AUTHORS, util/: Drop individual copyright notices

[coreboot.git] / util / cbfstool / cbfs_image.c

/* CBFS Image Manipulation */
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <inttypes.h>
#include <libgen.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <commonlib/endian.h>
#include <vb2_sha.h>

#include "common.h"
#include "cbfs_image.h"
#include "elfparsing.h"
#include "rmodule.h"

/* Even though the file-adding functions---cbfs_add_entry() and
 * cbfs_add_entry_at()---perform their sizing checks against the beginning of
 * the subsequent section rather than a stable recorded value such as an empty
 * file header's len field, it's possible to prove two interesting properties
 * about their behavior:
 *  - Placing a new file within an empty entry located below an existing file
 *    entry will never leave an aligned flash address containing neither the
 *    beginning of a file header nor part of a file.
 *  - Placing a new file in an empty entry at the very end of the image such
 *    that it fits, but leaves no room for a final header, is guaranteed not to
 *    change the total amount of space for entries, even if that new file is
 *    later removed from the CBFS.
 * These properties are somewhat nonobvious from the implementation, so the
 * reader is encouraged to blame this comment and examine the full proofs
 * in the commit message before making significant changes that would risk
 * removing said guarantees.
 */

/* The file name align is not defined in CBFS spec -- only a preference by
 * (old) cbfstool. */
#define CBFS_FILENAME_ALIGN     (16)

static const char *lookup_name_by_type(const struct typedesc_t *desc, uint32_t type,
                                const char *default_value)
{
        int i;
        for (i = 0; desc[i].name; i++)
                if (desc[i].type == type)
                        return desc[i].name;
        return default_value;
}

static int lookup_type_by_name(const struct typedesc_t *desc, const char *name)
{
        int i;
        for (i = 0; desc[i].name && strcasecmp(name, desc[i].name); ++i);
        return desc[i].name ? (int)desc[i].type : -1;
}

static const char *get_cbfs_entry_type_name(uint32_t type)
{
        return lookup_name_by_type(filetypes, type, "(unknown)");
}

int cbfs_parse_comp_algo(const char *name)
{
        return lookup_type_by_name(types_cbfs_compression, name);
}

static const char *get_hash_attr_name(uint16_t hash_type)
{
        return lookup_name_by_type(types_cbfs_hash, hash_type, "(invalid)");
}

int cbfs_parse_hash_algo(const char *name)
{
        return lookup_type_by_name(types_cbfs_hash, name);
}

/* CBFS image */

size_t cbfs_calculate_file_header_size(const char *name)
{
        return (sizeof(struct cbfs_file) +
                align_up(strlen(name) + 1, CBFS_FILENAME_ALIGN));
}

/* Only call on legacy CBFSes possessing a master header. */
static int cbfs_fix_legacy_size(struct cbfs_image *image, char *hdr_loc)
{
        assert(image);
        assert(cbfs_is_legacy_cbfs(image));
        // A bug in old cbfstool may produce extra few bytes (by alignment) and
        // cause cbfstool to overwrite things after free space -- which is
        // usually CBFS header on x86. We need to workaround that.
        // Except when we run across a file that contains the actual header,
        // in which case this image is a safe, new-style
        // `cbfstool add-master-header` based image.

        struct cbfs_file *entry, *first = NULL, *last = NULL;
        for (first = entry = cbfs_find_first_entry(image);
             entry && cbfs_is_valid_entry(image, entry);
             entry = cbfs_find_next_entry(image, entry)) {
                /* Is the header guarded by a CBFS file entry? Then exit */
                if (((char *)entry) + ntohl(entry->offset) == hdr_loc) {
                        return 0;
                }
                last = entry;
        }
        if ((char *)first < (char *)hdr_loc &&
            (char *)entry > (char *)hdr_loc) {
                WARN("CBFS image was created with old cbfstool with size bug. "
                     "Fixing size in last entry...\n");
                last->len = htonl(ntohl(last->len) - image->header.align);
                DEBUG("Last entry has been changed from 0x%x to 0x%x.\n",
                      cbfs_get_entry_addr(image, entry),
                      cbfs_get_entry_addr(image,
                                          cbfs_find_next_entry(image, last)));
        }
        return 0;
}

void cbfs_put_header(void *dest, const struct cbfs_header *header)
{
        struct buffer outheader;

        outheader.data = dest;
        outheader.size = 0;

        xdr_be.put32(&outheader, header->magic);
        xdr_be.put32(&outheader, header->version);
        xdr_be.put32(&outheader, header->romsize);
        xdr_be.put32(&outheader, header->bootblocksize);
        xdr_be.put32(&outheader, header->align);
        xdr_be.put32(&outheader, header->offset);
        xdr_be.put32(&outheader, header->architecture);
}

static void cbfs_decode_payload_segment(struct cbfs_payload_segment *output,
                                        struct cbfs_payload_segment *input)
{
        struct buffer seg = {
                .data = (void *)input,
                .size = sizeof(*input),
        };
        output->type = xdr_be.get32(&seg);
        output->compression = xdr_be.get32(&seg);
        output->offset = xdr_be.get32(&seg);
        output->load_addr = xdr_be.get64(&seg);
        output->len = xdr_be.get32(&seg);
        output->mem_len = xdr_be.get32(&seg);
        assert(seg.size == 0);
}

static int cbfs_file_get_compression_info(struct cbfs_file *entry,
        uint32_t *decompressed_size)
{
        unsigned int compression = CBFS_COMPRESS_NONE;
        if (decompressed_size)
                *decompressed_size = ntohl(entry->len);
        for (struct cbfs_file_attribute *attr = cbfs_file_first_attr(entry);
             attr != NULL;
             attr = cbfs_file_next_attr(entry, attr)) {
                if (ntohl(attr->tag) == CBFS_FILE_ATTR_TAG_COMPRESSION) {
                        struct cbfs_file_attr_compression *ac =
                                (struct cbfs_file_attr_compression *)attr;
                        compression = ntohl(ac->compression);
                        if (decompressed_size)
                                *decompressed_size =
                                        ntohl(ac->decompressed_size);
                }
        }
        return compression;
}

static struct cbfs_file_attr_hash *cbfs_file_get_next_hash(
        struct cbfs_file *entry, struct cbfs_file_attr_hash *cur)
{
        struct cbfs_file_attribute *attr = (struct cbfs_file_attribute *)cur;
        if (attr == NULL) {
                attr = cbfs_file_first_attr(entry);
                if (attr == NULL)
                        return NULL;
                if (ntohl(attr->tag) == CBFS_FILE_ATTR_TAG_HASH)
                        return (struct cbfs_file_attr_hash *)attr;
        }
        while ((attr = cbfs_file_next_attr(entry, attr)) != NULL) {
                if (ntohl(attr->tag) == CBFS_FILE_ATTR_TAG_HASH)
                        return (struct cbfs_file_attr_hash *)attr;
        };
        return NULL;
}

void cbfs_get_header(struct cbfs_header *header, void *src)
{
        struct buffer outheader;

        outheader.data = src;   /* We're not modifying the data */
        outheader.size = 0;

        header->magic = xdr_be.get32(&outheader);
        header->version = xdr_be.get32(&outheader);
        header->romsize = xdr_be.get32(&outheader);
        header->bootblocksize = xdr_be.get32(&outheader);
        header->align = xdr_be.get32(&outheader);
        header->offset = xdr_be.get32(&outheader);
        header->architecture = xdr_be.get32(&outheader);
}

int cbfs_image_create(struct cbfs_image *image, size_t entries_size)
{
        assert(image);
        assert(image->buffer.data);

        size_t empty_header_len = cbfs_calculate_file_header_size("");
        uint32_t entries_offset = 0;
        uint32_t align = CBFS_ENTRY_ALIGNMENT;
        if (image->has_header) {
                entries_offset = image->header.offset;

                if (entries_offset > image->buffer.size) {
                        ERROR("CBFS file entries are located outside CBFS itself\n");
                        return -1;
                }

                align = image->header.align;
        }

        // This attribute must be given in order to prove that this module
        // correctly preserves certain CBFS properties. See the block comment
        // near the top of this file (and the associated commit message).
        if (align < empty_header_len) {
                ERROR("CBFS must be aligned to at least %zu bytes\n",
                                                        empty_header_len);
                return -1;
        }

        if (entries_size > image->buffer.size - entries_offset) {
                ERROR("CBFS doesn't have enough space to fit its file entries\n");
                return -1;
        }

        if (empty_header_len > entries_size) {
                ERROR("CBFS is too small to fit any header\n");
                return -1;
        }
        struct cbfs_file *entry_header =
                (struct cbfs_file *)(image->buffer.data + entries_offset);
        // This alignment is necessary in order to prove that this module
        // correctly preserves certain CBFS properties. See the block comment
        // near the top of this file (and the associated commit message).
        entries_size -= entries_size % align;

        size_t capacity = entries_size - empty_header_len;
        LOG("Created CBFS (capacity = %zu bytes)\n", capacity);
        return cbfs_create_empty_entry(entry_header, CBFS_COMPONENT_NULL,
                capacity, "");
}

int cbfs_legacy_image_create(struct cbfs_image *image,
                             uint32_t architecture,
                             uint32_t align,
                             struct buffer *bootblock,
                             uint32_t bootblock_offset,
                             uint32_t header_offset,
                             uint32_t entries_offset)
{
        assert(image);
        assert(image->buffer.data);
        assert(bootblock);

        int32_t *rel_offset;
        uint32_t cbfs_len;
        void *header_loc;
        size_t size = image->buffer.size;

