Security Board Configuration¶
Security Configuration in System Firmware¶
The security portion of system firmware has options that can be configured independently of the main Board Configuration. These options are controlled through the security board configuration. In addition, initialization of the secure portion of the system firmware is deferred until the secure board configuration is sent to allow tuning of the system boot time.
Warning
This message MUST be sent in order to initialize the security capabilities of system firmware. Until it is received no security functionality is available.
A standalone board configuration message contains the security data within a flat-typed array. The security data is provided separately to reduce DMSC boot time. The security board cfg message is sent any time after the boot notification message is sent and has no dependence upon receipt of the standard board configuration message.
Note
Security Board configuration requires to be signed and encrypted on HS devices to ensure authenticity and protect secrets. Please refer to Signing Board Configuration on HS devices on how to sign and encrypt board configuration on HS devices.
TISCI API for Security Board Config¶
The following are the parameters required in the TI-SCI message to pass security board configuration data to DMSC after DMSC sends boot notification complete. The security board configuration message is not dependent on receipt of the standard board configuration message.
Usage¶
| Message Type | Normal |
| Secure Queue Only? | Yes |
TISCI Message ID¶
TISCI_MSG_BOARD_CONFIG_SECURITY (0x000DU)
Message Data Structures¶
struct tisci_msg_board_config_security_req
TISCI_MSG_BOARD_CONFIG_SECURITY request to provide the location and size of the boardcfg security configuration structure.
| Parameter | Type | Description |
|---|---|---|
| hdr | struct tisci_header | TISCI header |
| boardcfg_securityp_low | u32 | Low 32-bits of physical pointer to boardcfg security configuration struct. |
| boardcfg_securityp_high | u32 | High 32-bits of physical pointer to boardcfg security configuration struct. |
| boardcfg_security_size | u16 | Size of security configuration data. |
| boardcfg_security_devgrp | devgrp_t | Device group for the security board configuration. |
Note
Even though the security board configuration structure contains the
boardcfg_security_devgrp member, it is ignored. Initialization of
firewalls is performed for a devgrp when it is enabled via the core board
configuration message. This is necessary to ensure isolation. See
Board Configuration.
The reamining security services are initialized when the security board configuration is received for the first time. Subsequent security board configuration messages do not have any effect on operation of System Firmware.
struct tisci_msg_board_config_security_resp
Empty response for TISCI_MSG_BOARD_CONFIG_SECURITY.
| Parameter | Type | Description |
|---|---|---|
| hdr | struct tisci_header | TISCI header. |
Although this message is essentially empty and contains only a header a full data structure is created for consistency in implementation.
Warning
The boardcfg data structures described below must be placed in MCU OCMC SRAM. The address used in the TISCI message will be in MCU OCMC SRAM.
Configuration substructure enumeration¶
This is a fixed size c-structure which both defines the format of the configuration as well as reserves DMSC memory to store the configuration. The boardcfg_sec data structure makes use of the same ABI revision structure structure for the top level and boardcfg substructure header for each member structure as the top level boardcfg structure does..
| Element | Type | Description |
|---|---|---|
| boardcfg_abi_rev | ABI revision structure | Board Config ABI version (separate from DMSC ABI version) |
| processor_acl_list | Processor Access List | Processor access control list configuration |
| host_hierarchy | Host Hierarchy | Host hierarchy configuration |
| otp_config | Extended OTP array configuration | Extended OTP access configuration |
| dkek_config | Derived KEK Management | DKEK access configuration |
| sa2ul_config | SA2UL Configuration | SA2UL access configuration |
| sec_dbg_config | Secure Debug Unlock | Secure debug unlock configuration |
| sec_handover_cfg | Security Handover | Security handover configuration |
Processor Access List¶
Access Control List for various Processors in the SoC.
boardcfg_proc¶
| Element | Type | Description |
|---|---|---|
| subhdr | boardcfg substructure header | Magic and size for integrity check |
| proc_access_list | processor_access_list [32] | Processor access description |
The magic number to be populated in the subhdr is 0xF1EA.
Processor access list entry¶
| Element | Type | Description |
|---|---|---|
| processor_id | u8 | Processor ID (mandatory) - Use 0 to mark unused |
| proc_access_master | u8 | Recovery Host ID or Primary control master host ID (mandatory) |
| proc_access_secondary[0-2] | u8 | Other Host IDs that can control this processor(set to DMSC host ID if unused) |
Host Hierarchy¶
Host Hierarchy for various processing entities in the SoC. Host hierarchy defines the supervisory tree for all processing entities in the SoC.
boardcfg_host_hierarchy¶
| Element | Type | Description |
|---|---|---|
| subhdr | boardcfg substructure header | Magic and size for integrity check |
| host_hierarchy_entries | host_hierarchy_entries [32] | Host hierarchy description |
The magic number to be populated in the subhdr is 0x8D27.
