == -1)
+		return COMMAND_ERR;
+
+	const struct subpart_info *curr_subpart = &subparts[type];
+
+	if (curr_subpart->attr & AUTO_GENERATED) {
+		ERROR("Cannot add auto-generated sub-partitions.\n");
+		return COMMAND_ERR;
+	}
+
+	if (buffer_size(&ifwi_image.subpart_buf[type])) {
+		ERROR("Image already contains sub-partition %s(%d).\n",
+		      param.subpart_name, type);
+		return COMMAND_ERR;
+	}
+
+	if (param.dir_ops)
+		return ifwi_dir_add(type);
+
+	return ifwi_raw_add(type);
+}
+
+static enum ifwi_ret ifwi_delete(void)
+{
+	if (!param.subpart_name) {
+		ERROR("%s: -n option required\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	int type = find_type_by_name(param.subpart_name);
+
+	if (type == -1)
+		return COMMAND_ERR;
+
+	const struct subpart_info *curr_subpart = &subparts[type];
+
+	if (curr_subpart->attr & AUTO_GENERATED) {
+		ERROR("Cannot delete auto-generated sub-partitions.\n");
+		return COMMAND_ERR;
+	}
+
+	if (buffer_size(&ifwi_image.subpart_buf[type]) == 0) {
+		printf("Image does not contain sub-partition %s(%d).\n",
+		       param.subpart_name, type);
+		return NO_ACTION_REQUIRED;
+	}
+
+	buffer_delete(&ifwi_image.subpart_buf[type]);
+	printf("Sub-Partition %s(%d) deleted.\n", subparts[type].name, type);
+	return REPACK_REQUIRED;
+}
+
+static enum ifwi_ret ifwi_dir_extract(int type)
+{
+	if (!(subparts[type].attr & CONTAINS_DIR)) {
+		ERROR("Sub-Partition %s(%d) does not support dir ops.\n",
+		      subparts[type].name, type);
+		return COMMAND_ERR;
+	}
+
+	if (!param.dentry_name) {
+		ERROR("%s: -e option required.\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	struct buffer subpart_dir_buff;
+
+	parse_subpart_dir(&subpart_dir_buff, &ifwi_image.subpart_buf[type],
+			  subparts[type].name);
+
+	uint32_t i;
+	struct subpart_dir *s = buffer_get(&subpart_dir_buff);
+
+	for (i = 0; i < s->h.num_entries; i++) {
+		if (!strncmp((char *)s->e[i].name, param.dentry_name,
+			     sizeof(s->e[i].name)))
+			break;
+	}
+
+	if (i == s->h.num_entries) {
+		ERROR("Entry %s not found in subpartition for %s.\n",
+		      param.dentry_name, param.subpart_name);
+		exit(-1);
+	}
+
+	struct buffer dst;
+
+	DEBUG("Splicing buffer at 0x%x size 0x%x\n", s->e[i].offset,
+	      s->e[i].length);
+	buffer_splice(&dst, &ifwi_image.subpart_buf[type], s->e[i].offset,
+		      s->e[i].length);
+
+	if (buffer_write_file(&dst, param.file_name))
+		return COMMAND_ERR;
+
+	printf("Sub-Partition %s(%d), entry(%s) stored in %s.\n",
+	       param.subpart_name, type, param.dentry_name, param.file_name);
+
+	return NO_ACTION_REQUIRED;
+}
+
+static enum ifwi_ret ifwi_raw_extract(int type)
+{
+	if (buffer_write_file(&ifwi_image.subpart_buf[type], param.file_name))
+		return COMMAND_ERR;
+
+	printf("Sub-Partition %s(%d) stored in %s.\n", param.subpart_name, type,
+	       param.file_name);
+
+	return NO_ACTION_REQUIRED;
+}
+
+static enum ifwi_ret ifwi_extract(void)
+{
+	if (!param.file_name) {