        DEBUG("cbfs_image_create: bootblock=0x%x+0x%zx, "
              "header=0x%x+0x%zx, entries_offset=0x%x\n",
              bootblock_offset, bootblock->size, header_offset,
              sizeof(image->header), entries_offset);

        // Adjust legacy top-aligned address to ROM offset.
        if (IS_TOP_ALIGNED_ADDRESS(entries_offset))
                entries_offset = size + (int32_t)entries_offset;
        if (IS_TOP_ALIGNED_ADDRESS(bootblock_offset))
                bootblock_offset = size + (int32_t)bootblock_offset;
        if (IS_TOP_ALIGNED_ADDRESS(header_offset))
                header_offset = size + (int32_t)header_offset;

        DEBUG("cbfs_create_image: (real offset) bootblock=0x%x, "
              "header=0x%x, entries_offset=0x%x\n",
              bootblock_offset, header_offset, entries_offset);

        // Prepare bootblock
        if (bootblock_offset + bootblock->size > size) {
                ERROR("Bootblock (0x%x+0x%zx) exceed ROM size (0x%zx)\n",
                      bootblock_offset, bootblock->size, size);
                return -1;
        }
        if (entries_offset > bootblock_offset &&
            entries_offset < bootblock->size) {
                ERROR("Bootblock (0x%x+0x%zx) overlap CBFS data (0x%x)\n",
                      bootblock_offset, bootblock->size, entries_offset);
                return -1;
        }
        memcpy(image->buffer.data + bootblock_offset, bootblock->data,
               bootblock->size);

        // Prepare header
        if (header_offset + sizeof(image->header) > size - sizeof(int32_t)) {
                ERROR("Header (0x%x+0x%zx) exceed ROM size (0x%zx)\n",
                      header_offset, sizeof(image->header), size);
                return -1;
        }
        image->header.magic = CBFS_HEADER_MAGIC;
        image->header.version = CBFS_HEADER_VERSION;
        image->header.romsize = size;
        image->header.bootblocksize = bootblock->size;
        image->header.align = align;
        image->header.offset = entries_offset;
        image->header.architecture = architecture;

        header_loc = (image->buffer.data + header_offset);
        cbfs_put_header(header_loc, &image->header);
        image->has_header = true;

        // The last 4 byte of the image contain the relative offset from the end
        // of the image to the master header as a 32-bit signed integer. x86
        // relies on this also being its (memory-mapped, top-aligned) absolute
        // 32-bit address by virtue of how two's complement numbers work.
        assert(size % sizeof(int32_t) == 0);
        rel_offset = (int32_t *)(image->buffer.data + size - sizeof(int32_t));
        *rel_offset = header_offset - size;

        // Prepare entries
        if (align_up(entries_offset, align) != entries_offset) {
                ERROR("Offset (0x%x) must be aligned to 0x%x.\n",
                      entries_offset, align);
                return -1;
        }
        // To calculate available length, find
        //   e = min(bootblock, header, rel_offset) where e > entries_offset.
        cbfs_len = size - sizeof(int32_t);
        if (bootblock_offset > entries_offset && bootblock_offset < cbfs_len)
                cbfs_len = bootblock_offset;
        if (header_offset > entries_offset && header_offset < cbfs_len)
                cbfs_len = header_offset;

        if (cbfs_image_create(image, cbfs_len - entries_offset))
                return -1;
        return 0;
}

int cbfs_image_from_buffer(struct cbfs_image *out, struct buffer *in,
                           uint32_t offset)
{
        assert(out);
        assert(in);
        assert(in->data);

        buffer_clone(&out->buffer, in);
        out->has_header = false;

        if (cbfs_is_valid_cbfs(out)) {
                return 0;
        }

        void *header_loc = cbfs_find_header(in->data, in->size, offset);
        if (header_loc) {
                cbfs_get_header(&out->header, header_loc);
                out->has_header = true;
                cbfs_fix_legacy_size(out, header_loc);
                return 0;
        } else if (offset != ~0u) {
                ERROR("The -H switch is only valid on legacy images having CBFS master headers.\n");
                return 1;
        }
        ERROR("Selected image region is not a valid CBFS.\n");
        return 1;
}

int cbfs_copy_instance(struct cbfs_image *image, struct buffer *dst)
{
        assert(image);

        struct cbfs_file *src_entry, *dst_entry;
        size_t align;
        ssize_t last_entry_size;

        size_t copy_end = buffer_size(dst);

        align = CBFS_ENTRY_ALIGNMENT;

        dst_entry = (struct cbfs_file *)buffer_get(dst);

        /* Copy non-empty files */
        for (src_entry = cbfs_find_first_entry(image);
             src_entry && cbfs_is_valid_entry(image, src_entry);
             src_entry = cbfs_find_next_entry(image, src_entry)) {
                size_t entry_size;

                if ((src_entry->type == htonl(CBFS_COMPONENT_NULL)) ||
                    (src_entry->type == htonl(CBFS_COMPONENT_CBFSHEADER)) ||
                    (src_entry->type == htonl(CBFS_COMPONENT_DELETED)))
                        continue;

                entry_size = htonl(src_entry->len) + htonl(src_entry->offset);
                memcpy(dst_entry, src_entry, entry_size);
                dst_entry = (struct cbfs_file *)(
                        (uintptr_t)dst_entry + align_up(entry_size, align));

                if ((size_t)((uint8_t *)dst_entry - (uint8_t *)buffer_get(dst))
                                        >= copy_end) {
                        ERROR("Ran out of room in copy region.\n");
                        return 1;
                }
        }

        /* Last entry size is all the room above it, except for top 4 bytes
         * which may be used by the master header pointer. This messes with
         * the ability to stash something "top-aligned" into the region, but
         * keeps things simpler. */
        last_entry_size = copy_end -
                ((uint8_t *)dst_entry - (uint8_t *)buffer_get(dst)) -
                cbfs_calculate_file_header_size("") - sizeof(int32_t);

        if (last_entry_size < 0)
                WARN("No room to create the last entry!\n")
        else
                cbfs_create_empty_entry(dst_entry, CBFS_COMPONENT_NULL,
                        last_entry_size, "");

        return 0;
}

int cbfs_expand_to_region(struct buffer *region)
{
        if (buffer_get(region) == NULL)
                return 1;

        struct cbfs_image image;
        memset(&image, 0, sizeof(image));
        if (cbfs_image_from_buffer(&image, region, 0)) {
                ERROR("reading CBFS failed!\n");
                return 1;
        }

        uint32_t region_sz = buffer_size(region);

        struct cbfs_file *entry;
        for (entry = buffer_get(region);
             cbfs_is_valid_entry(&image, entry);
             entry = cbfs_find_next_entry(&image, entry)) {
             /* just iterate through */
        }

        /* entry now points to the first aligned address after the last valid
         * file header. That's either outside the image or exactly the place
         * where we need to create a new file.
         */
        int last_entry_size = region_sz -
                ((uint8_t *)entry - (uint8_t *)buffer_get(region)) -
                cbfs_calculate_file_header_size("") - sizeof(int32_t);

        if (last_entry_size > 0) {
                cbfs_create_empty_entry(entry, CBFS_COMPONENT_NULL,
                        last_entry_size, "");
                /* If the last entry was an empty file, merge them. */
                cbfs_walk(&image, cbfs_merge_empty_entry, NULL);
        }

        return 0;
}

int cbfs_truncate_space(struct buffer *region, uint32_t *size)
{
        if (buffer_get(region) == NULL)
                return 1;

        struct cbfs_image image;
        memset(&image, 0, sizeof(image));
        if (cbfs_image_from_buffer(&image, region, 0)) {
                ERROR("reading CBFS failed!\n");
                return 1;
        }

        struct cbfs_file *entry, *trailer;
        for (trailer = entry = buffer_get(region);
             cbfs_is_valid_entry(&image, entry);
             trailer = entry,
             entry = cbfs_find_next_entry(&image, entry)) {
             /* just iterate through */
        }

