xref: /aosp_15_r20/system/libufdt/utils/src/dt_table.h (revision 13e8728f0cffde9369df671f7b293a048a99c7ed)

/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef DT_TABLE_H
#define DT_TABLE_H

#include <stdint.h>

/*
 * For the image layout, refer README.md for the detail
 */

#define DT_TABLE_MAGIC 0xd7b7ab1e
#define DT_TABLE_DEFAULT_PAGE_SIZE 2048
#define DT_TABLE_DEFAULT_VERSION 0

struct dt_table_header {
  uint32_t magic;             /* DT_TABLE_MAGIC */
  uint32_t total_size;        /* includes dt_table_header + all dt_table_entry
                                 and all dtb/dtbo */
  uint32_t header_size;       /* sizeof(dt_table_header) */

  uint32_t dt_entry_size;     /* sizeof(dt_table_entry) */
  uint32_t dt_entry_count;    /* number of dt_table_entry */
  uint32_t dt_entries_offset; /* offset to the first dt_table_entry
                                 from head of dt_table_header.
                                 The value will be equal to header_size if
                                 no padding is appended */

  uint32_t page_size;         /* flash page size we assume */
  uint32_t version;           /* DTBO image version, the current version is 0.
                                 The version will be incremented when the dt_table_header
                                 struct is updated. */
};

enum dt_compression_info {
    NO_COMPRESSION,
    ZLIB_COMPRESSION,
    GZIP_COMPRESSION
};

struct dt_table_entry {
  uint32_t dt_size;
  uint32_t dt_offset;         /* offset from head of dt_table_header */

  uint32_t id;                /* optional, must be zero if unused */
  uint32_t rev;               /* optional, must be zero if unused */
  uint32_t custom[4];         /* optional, must be zero if unused */
};

struct dt_table_entry_v1 {
  uint32_t dt_size;
  uint32_t dt_offset;         /* offset from head of dt_table_header */

  uint32_t id;                /* optional, must be zero if unused */
  uint32_t rev;               /* optional, must be zero if unused */
  uint32_t flags;             /* For version 1 of dt_table_header, the 4 least significant bits
                                 of 'flags' will be used indicate the compression
                                 format of the DT entry as per the enum 'dt_compression_info' */
  uint32_t custom[3];         /* optional, must be zero if unused */
};
enum DT_TYPE { DTB, ACPI };

void dt_table_header_init(struct dt_table_header *header, enum DT_TYPE dt_type);

#endif