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", "apdp", "cmnlib", "cmnlib64", \
84             "devcfg", "dtbo", "hyp", "keymaster", "msadp", \
85             "qupfw", "storsec", "tz", "vbmeta", "vbmeta_system", "xbl_config"
86 
87 #define AB_PTN_LIST PTN_SWAP_LIST, "boot", "system", "vendor", "modem", "system_ext", "product"
88 #define BOOT_DEV_DIR    "/dev/block/bootdevice/by-name"
89 
90 /******************************************************************************
91  * HELPER MACROS
92  ******************************************************************************/
93 #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
94 /******************************************************************************
95  * TYPES
96  ******************************************************************************/
97 enum boot_update_stage {
98 	UPDATE_MAIN = 1,
99 	UPDATE_BACKUP,
100 	UPDATE_FINALIZE
101 };
102 
103 enum gpt_instance {
104 	PRIMARY_GPT = 0,
105 	SECONDARY_GPT
106 };
107 
108 enum boot_chain {
109 	NORMAL_BOOT = 0,
110 	BACKUP_BOOT
111 };
112 
113 struct gpt_disk {
114 	//GPT primary header
115 	uint8_t *hdr;
116 	//primary header crc
117 	uint32_t hdr_crc;
118 	//GPT backup header
119 	uint8_t *hdr_bak;
120 	//backup header crc
121 	uint32_t hdr_bak_crc;
122 	//Partition entries array
123 	uint8_t *pentry_arr;
124 	//Partition entries array for backup table
125 	uint8_t *pentry_arr_bak;
126 	//Size of the pentry array
127 	uint32_t pentry_arr_size;
128 	//Size of each element in the pentry array
129 	uint32_t pentry_size;
130 	//CRC of the partition entry array
131 	uint32_t pentry_arr_crc;
132 	//CRC of the backup partition entry array
133 	uint32_t pentry_arr_bak_crc;
134 	//Path to block dev representing the disk
135 	char devpath[PATH_MAX];
136 	//Block size of disk
137 	uint32_t block_size;
138 	uint32_t is_initialized;
139 };
140 
141 /******************************************************************************
142  * FUNCTION PROTOTYPES
143  ******************************************************************************/
144 int prepare_boot_update(enum boot_update_stage stage);
145 //GPT disk methods
146 struct gpt_disk* gpt_disk_alloc();
147 //Free previously allocated gpt_disk struct
148 void gpt_disk_free(struct gpt_disk *disk);
149 //Get the details of the disk holding the partition whose name
150 //is passed in via dev
151 int gpt_disk_get_disk_info(const char *dev, struct gpt_disk *disk);
152 
153 //Get pointer to partition entry from a allocated gpt_disk structure
154 uint8_t* gpt_disk_get_pentry(struct gpt_disk *disk,
155 		const char *partname,
156 		enum gpt_instance instance);
157 
158 //Update the crc fields of the modified disk structure
159 int gpt_disk_update_crc(struct gpt_disk *disk);
160 
161 //Write the contents of struct gpt_disk back to the actual disk
162 int gpt_disk_commit(struct gpt_disk *disk);
163 
164 //Return if the current device is UFS based or not
165 int gpt_utils_is_ufs_device();
166 
167 //Swtich betwieen using either the primary or the backup
168 //boot LUN for boot. This is required since UFS boot partitions
169 //cannot have a backup GPT which is what we use for failsafe
170 //updates of the other 'critical' partitions. This function will
171 //not be invoked for emmc targets and on UFS targets is only required
172 //to be invoked for XBL.
173 //
174 //The algorithm to do this is as follows:
175 //- Find the real block device(eg: /dev/block/sdb) that corresponds
176 //  to the /dev/block/bootdevice/by-name/xbl(bak) symlink
177 //
178 //- Once we have the block device 'node' name(sdb in the above example)
179 //  use this node to to locate the scsi generic device that represents
180 //  it by checking the file /sys/block/sdb/device/scsi_generic/sgY
181 //
182 //- Once we locate sgY we call the query ioctl on /dev/sgy to switch
183 //the boot lun to either LUNA or LUNB
184 int gpt_utils_set_xbl_boot_partition(enum boot_chain chain);
185 
186 //Given a vector of partition names as a input and a reference to a map,
187 //populate the map to indicate which physical disk each of the partitions
188 //sits on. The key in the map is the path to the block device where the
189 //partition lies and the value is a vector of strings indicating which of
190 //the passed in partition names sits on that device.
191 int gpt_utils_get_partition_map(std::vector<std::string>& partition_list,
192                 std::map<std::string,std::vector<std::string>>& partition_map);
193 #ifdef __cplusplus
194 }
195 #endif
196 #endif /* __GPT_UTILS_H__ */
197