        /* trailer now points to the last valid CBFS entry's header.
         * If that file is empty, remove it and report its header's offset as
         * maximum size.
         */
        if ((strlen(trailer->filename) != 0) &&
            (trailer->type != htonl(CBFS_COMPONENT_NULL)) &&
            (trailer->type != htonl(CBFS_COMPONENT_DELETED))) {
                /* nothing to truncate. Return de-facto CBFS size in case it
                 * was already truncated. */
                *size = (uint8_t *)entry - (uint8_t *)buffer_get(region);
                return 0;
        }
        *size = (uint8_t *)trailer - (uint8_t *)buffer_get(region);
        memset(trailer, 0xff, buffer_size(region) - *size);

        return 0;
}

static size_t cbfs_file_entry_metadata_size(const struct cbfs_file *f)
{
        return ntohl(f->offset);
}

static size_t cbfs_file_entry_data_size(const struct cbfs_file *f)
{
        return ntohl(f->len);
}

static size_t cbfs_file_entry_size(const struct cbfs_file *f)
{
        return cbfs_file_entry_metadata_size(f) + cbfs_file_entry_data_size(f);
}

int cbfs_compact_instance(struct cbfs_image *image)
{
        assert(image);

        struct cbfs_file *prev;
        struct cbfs_file *cur;

        /* The prev entry will always be an empty entry. */
        prev = NULL;

        /*
         * Note: this function does not honor alignment or fixed location files.
         * It's behavior is akin to cbfs_copy_instance() in that it expects
         * the caller to understand the ramifications of compacting a
         * fragmented CBFS image.
         */

        for (cur = cbfs_find_first_entry(image);
             cur && cbfs_is_valid_entry(image, cur);
             cur = cbfs_find_next_entry(image, cur)) {
                size_t prev_size;
                size_t cur_size;
                size_t empty_metadata_size;
                size_t spill_size;
                uint32_t type = htonl(cur->type);

                /* Current entry is empty. Kepp track of it. */
                if ((type == htonl(CBFS_COMPONENT_NULL)) ||
                    (type == htonl(CBFS_COMPONENT_DELETED))) {
                        prev = cur;
                        continue;
                }

                /* Need to ensure the previous entry is an empty one. */
                if (prev == NULL)
                        continue;

                /* At this point prev is an empty entry. Put the non-empty
                 * file in prev's location. Then add a new empty entry. This
                 * essentialy bubbles empty entries towards the end. */

                prev_size = cbfs_file_entry_size(prev);
                cur_size = cbfs_file_entry_size(cur);

                /*
                 * Adjust the empty file size by the actual space occupied
                 * bewtween the beginning of the empty file and the non-empty
                 * file.
                 */
                prev_size += (cbfs_get_entry_addr(image, cur) -
                                cbfs_get_entry_addr(image, prev)) - prev_size;

                /* Move the non-empty file over the empty file. */
                memmove(prev, cur, cur_size);

                /*
                 * Get location of the empty file. Note that since prev was
                 * overwritten with the non-empty file the previously moved
                 * file needs to be used to calculate the empty file's location.
                 */
                cur = cbfs_find_next_entry(image, prev);

                /*
                 * The total space to work with for swapping the 2 entries
                 * consists of the 2 files' sizes combined. However, the
                 * cbfs_file entries start on CBFS_ALIGNMENT boundaries.
                 * Because of this the empty file size may end up smaller
                 * because of the non-empty file's metadata and data length.
                 *
                 * Calculate the spill size which is the amount of data lost
                 * due to the alignment constraints after moving the non-empty
                 * file.
                 */
                spill_size = (cbfs_get_entry_addr(image, cur) -
                                cbfs_get_entry_addr(image, prev)) - cur_size;

                empty_metadata_size = cbfs_calculate_file_header_size("");

                /* Check if new empty size can contain the metadata. */
                if (empty_metadata_size + spill_size > prev_size) {
                        ERROR("Unable to swap '%s' with prev empty entry.\n",
                                prev->filename);
                        return 1;
                }

                /* Update the empty file's size. */
                prev_size -= spill_size + empty_metadata_size;

                /* Create new empty file. */
                cbfs_create_empty_entry(cur, CBFS_COMPONENT_NULL,
                                        prev_size, "");

                /* Merge any potential empty entries together. */
                cbfs_walk(image, cbfs_merge_empty_entry, NULL);

                /*
                 * Since current switched to an empty file keep track of it.
                 * Even if any empty files were merged the empty entry still
                 * starts at previously calculated location.
                 */
                prev = cur;
        }

        return 0;
}

int cbfs_image_delete(struct cbfs_image *image)
{
        if (image == NULL)
                return 0;

        buffer_delete(&image->buffer);
        return 0;
}

/* Tries to add an entry with its data (CBFS_SUBHEADER) at given offset. */
static int cbfs_add_entry_at(struct cbfs_image *image,
                             struct cbfs_file *entry,
                             const void *data,
                             uint32_t content_offset,
                             const struct cbfs_file *header,
                             const size_t len_align)
{
        struct cbfs_file *next = cbfs_find_next_entry(image, entry);
        uint32_t addr = cbfs_get_entry_addr(image, entry),
                 addr_next = cbfs_get_entry_addr(image, next);
        uint32_t min_entry_size = cbfs_calculate_file_header_size("");
        uint32_t len, header_offset;
        uint32_t align = image->has_header ? image->header.align :
                                                        CBFS_ENTRY_ALIGNMENT;
        uint32_t header_size = ntohl(header->offset);

        header_offset = content_offset - header_size;
        if (header_offset % align)
                header_offset -= header_offset % align;
        if (header_offset < addr) {
                ERROR("No space to hold cbfs_file header.");
                return -1;
        }

        // Process buffer BEFORE content_offset.
        if (header_offset - addr > min_entry_size) {
                DEBUG("|min|...|header|content|... <create new entry>\n");
                len = header_offset - addr - min_entry_size;
                cbfs_create_empty_entry(entry, CBFS_COMPONENT_NULL, len, "");
                if (verbose > 1) cbfs_print_entry_info(image, entry, stderr);
                entry = cbfs_find_next_entry(image, entry);
                addr = cbfs_get_entry_addr(image, entry);
        }

        len = content_offset - addr - header_size;
        memcpy(entry, header, header_size);
        if (len != 0) {
                /* the header moved backwards a bit to accommodate cbfs_file
                 * alignment requirements, so patch up ->offset to still point
                 * to file data.
                 */
                DEBUG("|..|header|content|... <use offset to create entry>\n");
                DEBUG("before: offset=0x%x\n", ntohl(entry->offset));
                // TODO reset expanded name buffer to 0xFF.
                entry->offset = htonl(ntohl(entry->offset) + len);
                DEBUG("after: offset=0x%x\n", ntohl(entry->len));
        }

        // Ready to fill data into entry.
        DEBUG("content_offset: 0x%x, entry location: %x\n",
              content_offset, (int)((char*)CBFS_SUBHEADER(entry) -
                                    image->buffer.data));
        assert((char*)CBFS_SUBHEADER(entry) - image->buffer.data ==
               (ptrdiff_t)content_offset);
        memcpy(CBFS_SUBHEADER(entry), data, ntohl(entry->len));
        if (verbose > 1) cbfs_print_entry_info(image, entry, stderr);

        // Align the length to a multiple of len_align
        if (len_align &&
            ((ntohl(entry->offset) + ntohl(entry->len)) % len_align)) {
                size_t off = (ntohl(entry->offset) + ntohl(entry->len)) % len_align;
                entry->len = htonl(ntohl(entry->len) + len_align - off);
        }

        // Process buffer AFTER entry.
        entry = cbfs_find_next_entry(image, entry);
        addr = cbfs_get_entry_addr(image, entry);
        if (addr == addr_next)
                return 0;

        assert(addr < addr_next);
        if (addr_next - addr < min_entry_size) {
                DEBUG("No need for new \"empty\" entry\n");
                /* No need to increase the size of the just
                 * stored file to extend to next file. Alignment
                 * of next file takes care of this.
                 */
                return 0;
        }

        len = addr_next - addr - min_entry_size;
        /* keep space for master header pointer */
        if ((uint8_t *)entry + min_entry_size + len >
                        (uint8_t *)buffer_get(&image->buffer) +
                        buffer_size(&image->buffer) - sizeof(int32_t)) {
                len -= sizeof(int32_t);
        }
        cbfs_create_empty_entry(entry, CBFS_COMPONENT_NULL, len, "");
        if (verbose > 1) cbfs_print_entry_info(image, entry, stderr);
        return 0;
}

int cbfs_add_entry(struct cbfs_image *image, struct buffer *buffer,
                   uint32_t content_offset,
                   struct cbfs_file *header,
                   const size_t len_align)
{
        assert(image);
        assert(buffer);
        assert(buffer->data);
        assert(!IS_TOP_ALIGNED_ADDRESS(content_offset));

        const char *name = header->filename;

        uint32_t entry_type;
        uint32_t addr, addr_next;
        struct cbfs_file *entry, *next;
        uint32_t need_size;
        uint32_t header_size = ntohl(header->offset);

        need_size = header_size + buffer->size;
        DEBUG("cbfs_add_entry('%s'@0x%x) => need_size = %u+%zu=%u\n",
              name, content_offset, header_size, buffer->size, need_size);

