docs: add Runtime Security Subsystem (RSS) documentation
Describe:
- RSS-AP communication
- RSS runtime services
- Measured boot
- Delegated Attestation
Signed-off-by: Tamas Ban <tamas.ban@arm.com>
Change-Id: Iaef93361a09355a1edaabcc0c59126e006ad251a
diff --git a/docs/design_documents/index.rst b/docs/design_documents/index.rst
index 765efe6..830af2a 100644
--- a/docs/design_documents/index.rst
+++ b/docs/design_documents/index.rst
@@ -10,6 +10,7 @@
context_mgmt_rework
measured_boot_poc
drtm_poc
+ rss
--------------
diff --git a/docs/design_documents/rss.rst b/docs/design_documents/rss.rst
new file mode 100644
index 0000000..2be8067
--- /dev/null
+++ b/docs/design_documents/rss.rst
@@ -0,0 +1,611 @@
+Runtime Security Subsystem (RSS)
+================================
+
+This document focuses on the relationship between the Runtime Security Subsystem
+(RSS) and the application processor (AP). According to the ARM reference design
+the RSS is an independent core next to the AP and the SCP on the same die. It
+provides fundamental security guarantees and runtime services for the rest of
+the system (e.g.: trusted boot, measured boot, platform attestation,
+key management, and key derivation).
+
+At power up RSS boots first from its private ROM code. It validates and loads
+its own images and the initial images of SCP and AP. When AP and SCP are
+released from reset and their initial code is loaded then they continue their
+own boot process, which is the same as on non-RSS systems. Please refer to the
+``RSS documentation`` [1]_ for more details about the RSS boot flow.
+
+The last stage of the RSS firmware is a persistent, runtime component. Much
+like AP_BL31, this is a passive entity which has no periodical task to do and
+just waits for external requests from other subsystems. RSS and other
+subsystems can communicate with each other over message exchange. RSS waits
+in idle for the incoming request, handles them, and sends a response then goes
+back to idle.
+
+RSS communication layer
+-----------------------
+
+The communication between RSS and other subsystems are primarily relying on the
+Message Handling Unit (MHU) module. The number of MHU interfaces between RSS
+and other cores is IMPDEF. Besides MHU other modules also could take part in
+the communication. RSS is capable of mapping the AP memory to its address space.
+Thereby either RSS core itself or a DMA engine if it is present, can move the
+data between memory belonging to RSS or AP. In this way, a bigger amount of data
+can be transferred in a short time.
+
+The MHU comes in pairs. There is a sender and receiver side. They are connected
+to each other. An MHU interface consists of two pairs of MHUs, one sender and
+one receiver on both sides. Bidirectional communication is possible over an
+interface. One pair provides message sending from AP to RSS and the other pair
+from RSS to AP. The sender and receiver are connected via channels. There is an
+IMPDEF number of channels (e.g: 4-16) between a sender and a receiver module.
+
+The RSS communication layer provides two ways for message exchange:
+
+- ``Embedded messaging``: The full message, including header and payload, are
+ exchanged over the MHU channels. A channel is capable of delivering a single
+ word. The sender writes the data to the channel register on its side and the
+ receiver can read the data from the channel on the other side. One dedicated
+ channel is used for signalling. It does not deliver any payload it is just
+ meant for signalling that the sender loaded the data to the channel registers
+ so the receiver can read them. The receiver uses the same channel to signal
+ that data was read. Signalling happens via IRQ. If the message is longer than
+ the data fit to the channel registers then the message is sent over in
+ multiple rounds. Both, sender and receiver allocate a local buffer for the
+ messages. Data is copied from/to these buffers to/from the channel registers.
+- ``Pointer-access messaging``: The message header and the payload are
+ separated and they are conveyed in different ways. The header is sent
+ over the channels, similar to the embedded messaging but the payload is
+ copied over by RSS core (or by DMA) between the sender and the receiver. This
+ could be useful in the case of long messages because transaction time is less
+ compared to the embedded messaging mode. Small payloads are copied by the RSS
+ core because setting up DMA would require more CPU cycles. The payload is
+ either copied into an internal buffer or directly read-written by RSS. Actual
+ behavior depends on RSS setup, whether the partition supports memory-mapped
+ ``iovec``. Therefore, the sender must handle both cases and prevent access to
+ the memory, where payload data lives, while the RSS handles the request.
+
+The RSS communication layer supports both ways of messaging in parallel. It is
+decided at runtime based on the message size which way to transfer the message.
+
+.. code-block:: bash
+
+ +----------------------------------------------+ +-------------------+
+ | | | |
+ | AP | | |
+ | | +--->| SRAM |
+ +----------------------------------------------| | | |
+ | BL1 / BL2 / BL31 | | | |
+ +----------------------------------------------+ | +-------------------+
+ | ^ | ^ ^
+ | send IRQ | receive |direct | |
+ V | |access | |
+ +--------------------+ +--------------------+ | | |
+ | MHU sender | | MHU receiver | | | Copy data |
+ +--------------------+ +--------------------+ | | |
+ | | | | | | | | | | |
+ | | channels | | | | channels | | | | |
+ | | e.g: 4-16 | | | | e.g: 4-16 | | | V |
+ +--------------------+ +--------------------+ | +-------+ |
+ | MHU receiver | | MHU sender | | +->| DMA | |
+ +--------------------+ +--------------------+ | | +-------+ |
+ | ^ | | ^ |
+ IRQ | receive | send | | | Copy data |
+ V | | | V V
+ +----------------------------------------------+ | | +-------------------+
+ | |--+-+ | |
+ | RSS | | SRAM |
+ | | | |
+ +----------------------------------------------+ +-------------------+
+
+.. Note::
+
+ The RSS communication layer is not prepared for concurrent execution. The
+ current use case only requires message exchange during the boot phase. In
+ the boot phase, only a single core is running and the rest of the cores are
+ in reset.
+
+Message structure
+^^^^^^^^^^^^^^^^^
+A description of the message format can be found in the ``RSS communication
+design`` [2]_ document.
+
+Source files
+^^^^^^^^^^^^
+- RSS comms: ``drivers/arm/rss``
+- MHU driver: ``drivers/arm/mhu``
+
+
+API for communication over MHU
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+The API is defined in these header files:
+
+- ``include/drivers/arm/rss_comms.h``
+- ``include/drivers/arm/mhu.h``
+
+RSS provided runtime services
+-----------------------------
+
+RSS provides the following runtime services:
+
+- ``Measured boot``: Securely store the firmware measurements which were
+ computed during the boot process and the associated metadata (image
+ description, measurement algorithm, etc.). More info on measured boot service
+ in RSS can be found in the ``measured_boot_integration_guide`` [3]_ .
+- ``Delegated attestation``: Query the platform attestation token and derive a
+ delegated attestation key. More info on the delegated attestation service
+ in RSS can be found in the ``delegated_attestation_integration_guide`` [4]_ .
+- ``OTP assets management``: RSS provides access for AP to assets in OTP.
+ These are keys for image signature verification and non-volatile counters
+ for anti-rollback protection. Only RSS has direct access to the OTP. Public
+ keys used by AP during the trusted boot process can be requested from RSS.
+ Furthermore, AP can request RSS to increase a non-volatile counter. Please
+ refer to the ``RSS key management`` [5]_ document for more details.
+
+Runtime service API
+^^^^^^^^^^^^^^^^^^^
+The RSS provided runtime services implement a PSA aligned API. The parameter
+encoding follows the PSA client protocol described in the
+``Firmware Framework for M`` [6]_ document in chapter 4.4. The implementation is
+restricted to the static handle use case therefore only the ``psa_call`` API is
+implemented.