+		ERROR("%s: -f option required\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	if (!param.subpart_name) {
+		ERROR("%s: -n option required\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	int type = find_type_by_name(param.subpart_name);
+
+	if (type == -1)
+		return COMMAND_ERR;
+
+	if (type == S_BPDT_TYPE) {
+		INFO("Tool does not support raw extract for %s\n",
+		     param.subpart_name);
+		return NO_ACTION_REQUIRED;
+	}
+
+	if (buffer_size(&ifwi_image.subpart_buf[type]) == 0) {
+		ERROR("Image does not contain sub-partition %s(%d).\n",
+		      param.subpart_name, type);
+		return COMMAND_ERR;
+	}
+
+	INFO("Extracting sub-partition %s(%d).\n", param.subpart_name, type);
+	if (param.dir_ops)
+		return ifwi_dir_extract(type);
+
+	return ifwi_raw_extract(type);
+}
+
+static enum ifwi_ret ifwi_print(void)
+{
+	verbose += 2;
+
+	struct bpdt *b = buffer_get(&ifwi_image.bpdt);
+
+	bpdt_print_header(&b->h, "BPDT");
+	bpdt_print_entries(&b->e[0], b->h.descriptor_count, "BPDT");
+
+	b = buffer_get(&ifwi_image.subpart_buf[S_BPDT_TYPE]);
+	bpdt_print_header(&b->h, "S-BPDT");
+	bpdt_print_entries(&b->e[0], b->h.descriptor_count, "S-BPDT");
+
+	if (param.dir_ops == 0) {
+		verbose -= 2;
+		return NO_ACTION_REQUIRED;
+	}
+
+	int i;
+	struct buffer subpart_dir_buf;
+
+	for (i = 0; i < MAX_SUBPARTS ; i++) {
+		if (!(subparts[i].attr & CONTAINS_DIR) ||
+		    (buffer_size(&ifwi_image.subpart_buf[i]) == 0))
+			continue;
+
+		parse_subpart_dir(&subpart_dir_buf, &ifwi_image.subpart_buf[i],
+				  subparts[i].name);
+		buffer_delete(&subpart_dir_buf);
+	}
+
+	verbose -= 2;
+
+	return NO_ACTION_REQUIRED;
+}
+
+static enum ifwi_ret ifwi_raw_replace(int type)
+{
+	buffer_delete(&ifwi_image.subpart_buf[type]);
+	return ifwi_raw_add(type);
+}
+
+static enum ifwi_ret ifwi_dir_replace(int type)
+{
+	if (!(subparts[type].attr & CONTAINS_DIR)) {
+		ERROR("Sub-Partition %s(%d) does not support dir ops.\n",
+		      subparts[type].name, type);
+		return COMMAND_ERR;
+	}
+
+	if (!param.dentry_name) {
+		ERROR("%s: -e option required.\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	struct buffer subpart_dir_buf;
+
+	parse_subpart_dir(&subpart_dir_buf, &ifwi_image.subpart_buf[type],
+			  subparts[type].name);
+
+	uint32_t i;
+	struct subpart_dir *s = buffer_get(&subpart_dir_buf);
+
+	for (i = 0; i < s->h.num_entries; i++) {
+		if (!strcmp((char *)s->e[i].name, param.dentry_name))
+			break;
+	}
+
+	if (i == s->h.num_entries) {
+		ERROR("Entry %s not found in subpartition for %s.\n",
+		      param.dentry_name, param.subpart_name);
+		exit(-1);
+	}
+
+	struct buffer b;
+
+	if (buffer_from_file(&b, param.file_name)) {
+		ERROR("Failed to read %s\n", param.file_name);
+		exit(-1);
+	}
+
+	struct buffer dst;
+	size_t dst_size = buffer_size(&ifwi_image.subpart_buf[type]) +
+				      buffer_size(&b) - s->e[i].length;
+	size_t subpart_start = s->e[i].offset;
+	size_t subpart_end = s->e[i].offset + s->e[i].length;
+
+	alloc_buffer(&dst, dst_size, ifwi_image.subpart_buf[type].name);