        // Merge empty entries.
        DEBUG("(trying to merge empty entries...)\n");
        cbfs_walk(image, cbfs_merge_empty_entry, NULL);

        for (entry = cbfs_find_first_entry(image);
             entry && cbfs_is_valid_entry(image, entry);
             entry = cbfs_find_next_entry(image, entry)) {

                entry_type = ntohl(entry->type);
                if (entry_type != CBFS_COMPONENT_NULL)
                        continue;

                addr = cbfs_get_entry_addr(image, entry);
                next = cbfs_find_next_entry(image, entry);
                addr_next = cbfs_get_entry_addr(image, next);

                DEBUG("cbfs_add_entry: space at 0x%x+0x%x(%d) bytes\n",
                      addr, addr_next - addr, addr_next - addr);

                /* Will the file fit? Don't yet worry if we have space for a new
                 * "empty" entry. We take care of that later.
                 */
                if (addr + need_size > addr_next)
                        continue;

                // Test for complicated cases
                if (content_offset > 0) {
                        if (addr_next < content_offset) {
                                DEBUG("Not for specified offset yet");
                                continue;
                        } else if (addr > content_offset) {
                                DEBUG("Exceed specified content_offset.");
                                break;
                        } else if (addr + header_size > content_offset) {
                                ERROR("Not enough space for header.\n");
                                break;
                        } else if (content_offset + buffer->size > addr_next) {
                                ERROR("Not enough space for content.\n");
                                break;
                        }
                }

                // TODO there are more few tricky cases that we may
                // want to fit by altering offset.

                if (content_offset == 0) {
                        // we tested every condition earlier under which
                        // placing the file there might fail
                        content_offset = addr + header_size;
                }

                DEBUG("section 0x%x+0x%x for content_offset 0x%x.\n",
                      addr, addr_next - addr, content_offset);

                if (cbfs_add_entry_at(image, entry, buffer->data,
                                      content_offset, header, len_align) == 0) {
                        return 0;
                }
                break;
        }

        ERROR("Could not add [%s, %zd bytes (%zd KB)@0x%x]; too big?\n",
              buffer->name, buffer->size, buffer->size / 1024, content_offset);
        return -1;
}

struct cbfs_file *cbfs_get_entry(struct cbfs_image *image, const char *name)
{
        struct cbfs_file *entry;
        for (entry = cbfs_find_first_entry(image);
             entry && cbfs_is_valid_entry(image, entry);
             entry = cbfs_find_next_entry(image, entry)) {
                if (strcasecmp(entry->filename, name) == 0) {
                        DEBUG("cbfs_get_entry: found %s\n", name);
                        return entry;
                }
        }
        return NULL;
}

static int cbfs_stage_decompress(struct cbfs_stage *stage, struct buffer *buff)
{
        struct buffer reader;
        char *orig_buffer;
        char *new_buffer;
        size_t new_buff_sz;
        decomp_func_ptr decompress;

        buffer_clone(&reader, buff);

        /* The stage metadata is in little endian. */
        stage->compression = xdr_le.get32(&reader);
        stage->entry = xdr_le.get64(&reader);
        stage->load = xdr_le.get64(&reader);
        stage->len = xdr_le.get32(&reader);
        stage->memlen = xdr_le.get32(&reader);

        /* Create a buffer just with the uncompressed program now that the
         * struct cbfs_stage has been peeled off. */
        if (stage->compression == CBFS_COMPRESS_NONE) {
                new_buff_sz = buffer_size(buff) - sizeof(struct cbfs_stage);

                orig_buffer = buffer_get(buff);
                new_buffer = calloc(1, new_buff_sz);
                memcpy(new_buffer, orig_buffer + sizeof(struct cbfs_stage),
                        new_buff_sz);
                buffer_init(buff, buff->name, new_buffer, new_buff_sz);
                free(orig_buffer);
                return 0;
        }

        decompress = decompression_function(stage->compression);
        if (decompress == NULL)
                return -1;

        orig_buffer = buffer_get(buff);

        /* This can be too big of a buffer needed, but there's no current
         * field indicating decompressed size of data. */
        new_buff_sz = stage->memlen;
        new_buffer = calloc(1, new_buff_sz);

        if (decompress(orig_buffer + sizeof(struct cbfs_stage),
                        (int)(buffer_size(buff) - sizeof(struct cbfs_stage)),
                        new_buffer, (int)new_buff_sz, &new_buff_sz)) {
                ERROR("Couldn't decompress stage.\n");
                free(new_buffer);
                return -1;
        }

        /* Include correct size for full stage info. */
        buffer_init(buff, buff->name, new_buffer, new_buff_sz);

        /* True decompressed size is just the data size -- no metadata. */
        stage->len = new_buff_sz;
        /* Stage is not compressed. */
        stage->compression = CBFS_COMPRESS_NONE;

        free(orig_buffer);

        return 0;
}

static int cbfs_payload_decompress(struct cbfs_payload_segment *segments,
                struct buffer *buff, int num_seg)
{
        struct buffer new_buffer;
        struct buffer seg_buffer;
        size_t new_buff_sz;
        char *in_ptr;
        char *out_ptr;
        size_t new_offset;
        decomp_func_ptr decompress;

        new_offset = num_seg * sizeof(*segments);
        new_buff_sz = num_seg * sizeof(*segments);

        /* Find out and allocate the amount of memory occupied
         * by the binary data */
        for (int i = 0; i < num_seg; i++)
                new_buff_sz += segments[i].mem_len;

        if (buffer_create(&new_buffer, new_buff_sz, "decompressed_buff"))
                return -1;

        in_ptr = buffer_get(buff) + new_offset;
        out_ptr = buffer_get(&new_buffer) + new_offset;

        for (int i = 0; i < num_seg; i++) {
                struct buffer tbuff;
                size_t decomp_size;

                /* Segments BSS and ENTRY do not have binary data. */
                if (segments[i].type == PAYLOAD_SEGMENT_BSS ||
                                segments[i].type == PAYLOAD_SEGMENT_ENTRY) {
                        continue;
                } else if (segments[i].type == PAYLOAD_SEGMENT_PARAMS) {
                        memcpy(out_ptr, in_ptr, segments[i].len);
                        segments[i].offset = new_offset;
                        new_offset += segments[i].len;
                        in_ptr += segments[i].len;
                        out_ptr += segments[i].len;
                        segments[i].compression = CBFS_COMPRESS_NONE;
                        continue;
                }

                /* The payload uses an unknown compression algorithm. */
                decompress = decompression_function(segments[i].compression);
                if (decompress == NULL) {
                        ERROR("Unknown decompression algorithm: %u\n",
                                        segments[i].compression);
                        return -1;
                }

                if (buffer_create(&tbuff, segments[i].mem_len, "segment")) {
                        buffer_delete(&new_buffer);
                        return -1;
                }

                if (decompress(in_ptr, segments[i].len, buffer_get(&tbuff),
                                        (int) buffer_size(&tbuff),
                                        &decomp_size)) {
                        ERROR("Couldn't decompress payload segment %u\n", i);
                        buffer_delete(&new_buffer);
                        buffer_delete(&tbuff);
                        return -1;
                }

                memcpy(out_ptr, buffer_get(&tbuff), decomp_size);

                in_ptr += segments[i].len;

                /* Update the offset of the segment. */
                segments[i].offset = new_offset;
                /* True decompressed size is just the data size. No metadata */
                segments[i].len = decomp_size;
                /* Segment is not compressed. */
                segments[i].compression = CBFS_COMPRESS_NONE;

                /* Update the offset and output buffer pointer. */
                new_offset += decomp_size;
                out_ptr += decomp_size;

                buffer_delete(&tbuff);
        }

        buffer_splice(&seg_buffer, &new_buffer, 0, 0);
        xdr_segs(&seg_buffer, segments, num_seg);

        buffer_delete(buff);
        *buff = new_buffer;

        return 0;
}

static int init_elf_from_arch(Elf64_Ehdr *ehdr, uint32_t cbfs_arch)
{
        int endian;
        int nbits;
        int machine;

        switch (cbfs_arch) {
        case CBFS_ARCHITECTURE_X86:
                endian = ELFDATA2LSB;
                nbits = ELFCLASS32;
                machine = EM_386;
                break;
        case CBFS_ARCHITECTURE_ARM:
                endian = ELFDATA2LSB;
                nbits = ELFCLASS32;
                machine = EM_ARM;
                break;
        case CBFS_ARCHITECTURE_AARCH64:
                endian = ELFDATA2LSB;
                nbits = ELFCLASS64;
                machine = EM_AARCH64;
                break;
        case CBFS_ARCHITECTURE_MIPS:
                endian = ELFDATA2LSB;
                nbits = ELFCLASS32;
                machine = EM_MIPS;
                break;
        case CBFS_ARCHITECTURE_RISCV:
                endian = ELFDATA2LSB;
                nbits = ELFCLASS32;
                machine = EM_RISCV;
                break;
        default:
                ERROR("Unsupported arch: %x\n", cbfs_arch);
                return -1;
        }

        elf_init_eheader(ehdr, machine, nbits, endian);
        return 0;
}

static int cbfs_stage_make_elf(struct buffer *buff, uint32_t arch)
{
        Elf64_Ehdr ehdr;
        Elf64_Shdr shdr;
        struct cbfs_stage stage;
        struct elf_writer *ew;
        struct buffer elf_out;
        size_t empty_sz;
        int rmod_ret;

        if (arch == CBFS_ARCHITECTURE_UNKNOWN) {
                ERROR("You need to specify -m ARCH.\n");
                return -1;
        }

        if (cbfs_stage_decompress(&stage, buff)) {
                ERROR("Failed to decompress stage.\n");
                return -1;
        }

        if (init_elf_from_arch(&ehdr, arch))
                return -1;

        ehdr.e_entry = stage.entry;