+
+
+Software and API layers
+^^^^^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: bash
+
+ +----------------+ +---------------------+
+ | BL1 / BL2 | | BL31 |
+ +----------------+ +---------------------+
+ | |
+ | extend_measurement() | get_delegated_key()
+ | | get_platform_token()
+ V V
+ +----------------+ +---------------------+
+ | PSA protocol | | PSA protocol |
+ +----------------+ +---------------------+
+ | |
+ | psa_call() | psa_call()
+ | |
+ V V
+ +------------------------------------------------+
+ | RSS communication protocol |
+ +------------------------------------------------+
+ | ^
+ | mhu_send_data() | mhu_receive_data()
+ | |
+ V |
+ +------------------------------------------------+
+ | MHU driver |
+ +------------------------------------------------+
+ | ^
+ | Register access | IRQ
+ V |
+ +------------------------------------------------+
+ | MHU HW on AP side |
+ +------------------------------------------------+
+ ^
+ | Physical wires
+ |
+ V
+ +------------------------------------------------+
+ | MHU HW on RSS side |
+ +------------------------------------------------+
+ | ^
+ | IRQ | Register access
+ V |
+ +------------------------------------------------+
+ | MHU driver |
+ +------------------------------------------------+
+ | |
+ V V
+ +---------------+ +------------------------+
+ | Measured boot | | Delegated attestation |
+ | service | | service |
+ +---------------+ +------------------------+
+
+
+RSS based Measured Boot
+-----------------------
+
+Measured Boot is the process of cryptographically measuring (computing the hash
+value of a binary) the code and critical data used at boot time. The
+measurement must be stored in a tamper-resistant way, so the security state
+of the device can be attested later to an external party. RSS provides a runtime
+service which is meant to store measurements and associated metadata alongside.
+
+Data is stored in internal SRAM which is only accessible by the secure runtime
+firmware of RSS. Data is stored in so-called measurement slots. A platform has
+IMPDEF number of measurement slots. The measurement storage follows extend
+semantics. This means that measurements are not stored directly (as it was
+taken) instead they contribute to the current value of the measurement slot.
+The extension implements this logic, where ``||`` stands for concatenation:
+
+.. code-block:: bash
+
+ new_value_of_measurement_slot = Hash(old_value_of_measurement_slot || measurement)
+
+Supported hash algorithms: sha-256, sha-512
+
+Measured Boot API
+^^^^^^^^^^^^^^^^^
+
+Defined here:
+
+- ``include/lib/psa/measured_boot.h``
+
+.. code-block:: c
+
+ psa_status_t
+ rss_measured_boot_extend_measurement(uint8_t index,
+ const uint8_t *signer_id,
+ size_t signer_id_size,
+ const uint8_t *version,
+ size_t version_size,
+ uint32_t measurement_algo,
+ const uint8_t *sw_type,
+ size_t sw_type_size,
+ const uint8_t *measurement_value,
+ size_t measurement_value_size,
+ bool lock_measurement);
+
+Measured Boot Metadata
+^^^^^^^^^^^^^^^^^^^^^^
+
+The following metadata can be stored alongside the measurement:
+
+- ``Signer-id``: Mandatory. The hash of the firmware image signing public key.
+- ``Measurement algorithm``: Optional. The hash algorithm which was used to
+ compute the measurement (e.g.: sha-256, etc.).
+- ``Version info``: Optional. The firmware version info (e.g.: 2.7).
+- ``SW type``: Optional. Short text description (e.g.: BL1, BL2, BL31, etc.)
+
+.. Note::
+ Signer-id and version info is not implemented in TF-A yet.
+
+The caller must specify in which measurement slot to extend a certain
+measurement and metadata. A measurement slot can be extended by multiple
+measurements. The default value is IMPDEF. All measurement slot is cleared at
+reset, there is no other way to clear them. In the reference implementation,
+the measurement slots are initialized to 0. At the first call to extend the
+measurement in a slot, the extend operation uses the default value of the
+measurement slot. All upcoming extend operation on the same slot contributes
+to the previous value of that measurement slot.
+
+The following rules are kept when a slot is extended multiple times:
+
+- ``Signer-id`` must be the same as the previous call(s), otherwise a
+ PSA_ERROR_NOT_PERMITTED error code is returned.
+
+- ``Measurement algorithm``: must be the same as the previous call(s),
+ otherwise, a PSA_ERROR_NOT_PERMITTED error code is returned.
+
+In case of error no further action is taken (slot is not locked). If there is
+a valid data in a sub-sequent call then measurement slot will be extended. The
+rest of the metadata is handled as follows when a measurement slot is extended
+multiple times:
+
+- ``SW type``: Cleared.
+- ``Version info``: Cleared.
+
+.. Note::
+
+ Extending multiple measurements in the same slot leads to some metadata
+ information loss. Since RSS is not constrained on special HW resources to
+ store the measurements and metadata, therefore it is worth considering to
+ store all of them one by one in distinct slots. However, they are one-by-one
+ included in the platform attestation token. So, the number of distinct
+ firmware image measurements has an impact on the size of the attestation
+ token.
+
+The allocation of the measurement slot among RSS, Root and Realm worlds is
+platform dependent. The platform must provide an allocation of the measurement
+slot at build time. An example can be found in
+``tf-a/plat/arm/board/tc/tc_bl1_measured_boot.c``
+Furthermore, the memory, which holds the metadata is also statically allocated
+in RSS memory. Some of the fields have a static value (measurement algorithm),
+and some of the values have a dynamic value (measurement value) which is updated
+by the bootloaders when the firmware image is loaded and measured. The metadata
+structure is defined in
+``include/drivers/measured_boot/rss/rss_measured_boot.h``.
+
+.. code-block:: c
+
+ struct rss_mboot_metadata {
+ unsigned int id;
+ uint8_t slot;
+ uint8_t signer_id[SIGNER_ID_MAX_SIZE];
+ size_t signer_id_size;
+ uint8_t version[VERSION_MAX_SIZE];
+ size_t version_size;
+ uint8_t sw_type[SW_TYPE_MAX_SIZE];
+ size_t sw_type_size;
+ bool lock_measurement;
+ };
+
+Build time config options
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+- ``MEASURED_BOOT``: Enable measured boot. It depends on the platform
+ implementation whether RSS or TPM (or both) backend based measured boot is
+ enabled.
+- ``MBOOT_RSS_HASH_ALG``: Determine the hash algorithm to measure the images.
+ The default value is sha-256.
+
+Measured boot flow
+^^^^^^^^^^^^^^^^^^
+
+.. figure:: ../resources/diagrams/rss_measured_boot_flow.svg
+ :align: center
+
+Sample console log
+^^^^^^^^^^^^^^^^^^
+
+.. code-block:: bash
+
+ INFO: Measured boot extend measurement:
+ INFO: - slot : 6
+ INFO: - signer_id : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: - version :
+ INFO: - version_size: 0
+ INFO: - sw_type : FW_CONFIG
+ INFO: - sw_type_size: 10
+ INFO: - algorithm : 2000009
+ INFO: - measurement : aa ea d3 a7 a8 e2 ab 7d 13 a6 cb 34 99 10 b9 a1
+ INFO: : 1b 9f a0 52 c5 a8 b1 d7 76 f2 c1 c1 ef ca 1a df
+ INFO: - locking : true
+ INFO: FCONF: Config file with image ID:31 loaded at address = 0x4001010
+ INFO: Loading image id=24 at address 0x4001300
+ INFO: Image id=24 loaded: 0x4001300 - 0x400153a
+ INFO: Measured boot extend measurement:
+ INFO: - slot : 7
+ INFO: - signer_id : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: - version :
+ INFO: - version_size: 0
+ INFO: - sw_type : TB_FW_CONFIG
+ INFO: - sw_type_size: 13
+ INFO: - algorithm : 2000009
+ INFO: - measurement : 05 b9 dc 98 62 26 a7 1c 2d e5 bb af f0 90 52 28
+ INFO: : f2 24 15 8a 3a 56 60 95 d6 51 3a 7a 1a 50 9b b7
+ INFO: - locking : true
+ INFO: FCONF: Config file with image ID:24 loaded at address = 0x4001300
+ INFO: BL1: Loading BL2
+ INFO: Loading image id=1 at address 0x404d000
+ INFO: Image id=1 loaded: 0x404d000 - 0x406412a
+ INFO: Measured boot extend measurement:
+ INFO: - slot : 8
+ INFO: - signer_id : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: : 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: - version :
+ INFO: - version_size: 0
+ INFO: - sw_type : BL_2
+ INFO: - sw_type_size: 5
+ INFO: - algorithm : 2000009
+ INFO: - measurement : 53 a1 51 75 25 90 fb a1 d9 b8 c8 34 32 3a 01 16
+ INFO: : c9 9e 74 91 7d 28 02 56 3f 5c 40 94 37 58 50 68
+ INFO: - locking : true
+
+Delegated Attestation
+---------------------
+
+Delegated Attestation Service was mainly developed to support the attestation
+flow on the ``ARM Confidential Compute Architecture`` (ARM CCA) [7]_.