+
+	uint8_t *src_data = buffer_get(&ifwi_image.subpart_buf[type]);
+	uint8_t *dst_data = buffer_get(&dst);
+	size_t curr_offset = 0;
+
+	/* Copy data before the sub-partition entry */
+	memcpy(dst_data + curr_offset, src_data, subpart_start);
+	curr_offset += subpart_start;
+
+	/* Copy sub-partition entry */
+	memcpy(dst_data + curr_offset, buffer_get(&b), buffer_size(&b));
+	curr_offset += buffer_size(&b);
+
+	/* Copy remaining data */
+	memcpy(dst_data + curr_offset, src_data + subpart_end,
+	       buffer_size(&ifwi_image.subpart_buf[type]) - subpart_end);
+
+	/* Update sub-partition buffer */
+	int offset = s->e[i].offset;
+
+	buffer_delete(&ifwi_image.subpart_buf[type]);
+	ifwi_image.subpart_buf[type] = dst;
+
+	/* Update length of entry in the subpartition */
+	s->e[i].length = buffer_size(&b);
+	buffer_delete(&b);
+
+	/* Adjust offsets of affected entries in subpartition */
+	offset = s->e[i].offset - offset;
+	for (; i < s->h.num_entries; i++)
+		s->e[i].offset += offset;
+
+	/* Re-calculate checksum */
+	s->h.checksum = calc_checksum(s);
+
+	/* Convert members to litte-endian */
+	subpart_dir_fixup_write_buffer(&subpart_dir_buf);
+
+	memcpy(dst_data, buffer_get(&subpart_dir_buf),
+	       buffer_size(&subpart_dir_buf));
+
+	buffer_delete(&subpart_dir_buf);
+
+	printf("Sub-partition %s(%d) entry %s replaced from file %s.\n",
+	       param.subpart_name, type, param.dentry_name, param.file_name);
+
+	return REPACK_REQUIRED;
+}
+
+static enum ifwi_ret ifwi_replace(void)
+{
+	if (!param.file_name) {
+		ERROR("%s: -f option required\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	if (!param.subpart_name) {
+		ERROR("%s: -n option required\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	int type = find_type_by_name(param.subpart_name);
+
+	if (type == -1)
+		return COMMAND_ERR;
+
+	const struct subpart_info *curr_subpart = &subparts[type];
+
+	if (curr_subpart->attr & AUTO_GENERATED) {
+		ERROR("Cannot replace auto-generated sub-partitions.\n");
+		return COMMAND_ERR;
+	}
+
+	if (buffer_size(&ifwi_image.subpart_buf[type]) == 0) {
+		ERROR("Image does not contain sub-partition %s(%d).\n",
+		      param.subpart_name, type);
+		return COMMAND_ERR;
+	}
+
+	if (param.dir_ops)
+		return ifwi_dir_replace(type);
+
+	return ifwi_raw_replace(type);
+}
+
+static enum ifwi_ret ifwi_create(void)
+{
+	/*
+	 * Create peels off any non-IFWI content present in the input buffer and
+	 * creates output file with only the IFWI present.
+	 */
+
+	if (!param.file_name) {
+		ERROR("%s: -f option required\n", __func__);
+		return COMMAND_ERR;
+	}
+
+	/* Peel off any non-IFWI prefix */
+	buffer_seek(&ifwi_image.input_buff,
+		    ifwi_image.input_ifwi_start_offset);
+	/* Peel off any non-IFWI suffix */
+	buffer_set_size(&ifwi_image.input_buff,
+			ifwi_image.input_ifwi_end_offset -
+			ifwi_image.input_ifwi_start_offset);
+
+	/*
+	 * Adjust start and end offset of IFWI now that non-IFWI prefix is gone.
