./android/external/avb/avbtool info_image --image out/evb/download_images/emmc/vbmeta.img
Minimum libavb version: 1.0
Header Block: 256 bytes
Authentication Block: 576 bytes
Auxiliary Block: 3456 bytes
Public key (sha1): xxxx
Algorithm: SHA256_RSA4096
Rollback Index: 0
Flags: 0
Release String: 'avbtool 1.1.0'
Descriptors:
Chain Partition descriptor:
Partition Name: vbmeta_system
Rollback Index Location: 2
Public key (sha1): xxxx
Prop: com.android.build.boot.fingerprint -> 'Android/evb/evb:11/RD2A.211001.002/test:userdebug/test-keys'
Prop: com.android.build.boot.os_version -> '11'
Prop: com.android.build.boot.security_patch -> '2022-11-05'
Prop: com.android.build.vendor_boot.fingerprint -> 'Android/evb/evb:11/RD2A.211001.002/test:userdebug/test-keys'
Prop: com.android.build.vendor.fingerprint -> 'Android/evb/evb:11/RD2A.211001.002/test:userdebug/test-keys'
Prop: com.android.build.vendor.os_version -> '11'
Prop: com.android.build.vendor.security_patch -> '2022-11-05'
Prop: com.android.build.dtbo.fingerprint -> 'Android/evb/evb:11/RD2A.211001.002/test:userdebug/test-keys'
Hash descriptor:
Image Size: 28246016 bytes
Hash Algorithm: sha256
Partition Name: boot
Salt: xxxx
Digest: xxxx
Flags: 0
Hash descriptor:
Image Size: 1193543 bytes
Hash Algorithm: sha256
Partition Name: dtbo
Salt: xxxx
Digest: xxxx
Flags: 0
Hash descriptor:
Image Size: 327680 bytes
Hash Algorithm: sha256
Partition Name: vendor_boot
Salt: xxxx
Digest: xxxx
Flags: 0
Hashtree descriptor:
Version of dm-verity: 1
Image Size: 611209216 bytes
Tree Offset: 611209216
Tree Size: 4820992 bytes
Data Block Size: 4096 bytes
Hash Block Size: 4096 bytes
FEC num roots: 2
FEC offset: 616030208
FEC size: 4874240 bytes
Hash Algorithm: sha1
Partition Name: vendor
Salt: xxxx
Root Digest: xxxx
Flags: 0
/* A descriptor containing a pointer to signed integrity data stored
* on another partition. The descriptor contains the partition name in
* question (without the A/B suffix), the public key used to sign the
* integrity data, and rollback index location to use for rollback
* protection.
*
* Following this struct are |partition_name_len| bytes of the
* partition name (UTF-8 encoded) and |public_key_len| bytes of the
* public key.
*
* The |reserved| field is for future expansion and must be set to NUL
* bytes.
*/
typedef struct AvbChainPartitionDescriptor {
AvbDescriptor parent_descriptor;
uint32_t rollback_index_location;
uint32_t partition_name_len;
uint32_t public_key_len;
uint8_t reserved[64];
} AVB_ATTR_PACKED AvbChainPartitionDescriptor;
/* Well-known descriptor tags.
*
* AVB_DESCRIPTOR_TAG_PROPERTY: see |AvbPropertyDescriptor| struct.
* AVB_DESCRIPTOR_TAG_HASHTREE: see |AvbHashtreeDescriptor| struct.
* AVB_DESCRIPTOR_TAG_HASH: see |AvbHashDescriptor| struct.
* AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE: see |AvbKernelCmdlineDescriptor| struct.
* AVB_DESCRIPTOR_TAG_CHAIN_PARTITION: see |AvbChainPartitionDescriptor| struct.
*/
typedef enum {
AVB_DESCRIPTOR_TAG_PROPERTY,
AVB_DESCRIPTOR_TAG_HASHTREE,
AVB_DESCRIPTOR_TAG_HASH,
AVB_DESCRIPTOR_TAG_KERNEL_CMDLINE,
AVB_DESCRIPTOR_TAG_CHAIN_PARTITION,
} AvbDescriptorTag;
/* The header for a serialized descriptor.
*
* A descriptor always have two fields, a |tag| (denoting its type,
* see the |AvbDescriptorTag| enumeration) and the size of the bytes
* following, |num_bytes_following|.
*
* For padding, |num_bytes_following| is always a multiple of 8.
*/
typedef struct AvbDescriptor {
uint64_t tag;
uint64_t num_bytes_following;
} AVB_ATTR_PACKED AvbDescriptor;
/* A descriptor containing information about hash for an image.
*
* This descriptor is typically used for boot partitions to verify the
* entire kernel+initramfs image before executing it.
*
* Following this struct are |partition_name_len| bytes of the
* partition name (UTF-8 encoded), |salt_len| bytes of salt, and then
* |digest_len| bytes of the digest.
*
* The |reserved| field is for future expansion and must be set to NUL
* bytes.
*/
typedef struct AvbHashDescriptor {
AvbDescriptor parent_descriptor;
uint64_t image_size;
uint8_t hash_algorithm[32];
uint32_t partition_name_len;
uint32_t salt_len;
uint32_t digest_len;
uint8_t reserved[64];
} AVB_ATTR_PACKED AvbHashDescriptor;
/* A descriptor containing information about a dm-verity hashtree.
*
* Hash-trees are used to verify large partitions typically containing
* file systems. See
* https://gitlab.com/cryptsetup/cryptsetup/wikis/DMVerity for more
* information about dm-verity.
*
* Following this struct are |partition_name_len| bytes of the
* partition name (UTF-8 encoded), |salt_len| bytes of salt, and then
* |root_digest_len| bytes of the root digest.
*
* The |reserved| field is for future expansion and must be set to NUL
* bytes.
*/
typedef struct AvbHashtreeDescriptor {
AvbDescriptor parent_descriptor;
uint32_t dm_verity_version;
uint64_t image_size;
uint64_t tree_offset;
uint64_t tree_size;
uint32_t data_block_size;
uint32_t hash_block_size;
uint32_t fec_num_roots;
uint64_t fec_offset;
uint64_t fec_size;
uint8_t hash_algorithm[32];
uint32_t partition_name_len;
uint32_t salt_len;
uint32_t root_digest_len;
uint8_t reserved[64];
} AVB_ATTR_PACKED AvbHashtreeDescriptor;