1  /*
 2   *
 3   * Copyright (C) 2015 Google Inc.
 4   *
 5   * Redistribution and use in source and binary forms, with or without
 6   * modification, are permitted provided that the following conditions
 7   * are met:
 8   * 1. Redistributions of source code must retain the above copyright
 9   *    notice, this list of conditions and the following disclaimer.
10   * 2. Redistributions in binary form must reproduce the above copyright
11   *    notice, this list of conditions and the following disclaimer in the
12   *    documentation and/or other materials provided with the distribution.
13   * 3. The name of the author may not be used to endorse or promote products
14   *    derived from this software without specific prior written permission.
15   *
16   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26   * SUCH DAMAGE.
27   */
28  
29  #include <libpayload-config.h>
30  #include <libpayload.h>
31  #include <commonlib/bsd/fmap_serialized.h>
32  #include <coreboot_tables.h>
33  #include <cbfs.h>
34  #include <boot_device.h>
35  #include <stdint.h>
36  #include <arch/virtual.h>
37  
38  /* Private fmap cache. */
39  static struct fmap *_fmap_cache;
40  
41  static enum cb_err fmap_find_area(struct fmap *fmap, const char *name, size_t *offset,
42  				  size_t *size)
43  {
44  	for (size_t i = 0; i < le32toh(fmap->nareas); ++i) {
45  		if (strncmp((const char *)fmap->areas[i].name, name, FMAP_STRLEN) != 0)
46  			continue;
47  		if (offset)
48  			*offset = le32toh(fmap->areas[i].offset);
49  		if (size)
50  			*size = le32toh(fmap->areas[i].size);
51  		return CB_SUCCESS;
52  	}
53  
54  	return CB_ERR;
55  }
56  
57  static bool fmap_is_signature_valid(struct fmap *fmap)
58  {
59  	return memcmp(fmap->signature, FMAP_SIGNATURE, sizeof(fmap->signature)) == 0;
60  }
61  
62  static bool fmap_setup_cache(void)
63  {
64  	/* Use FMAP cache if available */
65  	if (lib_sysinfo.fmap_cache
66  	    && fmap_is_signature_valid((struct fmap *)phys_to_virt(lib_sysinfo.fmap_cache))) {
67  		_fmap_cache = (struct fmap *)phys_to_virt(lib_sysinfo.fmap_cache);
68  		return true;
69  	}
70  
71  	return false;
72  }
73  
74  enum cb_err fmap_locate_area(const char *name, size_t *offset, size_t *size)
75  {
76  	if (!_fmap_cache && !fmap_setup_cache())
77  		return CB_ERR;
78  
79  	return fmap_find_area(_fmap_cache, name, offset, size);
80  }