+	 */
+	ifwi_image.input_ifwi_end_offset -= ifwi_image.input_ifwi_start_offset;
+	ifwi_image.input_ifwi_start_offset = 0;
+
+	param.image_name = param.file_name;
+
+	return REPACK_REQUIRED;
+}
+
+struct command {
+	const char *name;
+	const char *optstring;
+	enum ifwi_ret (*function)(void);
+};
+
+static const struct command commands[] = {
+	{"add", "f:n:e:dvh?", ifwi_add},
+	{"create", "f:vh?", ifwi_create},
+	{"delete", "f:n:vh?", ifwi_delete},
+	{"extract", "f:n:e:dvh?", ifwi_extract},
+	{"print", "dh?", ifwi_print},
+	{"replace", "f:n:e:dvh?", ifwi_replace},
+};
+
+static struct option long_options[] = {
+	{"subpart_dentry",  required_argument, 0, 'e'},
+	{"file",	    required_argument, 0, 'f'},
+	{"help",	    required_argument, 0, 'h'},
+	{"name",	    required_argument, 0, 'n'},
+	{"dir_ops",         no_argument,       0, 'd'},
+	{"verbose",	    no_argument,       0, 'v'},
+	{NULL,		    0,                 0,  0 }
+};
+
+static void usage(const char *name)
+{
+	printf("ifwitool: Utility for IFWI manipulation\n\n"
+	       "USAGE:\n"
+	       " %s [-h]\n"
+	       " %s FILE COMMAND [PARAMETERS]\n\n"
+	       "COMMANDs:\n"
+	       " add -f FILE -n NAME [-d -e ENTRY]\n"
+	       " create -f FILE\n"
+	       " delete -n NAME\n"
+	       " extract -f FILE -n NAME [-d -e ENTRY]\n"
+	       " print [-d]\n"
+	       " replace -f FILE -n NAME [-d -e ENTRY]\n"
+	       "OPTIONs:\n"
+	       " -f FILE : File to read/write/create/extract\n"
+	       " -d      : Perform directory operation\n"
+	       " -e ENTRY: Name of directory entry to operate on\n"
+	       " -v      : Verbose level\n"
+	       " -h      : Help message\n"
+	       " -n NAME : Name of sub-partition to operate on\n",
+	       name, name
+	       );
+
+	printf("\nNAME should be one of:\n");
+	int i;
+
+	for (i = 0; i < MAX_SUBPARTS; i++)
+		printf("%s(%s)\n", subparts[i].name, subparts[i].readable_name);
+	printf("\n");
+}
+
+int main(int argc, char **argv)
+{
+	if (argc < 3) {
+		usage(argv[0]);
+		return 1;
+	}
+
+	param.image_name = argv[1];
+	char *cmd = argv[2];
+
+	optind += 2;
+
+	uint32_t i;
+
+	for (i = 0; i < ARRAY_SIZE(commands); i++) {
+		if (strcmp(cmd, commands[i].name) != 0)
+			continue;
+
+		int c;
+
+		while (1) {
+			int option_index;
+
+			c = getopt_long(argc, argv, commands[i].optstring,
+					long_options, &option_index);
+
+			if (c == -1)
+				break;
+
+			/* Filter out illegal long options */
+			if (!strchr(commands[i].optstring, c)) {
+				ERROR("%s: invalid option -- '%c'\n", argv[0],
+				      c);
+				c = '?';
+			}
+
+			switch (c) {
+			case 'n':
+				param.subpart_name = optarg;
+				break;
+			case 'f':
+				param.file_name = optarg;
+				break;
+			case 'd':
+				param.dir_ops = 1;
+				break;
+			case 'e':
+				param.dentry_name = optarg;
+				break;
+			case 'v':
+				verbose++;
+				break;
+			case 'h':
+			case '?':
+				usage(argv[0]);
+				return 1;
+			default:
+				break;
+			}
+		}
+
+		if (ifwi_parse()) {
+			ERROR("%s: ifwi parsing failed\n", argv[0]);
+			return 1;
+		}
+
+		enum ifwi_ret ret = commands[i].function();
+
+		if (ret == COMMAND_ERR) {
+			ERROR("%s: failed execution\n", argv[0]);
+			return 1;
+		}
+
+		if (ret == REPACK_REQUIRED)
+			ifwi_repack();
+
+		return 0;
+	}
+
+	ERROR("%s: invalid command\n", argv[0]);
+	return 1;
+}