Home | History | Annotate | Download | only in include 
      1 /* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
      2  * Use of this source code is governed by a BSD-style license that can be
      3  * found in the LICENSE file.
      4  */
      5 
      6 #ifndef VBOOT_REFERENCE_CGPTLIB_INTERNAL_H_
      7 #define VBOOT_REFERENCE_CGPTLIB_INTERNAL_H_
      8 
      9 #include "sysincludes.h"
     10 #include "cgptlib.h"
     11 #include "gpt.h"
     12 
     13 /*
     14  * If gpt->current_kernel is this value, means either:
     15  *   1. an initial value before scanning GPT entries,
     16  *   2. after scanning, no any valid kernel is found.
     17  */
     18 #define CGPT_KERNEL_ENTRY_NOT_FOUND (-1)
     19 
     20 /*
     21  * Bit definitions and masks for GPT attributes.
     22  *
     23  *  63-61  -- (reserved)
     24  *     60  -- read-only
     25  *  59-57  -- (reserved)
     26  *     56  -- success
     27  *  55-52  -- tries
     28  *  51-48  -- priority
     29  *   47-2  -- UEFI: reserved for future use
     30  *      1  -- UEFI: partition is not mapped
     31  *      0  -- UEFI: partition is required
     32  */
     33 #define CGPT_ATTRIBUTE_SUCCESSFUL_OFFSET (56 - 48)
     34 #define CGPT_ATTRIBUTE_MAX_SUCCESSFUL (1ULL)
     35 #define CGPT_ATTRIBUTE_SUCCESSFUL_MASK (CGPT_ATTRIBUTE_MAX_SUCCESSFUL << \
     36                                      CGPT_ATTRIBUTE_SUCCESSFUL_OFFSET)
     37 
     38 #define CGPT_ATTRIBUTE_TRIES_OFFSET (52 - 48)
     39 #define CGPT_ATTRIBUTE_MAX_TRIES (15ULL)
     40 #define CGPT_ATTRIBUTE_TRIES_MASK (CGPT_ATTRIBUTE_MAX_TRIES << \
     41                                    CGPT_ATTRIBUTE_TRIES_OFFSET)
     42 
     43 #define CGPT_ATTRIBUTE_PRIORITY_OFFSET (48 - 48)
     44 #define CGPT_ATTRIBUTE_MAX_PRIORITY (15ULL)
     45 #define CGPT_ATTRIBUTE_PRIORITY_MASK (CGPT_ATTRIBUTE_MAX_PRIORITY << \
     46                                       CGPT_ATTRIBUTE_PRIORITY_OFFSET)
     47 
     48 /* Defines ChromeOS-specific limitation on GPT */
     49 #define MIN_SIZE_OF_HEADER 92
     50 #define MAX_SIZE_OF_HEADER 512
     51 #define MIN_SIZE_OF_ENTRY 128
     52 #define MAX_SIZE_OF_ENTRY 512
     53 #define SIZE_OF_ENTRY_MULTIPLE 8
     54 #define MIN_NUMBER_OF_ENTRIES 16
     55 #define MAX_NUMBER_OF_ENTRIES 128
     56 
     57 /* Defines GPT sizes */
     58 #define GPT_PMBR_SECTORS 1  /* size (in sectors) of PMBR */
     59 #define GPT_HEADER_SECTORS 1
     60 
     61 /*
     62  * Alias name of index in internal array for primary and secondary header and
     63  * entries.
     64  */
     65 enum {
     66 	/* constants for index */
     67 	PRIMARY = 0,
     68 	SECONDARY = 1,
     69 	ANY_VALID = 9999,  /* accept any between primary and secondary */
     70 
     71 	/* constants for bit mask */
     72 	MASK_NONE = 0,
     73 	MASK_PRIMARY = 1,
     74 	MASK_SECONDARY = 2,
     75 	MASK_BOTH = 3,
     76 };
     77 
     78 /**
     79  * Verify GptData parameters are sane.
     80  */
     81 int CheckParameters(GptData* gpt);
     82 
     83 /**
     84  * Check header fields.
     85  *
     86  * Returns 0 if header is valid, 1 if invalid.
     87  */
     88 int CheckHeader(GptHeader *h, int is_secondary,
     89                 uint64_t streaming_drive_sectors,
     90                 uint64_t gpt_drive_sectors, uint32_t flags);
     91 
     92 /**
     93  * Calculate and return the header CRC.
     94  */
     95 uint32_t HeaderCrc(GptHeader *h);
     96 
     97 /**
     98  * Check entries.
     99  *
    100  * Returns 0 if entries are valid, 1 if invalid.
    101  */
    102 int CheckEntries(GptEntry *entries, GptHeader *h);
    103 
    104 /**
    105  * Return 0 if the GptHeaders are the same for all fields which don't differ
    106  * between the primary and secondary headers - that is, all fields other than:
    107  *
    108  * my_lba
    109  * alternate_lba
    110  * entries_lba
    111  */
    112 int HeaderFieldsSame(GptHeader *h1, GptHeader *h2);
    113 
    114 /**
    115  * Check GptData, headers, entries.
    116  *
    117  * If successful, sets gpt->valid_headers and gpt->valid_entries and returns
    118  * GPT_SUCCESS.
    119  *
    120  * On error, returns a GPT_ERROR_* return code.
    121  */
    122 int GptSanityCheck(GptData *gpt);
    123 
    124 /**
    125  * Repair GPT data by copying from one set of valid headers/entries to the
    126  * other.  Assumes GptSanityCheck() has been run to determine which headers
    127  * and/or entries are already valid.
    128  */
    129 void GptRepair(GptData *gpt);
    130 
    131 /**
    132  * Called when the primary entries are modified and the CRCs need to be
    133  * recalculated and propagated to the secondary entries
    134  */
    135 void GptModified(GptData *gpt);
    136 
    137 /* Getters and setters for partition attribute fields. */
    138 
    139 int GetEntrySuccessful(const GptEntry *e);
    140 int GetEntryPriority(const GptEntry *e);
    141 int GetEntryTries(const GptEntry *e);
    142 void SetEntrySuccessful(GptEntry *e, int successful);
    143 void SetEntryPriority(GptEntry *e, int priority);
    144 void SetEntryTries(GptEntry *e, int tries);
    145 
    146 /**
    147  * Return 1 if the entry is a Chrome OS kernel partition, else 0.
    148  */
    149 int IsKernelEntry(const GptEntry *e);
    150 
    151 /**
    152  * Copy the current kernel partition's UniquePartitionGuid to the dest.
    153  */
    154 void GetCurrentKernelUniqueGuid(GptData *gpt, void *dest);
    155 
    156 /**
    157  * Return a pointer to text describing the passed in error.
    158  */
    159 const char *GptErrorText(int error_code);
    160 
    161 /**
    162  * Return number of 512-byte sectors required to store the entries table.
    163  */
    164 size_t CalculateEntriesSectors(GptHeader* h);
    165 
    166 #endif /* VBOOT_REFERENCE_CGPTLIB_INTERNAL_H_ */
    167