1 /*
2  * Copyright (c) 2013, The Linux Foundation. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are
6  * met:
7  *     * Redistributions of source code must retain the above copyright
8  *       notice, this list of conditions and the following disclaimer.
9  *     * Redistributions in binary form must reproduce the above
10  *       copyright notice, this list of conditions and the following
11  *       disclaimer in the documentation and/or other materials provided
12  *       with the distribution.
13  *     * Neither the name of The Linux Foundation nor the names of its
14  *       contributors may be used to endorse or promote products derived
15  *       from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
18  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
24  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
26  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
27  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #ifndef __GPT_UTILS_H__
31 #define __GPT_UTILS_H__
32 #include <vector>
33 #include <string>
34 #include <map>
35 #ifdef __cplusplus
36 extern "C" {
37 #endif
38 #include <unistd.h>
39 #include <stdlib.h>
40 /******************************************************************************
41  * GPT HEADER DEFINES
42  ******************************************************************************/
43 #define GPT_SIGNATURE               "EFI PART"
44 #define HEADER_SIZE_OFFSET          12
45 #define HEADER_CRC_OFFSET           16
46 #define PRIMARY_HEADER_OFFSET       24
47 #define BACKUP_HEADER_OFFSET        32
48 #define FIRST_USABLE_LBA_OFFSET     40
49 #define LAST_USABLE_LBA_OFFSET      48
50 #define PENTRIES_OFFSET             72
51 #define PARTITION_COUNT_OFFSET      80
52 #define PENTRY_SIZE_OFFSET          84
53 #define PARTITION_CRC_OFFSET        88
54 
55 #define TYPE_GUID_OFFSET            0
56 #define TYPE_GUID_SIZE              16
57 #define PTN_ENTRY_SIZE              128
58 #define UNIQUE_GUID_OFFSET          16
59 #define FIRST_LBA_OFFSET            32
60 #define LAST_LBA_OFFSET             40
61 #define ATTRIBUTE_FLAG_OFFSET       48
62 #define PARTITION_NAME_OFFSET       56
63 #define MAX_GPT_NAME_SIZE           72
64 
65 /******************************************************************************
66  * AB RELATED DEFINES
67  ******************************************************************************/
68 //Bit 48 onwords in the attribute field are the ones where we are allowed to
69 //store our AB attributes.
70 #define AB_FLAG_OFFSET (ATTRIBUTE_FLAG_OFFSET + 6)
71 #define GPT_DISK_INIT_MAGIC 0xABCD
72 #define AB_PARTITION_ATTR_SLOT_ACTIVE (0x1<<2)
73 #define AB_PARTITION_ATTR_BOOT_SUCCESSFUL (0x1<<6)
74 #define AB_PARTITION_ATTR_UNBOOTABLE (0x1<<7)
75 #define AB_SLOT_ACTIVE_VAL              0x1F
76 #define AB_SLOT_INACTIVE_VAL            0x0
77 #define AB_SLOT_ACTIVE                  1
78 #define AB_SLOT_INACTIVE                0
79 #define AB_SLOT_A_SUFFIX                "_a"
80 #define AB_SLOT_B_SUFFIX                "_b"
81 #define PTN_XBL                         "xbl"
82 #define PTN_SWAP_LIST                   PTN_XBL, \
83             "abl", "aop", "devcfg", \
84             "dtbo", "hyp", "keymaster", "qupfw", "storsec", \
85             "tz", "uefisecapp", "vbmeta", "vbmeta_system", "xbl_config"
86 
87 #define AB_PTN_LIST PTN_SWAP_LIST, "boot", "system", "vendor", "modem", \
88                                    "system_ext", "product"
89 #define BOOT_DEV_DIR    "/dev/block/bootdevice/by-name"
90 
91 /******************************************************************************
92  * HELPER MACROS
93  ******************************************************************************/
94 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
95 /******************************************************************************