        /* Attempt rmodule translation first. */
        rmod_ret = rmodule_stage_to_elf(&ehdr, buff);

        if (rmod_ret < 0) {
                ERROR("rmodule parsing failed\n");
                return -1;
        } else if (rmod_ret == 0)
                return 0;

        /* Rmodule couldn't do anything with the data. Continue on with SELF. */

        ew = elf_writer_init(&ehdr);
        if (ew == NULL) {
                ERROR("Unable to init ELF writer.\n");
                return -1;
        }

        memset(&shdr, 0, sizeof(shdr));
        shdr.sh_type = SHT_PROGBITS;
        shdr.sh_flags = SHF_WRITE | SHF_ALLOC | SHF_EXECINSTR;
        shdr.sh_addr = stage.load;
        shdr.sh_size = stage.len;
        empty_sz = stage.memlen - stage.len;

        if (elf_writer_add_section(ew, &shdr, buff, ".program")) {
                ERROR("Unable to add ELF section: .program\n");
                elf_writer_destroy(ew);
                return -1;
        }

        if (empty_sz != 0) {
                struct buffer b;

                buffer_init(&b, NULL, NULL, 0);
                memset(&shdr, 0, sizeof(shdr));
                shdr.sh_type = SHT_NOBITS;
                shdr.sh_flags = SHF_WRITE | SHF_ALLOC;
                shdr.sh_addr = stage.load + stage.len;
                shdr.sh_size = empty_sz;
                if (elf_writer_add_section(ew, &shdr, &b, ".empty")) {
                        ERROR("Unable to add ELF section: .empty\n");
                        elf_writer_destroy(ew);
                        return -1;
                }
        }

        if (elf_writer_serialize(ew, &elf_out)) {
                ERROR("Unable to create ELF file from stage.\n");
                elf_writer_destroy(ew);
                return -1;
        }

        /* Flip buffer with the created ELF one. */
        buffer_delete(buff);
        *buff = elf_out;

        elf_writer_destroy(ew);

        return 0;
}

static int cbfs_payload_make_elf(struct buffer *buff, uint32_t arch)
{
        Elf64_Ehdr ehdr;
        Elf64_Shdr shdr;
        struct cbfs_payload_segment *segs = NULL;
        struct elf_writer *ew = NULL;
        struct buffer elf_out;
        int segments = 0;
        int retval = -1;

        if (arch == CBFS_ARCHITECTURE_UNKNOWN) {
                ERROR("You need to specify -m ARCH.\n");
                goto out;
        }

        /* Count the number of segments inside buffer */
        while (true) {
                uint32_t payload_type = 0;

                struct cbfs_payload_segment *seg;

                seg = buffer_get(buff);
                payload_type = read_be32(&seg[segments].type);

                if (payload_type == PAYLOAD_SEGMENT_CODE) {
                        segments++;
                } else if (payload_type == PAYLOAD_SEGMENT_DATA) {
                        segments++;
                } else if (payload_type == PAYLOAD_SEGMENT_BSS) {
                        segments++;
                } else if (payload_type == PAYLOAD_SEGMENT_PARAMS) {
                        segments++;
                } else if (payload_type == PAYLOAD_SEGMENT_ENTRY) {
                        /* The last segment in a payload is always ENTRY as
                         * specified by the  parse_elf_to_payload() function.
                         * Therefore there is no need to continue looking for
                         * segments.*/
                        segments++;
                        break;
                } else {
                        ERROR("Unknown payload segment type: %x\n",
                                        payload_type);
                        goto out;
                }
        }

        segs = malloc(segments * sizeof(*segs));

        /* Decode xdr segments */
        for (int i = 0; i < segments; i++) {
                struct cbfs_payload_segment *serialized_seg = buffer_get(buff);
                xdr_get_seg(&segs[i], &serialized_seg[i]);
        }

        if (cbfs_payload_decompress(segs, buff, segments)) {
                ERROR("Failed to decompress payload.\n");
                goto out;
        }

        if (init_elf_from_arch(&ehdr, arch))
                goto out;

        ehdr.e_entry = segs[segments-1].load_addr;

        ew = elf_writer_init(&ehdr);
        if (ew == NULL) {
                ERROR("Unable to init ELF writer.\n");
                goto out;
        }

        for (int i = 0; i < segments; i++) {
                struct buffer tbuff;
                size_t empty_sz = 0;

                memset(&shdr, 0, sizeof(shdr));
                char *name = NULL;

                if (segs[i].type == PAYLOAD_SEGMENT_CODE) {
                        shdr.sh_type = SHT_PROGBITS;
                        shdr.sh_flags = SHF_WRITE | SHF_ALLOC | SHF_EXECINSTR;
                        shdr.sh_addr = segs[i].load_addr;
                        shdr.sh_size = segs[i].len;
                        empty_sz = segs[i].mem_len - segs[i].len;
                        name = strdup(".text");
                        buffer_splice(&tbuff, buff, segs[i].offset,
                                       segs[i].len);
                } else if (segs[i].type == PAYLOAD_SEGMENT_DATA) {
                        shdr.sh_type = SHT_PROGBITS;
                        shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
                        shdr.sh_addr = segs[i].load_addr;
                        shdr.sh_size = segs[i].len;
                        empty_sz = segs[i].mem_len - segs[i].len;
                        name = strdup(".data");
                        buffer_splice(&tbuff, buff, segs[i].offset,
                                       segs[i].len);
                } else if (segs[i].type == PAYLOAD_SEGMENT_BSS) {
                        shdr.sh_type = SHT_NOBITS;
                        shdr.sh_flags = SHF_ALLOC | SHF_WRITE;
                        shdr.sh_addr = segs[i].load_addr;
                        shdr.sh_size = segs[i].len;
                        name = strdup(".bss");
                        buffer_splice(&tbuff, buff, 0, 0);
                } else if (segs[i].type == PAYLOAD_SEGMENT_PARAMS) {
                        shdr.sh_type = SHT_NOTE;
                        shdr.sh_flags = 0;
                        shdr.sh_size = segs[i].len;
                        name = strdup(".note.pinfo");
                        buffer_splice(&tbuff, buff, segs[i].offset,
                                       segs[i].len);
                } else if (segs[i].type == PAYLOAD_SEGMENT_ENTRY) {
                        break;
                } else {
                        ERROR("unknown ELF segment type\n");
                        goto out;
                }

                if (!name) {
                        ERROR("out of memory\n");
                        goto out;
                }

                if (elf_writer_add_section(ew, &shdr, &tbuff, name)) {
                        ERROR("Unable to add ELF section: %s\n", name);
                        free(name);
                        goto out;
                }
                free(name);

                if (empty_sz != 0) {
                        struct buffer b;

                        buffer_init(&b, NULL, NULL, 0);
                        memset(&shdr, 0, sizeof(shdr));
                        shdr.sh_type = SHT_NOBITS;
                        shdr.sh_flags = SHF_WRITE | SHF_ALLOC;
                        shdr.sh_addr = segs[i].load_addr + segs[i].len;
                        shdr.sh_size = empty_sz;
                        name = strdup(".empty");
                        if (!name) {
                                ERROR("out of memory\n");
                                goto out;
                        }
                        if (elf_writer_add_section(ew, &shdr, &b, name)) {
                                ERROR("Unable to add ELF section: %s\n", name);
                                free(name);
                                goto out;
                        }
                        free(name);
                }
        }

        if (elf_writer_serialize(ew, &elf_out)) {
                ERROR("Unable to create ELF file from stage.\n");
                goto out;
        }