+The detailed description of the delegated attestation service can be found in
+the ``Delegated Attestation Service Integration Guide`` [4]_ document.
+
+In the CCA use case, the Realm Management Monitor (RMM) relies on the delegated
+attestation service of the RSS to get a realm attestation key and the CCA
+platform token. BL31 does not use the service for its own purpose, only calls
+it on behalf of RMM. The access to MHU interface and thereby to RSS is
+restricted to BL31 only. Therefore, RMM does not have direct access, all calls
+need to go through BL31. The RMM dispatcher module of the BL31 is responsible
+for delivering the calls between the two parties.
+
+.. Note::
+ Currently the connection between the RMM dispatcher and the PSA/RSS layer
+ is not yet implemented. RMM dispatcher just returns hard coded data.
+
+Delegated Attestation API
+^^^^^^^^^^^^^^^^^^^^^^^^^
+Defined here:
+
+- ``include/lib/psa/delegated_attestation.h``
+
+.. code-block:: c
+
+ psa_status_t
+ rss_delegated_attest_get_delegated_key(uint8_t ecc_curve,
+ uint32_t key_bits,
+ uint8_t *key_buf,
+ size_t key_buf_size,
+ size_t *key_size,
+ uint32_t hash_algo);
+
+ psa_status_t
+ rss_delegated_attest_get_token(const uint8_t *dak_pub_hash,
+ size_t dak_pub_hash_size,
+ uint8_t *token_buf,
+ size_t token_buf_size,
+ size_t *token_size);
+
+Attestation flow
+^^^^^^^^^^^^^^^^
+
+.. figure:: ../resources/diagrams/rss_attestation_flow.svg
+ :align: center
+
+Sample attestation token
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+Binary format:
+
+.. code-block:: bash
+
+ INFO: DELEGATED ATTEST TEST START
+ INFO: Get delegated attestation key start
+ INFO: Get delegated attest key succeeds, len: 48
+ INFO: Delegated attest key:
+ INFO: 0d 2a 66 61 d4 89 17 e1 70 c6 73 56 df f4 11 fd
+ INFO: 7d 1f 3b 8a a3 30 3d 70 4c d9 06 c3 c7 ef 29 43
+ INFO: 0f ee b5 e7 56 e0 71 74 1b c4 39 39 fd 85 f6 7b
+ INFO: Get platform token start
+ INFO: Get platform token succeeds, len: 1086
+ INFO: Platform attestation token:
+ INFO: d2 84 44 a1 01 38 22 a0 59 03 d1 a9 0a 58 20 00
+ INFO: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 19
+ INFO: 01 00 58 21 01 cb 8c 79 f7 a0 0a 6c ce 12 66 f8
+ INFO: 64 45 48 42 0e c5 10 bf 84 ee 22 18 b9 8f 11 04
+ INFO: c7 22 31 9d fb 19 09 5c 58 20 aa aa aa aa aa aa
+ INFO: aa aa bb bb bb bb bb bb bb bb cc cc cc cc cc cc
+ INFO: cc cc dd dd dd dd dd dd dd dd 19 09 5b 19 30 00
+ INFO: 19 09 5f 89 a4 05 58 20 bf e6 d8 6f 88 26 f4 ff
+ INFO: 97 fb 96 c4 e6 fb c4 99 3e 46 19 fc 56 5d a2 6a
+ INFO: df 34 c3 29 48 9a dc 38 04 67 31 2e 36 2e 30 2b
+ INFO: 30 01 64 52 54 5f 30 02 58 20 90 27 f2 46 ab 31
+ INFO: 85 36 46 c4 d7 c6 60 ed 31 0d 3c f0 14 de f0 6c
+ INFO: 24 0b de b6 7a 84 fc 3f 5b b7 a4 05 58 20 b3 60
+ INFO: ca f5 c9 8c 6b 94 2a 48 82 fa 9d 48 23 ef b1 66
+ INFO: a9 ef 6a 6e 4a a3 7c 19 19 ed 1f cc c0 49 04 67
+ INFO: 30 2e 30 2e 30 2b 30 01 64 52 54 5f 31 02 58 20
+ INFO: 52 13 15 d4 9d b2 cf 54 e4 99 37 44 40 68 f0 70
+ INFO: 7d 73 64 ae f7 08 14 b0 f7 82 ad c6 17 db a3 91
+ INFO: a4 05 58 20 bf e6 d8 6f 88 26 f4 ff 97 fb 96 c4
+ INFO: e6 fb c4 99 3e 46 19 fc 56 5d a2 6a df 34 c3 29
+ INFO: 48 9a dc 38 04 67 31 2e 35 2e 30 2b 30 01 64 52
+ INFO: 54 5f 32 02 58 20 8e 5d 64 7e 6f 6c c6 6f d4 4f
+ INFO: 54 b6 06 e5 47 9a cc 1b f3 7f ce 87 38 49 c5 92
+ INFO: d8 2f 85 2e 85 42 a4 05 58 20 bf e6 d8 6f 88 26
+ INFO: f4 ff 97 fb 96 c4 e6 fb c4 99 3e 46 19 fc 56 5d
+ INFO: a2 6a df 34 c3 29 48 9a dc 38 04 67 31 2e 35 2e
+ INFO: 30 2b 30 01 60 02 58 20 b8 01 65 a7 78 8b c6 59
+ INFO: 42 8d 33 10 85 d1 49 0a dc 9e c3 ee df 85 1b d2
+ INFO: f0 73 73 6a 0c 07 11 b8 a4 05 58 20 00 00 00 00
+ INFO: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: 00 00 00 00 00 00 00 00 00 00 00 00 04 60 01 6a
+ INFO: 46 57 5f 43 4f 4e 46 49 47 00 02 58 20 21 9e a0
+ INFO: 13 82 e6 d7 97 5a 11 13 a3 5f 45 39 68 b1 d9 a3
+ INFO: ea 6a ab 84 23 3b 8c 06 16 98 20 ba b9 a4 05 58
+ INFO: 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: 00 04 60 01 6d 54 42 5f 46 57 5f 43 4f 4e 46 49
+ INFO: 47 00 02 58 20 41 39 f6 c2 10 84 53 c5 17 ae 9a
+ INFO: e5 be c1 20 7b cc 24 24 f3 9d 20 a8 fb c7 b3 10
+ INFO: e3 ee af 1b 05 a4 05 58 20 00 00 00 00 00 00 00
+ INFO: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: 00 00 00 00 00 00 00 00 00 04 60 01 65 42 4c 5f
+ INFO: 32 00 02 58 20 5c 96 20 e1 e3 3b 0f 2c eb c1 8e
+ INFO: 1a 02 a6 65 86 dd 34 97 a7 4c 98 13 bf 74 14 45
+ INFO: 2d 30 28 05 c3 a4 05 58 20 00 00 00 00 00 00 00
+ INFO: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: 00 00 00 00 00 00 00 00 00 04 60 01 6e 53 45 43
+ INFO: 55 52 45 5f 52 54 5f 45 4c 33 00 02 58 20 f6 fb
+ INFO: 62 99 a5 0c df db 02 0b 72 5b 1c 0b 63 6e 94 ee
+ INFO: 66 50 56 3a 29 9c cb 38 f0 ec 59 99 d4 2e a4 05
+ INFO: 58 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+ INFO: 00 00 04 60 01 6a 48 57 5f 43 4f 4e 46 49 47 00
+ INFO: 02 58 20 98 5d 87 21 84 06 33 9d c3 1f 91 f5 68
+ INFO: 8d a0 5a f0 d7 7e 20 51 ce 3b f2 a5 c3 05 2e 3c
+ INFO: 8b 52 31 19 01 09 78 1c 68 74 74 70 3a 2f 2f 61
+ INFO: 72 6d 2e 63 6f 6d 2f 43 43 41 2d 53 53 44 2f 31
+ INFO: 2e 30 2e 30 19 09 62 71 6e 6f 74 2d 68 61 73 68
+ INFO: 2d 65 78 74 65 6e 64 65 64 19 09 61 44 ef be ad
+ INFO: de 19 09 60 77 77 77 77 2e 74 72 75 73 74 65 64
