linux-imx

// SPDX-License-Identifier: GPL-2.0-only

/* ----------------------------------------------------------------------- *

 *

 *   Copyright 2012 Intel Corporation; author H. Peter Anvin

 *

 * ----------------------------------------------------------------------- */

​

/*

 * earlycpio.c

 *

 * Find a specific cpio member; must precede any compressed content.

 * This is used to locate data items in the initramfs used by the

 * kernel itself during early boot (before the main initramfs is

 * decompressed.)  It is the responsibility of the initramfs creator

 * to ensure that these items are uncompressed at the head of the

 * blob.  Depending on the boot loader or package tool that may be a

 * separate file or part of the same file.

 */

​

#include <linux/earlycpio.h>

#include <linux/kernel.h>

#include <linux/string.h>

​

enum cpio_fields {

    C_MAGIC,

    C_INO,

    C_MODE,

    C_UID,

    C_GID,

    C_NLINK,

    C_MTIME,

    C_FILESIZE,

    C_MAJ,

    C_MIN,

    C_RMAJ,

    C_RMIN,

    C_NAMESIZE,

    C_CHKSUM,

    C_NFIELDS

};

​

/**

 * cpio_data find_cpio_data - Search for files in an uncompressed cpio

 * @path:       The directory to search for, including a slash at the end

 * @data:       Pointer to the the cpio archive or a header inside

 * @len:        Remaining length of the cpio based on data pointer

 * @nextoff:    When a matching file is found, this is the offset from the

 *              beginning of the cpio to the beginning of the next file, not the

 *              matching file itself. It can be used to iterate through the cpio

 *              to find all files inside of a directory path.

 *

 * @return:     struct cpio_data containing the address, length and

 *              filename (with the directory path cut off) of the found file.

 *              If you search for a filename and not for files in a directory,

 *              pass the absolute path of the filename in the cpio and make sure

 *              the match returned an empty filename string.

 */

​

struct cpio_data find_cpio_data(const char *path, void *data,

                size_t len,  long *nextoff)

{

    const size_t cpio_header_len = 8*C_NFIELDS - 2;

    struct cpio_data cd = { NULL, 0, "" };