Host hierarchy entry¶
| Element | Type | Description |
|---|---|---|
| host_id | u8 | Processing entity Host ID (mandatory) - Use 0 to mark unused |
| supervisor_host_id | u8 | Supervisor Host ID |
Extended OTP array configuration¶
The below structure defines which hosts read the OTP area and which host has permissions to write to the OTP area. Please also refer to the below documents to understand the usage of the board configuration structure.
| Element | Type | Description |
|---|---|---|
| subhdr | boardcfg substructure header | Magic and size for integrity check |
| otp_entry | otp_entry [32] | OTP MMR access control per row |
| write_host | u8 | ID of the host who can perform writes to OTP rows |
The magic number to be populated in the subhdr is 0x4081.
Note
Wildcard host ID (128U/0x80) cannot be used in the write_host field. The host ID used here must map to
a secure proxy thread.
Important
Only write_host can perform writes to OTP revision (swrev, keyrev) using
TISCI_MSG_WRITE_SWREV and
TISCI_MSG_WRITE_KEYREV
Warning
Even though OTP functionality is not available on GP devices, the boardcfg structure for OTP must be present. The header must be populated with the size and magic number correctly.
Extended OTP Row Entry¶
| Element | Type | Description |
|---|---|---|
| host_id | u8 | Host ID
|
| host_perms | u8 | 2 bit wide fields specifying permissions
|
Derived KEK Management¶
The below structure controls access to DKEK on the SOC. Please also refer to the below documents to understand the usage of the board configuration structure.
| Element | Type | Description |
|---|---|---|
| subhdr | boardcfg substructure header | Magic and size for integrity check |
| dkek_allowed_hosts | u8[4] | Hosts allowed access to DKEK Set one of the entries to 128 if DKEK must accessible to all hosts. |
| allow_dkek_export_tisci | u8 | Flag indicating whether DKEK can be exported via TISCI API Set to 0x5A if TISCI export is allowed. |
| rsvd | u8[3] | Reserved field. Currently unused. Set to 0. |
The magic number to be populated in the subhdr is 0x5170.
SA2UL Configuration¶
The below entry controls the SAUL configuration on the SOC.
| Element | Type | Description |
|---|---|---|
| subhdr | boardcfg substructure header | Magic and size for integrity check |
| auth_resource_owner | u8 | ID of the host allowed to acquire/release the authentication resources This feature is not currently supported |
| enable_saul_psil_global_config_writes | ftbool | Flag for allowing pairing requests from PSIL. Set to 0x5A to enable |
| rsvd | u8[2] | Reserved for future use. Set to 0 |
The magic number to be populated in the subhdr is 0x23BE.
Secure Debug Unlock¶
| Element | Type | Description |
|---|---|---|
| subhdr | boardcfg substructure header | Magic and size for integrity check |
| allow_jtag_unlock | u8 | Set to 0x5A if runtime jtag unlock is allowed. Set to 0 otherwise. |
| allow_wildcard_unlock | u8 | If this field is set to 0x5A, the same debug unlock certificate will work across all devices where it passes the remaining checks. Set to 0 otherwise to enforce UID match before jtag unlock The X509 certificate must contain the UID of the device being unlocked in the designated field NOTE: This field is dependent on the |
| allow_debug_level_rsvd | u8 | Reserved field. Currently unused. Set to 0. This field can be used in the future to control the level of debug allowed with a certificate. |
| rsvd | u8 | Reserved field. Currently unused. Set to 0. |
| min_cert_rev | u32 | Minimum revision value that must be contained in the debug unlock certificate for it to be accepted. Use this field to enforce rollback protection for debug unlock certificates. Set to 0 if you do not wish to use this field. |
| jtag_unlock_hosts | u8[4] | Hosts allowed send jtag unlock message via TISCI Set one of the entries to 128 if jtag unlock must be allowed for all hosts. |
The magic number to be populated in the subhdr is 0x42AF.
Security Handover¶
Note
This section is only processed on AM64 devices.
Please also refer to the below documents to understand the usage of the board configuration structure.
| Element | Type | Description |
|---|---|---|
| subhdr | boardcfg substructure header | Magic and size for integrity check |
| handover_msg_sender | u8 | ID of the host who will send the security handover message Set to 0 if security handover is not desired or is unsupported on the device. |
| handover_to_host_id | u8 | ID of the host who takes over the security functionality The credentials of this host are programmed in the firewalls protecting the security configuration registers. Set to 0 if security handover is not desired or is unsupported on the device. |
| rsvd | u8[4] | Reserved field. Currently unused. Set to 0. Security handover currently transfers ownership of the SOC firewalls. These flags are intended for future use to indicate whether ownership of additional resources must be transferred |
The magic number to be populated in the subhdr is 0x608F.