SLAAE29A January   2023  – December 2025 MSPM0C1105 , MSPM0C1106 , MSPM0G1105 , MSPM0G1106 , MSPM0G1107 , MSPM0G1505 , MSPM0G1506 , MSPM0G1507 , MSPM0G1518 , MSPM0G1519 , MSPM0G3105 , MSPM0G3106 , MSPM0G3106-Q1 , MSPM0G3107 , MSPM0G3107-Q1 , MSPM0G3505 , MSPM0G3506 , MSPM0G3506-Q1 , MSPM0G3507 , MSPM0G3507-Q1 , MSPM0G3518 , MSPM0G3518-Q1 , MSPM0G3519 , MSPM0G3519-Q1 , MSPM0L1105 , MSPM0L1106 , MSPM0L1227 , MSPM0L1227-Q1 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2227 , MSPM0L2227-Q1 , MSPM0L2228 , MSPM0L2228-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Key Concepts
    2. 1.2 Goals of Cybersecurity
    3. 1.3 Platform Security Enablers
  5. 2Device Security Model
    1. 2.1 Device Identity
    2. 2.2 Initial Conditions at Boot
    3. 2.3 Boot Configuration Routine (BCR)
    4. 2.4 Bootstrap Loader (BSL)
    5. 2.5 Boot Flow
    6. 2.6 User-Specified Security Policies
      1. 2.6.1 Boot Configuration Routine (BCR) Policies
        1. 2.6.1.1 Serial Wire Debug Related Policies
          1. 2.6.1.1.1 SWD Security Level 0
          2. 2.6.1.1.2 SWD Security Level 1
          3. 2.6.1.1.3 SWD Security Level 2
        2. 2.6.1.2 Bootstrap Loader (BSL) Enable/Disable Policy
        3. 2.6.1.3 Flash Memory Protection and Integrity Related Policies
          1. 2.6.1.3.1 Locking the Application (MAIN) Flash Memory
          2. 2.6.1.3.2 Locking the Configuration (NONMAIN) Flash Memory
          3. 2.6.1.3.3 Verifying Integrity of Application (MAIN) Flash Memory
        4. 2.6.1.4 Bootstrap Loader (BSL) Security Policies
          1. 2.6.1.4.1 BSL Access Password
          2. 2.6.1.4.2 BSL Read-out Policy
          3. 2.6.1.4.3 BSL Security Alert Policy
      2. 2.6.2 Customer Secure Code (CSC) Security Policies
        1. 2.6.2.1 CSC Enforced Bankswap
        2. 2.6.2.2 CSC Enforced Firewalls
        3. 2.6.2.3 CSC Key Write to KEYSTORE
      3. 2.6.3 Configuration Data Error Resistance
        1. 2.6.3.1 CRC-Backed Configuration Data
        2. 2.6.3.2 16-bit Pattern Match for Critical Fields
  6. 3Secure Boot
    1. 3.1 Secure Processing Environment Isolation
    2. 3.2 Customer Secure Code (CSC)
      1. 3.2.1 Secure Boot Flow
      2. 3.2.2 Flash Memory Map
      3. 3.2.3 Features
        1. 3.2.3.1 CMAC Acceleration
        2. 3.2.3.2 Asymmetric Verification
        3. 3.2.3.3 KEYSTORE and Firewall
        4. 3.2.3.4 CSC Performance
      4. 3.2.4 Quick Start Guide
        1. 3.2.4.1 Environment Setup
        2. 3.2.4.2 Step by Step Guidance
        3. 3.2.4.3 CSC NONMAIN Configuration
        4. 3.2.4.4 Customize Changes on CSC Example
    3. 3.3 Boot Image Manager (BIM)
      1. 3.3.1 Secure Boot Flow
      2. 3.3.2 Flash Memory Map
      3. 3.3.3 Quick Start Guide
  7. 4Secure Storage
    1. 4.1 Flash Write Protection
    2. 4.2 Flash Read-Execute Protection
    3. 4.3 Flash IP Protection
    4. 4.4 Data Bank Protection
    5. 4.5 Secure Key Storage
    6. 4.6 SRAM Protection
    7. 4.7 Hardware Monotonic Counter
  8. 5Cryptographic Acceleration
    1. 5.1 Hardware AES Acceleration
      1. 5.1.1 AES
      2. 5.1.2 AESADV
    2. 5.2 Hardware True Random Number Generator (TRNG)
  9. 6FAQ
  10. 7Summary
  11. 8References
  12. 9Revision History
2.6.1.3.1 Locking the Application (MAIN) Flash Memory

MSPM0 MCUs implement a static write protection scheme to lock out user defined sectors in the MAIN flash region from any program or erase operations at runtime. The desired static write protection scheme is configured as a part of the boot security policies in the NONMAIN flash region.

Purpose

Static write protection enables placement of a fixed, user-defined, application in the flash memory that has the following characteristics:

  • Once programmed and locked, the application is not modifiable by the application code or ROM bootloader
  • If placed at the beginning of the flash memory, the application is the first code that executes when the ROM boot configuration routine transfers execution to the user application

MSPM0 static write protection supports both characteristics, which must be satisfied to implement a secure boot image manager.

Capabilities

Any sector that is configured in the NONMAIN to be write-locked is functionally immutable when the boot configuration routine transfers execution to either the bootstrap loader or the user application code in MAIN flash. Any attempt to program or erase a statically protected sector by the application code or the bootstrap loader results in a hardware flash operation error, and the sector is not modified.

While static write protection prevents any modification by application code or the bootloader, a mass erase or factory reset command sent through the SWD interface is honored. If this behavior is not desired, the mass erase or factory reset SWD commands can be protected with unique passwords or disabled(see the SWD policies). To completely remove any means of modifying statically write protected MAIN flash sectors, the mass erase and factory reset commands (or the SW-DP) must be disabled, and the NONMAIN boot configuration memory must also be statically write protected to prevent application code from changing the underling write protection scheme by modifying the contents NONMAIN region. This is discussed in the following section.