        /* Flip buffer with the created ELF one. */
        buffer_delete(buff);
        *buff = elf_out;
        retval = 0;

out:
        free(segs);
        elf_writer_destroy(ew);
        return retval;
}

int cbfs_export_entry(struct cbfs_image *image, const char *entry_name,
                      const char *filename, uint32_t arch, bool do_processing)
{
        struct cbfs_file *entry = cbfs_get_entry(image, entry_name);
        struct buffer buffer;
        if (!entry) {
                ERROR("File not found: %s\n", entry_name);
                return -1;
        }

        unsigned int compressed_size = ntohl(entry->len);
        unsigned int decompressed_size = 0;
        unsigned int compression = cbfs_file_get_compression_info(entry,
                &decompressed_size);
        unsigned int buffer_len;
        decomp_func_ptr decompress;

        if (do_processing) {
                decompress = decompression_function(compression);
                if (!decompress) {
                        ERROR("looking up decompression routine failed\n");
                        return -1;
                }
                buffer_len = decompressed_size;
        } else {
                /* Force nop decompression */
                decompress = decompression_function(CBFS_COMPRESS_NONE);
                buffer_len = compressed_size;
        }

        LOG("Found file %.30s at 0x%x, type %.12s, compressed %d, size %d\n",
            entry_name, cbfs_get_entry_addr(image, entry),
            get_cbfs_entry_type_name(ntohl(entry->type)), compressed_size,
            decompressed_size);

        buffer_init(&buffer, strdup("(cbfs_export_entry)"), NULL, 0);
        buffer.data = malloc(buffer_len);
        buffer.size = buffer_len;

        if (decompress(CBFS_SUBHEADER(entry), compressed_size,
                       buffer.data, buffer.size, NULL)) {
                ERROR("decompression failed for %s\n", entry_name);
                buffer_delete(&buffer);
                return -1;
        }

        /*
         * The stage metadata is never compressed proper for cbfs_stage
         * files. The contents of the stage data can be though. Therefore
         * one has to do a second pass for stages to potentially decompress
         * the stage data to make it more meaningful.
         */
        if (do_processing) {
                int (*make_elf)(struct buffer *, uint32_t) = NULL;
                switch (ntohl(entry->type)) {
                case CBFS_COMPONENT_STAGE:
                        make_elf = cbfs_stage_make_elf;
                        break;
                case CBFS_COMPONENT_SELF:
                        make_elf = cbfs_payload_make_elf;
                        break;
                }
                if (make_elf && make_elf(&buffer, arch)) {
                        ERROR("Failed to write %s into %s.\n",
                              entry_name, filename);
                        buffer_delete(&buffer);
                        return -1;
                }
        }

        if (buffer_write_file(&buffer, filename) != 0) {
                ERROR("Failed to write %s into %s.\n",
                      entry_name, filename);
                buffer_delete(&buffer);
                return -1;
        }

        buffer_delete(&buffer);
        INFO("Successfully dumped the file to: %s\n", filename);
        return 0;
}

int cbfs_remove_entry(struct cbfs_image *image, const char *name)
{
        struct cbfs_file *entry;
        entry = cbfs_get_entry(image, name);
        if (!entry) {
                ERROR("CBFS file %s not found.\n", name);
                return -1;
        }
        DEBUG("cbfs_remove_entry: Removed %s @ 0x%x\n",
              entry->filename, cbfs_get_entry_addr(image, entry));
        entry->type = htonl(CBFS_COMPONENT_DELETED);
        cbfs_walk(image, cbfs_merge_empty_entry, NULL);
        return 0;
}

int cbfs_print_header_info(struct cbfs_image *image)
{
        char *name = strdup(image->buffer.name);
        assert(image);
        printf("%s: %zd kB, bootblocksize %d, romsize %d, offset 0x%x\n"
               "alignment: %d bytes, architecture: %s\n\n",
               basename(name),
               image->buffer.size / 1024,
               image->header.bootblocksize,
               image->header.romsize,
               image->header.offset,
               image->header.align,
               arch_to_string(image->header.architecture));
        free(name);
        return 0;
}

static int cbfs_print_stage_info(struct cbfs_stage *stage, FILE* fp)
{
        fprintf(fp,
                "    %s compression, entry: 0x%" PRIx64 ", load: 0x%" PRIx64 ", "
                "length: %d/%d\n",
                lookup_name_by_type(types_cbfs_compression,
                                    stage->compression, "(unknown)"),
                stage->entry,
                stage->load,
                stage->len,
                stage->memlen);
        return 0;
}

static int cbfs_print_decoded_payload_segment_info(
                struct cbfs_payload_segment *seg, FILE *fp)
{
        /* The input (seg) must be already decoded by
         * cbfs_decode_payload_segment.
         */
        switch (seg->type) {
                case PAYLOAD_SEGMENT_CODE:
                case PAYLOAD_SEGMENT_DATA:
                        fprintf(fp, "    %s (%s compression, offset: 0x%x, "
                                "load: 0x%" PRIx64 ", length: %d/%d)\n",
                                (seg->type == PAYLOAD_SEGMENT_CODE ?
                                 "code " : "data"),
                                lookup_name_by_type(types_cbfs_compression,
                                                    seg->compression,
                                                    "(unknown)"),
                                seg->offset, seg->load_addr, seg->len,
                                seg->mem_len);
                        break;

                case PAYLOAD_SEGMENT_ENTRY:
                        fprintf(fp, "    entry (0x%" PRIx64 ")\n",
                                seg->load_addr);
                        break;

                case PAYLOAD_SEGMENT_BSS:
                        fprintf(fp, "    BSS (address 0x%016" PRIx64 ", "
                                "length 0x%x)\n",
                                seg->load_addr, seg->len);
                        break;

                case PAYLOAD_SEGMENT_PARAMS:
                        fprintf(fp, "    parameters\n");
                        break;

                default:
                        fprintf(fp, "   0x%x (%s compression, offset: 0x%x, "
                                "load: 0x%" PRIx64 ", length: %d/%d\n",
                                seg->type,
                                lookup_name_by_type(types_cbfs_compression,
                                                    seg->compression,
                                                    "(unknown)"),
                                seg->offset, seg->load_addr, seg->len,
                                seg->mem_len);
                        break;
        }
        return 0;
}

int cbfs_print_entry_info(struct cbfs_image *image, struct cbfs_file *entry,
                          void *arg)
{
        const char *name = entry->filename;
        struct cbfs_payload_segment *payload;
        FILE *fp = (FILE *)arg;

        if (!cbfs_is_valid_entry(image, entry)) {
                ERROR("cbfs_print_entry_info: Invalid entry at 0x%x\n",
                      cbfs_get_entry_addr(image, entry));
                return -1;
        }
        if (!fp)
                fp = stdout;

        unsigned int decompressed_size = 0;
        unsigned int compression = cbfs_file_get_compression_info(entry,
                &decompressed_size);
        const char *compression_name = lookup_name_by_type(
                        types_cbfs_compression, compression, "????");

        if (compression == CBFS_COMPRESS_NONE)
                fprintf(fp, "%-30s 0x%-8x %-12s %8d %-4s\n",
                        *name ? name : "(empty)",
                        cbfs_get_entry_addr(image, entry),
                        get_cbfs_entry_type_name(ntohl(entry->type)),
                        ntohl(entry->len),
                        compression_name
                        );
        else
                fprintf(fp, "%-30s 0x%-8x %-12s %8d %-4s (%d decompressed)\n",
                        *name ? name : "(empty)",
                        cbfs_get_entry_addr(image, entry),
                        get_cbfs_entry_type_name(ntohl(entry->type)),
                        ntohl(entry->len),
                        compression_name,
                        decompressed_size
                        );

        struct cbfs_file_attr_hash *hash = NULL;
        while ((hash = cbfs_file_get_next_hash(entry, hash)) != NULL) {
                unsigned int hash_type = ntohl(hash->hash_type);
                if (hash_type >= CBFS_NUM_SUPPORTED_HASHES) {
                        fprintf(fp, "invalid hash type %d\n", hash_type);
                        break;
                }
                size_t hash_len = widths_cbfs_hash[hash_type];
                char *hash_str = bintohex(hash->hash_data, hash_len);
                uint8_t local_hash[hash_len];
                if (vb2_digest_buffer(CBFS_SUBHEADER(entry),
                        ntohl(entry->len), hash_type, local_hash,
                        hash_len) != VB2_SUCCESS) {
                        fprintf(fp, "failed to hash '%s'\n", name);
                        free(hash_str);
                        break;
                }
                int valid = memcmp(local_hash, hash->hash_data, hash_len) == 0;
                const char *valid_str = valid ? "valid" : "invalid";

                fprintf(fp, "    hash %s:%s %s\n",
                        get_hash_attr_name(hash_type),
                        hash_str, valid_str);
                free(hash_str);
        }

        if (!verbose)
                return 0;

        DEBUG(" cbfs_file=0x%x, offset=0x%x, content_address=0x%x+0x%x\n",
              cbfs_get_entry_addr(image, entry), ntohl(entry->offset),
              cbfs_get_entry_addr(image, entry) + ntohl(entry->offset),
              ntohl(entry->len));

