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_CGPT_MISC_H_
7 #define VBOOT_REFERENCE_CGPT_MISC_H_
8 
9 #include "gpt.h"
10 #include "vboot_api.h"
11 
12 enum {
13 	GPT_SUCCESS = 0,
14 	GPT_ERROR_NO_VALID_KERNEL,
15 	GPT_ERROR_INVALID_HEADERS,
16 	GPT_ERROR_INVALID_ENTRIES,
17 	GPT_ERROR_INVALID_SECTOR_SIZE,
18 	GPT_ERROR_INVALID_SECTOR_NUMBER,
19 	GPT_ERROR_INVALID_UPDATE_TYPE,
20 	GPT_ERROR_CRC_CORRUPTED,
21 	GPT_ERROR_OUT_OF_REGION,
22 	GPT_ERROR_START_LBA_OVERLAP,
23 	GPT_ERROR_END_LBA_OVERLAP,
24 	GPT_ERROR_DUP_GUID,
25 	GPT_ERROR_INVALID_FLASH_GEOMETRY,
26 	GPT_ERROR_NO_SUCH_ENTRY,
27 	/* Number of errors */
28 	GPT_ERROR_COUNT
29 };
30 
31 /* Bit masks for GptData.modified field. */
32 #define GPT_MODIFIED_HEADER1 0x01
33 #define GPT_MODIFIED_HEADER2 0x02
34 #define GPT_MODIFIED_ENTRIES1 0x04
35 #define GPT_MODIFIED_ENTRIES2 0x08
36 
37 /*
38  * The 'update_type' of GptUpdateKernelEntry().  We expose TRY and BAD only
39  * because those are what verified boot needs.  For more precise control on GPT
40  * attribute bits, please refer to gpt_internal.h.
41  */
42 enum {
43 	/*
44 	 * System will be trying to boot the currently selected kernel
45 	 * partition.  Update its try count if necessary.
46 	 */
47 	GPT_UPDATE_ENTRY_TRY = 1,
48 	/*
49 	 * The currently selected kernel partition failed validation.  Mark
50 	 * entry as invalid.
51 	 */
52 	GPT_UPDATE_ENTRY_BAD = 2,
53 	/*
54 	 * Used for fastboot mode. When an image is written to kernel partition,
55 	 * its GPT entry is marked with S1,P1,T15.
56 	 */
57 	GPT_UPDATE_ENTRY_RESET = 3,
58 	/*
59 	 * Used for fastboot mode. When an image is written to kernel partition,
60 	 * its GPT entry is marked with S0,P0,T0.
61 	 */
62 	GPT_UPDATE_ENTRY_INVALID = 4,
63 };
64 
65 /* If this bit is 1, the GPT is stored in another from the streaming data */
66 #define GPT_FLAG_EXTERNAL	0x1
67 
68 /*
69  * A note about stored_on_device and gpt_drive_sectors:
70  *
71  * This code is used by both the "cgpt" utility and depthcharge/vboot. ATM,
72  * depthcharge does not have logic to properly setup stored_on_device and
73  * gpt_drive_sectors, but it does do a memset(gpt, 0, sizeof(GptData)). And so,
74  * GPT_STORED_ON_DEVICE should be 0 to make stored_on_device compatible with
75  * present behavior. At the same time, in vboot_kernel:LoadKernel(), and
76  * cgpt_common:GptLoad(), we need to have simple shims to set gpt_drive_sectors
77  * to drive_sectors.
78  *
79  * TODO(namnguyen): Remove those shims when the firmware can set these fields.
80  */
81 typedef struct {
82 	/* Fill in the following fields before calling GptInit() */
83 	/* GPT primary header, from sector 1 of disk (size: 512 bytes) */
84 	uint8_t *primary_header;
85 	/* GPT secondary header, from last sector of disk (size: 512 bytes) */
86 	uint8_t *secondary_header;
87 	/* Primary GPT table, follows primary header (size: 16 KB) */
88 	uint8_t *primary_entries;
89 	/* Secondary GPT table, precedes secondary header (size: 16 KB) */
90 	uint8_t *secondary_entries;
91 	/* Size of a LBA sector, in bytes */
92 	uint32_t sector_bytes;
93 	/* Size of drive (that the partitions are on) in LBA sectors */
94 	uint64_t streaming_drive_sectors;
95 	/* Size of the device that holds the GPT structures, 512-byte sectors */
96 	uint64_t gpt_drive_sectors;
97 	/* Flags */
98 	uint32_t flags;
99 
100 	/* Outputs */
101 	/* Which inputs have been modified?  GPT_MODIFIED_* */
102 	uint8_t modified;
103 	/*
104 	 * The current chromeos kernel index in partition table.  -1 means not
105 	 * found on drive. Note that GPT partition numbers are traditionally
106 	 * 1-based, but we're using a zero-based index here.