+ INFO: 66 69 72 6d 77 61 72 65 2e 6f 72 67 58 60 29 4e
+ INFO: 4a d3 98 1e 3b 70 9f b6 66 ed 47 33 0e 99 f0 b1
+ INFO: c3 f2 bc b2 1d b0 ae 90 0c c4 82 ff a2 6f ae 45
+ INFO: f6 87 09 4a 09 21 77 ec 36 1c 53 b8 a7 9b 8e f7
+ INFO: 27 eb 7a 09 da 6f fb bf cb fd b3 e5 e9 36 91 b1
+ INFO: 92 13 c1 30 16 b4 5c 49 5e c0 c1 b9 01 5c 88 2c
+ INFO: f8 2f 3e a4 a2 6d e4 9d 31 6a 06 f7 a7 73
+ INFO: DELEGATED ATTEST TEST END
+
+JSON format:
+
+.. code-block:: JSON
+
+ {
+ "CCA_PLATFORM_CHALLENGE": "b'0000000000000000000000000000000000000000000000000000000000000000'",
+ "CCA_PLATFORM_INSTANCE_ID": "b'01CB8C79F7A00A6CCE1266F8644548420EC510BF84EE2218B98F1104C722319DFB'",
+ "CCA_PLATFORM_IMPLEMENTATION_ID": "b'AAAAAAAAAAAAAAAABBBBBBBBBBBBBBBBCCCCCCCCCCCCCCCCDDDDDDDDDDDDDDDD'",
+ "CCA_PLATFORM_LIFECYCLE": "secured_3000",
+ "CCA_PLATFORM_SW_COMPONENTS": [
+ {
+ "SIGNER_ID": "b'BFE6D86F8826F4FF97FB96C4E6FBC4993E4619FC565DA26ADF34C329489ADC38'",
+ "SW_COMPONENT_VERSION": "1.6.0+0",
+ "SW_COMPONENT_TYPE": "RT_0",
+ "MEASUREMENT_VALUE": "b'9027F246AB31853646C4D7C660ED310D3CF014DEF06C240BDEB67A84FC3F5BB7'"
+ },
+ {
+ "SIGNER_ID": "b'B360CAF5C98C6B942A4882FA9D4823EFB166A9EF6A6E4AA37C1919ED1FCCC049'",
+ "SW_COMPONENT_VERSION": "0.0.0+0",
+ "SW_COMPONENT_TYPE": "RT_1",
+ "MEASUREMENT_VALUE": "b'521315D49DB2CF54E49937444068F0707D7364AEF70814B0F782ADC617DBA391'"
+ },
+ {
+ "SIGNER_ID": "b'BFE6D86F8826F4FF97FB96C4E6FBC4993E4619FC565DA26ADF34C329489ADC38'",
+ "SW_COMPONENT_VERSION": "1.5.0+0",
+ "SW_COMPONENT_TYPE": "RT_2",
+ "MEASUREMENT_VALUE": "b'8E5D647E6F6CC66FD44F54B606E5479ACC1BF37FCE873849C592D82F852E8542'"
+ },
+ {
+ "SIGNER_ID": "b'BFE6D86F8826F4FF97FB96C4E6FBC4993E4619FC565DA26ADF34C329489ADC38'",
+ "SW_COMPONENT_VERSION": "1.5.0+0",
+ "SW_COMPONENT_TYPE": "",
+ "MEASUREMENT_VALUE": "b'B80165A7788BC659428D331085D1490ADC9EC3EEDF851BD2F073736A0C0711B8'"
+ },
+ {
+ "SIGNER_ID": "b'0000000000000000000000000000000000000000000000000000000000000000'",
+ "SW_COMPONENT_VERSION": "",
+ "SW_COMPONENT_TYPE": "FW_CONFIG\u0000",
+ "MEASUREMENT_VALUE": "b'219EA01382E6D7975A1113A35F453968B1D9A3EA6AAB84233B8C06169820BAB9'"
+ },
+ {
+ "SIGNER_ID": "b'0000000000000000000000000000000000000000000000000000000000000000'",
+ "SW_COMPONENT_VERSION": "",
+ "SW_COMPONENT_TYPE": "TB_FW_CONFIG\u0000",
+ "MEASUREMENT_VALUE": "b'4139F6C2108453C517AE9AE5BEC1207BCC2424F39D20A8FBC7B310E3EEAF1B05'"
+ },
+ {
+ "SIGNER_ID": "b'0000000000000000000000000000000000000000000000000000000000000000'",
+ "SW_COMPONENT_VERSION": "",
+ "SW_COMPONENT_TYPE": "BL_2\u0000",
+ "MEASUREMENT_VALUE": "b'5C9620E1E33B0F2CEBC18E1A02A66586DD3497A74C9813BF7414452D302805C3'"
+ },
+ {
+ "SIGNER_ID": "b'0000000000000000000000000000000000000000000000000000000000000000'",
+ "SW_COMPONENT_VERSION": "",
+ "SW_COMPONENT_TYPE": "SECURE_RT_EL3\u0000",
+ "MEASUREMENT_VALUE": "b'F6FB6299A50CDFDB020B725B1C0B636E94EE6650563A299CCB38F0EC5999D42E'"
+ },
+ {
+ "SIGNER_ID": "b'0000000000000000000000000000000000000000000000000000000000000000'",
+ "SW_COMPONENT_VERSION": "",
+ "SW_COMPONENT_TYPE": "HW_CONFIG\u0000",
+ "MEASUREMENT_VALUE": "b'985D87218406339DC31F91F5688DA05AF0D77E2051CE3BF2A5C3052E3C8B5231'"
+ }
+ ],
+ "CCA_ATTESTATION_PROFILE": "http://arm.com/CCA-SSD/1.0.0",
+ "CCA_PLATFORM_HASH_ALGO_ID": "not-hash-extended",
+ "CCA_PLATFORM_CONFIG": "b'EFBEADDE'",
+ "CCA_PLATFORM_VERIFICATION_SERVICE": "www.trustedfirmware.org"
+ }
+
+References
+----------
+
+.. [1] https://tf-m-user-guide.trustedfirmware.org/platform/arm/rss/readme.html
+.. [2] https://tf-m-user-guide.trustedfirmware.org/platform/arm/rss/rss_comms.html
+.. [3] https://git.trustedfirmware.org/TF-M/tf-m-extras.git/tree/partitions/measured_boot/measured_boot_integration_guide.rst
+.. [4] https://git.trustedfirmware.org/TF-M/tf-m-extras.git/tree/partitions/delegated_attestation/delegated_attest_integration_guide.rst
+.. [5] https://tf-m-user-guide.trustedfirmware.org/platform/arm/rss/rss_key_management.html
+.. [6] https://developer.arm.com/-/media/Files/pdf/PlatformSecurityArchitecture/Architect/DEN0063-PSA_Firmware_Framework-1.0.0-2.pdf?revision=2d1429fa-4b5b-461a-a60e-4ef3d8f7f4b4&hash=3BFD6F3E687F324672F18E5BE9F08EDC48087C93
+.. [7] https://developer.arm.com/documentation/DEN0096/A_a/?lang=en
+
+--------------
+
+*Copyright (c) 2023, Arm Limited. All rights reserved.*
diff --git a/docs/resources/diagrams/plantuml/rss_attestation_flow.puml b/docs/resources/diagrams/plantuml/rss_attestation_flow.puml
new file mode 100644
index 0000000..aca5c01
--- /dev/null
+++ b/docs/resources/diagrams/plantuml/rss_attestation_flow.puml
@@ -0,0 +1,39 @@
+@startuml
+skinparam ParticipantPadding 10
+skinparam BoxPadding 10
+box AP
+participant RMM
+participant BL31
+endbox
+box RSS
+participant DelegAttest
+participant InitAttest
+participant MeasuredBoot
+participant Crypto
+endbox
+
+== RMM Boot phase ==
+
+RMM -> BL31: get_realm_key(\n\t**hash_algo**, ...)
+BL31 -> DelegAttest: get_delegated_key
+DelegAttest -> MeasuredBoot: read_measurement
+Rnote over DelegAttest: Compute input\n\ for key derivation\n\ (hash of measurements)
+DelegAttest -> Crypto: derive_key
+Rnote over DelegAttest: Compute public key\n\ hash with **hash_algo**.
+Rnote over Crypto: Seed is provisioned\n\ in the factory.