96  * TYPES
97  ******************************************************************************/
98 enum boot_update_stage {
99 	UPDATE_MAIN = 1,
100 	UPDATE_BACKUP,
101 	UPDATE_FINALIZE
102 };
103 
104 enum gpt_instance {
105 	PRIMARY_GPT = 0,
106 	SECONDARY_GPT
107 };
108 
109 enum boot_chain {
110 	NORMAL_BOOT = 0,
111 	BACKUP_BOOT
112 };
113 
114 struct gpt_disk {
115 	//GPT primary header
116 	uint8_t *hdr;
117 	//primary header crc
118 	uint32_t hdr_crc;
119 	//GPT backup header
120 	uint8_t *hdr_bak;
121 	//backup header crc
122 	uint32_t hdr_bak_crc;
123 	//Partition entries array
124 	uint8_t *pentry_arr;
125 	//Partition entries array for backup table
126 	uint8_t *pentry_arr_bak;
127 	//Size of the pentry array
128 	uint32_t pentry_arr_size;
129 	//Size of each element in the pentry array
130 	uint32_t pentry_size;
131 	//CRC of the partition entry array
132 	uint32_t pentry_arr_crc;
133 	//CRC of the backup partition entry array
134 	uint32_t pentry_arr_bak_crc;
135 	//Path to block dev representing the disk
136 	char devpath[PATH_MAX];
137 	//Block size of disk
138 	uint32_t block_size;
139 	uint32_t is_initialized;
140 };
141 
142 /******************************************************************************
143  * FUNCTION PROTOTYPES
144  ******************************************************************************/
145 int prepare_boot_update(enum boot_update_stage stage);
146 //GPT disk methods
147 struct gpt_disk* gpt_disk_alloc();
148 //Free previously allocated gpt_disk struct
149 void gpt_disk_free(struct gpt_disk *disk);
150 //Get the details of the disk holding the partition whose name
151 //is passed in via dev
152 int gpt_disk_get_disk_info(const char *dev, struct gpt_disk *disk);
153 
154 //Get pointer to partition entry from a allocated gpt_disk structure
155 uint8_t* gpt_disk_get_pentry(struct gpt_disk *disk,
156 		const char *partname,
157 		enum gpt_instance instance);
158 
159 //Update the crc fields of the modified disk structure
160 int gpt_disk_update_crc(struct gpt_disk *disk);
161 
162 //Write the contents of struct gpt_disk back to the actual disk
163 int gpt_disk_commit(struct gpt_disk *disk);
164 
165 //Return if the current device is UFS based or not
166 int gpt_utils_is_ufs_device();
167 
168 //Swtich betwieen using either the primary or the backup
169 //boot LUN for boot. This is required since UFS boot partitions
170 //cannot have a backup GPT which is what we use for failsafe
171 //updates of the other 'critical' partitions. This function will
172 //not be invoked for emmc targets and on UFS targets is only required
173 //to be invoked for XBL.
174 //
175 //The algorithm to do this is as follows:
176 //- Find the real block device(eg: /dev/block/sdb) that corresponds
177 //  to the /dev/block/bootdevice/by-name/xbl(bak) symlink
178 //
179 //- Once we have the block device 'node' name(sdb in the above example)
180 //  use this node to to locate the scsi generic device that represents
181 //  it by checking the file /sys/block/sdb/device/scsi_generic/sgY
182 //
183 //- Once we locate sgY we call the query ioctl on /dev/sgy to switch
184 //the boot lun to either LUNA or LUNB
185 int gpt_utils_set_xbl_boot_partition(enum boot_chain chain);
186 
187 //Given a vector of partition names as a input and a reference to a map,
188 //populate the map to indicate which physical disk each of the partitions
189 //sits on. The key in the map is the path to the block device where the
190 //partition lies and the value is a vector of strings indicating which of
191 //the passed in partition names sits on that device.
192 int gpt_utils_get_partition_map(std::vector<std::string>& partition_list,
193                 std::map<std::string,std::vector<std::string>>& partition_map);
194 #ifdef __cplusplus
195 }
196 #endif
197 #endif /* __GPT_UTILS_H__ */
198