cortex-r5-debug

# Cortex-R5 Debug ## Overview Use this skill to debug Cortex-R5 (ARMv7-R, PMSA) systems by separating core mode, boot source, memory map, exception vectors, TCM, MPU/cache policy, interrupt controller, and safety configuration. Cortex-R5 uses an `MPU` (not an MMU) and CP15-based control; failures usually come from memory attributes, ECC/TCM setup, or lockstep configuration rather than C code. ## When To Use Use this skill when: - The user is bringing up or debugging Cortex-R5/R5F, Cortex-R4, or Cortex-R7 firmware (Xilinx Zynq UltraScale+ RPU, TI Hercules/Sitara, and similar). - The issue involves early boot, Undefined/Prefetch Abort/Data Abort exceptions, IRQ/FIQ, ATCM/BTCM, MPU regions, caches, ECC/parity, lockstep, split mode, or JTAG attach. - The platform is an SoC with real-time cores, safety islands, motor/control firmware, storage controllers, or heterogeneous Linux + R5 systems. Do not use this skill for Cortex-M microcontrollers. Use `cortex-m-debug` when the target has `NVIC`, `VTOR`, and M-profile exception behavior instead of CP15/CPSR. ## First Questions Ask for: - SoC/board, exact core, boot owner, toolchain, debugger, and whether the R5 runs bare metal or an RTOS. - Core mode: single core, split (performance) mode, or lock-step (`DCLS`); which core the debugger is attached to. - Memory map: boot ROM, flash, DDR, OCM/SRAM, `ATCM`/`BTCM` base and size, stacks, heaps, and linker script. - MPU/cache policy, TCM enable state (`INITRAMA`/`INITRAMB` reset str...