In a general-purpose (GP) device, M4 ROM performs
the following functions:
- Device management
- Configures the boot vectors (in BOOT_CFG) and controls reset release of R5
core. That is, M4 is the boot controller of R5 core.
- IPC configuration via Main DMSS rings and Secure Proxy
- PLL configuration (R5 and SA2UL)
- X509 certificate parsing
- SA2UL configuration to SHA512 for image integrity checks
- M4 firmware loading