+DelegAttest --> BL31: get_delegated_key
+BL31 --> RMM: get_realm_key
+Rnote over RMM: Only private key\n\ is returned. Public\n\ key and its hash\n\ must be computed.\n\
+Public key is included\n\ in the realm token.\n\ Its hash is the input\n\ for get_platform_token
+RMM -> BL31: get_platform_token(\n\t**pub_key_hash**, ...)
+BL31 -> DelegAttest: get_delegated_token
+Rnote over DelegAttest: Check **pub_key_hash**\n\ against derived key.
+DelegAttest -> InitAttest: get_initial_token
+Rnote over InitAttest: Create the token including\n\ the **pub_key_hash** as the\n\ challenge claim
+InitAttest -> MeasuredBoot: read_measurement
+InitAttest -> Crypto: sign_token
+InitAttest --> DelegAttest: get_initial_token
+DelegAttest --> BL31: get_delegated_token
+BL31 --> RMM: get_platform_token
+Rnote over RMM: Platform token is\n\ cached. It is not\n\ changing within\n\ a power cycle.
+@enduml
diff --git a/docs/resources/diagrams/plantuml/rss_measured_boot_flow.puml b/docs/resources/diagrams/plantuml/rss_measured_boot_flow.puml
new file mode 100644
index 0000000..1aeb1a9
--- /dev/null
+++ b/docs/resources/diagrams/plantuml/rss_measured_boot_flow.puml
@@ -0,0 +1,79 @@
+@startuml
+skinparam ParticipantPadding 10
+skinparam BoxPadding 10
+box RSS
+participant RSS_BL1_1
+participant RSS_BL1_2
+participant RSS_BL2
+participant RSS_S
+endbox
+box SCP
+participant SCP_BL1
+endbox
+box AP
+participant AP_BL1
+participant AP_BL2
+participant AP_BL31
+endbox
+
+== RSS Boot phase ==
+-> RSS_BL1_1: Reset
+Rnote over RSS_BL1_1: ROM code, XIP
+Rnote over RSS_BL1_2: OTP code, XIP
+Rnote over RSS_BL2, AP_BL31: Stored in flash, loaded and executed in RAM
+activate RSS_BL1_1 #Green
+RSS_BL1_1 -->> RSS_BL1_2: Validate, measure
+Rnote over RSS_BL1_1: BL1_2 measurement\n\ saved to a shared buffer
+RSS_BL1_1 -> RSS_BL1_2: Pass execution
+deactivate RSS_BL1_1
+activate RSS_BL1_2 #Green
+RSS_BL1_2 -->> RSS_BL2: Validate, measure, load
+Rnote over RSS_BL1_2: RSS_BL2 measurement\n\ saved to a shared buffer
+RSS_BL1_2 -> RSS_BL2: Pass execution
+deactivate RSS_BL1_2
+activate RSS_BL2 #Green
+RSS_BL2 -->> RSS_S: Validate, measure, load
+RSS_BL2 -->> SCP_BL1: Validate, measure, load
+Rnote over RSS_BL2: RSS_S and SCP_BL1\n\ measurements saved\n\ to a shared buffer
+RSS_BL2 -> SCP_BL1: Release from reset
+activate SCP_BL1 #Green
+Rnote over RSS_BL2, SCP_BL1: MHU init between RSS and SCP
+Rnote over SCP_BL1: Configure memory
+Rnote over RSS_BL2: Waits for SCP
+SCP_BL1 --> RSS_BL2: Done
+RSS_BL2 -->> AP_BL1: Validate, measure, load
+Rnote over RSS_BL2: AP_BL1 measurement\n\ saved to a shared buffer
+RSS_BL2 -> AP_BL1: Release from reset
+activate AP_BL1 #Green
+RSS_BL2 -> RSS_S: Pass execution
+deactivate RSS_BL2
+activate RSS_S #Green
+Rnote over RSS_S: Measurements read from\n\ shared buffer and saved by\n\
+Measured Boot service to\n\ measurement slots.
+
+== RSS Runtime / AP Boot phase ==
+Rnote over RSS_S, AP_BL1: MHU init between RSS and AP
+Rnote over AP_BL1: Measure and load:\n\ FW_CONFIG\n\ TB_FW_CONFIG
+AP_BL1 -> RSS_S: Extend measurement
+Rnote over RSS_S: Measured Boot:\n\ store measurement
+AP_BL1 -->> AP_BL2: Validate, measure,load
+AP_BL1 -> RSS_S: Extend measurement
+Rnote over RSS_S: Measured Boot:\n\ store measurement
+AP_BL1 -> AP_BL2: Pass execution
+deactivate AP_BL1
+activate AP_BL2 #Green
+Rnote over AP_BL2: Measure and load:\n\ HW_CONFIG
+AP_BL2 -> RSS_S: Extend measurement
+Rnote over RSS_S: Measured Boot:\n\ store measurement
+AP_BL2 -->> AP_BL31: Validate, measure,load
+Rnote over AP_BL2: Measure and load:\n\ BL31
+AP_BL2 -> RSS_S: Extend measurement
+Rnote over RSS_S: Measured Boot:\n\ store measurement
+Rnote over AP_BL2: Measure and load:\n\ RMM
+AP_BL2 -> RSS_S: Extend measurement
+Rnote over RSS_S: Measured Boot:\n\ store measurement
+AP_BL2 -> AP_BL31: Pass execution
+deactivate AP_BL2
+activate AP_BL31 #Green
+== RSS / AP Runtime ==
+@enduml
diff --git a/docs/resources/diagrams/rss_attestation_flow.svg b/docs/resources/diagrams/rss_attestation_flow.svg
new file mode 100644
index 0000000..3728c6f
--- /dev/null
+++ b/docs/resources/diagrams/rss_attestation_flow.svg
@@ -0,0 +1,48 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?><svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" contentStyleType="text/css" height="1087px" preserveAspectRatio="none" style="width:900px;height:1087px;background:#FFFFFF;" version="1.1" viewBox="0 0 900 1087" width="900px" zoomAndPan="magnify"><defs/><g><rect fill="#DDDDDD" height="1075.1719" style="stroke:#181818;stroke-width:0.5;" width="261.5" x="44" y="6"/><text fill="#000000" font-family="sans-serif" font-size="13" font-weight="bold" lengthAdjust="spacing" textLength="20" x="164.75" y="18.0669">AP</text><rect fill="#DDDDDD" height="1075.1719" style="stroke:#181818;stroke-width:0.5;" width="502" x="364" y="6"/><text fill="#000000" font-family="sans-serif" font-size="13" font-weight="bold" lengthAdjust="spacing" textLength="28" x="601" y="18.0669">RSS</text><line style="stroke:#181818;stroke-width:0.5;stroke-dasharray:5.0,5.0;" x1="82" x2="82" y1="56.4297" y2="1046.875"/><line style="stroke:#181818;stroke-width:0.5;stroke-dasharray:5.0,5.0;" x1="266.5" x2="266.5" y1="56.4297" y2="1046.875"/><line style="stroke:#181818;stroke-width:0.5;stroke-dasharray:5.0,5.0;" x1="426" x2="426" y1="56.4297" y2="1046.875"/><line style="stroke:#181818;stroke-width:0.5;stroke-dasharray:5.0,5.0;" x1="553.5" x2="553.5" y1="56.4297" y2="1046.875"/><line style="stroke:#181818;stroke-width:0.5;stroke-dasharray:5.0,5.0;" x1="705" x2="705" y1="56.4297" y2="1046.875"/><line style="stroke:#181818;stroke-width:0.5;stroke-dasharray:5.0,5.0;" x1="822" x2="822" y1="56.4297" y2="1046.875"/><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="48" x="58" y="25.1328"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="34" x="65" y="45.1279">RMM</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="48" x="58" y="1045.875"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="34" x="65" y="1065.8701">RMM</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="49" x="242.5" y="25.1328"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="35" x="249.5" y="45.1279">BL31</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="49" x="242.5" y="1045.875"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="35" x="249.5" y="1065.8701">BL31</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="96" x="378" y="25.1328"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="82" x="385" y="45.1279">DelegAttest</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="96" x="378" y="1045.875"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="82" x="385" y="1065.8701">DelegAttest</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="75" x="516.5" y="25.1328"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="61" x="523.5" y="45.1279">InitAttest</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="75" x="516.5" y="1045.875"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="61" x="523.5" y="1065.8701">InitAttest</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="116" x="647" y="25.1328"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="102" x="654" y="45.1279">MeasuredBoot</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="116" x="647" y="1045.875"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="102" x="654" y="1065.8701">MeasuredBoot</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="59" x="793" y="25.1328"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="45" x="800" y="45.1279">Crypto</text><rect fill="#E2E2F0" height="30.2969" rx="2.5" ry="2.5" style="stroke:#181818;stroke-width:0.5;" width="59" x="793" y="1045.875"/><text fill="#000000" font-family="sans-serif" font-size="14" lengthAdjust="spacing" textLength="45" x="800" y="1065.8701">Crypto</text><rect fill="#EEEEEE" height="3" style="stroke:#EEEEEE;stroke-width:1.0;" width="893" x="0" y="86.9961"/><line style="stroke:#000000;stroke-width:1.0;" x1="0" x2="893" y1="86.9961" y2="86.9961"/><line style="stroke:#000000;stroke-width:1.0;" x1="0" x2="893" y1="89.9961" y2="89.9961"/><rect fill="#EEEEEE" height="23.1328" style="stroke:#000000;stroke-width:2.0;" width="144" x="374.5" y="76.4297"/><text fill="#000000" font-family="sans-serif" font-size="13" font-weight="bold" lengthAdjust="spacing" textLength="125" x="380.5" y="92.4966">RMM Boot phase</text><polygon fill="#181818" points="255,141.8281,265,145.8281,255,149.8281,259,145.8281" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="82" x2="261" y1="145.8281" y2="145.8281"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="99" x="89" y="125.6294">get_realm_key(</text><text fill="#000000" font-family="sans-serif" font-size="13" font-weight="bold" lengthAdjust="spacing" textLength="74" x="121" y="140.7622">hash_algo</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="25" x="195" y="140.7622">, ...)