PMC firmware (fw/pmc/)

Target: Ibex RV32IMC management core on the AON island.

Layout

fw/pmc/
  include/
    pmc.h               - shared types, register map
    rpmi.h              - RPMI v1.0 frame format
    dvfs.h              - DVFS table format
  src/
    main.c              - boot + scheduler loop
    rpmi_server.c       - RPMI v1.0 frame parser, service dispatcher
    dvfs_arbiter.c      - DVFS table lookup + AVFS merge
    pmic_sequencer.c    - external PMIC power-up/down sequence
    spmi.c              - SPMI v2.0 master bit-bang
    i2c.c               - I2C-FM-plus fallback
    thermal_policy.c    - DTS throttle ladder
    droop_telemetry.c   - droop counter aggregation
    secure_boot.c       - HMAC/ECDSA placeholder

Build

The PMC firmware is built separately from the SoC RTL using the riscv-none-elf toolchain in external/xpack-riscv-none-elf-gcc-*. Each translation unit is deliberately small and headers are self-contained so the skeleton can be compiled and linted independently of the Ibex sources.

make -C fw/pmc        # planning_only target; release_blocked

Release blockers

• Ibex source pin not committed to repo external/ manifest.
• Linker script for AON SRAM not authored.
• Secure-boot key provisioning not closed.
• DVFS tables (docs/pd/dvfs-tables/) are placeholders only.

Cross-references

• Architecture: docs/pd/power-management-firmware.md
• Rail plan: docs/pd/rail-plan-2028.yaml
• Mailbox register map: rtl/power/power_pkg.sv PMC_REG_*
• AVFS contract: docs/pd/avfs.md
• Droop contract: docs/pd/droop-detection.md