Core 1 Execution Start Address Ambiguity in Dual-Core Bare-Metal Systems In a dual-core ARM Cortex-A9 system running bare-metal programs, one of the most critical challenges is ensuring that Core 1 begins execution at the correct memory address after being released from reset. The Cortex-A9 cores, by default, start executing instructions from address 0x00000000 or 0xFFFF0000…
NVIC_EnableIRQ Functionality and ISER Register Behavior The NVIC_EnableIRQ function is a commonly used utility in ARM Cortex-M processors to enable specific interrupts via the Nested Vectored Interrupt Controller (NVIC). The function operates by setting a bit in the Interrupt Set Enable Register (ISER), which is part of the NVIC. The ISER is a memory-mapped register…
Cortex-M7 TCMWAIT Signal Behavior and System Hang The Cortex-M7 processor, known for its high performance and efficiency, utilizes Tightly Coupled Memory (TCM) for low-latency access to critical data and instructions. The TCM interface includes the TCMWAIT signal, which is used to handle multi-cycle memory accesses. When the TCMWAIT signal is asserted, the processor stalls, waiting…
ARM Cortex-A9 Processor Halting During __libc_init_array Execution The issue at hand involves an ARM Cortex-A9 processor halting during the execution of the __libc_init_array function, specifically when attempting to execute a function pointer from the .init_array section. This behavior is observed on two out of three identical hardware setups, while the third operates as expected. The…
Undefined Instruction Error on ICC_HSRE Access in AArch32 EL2 The core issue revolves around an undefined instruction error when attempting to access the ICC_HSRE (Interrupt Controller Hyp System Register Enable) register in AArch32 EL2 mode on a Cortex-A53 processor with a GICv3 (Generic Interrupt Controller version 3) implementation. The specific instruction causing the error is:…
Cortex-M0+ DSP Performance Bottlenecks in FFT and FIR Processing The Cortex-M0+ is a highly efficient, low-power microcontroller core designed for cost-sensitive and power-constrained applications. However, its simplicity and lack of specialized hardware for digital signal processing (DSP) operations, such as Fast Fourier Transform (FFT) and Finite Impulse Response (FIR) filtering, can lead to significant performance…
ARM Cortex-A53 Stage-2 Translation Table Initialization and HCR.VM Crash When enabling stage-2 translation on an ARM Cortex-A53 processor in AArch32 mode, setting the HCR.VM bit to 1 can lead to a system crash if the stage-2 translation table is not properly configured. Stage-2 translation is a critical component of ARM virtualization, allowing a hypervisor to…
DRAM Address Mapping and Physical Memory Hierarchy on Cortex-A72 ARMv8 The Cortex-A72 ARMv8 processor, like many modern ARM cores, relies on a complex memory hierarchy to manage data efficiently. One critical aspect of this hierarchy is the DRAM address mapping, which determines how physical memory addresses are translated into specific locations within the DRAM structure….
ARMv8-A Real-Time Counter Requirements and Challenges In ARMv8-A architectures, particularly in multicore systems like the Xilinx RFSoC with four Cortex-A53 cores, achieving a low-overhead, high-resolution real-time counter that is consistent across all cores and accessible from user-level code (EL0) is a non-trivial task. The primary requirement is to read a counter with a resolution of…
ARM Cortex-A Bare Metal I/O Architecture and Documentation Gaps When working with ARM Cortex-A processors in a bare-metal environment, one of the most significant challenges is understanding and implementing I/O operations without the abstraction layers provided by an operating system. The Cortex-A series, known for its application-grade performance, is typically integrated into complex System-on-Chip (SoC)…