        /* note the components of the subheader may be in host order ... */
        switch (ntohl(entry->type)) {
                case CBFS_COMPONENT_STAGE:
                        cbfs_print_stage_info((struct cbfs_stage *)
                                              CBFS_SUBHEADER(entry), fp);
                        break;

                case CBFS_COMPONENT_SELF:
                        payload = (struct cbfs_payload_segment *)
                                        CBFS_SUBHEADER(entry);
                        while (payload) {
                                struct cbfs_payload_segment seg;
                                cbfs_decode_payload_segment(&seg, payload);
                                cbfs_print_decoded_payload_segment_info(
                                                &seg, fp);
                                if (seg.type == PAYLOAD_SEGMENT_ENTRY)
                                        break;
                                else
                                payload ++;
                        }
                        break;
                default:
                        break;
        }
        return 0;
}

static int cbfs_print_parseable_entry_info(struct cbfs_image *image,
                                        struct cbfs_file *entry, void *arg)
{
        FILE *fp = (FILE *)arg;
        const char *name;
        const char *type;
        size_t offset;
        size_t metadata_size;
        size_t data_size;
        const char *sep = "\t";

        if (!cbfs_is_valid_entry(image, entry)) {
                ERROR("cbfs_print_entry_info: Invalid entry at 0x%x\n",
                      cbfs_get_entry_addr(image, entry));
                return -1;
        }

        name = entry->filename;
        if (*name == '\0')
                name = "(empty)";
        type = get_cbfs_entry_type_name(ntohl(entry->type)),
        metadata_size = ntohl(entry->offset);
        data_size = ntohl(entry->len);
        offset = cbfs_get_entry_addr(image, entry);

        fprintf(fp, "%s%s", name, sep);
        fprintf(fp, "0x%zx%s", offset, sep);
        fprintf(fp, "%s%s", type, sep);
        fprintf(fp, "0x%zx%s", metadata_size, sep);
        fprintf(fp, "0x%zx%s", data_size, sep);
        fprintf(fp, "0x%zx\n", metadata_size + data_size);

        return 0;
}

int cbfs_print_directory(struct cbfs_image *image)
{
        if (cbfs_is_legacy_cbfs(image))
                cbfs_print_header_info(image);
        printf("%-30s %-10s %-12s   Size   Comp\n", "Name", "Offset", "Type");
        cbfs_walk(image, cbfs_print_entry_info, NULL);
        return 0;
}

int cbfs_print_parseable_directory(struct cbfs_image *image)
{
        size_t i;
        const char *header[] = {
                "Name",
                "Offset",
                "Type",
                "Metadata Size",
                "Data Size",
                "Total Size",
        };
        const char *sep = "\t";

        for (i = 0; i < ARRAY_SIZE(header) - 1; i++)
                fprintf(stdout, "%s%s", header[i], sep);
        fprintf(stdout, "%s\n", header[i]);
        cbfs_walk(image, cbfs_print_parseable_entry_info, stdout);
        return 0;
}

int cbfs_merge_empty_entry(struct cbfs_image *image, struct cbfs_file *entry,
                           unused void *arg)
{
        struct cbfs_file *next;
        uint32_t next_addr = 0;

        /* We don't return here even if this entry is already empty because we
           want to merge the empty entries following after it. */

        /* Loop until non-empty entry is found, starting from the current entry.
           After the loop, next_addr points to the next non-empty entry. */
        next = entry;
        while (ntohl(next->type) == CBFS_COMPONENT_DELETED ||
                        ntohl(next->type) == CBFS_COMPONENT_NULL) {
                next = cbfs_find_next_entry(image, next);
                if (!next)
                        break;
                next_addr = cbfs_get_entry_addr(image, next);
                if (!cbfs_is_valid_entry(image, next))
                        /* 'next' could be the end of cbfs */
                        break;
        }

        if (!next_addr)
                /* Nothing to empty */
                return 0;

        /* We can return here if we find only a single empty entry.
           For simplicity, we just proceed (and make it empty again). */

        /* We're creating one empty entry for combined empty spaces */
        uint32_t addr = cbfs_get_entry_addr(image, entry);
        size_t len = next_addr - addr - cbfs_calculate_file_header_size("");
        DEBUG("join_empty_entry: [0x%x, 0x%x) len=%zu\n", addr, next_addr, len);
        cbfs_create_empty_entry(entry, CBFS_COMPONENT_NULL, len, "");

        return 0;
}

int cbfs_walk(struct cbfs_image *image, cbfs_entry_callback callback,
              void *arg)
{
        int count = 0;
        struct cbfs_file *entry;
        for (entry = cbfs_find_first_entry(image);
             entry && cbfs_is_valid_entry(image, entry);
             entry = cbfs_find_next_entry(image, entry)) {
                count ++;
                if (callback(image, entry, arg) != 0)
                        break;
        }
        return count;
}

static int cbfs_header_valid(struct cbfs_header *header)
{
        if ((ntohl(header->magic) == CBFS_HEADER_MAGIC) &&
            ((ntohl(header->version) == CBFS_HEADER_VERSION1) ||
             (ntohl(header->version) == CBFS_HEADER_VERSION2)) &&
            (ntohl(header->offset) < ntohl(header->romsize)))
                return 1;
        return 0;
}

struct cbfs_header *cbfs_find_header(char *data, size_t size,
                                     uint32_t forced_offset)
{
        size_t offset;
        int found = 0;
        int32_t rel_offset;
        struct cbfs_header *header, *result = NULL;

        if (forced_offset < (size - sizeof(struct cbfs_header))) {
                /* Check if the forced header is valid. */
                header = (struct cbfs_header *)(data + forced_offset);
                if (cbfs_header_valid(header))
                        return header;
                return NULL;
        }

        // Try finding relative offset of master header at end of file first.
        rel_offset = *(int32_t *)(data + size - sizeof(int32_t));
        offset = size + rel_offset;
        DEBUG("relative offset: %#zx(-%#zx), offset: %#zx\n",
              (size_t)rel_offset, (size_t)-rel_offset, offset);

        if (offset >= size - sizeof(*header) ||
            !cbfs_header_valid((struct cbfs_header *)(data + offset))) {
                // Some use cases append non-CBFS data to the end of the ROM.
                DEBUG("relative offset seems wrong, scanning whole image...\n");
                offset = 0;
        }

        for (; offset + sizeof(*header) < size; offset++) {
                header = (struct cbfs_header *)(data + offset);
                if (!cbfs_header_valid(header))
                        continue;
                if (!found++)
                        result = header;
        }
        if (found > 1)
                // Top-aligned images usually have a working relative offset
                // field, so this is more likely to happen on bottom-aligned
                // ones (where the first header is the "outermost" one)
                WARN("Multiple (%d) CBFS headers found, using the first one.\n",
                       found);
        return result;
}


struct cbfs_file *cbfs_find_first_entry(struct cbfs_image *image)
{
        assert(image);
        if (image->has_header)
                /* header.offset is relative to start of flash, not
                 * start of region, so use it with the full image.
                 */
                return (struct cbfs_file *)
                        (buffer_get_original_backing(&image->buffer) +
                        image->header.offset);
        else
                return (struct cbfs_file *)buffer_get(&image->buffer);
}

struct cbfs_file *cbfs_find_next_entry(struct cbfs_image *image,
                                       struct cbfs_file *entry)
{
        uint32_t addr = cbfs_get_entry_addr(image, entry);
        int align = image->has_header ? image->header.align :
                                                        CBFS_ENTRY_ALIGNMENT;
        assert(entry && cbfs_is_valid_entry(image, entry));
        addr += ntohl(entry->offset) + ntohl(entry->len);
        addr = align_up(addr, align);
        return (struct cbfs_file *)(image->buffer.data + addr);
}

uint32_t cbfs_get_entry_addr(struct cbfs_image *image, struct cbfs_file *entry)
{
        assert(image && image->buffer.data && entry);
        return (int32_t)((char *)entry - image->buffer.data);
}

int cbfs_is_valid_cbfs(struct cbfs_image *image)
{
        return buffer_check_magic(&image->buffer, CBFS_FILE_MAGIC,
                                                strlen(CBFS_FILE_MAGIC));
}

int cbfs_is_legacy_cbfs(struct cbfs_image *image)
{
        return image->has_header;
}

int cbfs_is_valid_entry(struct cbfs_image *image, struct cbfs_file *entry)
{
        uint32_t offset = cbfs_get_entry_addr(image, entry);

        if (offset >= image->buffer.size)
                return 0;

        struct buffer entry_data;
        buffer_clone(&entry_data, &image->buffer);
        buffer_seek(&entry_data, offset);
        return buffer_check_magic(&entry_data, CBFS_FILE_MAGIC,
                                                strlen(CBFS_FILE_MAGIC));
}

struct cbfs_file *cbfs_create_file_header(int type,
                            size_t len, const char *name)
{
        struct cbfs_file *entry = malloc(MAX_CBFS_FILE_HEADER_BUFFER);
        memset(entry, CBFS_CONTENT_DEFAULT_VALUE, MAX_CBFS_FILE_HEADER_BUFFER);
        memcpy(entry->magic, CBFS_FILE_MAGIC, sizeof(entry->magic));
        entry->type = htonl(type);
        entry->len = htonl(len);
        entry->attributes_offset = 0;
        entry->offset = htonl(cbfs_calculate_file_header_size(name));
        memset(entry->filename, 0, ntohl(entry->offset) - sizeof(*entry));
        strcpy(entry->filename, name);
        return entry;
}

int cbfs_create_empty_entry(struct cbfs_file *entry, int type,
                            size_t len, const char *name)
{
        struct cbfs_file *tmp = cbfs_create_file_header(type, len, name);
        memcpy(entry, tmp, ntohl(tmp->offset));
        free(tmp);
        memset(CBFS_SUBHEADER(entry), CBFS_CONTENT_DEFAULT_VALUE, len);
        return 0;
}

struct cbfs_file_attribute *cbfs_file_first_attr(struct cbfs_file *file)
{
        /* attributes_offset should be 0 when there is no attribute, but all
         * values that point into the cbfs_file header are invalid, too. */
        if (ntohl(file->attributes_offset) <= sizeof(*file))
                return NULL;