</text><polygon fill="#181818" points="414,170.9609,424,174.9609,414,178.9609,418,174.9609" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="267" x2="420" y1="174.9609" y2="174.9609"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="121" x="274" y="169.895">get_delegated_key</text><polygon fill="#181818" points="693,200.0938,703,204.0938,693,208.0938,697,204.0938" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="426" x2="699" y1="204.0938" y2="204.0938"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="127" x="433" y="199.0278">read_measurement</text><rect fill="#FEFFDD" height="53" style="stroke:#181818;stroke-width:0.5;" width="167" x="342" y="217.0938"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="95" x="346" y="233.1606">Compute input</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="110" x="346" y="248.2935">for key derivation</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="159" x="346" y="263.4263">(hash of measurements)</text><polygon fill="#181818" points="810.5,292.625,820.5,296.625,810.5,300.625,814.5,296.625" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="426" x2="816.5" y1="296.625" y2="296.625"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="68" x="433" y="291.5591">derive_key</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="150" x="351" y="309.625"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="126" x="355" y="325.6919">Compute public key</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="60" x="355" y="340.8247">hash with</text><text fill="#000000" font-family="sans-serif" font-size="13" font-weight="bold" lengthAdjust="spacing" textLength="74" x="419" y="340.8247">hash_algo</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="4" x="493" y="340.8247">.</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="132" x="756" y="357.8906"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="124" x="760" y="373.9575">Seed is provisioned</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="88" x="760" y="389.0903">in the factory.</text><polygon fill="#181818" points="278,418.2891,268,422.2891,278,426.2891,274,422.2891" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="272" x2="425" y1="422.2891" y2="422.2891"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="121" x="284" y="417.2231">get_delegated_key</text><polygon fill="#181818" points="93,447.4219,83,451.4219,93,455.4219,89,451.4219" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="87" x2="266" y1="451.4219" y2="451.4219"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="94" x="99" y="446.356">get_realm_key</text><rect fill="#FEFFDD" height="129" style="stroke:#181818;stroke-width:0.5;" width="154" x="5" y="464.4219"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="102" x="9" y="480.4888">Only private key</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="114" x="9" y="495.6216">is returned. Public</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="104" x="9" y="510.7544">key and its hash</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="126" x="9" y="525.8872">must be computed.</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="134" x="9" y="541.02">Public key is included</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="121" x="9" y="556.1528">in the realm token.</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="125" x="9" y="571.2856">Its hash is the input</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="146" x="9" y="586.4185">for get_platform_token</text><polygon fill="#181818" points="255,630.75,265,634.75,255,638.75,259,634.75" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="82" x2="261" y1="634.75" y2="634.75"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="130" x="89" y="614.5513">get_platform_token(</text><text fill="#000000" font-family="sans-serif" font-size="13" font-weight="bold" lengthAdjust="spacing" textLength="104" x="121" y="629.6841">pub_key_hash</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="25" x="225" y="629.6841">, ...)</text><polygon fill="#181818" points="414,659.8828,424,663.8828,414,667.8828,418,663.8828" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="267" x2="420" y1="663.8828" y2="663.8828"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="135" x="274" y="658.8169">get_delegated_token</text><rect fill="#FEFFDD" height="38" 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fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="168" x="467" y="770.3481">Create the token including</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="21" x="467" y="785.481">the</text><text fill="#000000" font-family="sans-serif" font-size="13" font-weight="bold" lengthAdjust="spacing" textLength="104" x="492" y="785.481">pub_key_hash</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="40" x="600" y="785.481">as the</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="99" x="467" y="800.6138">challenge claim</text><polygon fill="#181818" points="693,829.8125,703,833.8125,693,837.8125,697,833.8125" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="554" x2="699" y1="833.8125" y2="833.8125"/><text fill="#000000" font-family="sans-serif" font-size="13" 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style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="272" x2="425" y1="921.2109" y2="921.2109"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="135" x="284" y="916.145">get_delegated_token</text><polygon fill="#181818" points="93,946.3438,83,950.3438,93,954.3438,89,950.3438" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="87" x2="266" y1="950.3438" y2="950.3438"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="125" x="99" y="945.2778">get_platform_token</text><rect fill="#FEFFDD" height="68" style="stroke:#181818;stroke-width:0.5;" width="116" x="24" y="963.3438"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="108" x="28" y="979.4106">Platform token is</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="101" x="28" y="994.5435">cached. It is not</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="98" x="28" y="1009.6763">changing within</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="90" x="28" y="1024.8091">a power cycle.</text><!--MD5=[84fabec568a656165bea957fac178b53]
+@startuml
+skinparam ParticipantPadding 10
+skinparam BoxPadding 10
+box AP
+participant RMM
+participant BL31
+endbox
+box RSS
+participant DelegAttest
+participant InitAttest
+participant MeasuredBoot
+participant Crypto
+endbox
+
+== RMM Boot phase ==
+
+RMM -> BL31: get_realm_key(\n\t**hash_algo**, ...)
+BL31 -> DelegAttest: get_delegated_key
+DelegAttest -> MeasuredBoot: read_measurement
+Rnote over DelegAttest: Compute input\n\ for key derivation\n\ (hash of measurements)
+DelegAttest -> Crypto: derive_key
+Rnote over DelegAttest: Compute public key\n\ hash with **hash_algo**.
+Rnote over Crypto: Seed is provisioned\n\ in the factory.
+DelegAttest - -> BL31: get_delegated_key
+BL31 - -> RMM: get_realm_key
+Rnote over RMM: Only private key\n\ is returned. Public\n\ key and its hash\n\ must be computed.\nPublic key is included\n\ in the realm token.\n\ Its hash is the input\n\ for get_platform_token
+RMM -> BL31: get_platform_token(\n\t**pub_key_hash**, ...)
+BL31 -> DelegAttest: get_delegated_token
+Rnote over DelegAttest: Check **pub_key_hash**\n\ against derived key.
+DelegAttest -> InitAttest: get_initial_token
+Rnote over InitAttest: Create the token including\n\ the **pub_key_hash** as the\n\ challenge claim
+InitAttest -> MeasuredBoot: read_measurement
+InitAttest -> Crypto: sign_token
+InitAttest - -> DelegAttest: get_initial_token
+DelegAttest - -> BL31: get_delegated_token
+BL31 - -> RMM: get_platform_token
+Rnote over RMM: Platform token is\n\ cached. It is not\n\ changing within\n\ a power cycle.