107 	 */
108 	int current_kernel;
109 
110 	/* Internal variables */
111 	uint32_t valid_headers, valid_entries;
112 	int current_priority;
113 } GptData;
114 
115 /**
116  * Initializes the GPT data structure's internal state.
117  *
118  * The following fields must be filled before calling this function:
119  *
120  *   primary_header
121  *   secondary_header
122  *   primary_entries
123  *   secondary_entries
124  *   sector_bytes
125  *   drive_sectors
126  *   stored_on_device
127  *   gpt_device_sectors
128  *
129  * On return the modified field may be set, if the GPT data has been modified
130  * and should be written to disk.
131  *
132  * Returns GPT_SUCCESS if successful, non-zero if error:
133  *   GPT_ERROR_INVALID_HEADERS, both partition table headers are invalid, enters
134  *                              recovery mode,
135  *   GPT_ERROR_INVALID_ENTRIES, both partition table entries are invalid, enters
136  *                              recovery mode,
137  *   GPT_ERROR_INVALID_SECTOR_SIZE, size of a sector is not supported,
138  *   GPT_ERROR_INVALID_SECTOR_NUMBER, number of sectors in drive is invalid (too
139  *                                    small) */
140 int GptInit(GptData *gpt);
141 
142 /**
143  * Return the nth instance of parition entry matching the partition type guid
144  * from the gpt table. Instance value starts from 0. If the entry is not found,
145  * it returns NULL.
146  */
147 GptEntry *GptFindNthEntry(GptData *gpt, const Guid *guid, unsigned int n);
148 
149 /**
150  * Allocate and read GPT data from the drive.  The sector_bytes and
151  * drive_sectors fields should be filled on input.  The primary and secondary
152  * header and entries are filled on output.
153  *
154  * Returns 0 if successful, 1 if error.
155  */
156 int AllocAndReadGptData(VbExDiskHandle_t disk_handle, GptData *gptdata);
157 
158 /**
159  * Write any changes for the GPT data back to the drive, then free the buffers.
160  */
161 int WriteAndFreeGptData(VbExDiskHandle_t disk_handle, GptData *gptdata);
162 
163 /**
164  * Return 1 if the entry is unused, 0 if it is used.
165  */
166 int IsUnusedEntry(const GptEntry *e);
167 
168 /**
169  * Return size(in lba) of a partition represented by given GPT entry.
170  */
171 size_t GptGetEntrySizeLba(const GptEntry *e);
172 
173 /**
174  * Return size(in bytes) of a partition represented by given GPT entry.
175  */
176 size_t GptGetEntrySizeBytes(const GptData *gpt, const GptEntry *e);
177 
178 /**
179  * Updates the kernel entry with the specified index, using the specified type
180  * of update (GPT_UPDATE_ENTRY_*).
181  *
182  * On return the modified field may be set, if the GPT data has been modified
183  * and should be written to disk.
184  *
185  * Returns GPT_SUCCESS if successful, else
186  *   GPT_ERROR_INVALID_UPDATE_TYPE, invalid 'update_type' is given.
187  */
188 int GptUpdateKernelWithEntry(GptData *gpt, GptEntry *e, uint32_t update_type);
189 
190 /**
191  * Updates the kernel entry identified by current_kernel field. If
192  * current_kernel is not set it returns an error.
193  *
194  * Returns GPT_SUCCESS if successful, else
195  *   GPT_ERROR_INVALID_UPDATE_TYPE, invalid 'update_type' is given.
196  */
197 int GptUpdateKernelEntry(GptData *gpt, uint32_t update_type);
198 
199 #endif  /* VBOOT_REFERENCE_CGPT_MISC_H_ */
200