        /* There needs to be enough space for the file header and one
         * attribute header for this to make sense. */
        if (ntohl(file->offset) <=
                sizeof(*file) + sizeof(struct cbfs_file_attribute))
                return NULL;

        return (struct cbfs_file_attribute *)
                (((uint8_t *)file) + ntohl(file->attributes_offset));
}

struct cbfs_file_attribute *cbfs_file_next_attr(struct cbfs_file *file,
        struct cbfs_file_attribute *attr)
{
        /* ex falso sequitur quodlibet */
        if (attr == NULL)
                return NULL;

        /* Is there enough space for another attribute? */
        if ((uint8_t *)attr + ntohl(attr->len) +
                sizeof(struct cbfs_file_attribute) >
                (uint8_t *)file + ntohl(file->offset))
                return NULL;

        struct cbfs_file_attribute *next = (struct cbfs_file_attribute *)
                (((uint8_t *)attr) + ntohl(attr->len));
        /* If any, "unused" attributes must come last. */
        if (ntohl(next->tag) == CBFS_FILE_ATTR_TAG_UNUSED)
                return NULL;
        if (ntohl(next->tag) == CBFS_FILE_ATTR_TAG_UNUSED2)
                return NULL;

        return next;
}

struct cbfs_file_attribute *cbfs_add_file_attr(struct cbfs_file *header,
                                               uint32_t tag,
                                               uint32_t size)
{
        struct cbfs_file_attribute *attr, *next;
        next = cbfs_file_first_attr(header);
        do {
                attr = next;
                next = cbfs_file_next_attr(header, attr);
        } while (next != NULL);
        uint32_t header_size = ntohl(header->offset) + size;
        if (header_size > MAX_CBFS_FILE_HEADER_BUFFER) {
                DEBUG("exceeding allocated space for cbfs_file headers");
                return NULL;
        }
        /* attr points to the last valid attribute now.
         * If NULL, we have to create the first one. */
        if (attr == NULL) {
                /* New attributes start where the header ends.
                 * header->offset is later set to accommodate the
                 * additional structure.
                 * No endianness translation necessary here, because both
                 * fields are encoded the same way. */
                header->attributes_offset = header->offset;
                attr = (struct cbfs_file_attribute *)
                        (((uint8_t *)header) +
                        ntohl(header->attributes_offset));
        } else {
                attr = (struct cbfs_file_attribute *)
                        (((uint8_t *)attr) +
                        ntohl(attr->len));
        }
        header->offset = htonl(header_size);
        memset(attr, CBFS_CONTENT_DEFAULT_VALUE, size);
        attr->tag = htonl(tag);
        attr->len = htonl(size);
        return attr;
}

int cbfs_add_file_hash(struct cbfs_file *header, struct buffer *buffer,
        enum vb2_hash_algorithm hash_type)
{
        uint32_t hash_index = hash_type;

        if (hash_index >= CBFS_NUM_SUPPORTED_HASHES)
                return -1;

        unsigned hash_size = widths_cbfs_hash[hash_type];
        if (hash_size == 0)
                return -1;

        struct cbfs_file_attr_hash *attrs =
                (struct cbfs_file_attr_hash *)cbfs_add_file_attr(header,
                        CBFS_FILE_ATTR_TAG_HASH,
                        sizeof(struct cbfs_file_attr_hash) + hash_size);

        if (attrs == NULL)
                return -1;

        attrs->hash_type = htonl(hash_type);
        if (vb2_digest_buffer(buffer_get(buffer), buffer_size(buffer),
                hash_type, attrs->hash_data, hash_size) != VB2_SUCCESS)
                return -1;

        return 0;
}

/* Finds a place to hold whole data in same memory page. */
static int is_in_same_page(uint32_t start, uint32_t size, uint32_t page)
{
        if (!page)
                return 1;
        return (start / page) == (start + size - 1) / page;
}

/* Tests if data can fit in a range by given offset:
 *  start ->| metadata_size | offset (+ size) |<- end
 */
static int is_in_range(size_t start, size_t end, size_t metadata_size,
                       size_t offset, size_t size)
{
        return (offset >= start + metadata_size && offset + size <= end);
}

static size_t absolute_align(const struct cbfs_image *image, size_t val,
                                size_t align)
{
        const size_t region_offset = buffer_offset(&image->buffer);
        /* To perform alignment on absolute address, take the region offset */
        /* of the image into account.                                       */
        return align_up(val + region_offset, align) - region_offset;

}

int32_t cbfs_locate_entry(struct cbfs_image *image, size_t size,
                          size_t page_size, size_t align, size_t metadata_size)
{
        struct cbfs_file *entry;
        size_t need_len;
        size_t addr, addr_next, addr2, addr3, offset;

        /* Default values: allow fitting anywhere in ROM. */
        if (!page_size)
                page_size = image->has_header ? image->header.romsize :
                                                        image->buffer.size;
        if (!align)
                align = 1;

        if (size > page_size)
                ERROR("Input file size (%zd) greater than page size (%zd).\n",
                      size, page_size);

        size_t image_align = image->has_header ? image->header.align :
                                                        CBFS_ENTRY_ALIGNMENT;
        if (page_size % image_align)
                WARN("%s: Page size (%#zx) not aligned with CBFS image (%#zx).\n",
                     __func__, page_size, image_align);

        need_len = metadata_size + size;

        // Merge empty entries to build get max available space.
        cbfs_walk(image, cbfs_merge_empty_entry, NULL);

        /* Three cases of content location on memory page:
         * case 1.
         *          |  PAGE 1  |   PAGE 2  |
         *          |     <header><content>| Fit. Return start of content.
         *
         * case 2.
         *          |  PAGE 1  |   PAGE 2  |
         *          | <header><content>    | Fits when we shift content to align
         *  shift-> |  <header>|<content>  | at starting of PAGE 2.
         *
         * case 3. (large content filling whole page)
         *  | PAGE 1 |  PAGE 2  | PAGE 3 |
         *  |  <header>< content >       | Can't fit. If we shift content to
         *  |trial-> <header>< content > | PAGE 2, header can't fit in free
         *  |  shift->  <header><content> space, so we must use PAGE 3.
         *
         * The returned address can be then used as "base-address" (-b) in add-*
         * commands (will be re-calculated and positioned by cbfs_add_entry_at).
         * For stage targets, the address is also used to re-link stage before
         * being added into CBFS.
         */
        for (entry = cbfs_find_first_entry(image);
             entry && cbfs_is_valid_entry(image, entry);
             entry = cbfs_find_next_entry(image, entry)) {

                uint32_t type = ntohl(entry->type);
                if (type != CBFS_COMPONENT_NULL)
                        continue;

                addr = cbfs_get_entry_addr(image, entry);
                addr_next = cbfs_get_entry_addr(image, cbfs_find_next_entry(
                                image, entry));
                if (addr_next - addr < need_len)
                        continue;

                offset = absolute_align(image, addr + metadata_size, align);
                if (is_in_same_page(offset, size, page_size) &&
                    is_in_range(addr, addr_next, metadata_size, offset, size)) {
                        DEBUG("cbfs_locate_entry: FIT (PAGE1).");
                        return offset;
                }

                addr2 = align_up(addr, page_size);
                offset = absolute_align(image, addr2, align);
                if (is_in_range(addr, addr_next, metadata_size, offset, size)) {
                        DEBUG("cbfs_locate_entry: OVERLAP (PAGE2).");
                        return offset;
                }

                /* Assume page_size >= metadata_size so adding one page will
                 * definitely provide the space for header. */
                assert(page_size >= metadata_size);
                addr3 = addr2 + page_size;
                offset = absolute_align(image, addr3, align);
                if (is_in_range(addr, addr_next, metadata_size, offset, size)) {
                        DEBUG("cbfs_locate_entry: OVERLAP+ (PAGE3).");
                        return offset;
                }
        }
        return -1;
}