+@enduml
+
+PlantUML version 1.2022.7(Mon Aug 22 19:01:30 CEST 2022)
+(GPL source distribution)
+Java Runtime: OpenJDK Runtime Environment
+JVM: OpenJDK 64-Bit Server VM
+Default Encoding: UTF-8
+Language: hu
+Country: HU
+--></g></svg>
\ No newline at end of file
diff --git a/docs/resources/diagrams/rss_measured_boot_flow.svg b/docs/resources/diagrams/rss_measured_boot_flow.svg
new file mode 100644
index 0000000..f5bf311
--- /dev/null
+++ b/docs/resources/diagrams/rss_measured_boot_flow.svg
@@ -0,0 +1,88 @@
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flash, loaded and executed in RAM</text><line style="stroke:#181818;stroke-width:1.0;" x1="230.5" x2="220.5" y1="259.2266" y2="255.2266"/><line style="stroke:#181818;stroke-width:1.0;" x1="230.5" x2="220.5" y1="259.2266" y2="263.2266"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="91.5" x2="231.5" y1="259.2266" y2="259.2266"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="117" x="98.5" y="254.1606">Validate, measure</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="164" x="5" y="272.2266"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="134" x="9" y="288.2935">BL1_2 measurement</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="156" x="9" y="303.4263">saved to a shared buffer</text><polygon fill="#181818" points="215.5,332.625,225.5,336.625,215.5,340.625,219.5,336.625" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="86.5" x2="221.5" y1="336.625" y2="336.625"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="96" x="93.5" y="331.5591">Pass execution</text><line style="stroke:#181818;stroke-width:1.0;" x1="411.5" x2="401.5" y1="365.7578" y2="361.7578"/><line style="stroke:#181818;stroke-width:1.0;" x1="411.5" x2="401.5" y1="365.7578" y2="369.7578"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="237.5" x2="412.5" y1="365.7578" y2="365.7578"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="152" x="244.5" y="360.6919">Validate, measure, load</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="164" x="150" y="378.7578"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="152" x="154" y="394.8247">RSS_BL2 measurement</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="156" x="154" y="409.9575">saved to a shared buffer</text><polygon fill="#181818" points="396.5,439.1563,406.5,443.1563,396.5,447.1563,400.5,443.1563" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="232.5" x2="402.5" y1="443.1563" y2="443.1563"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="96" x="239.5" y="438.0903">Pass execution</text><line style="stroke:#181818;stroke-width:1.0;" x1="592.5" x2="582.5" y1="472.2891" y2="468.2891"/><line style="stroke:#181818;stroke-width:1.0;" x1="592.5" x2="582.5" y1="472.2891" y2="476.2891"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="418.5" x2="593.5" y1="472.2891" y2="472.2891"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="152" x="425.5" y="467.2231">Validate, measure, load</text><line style="stroke:#181818;stroke-width:1.0;" x1="709" x2="699" y1="501.4219" y2="497.4219"/><line style="stroke:#181818;stroke-width:1.0;" x1="709" x2="699" y1="501.4219" y2="505.4219"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="418.5" x2="710" y1="501.4219" y2="501.4219"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="152" x="425.5" y="496.356">Validate, measure, load</text><rect fill="#FEFFDD" height="53" style="stroke:#181818;stroke-width:0.5;" width="148" x="339" y="514.4219"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="131" x="343" y="530.4888">RSS_S and SCP_BL1</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="140" x="343" y="545.6216">measurements saved</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="114" x="343" y="560.7544">to a shared buffer</text><polygon fill="#181818" points="694,589.9531,704,593.9531,694,597.9531,698,593.9531" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="418.5" x2="700" y1="593.9531" y2="593.9531"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="121" x="425.5" y="588.8872">Release from reset</text><rect fill="#FEFFDD" height="23" style="stroke:#181818;stroke-width:0.5;" width="387" x="368" y="606.9531"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="200" x="461.75" y="623.02">MHU init between RSS and SCP</text><rect fill="#FEFFDD" height="23" style="stroke:#181818;stroke-width:0.5;" width="127" x="647" y="640.0859"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="119" x="651" y="656.1528">Configure memory</text><rect fill="#FEFFDD" height="23" style="stroke:#181818;stroke-width:0.5;" width="93" x="367" y="673.2188"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="85" x="371" y="689.2856">Waits for SCP</text><polygon fill="#181818" points="429.5,718.4844,419.5,722.4844,429.5,726.4844,425.5,722.4844" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="423.5" x2="705" y1="722.4844" y2="722.4844"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="34" x="435.5" y="717.4185">Done</text><line style="stroke:#181818;stroke-width:1.0;" x1="829" x2="819" y1="751.6172" y2="747.6172"/><line style="stroke:#181818;stroke-width:1.0;" x1="829" x2="819" y1="751.6172" y2="755.6172"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="418.5" x2="830" y1="751.6172" y2="751.6172"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="152" x="425.5" y="746.5513">Validate, measure, load</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="164" x="331" y="764.6172"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="143" x="335" y="780.6841">AP_BL1 measurement</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="156" x="335" y="795.8169">saved to a shared buffer</text><polygon fill="#181818" points="814,825.0156,824,829.0156,814,833.0156,818,829.0156" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="418.5" x2="820" y1="829.0156" y2="829.0156"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="121" x="425.5" y="823.9497">Release from reset</text><polygon fill="#181818" points="577.5,854.1484,587.5,858.1484,577.5,862.1484,581.5,858.1484" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="413.5" x2="583.5" y1="858.1484" y2="858.1484"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="96" x="420.5" y="853.0825">Pass execution</text><rect fill="#FEFFDD" height="68" style="stroke:#181818;stroke-width:0.5;" width="182" x="503" y="871.1484"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="163" x="507" y="887.2153">Measurements read from</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="174" x="507" y="902.3481">shared buffer and saved by</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="163" x="507" y="917.481">Measured Boot service to</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="129" x="507" y="932.6138">measurement slots.</text><rect fill="#EEEEEE" height="3" style="stroke:#EEEEEE;stroke-width:1.0;" width="1247" x="0" y="965.2461"/><line style="stroke:#000000;stroke-width:1.0;" x1="0" x2="1247" y1="965.2461" y2="965.2461"/><line style="stroke:#000000;stroke-width:1.0;" x1="0" x2="1247" y1="968.2461" y2="968.2461"/><rect fill="#EEEEEE" height="23.1328" style="stroke:#000000;stroke-width:2.0;" width="237" x="505" y="954.6797"/><text fill="#000000" font-family="sans-serif" font-size="13" font-weight="bold" lengthAdjust="spacing" textLength="218" x="511" y="970.7466">RSS Runtime / AP Boot phase</text><rect fill="#FEFFDD" height="23" style="stroke:#181818;stroke-width:0.5;" width="313" x="556" y="992.8125"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="191" x="617" y="1008.8794">MHU init between RSS and AP</text><rect fill="#FEFFDD" height="53" style="stroke:#181818;stroke-width:0.5;" width="126" x="768" y="1025.9453"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="118" x="772" y="1042.0122">Measure and load:</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="74" x="772" y="1057.145">FW_CONFIG</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="97" x="772" y="1072.2778">TB_FW_CONFIG</text><polygon fill="#181818" points="610.5,1101.4766,600.5,1105.4766,610.5,1109.4766,606.5,1105.4766" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="604.5" x2="825" y1="1105.4766" y2="1105.4766"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="139" x="616.5" y="1100.4106">Extend measurement</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="136" x="526" y="1118.4766"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="101" x="530" y="1134.5435">Measured Boot:</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="128" x="530" y="1149.6763">store measurement</text><line style="stroke:#181818;stroke-width:1.0;" x1="1006" x2="996" y1="1182.875" y2="1178.875"/><line style="stroke:#181818;stroke-width:1.0;" x1="1006" x2="996" y1="1182.875" y2="1186.875"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="836" x2="1007" y1="1182.875" y2="1182.875"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="148" x="843" y="1177.8091">Validate, measure,load</text><polygon fill="#181818" points="610.5,1208.0078,600.5,1212.0078,610.5,1216.0078,606.5,1212.0078" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="604.5" x2="825" y1="1212.0078" y2="1212.0078"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="139" x="616.5" y="1206.9419">Extend measurement</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="136" x="526" y="1225.0078"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="101" x="530" y="1241.0747">Measured Boot:</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="128" x="530" y="1256.2075">store measurement</text><polygon fill="#181818" points="991,1285.4063,1001,1289.4063,991,1293.4063,995,1289.4063" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="831" x2="997" y1="1289.4063" y2="1289.4063"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="96" x="838" y="1284.3403">Pass execution</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="126" x="945" y="1302.4063"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="118" x="949" y="1318.4731">Measure and load:</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="77" x="949" y="1333.606">HW_CONFIG</text><polygon fill="#181818" points="610.5,1362.8047,600.5,1366.8047,610.5,1370.8047,606.5,1366.8047" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="604.5" x2="1002" y1="1366.8047" y2="1366.8047"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="139" x="616.5" y="1361.7388">Extend measurement</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="136" x="526" y="1379.8047"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="101" x="530" y="1395.8716">Measured Boot:</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="128" x="530" y="1411.0044">store measurement</text><line style="stroke:#181818;stroke-width:1.0;" x1="1183" x2="1173" y1="1444.2031" y2="1440.2031"/><line style="stroke:#181818;stroke-width:1.0;" x1="1183" x2="1173" y1="1444.2031" y2="1448.2031"/><line style="stroke:#181818;stroke-width:1.0;stroke-dasharray:2.0,2.0;" x1="1013" x2="1184" y1="1444.2031" y2="1444.2031"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="148" x="1020" y="1439.1372">Validate, measure,load</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="126" x="945" y="1457.2031"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="118" x="949" y="1473.27">Measure and load:</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="32" x="949" y="1488.4028">BL31</text><polygon fill="#181818" points="610.5,1517.6016,600.5,1521.6016,610.5,1525.6016,606.5,1521.6016" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="604.5" x2="1002" y1="1521.6016" y2="1521.6016"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="139" x="616.5" y="1516.5356">Extend measurement</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="136" x="526" y="1534.6016"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="101" x="530" y="1550.6685">Measured Boot:</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="128" x="530" y="1565.8013">store measurement</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="126" x="945" y="1582.8672"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="118" x="949" y="1598.9341">Measure and load:</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="30" x="949" y="1614.0669">RMM</text><polygon fill="#181818" points="610.5,1643.2656,600.5,1647.2656,610.5,1651.2656,606.5,1647.2656" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="604.5" x2="1002" y1="1647.2656" y2="1647.2656"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="139" x="616.5" y="1642.1997">Extend measurement</text><rect fill="#FEFFDD" height="38" style="stroke:#181818;stroke-width:0.5;" width="136" x="526" y="1660.2656"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="101" x="530" y="1676.3325">Measured Boot:</text><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="128" x="530" y="1691.4653">store measurement</text><polygon fill="#181818" points="1168,1720.6641,1178,1724.6641,1168,1728.6641,1172,1724.6641" style="stroke:#181818;stroke-width:1.0;"/><line style="stroke:#181818;stroke-width:1.0;" x1="1008" x2="1174" y1="1724.6641" y2="1724.6641"/><text fill="#000000" font-family="sans-serif" font-size="13" lengthAdjust="spacing" textLength="96" x="1015" y="1719.5981">Pass execution</text><rect fill="#EEEEEE" height="3" style="stroke:#EEEEEE;stroke-width:1.0;" width="1247" x="0" y="1753.2305"/><line style="stroke:#000000;stroke-width:1.0;" x1="0" x2="1247" y1="1753.2305" y2="1753.2305"/><line style="stroke:#000000;stroke-width:1.0;" x1="0" x2="1247" y1="1756.2305" y2="1756.2305"/><rect fill="#EEEEEE" height="23.1328" style="stroke:#000000;stroke-width:2.0;" width="148" x="549.5" y="1742.6641"/><text fill="#000000" font-family="sans-serif" font-size="13" font-weight="bold" lengthAdjust="spacing" textLength="129" x="555.5" y="1758.731">RSS / AP Runtime</text><!--MD5=[e3f0ee259d2a4aa9c2a97ff856de0312]
+@startuml
+skinparam ParticipantPadding 10
+skinparam BoxPadding 10
+box RSS
+participant RSS_BL1_1
+participant RSS_BL1_2
+participant RSS_BL2
+participant RSS_S
+endbox
+box SCP
+participant SCP_BL1
+endbox
+box AP
+participant AP_BL1
+participant AP_BL2
+participant AP_BL31
+endbox
+
+== RSS Boot phase ==
+-> RSS_BL1_1: Reset
+Rnote over RSS_BL1_1: ROM code, XIP
+Rnote over RSS_BL1_2: OTP code, XIP
+Rnote over RSS_BL2, AP_BL31: Stored in flash, loaded and executed in RAM
+activate RSS_BL1_1 #Green
+RSS_BL1_1 - ->> RSS_BL1_2: Validate, measure
+Rnote over RSS_BL1_1: BL1_2 measurement\n\ saved to a shared buffer
+RSS_BL1_1 -> RSS_BL1_2: Pass execution
+deactivate RSS_BL1_1
+activate RSS_BL1_2 #Green
+RSS_BL1_2 - ->> RSS_BL2: Validate, measure, load
+Rnote over RSS_BL1_2: RSS_BL2 measurement\n\ saved to a shared buffer
+RSS_BL1_2 -> RSS_BL2: Pass execution
+deactivate RSS_BL1_2
+activate RSS_BL2 #Green
+RSS_BL2 - ->> RSS_S: Validate, measure, load
+RSS_BL2 - ->> SCP_BL1: Validate, measure, load
+Rnote over RSS_BL2: RSS_S and SCP_BL1\n\ measurements saved\n\ to a shared buffer
+RSS_BL2 -> SCP_BL1: Release from reset
+activate SCP_BL1 #Green
+Rnote over RSS_BL2, SCP_BL1: MHU init between RSS and SCP
+Rnote over SCP_BL1: Configure memory
+Rnote over RSS_BL2: Waits for SCP
+SCP_BL1 - -> RSS_BL2: Done
+RSS_BL2 - ->> AP_BL1: Validate, measure, load
+Rnote over RSS_BL2: AP_BL1 measurement\n\ saved to a shared buffer
+RSS_BL2 -> AP_BL1: Release from reset
+activate AP_BL1 #Green
+RSS_BL2 -> RSS_S: Pass execution
+deactivate RSS_BL2
+activate RSS_S #Green
+Rnote over RSS_S: Measurements read from\n\ shared buffer and saved by\nMeasured Boot service to\n\ measurement slots.
+
+== RSS Runtime / AP Boot phase ==
+Rnote over RSS_S, AP_BL1: MHU init between RSS and AP
+Rnote over AP_BL1: Measure and load:\n\ FW_CONFIG\n\ TB_FW_CONFIG
+AP_BL1 -> RSS_S: Extend measurement
+Rnote over RSS_S: Measured Boot:\n\ store measurement
+AP_BL1 - ->> AP_BL2: Validate, measure,load
+AP_BL1 -> RSS_S: Extend measurement
+Rnote over RSS_S: Measured Boot:\n\ store measurement
+AP_BL1 -> AP_BL2: Pass execution
+deactivate AP_BL1
+activate AP_BL2 #Green
+Rnote over AP_BL2: Measure and load:\n\ HW_CONFIG
+AP_BL2 -> RSS_S: Extend measurement
+Rnote over RSS_S: Measured Boot:\n\ store measurement
+AP_BL2 - ->> AP_BL31: Validate, measure,load
+Rnote over AP_BL2: Measure and load:\n\ BL31
+AP_BL2 -> RSS_S: Extend measurement
+Rnote over RSS_S: Measured Boot:\n\ store measurement
+Rnote over AP_BL2: Measure and load:\n\ RMM
+AP_BL2 -> RSS_S: Extend measurement
+Rnote over RSS_S: Measured Boot:\n\ store measurement
+AP_BL2 -> AP_BL31: Pass execution
+deactivate AP_BL2
+activate AP_BL31 #Green
+== RSS / AP Runtime ==
+@enduml
+
+PlantUML version 1.2022.7(Mon Aug 22 19:01:30 CEST 2022)
+(GPL source distribution)
+Java Runtime: OpenJDK Runtime Environment
+JVM: OpenJDK 64-Bit Server VM
+Default Encoding: UTF-8
+Language: hu
+Country: HU
+--></g></svg>
\ No newline at end of file
