ARM Cortex-M4 Hard Fault During PWM and Sensor Input Iteration The issue described involves an ARM Cortex-M4 microcontroller (specifically the Tiva C series) entering a Hard Fault state during the second iteration of a loop that reads sensor input from GPIO Port B and generates PWM signals on GPIO Port F. The program operates correctly…
ARM SPE Sampling Interval and PMSIRR_EL1.INTERVAL Configuration Challenges The Statistical Profiling Extension (SPE) in ARM architectures is a powerful tool for performance analysis, enabling developers to trace program execution flow and gather insights into branch behavior, memory access patterns, and other critical metrics. However, a common issue arises when attempting to configure the sampling interval…
GICv3 Initialization and IRQ Handling in AArch64 Bare-Metal Environments The Generic Interrupt Controller version 3 (GICv3) is a critical component in ARM-based systems, particularly when working with AArch64 architectures. It manages interrupt routing, prioritization, and distribution across multiple cores. Implementing a bare-metal GICv3 setup involves configuring the GIC Distributor (GICD), CPU Interfaces (GICC), and Redistributors…
ARM Cortex-A32 Boot Process with Trusted Firmware-A: Key Considerations The ARM Cortex-A32 is a 32-bit processor core that implements the ARMv8-A architecture but operates exclusively in AArch32 execution state. This unique characteristic raises important questions about its compatibility with Trusted Firmware-A (TF-A), which is typically associated with 64-bit ARMv8-A processors. The Cortex-A32’s boot process, when…
Cortex-M33 and CryptoCell-312 Boot Code and Startup Code Requirements When integrating the ARM Cortex-M33 processor with the CryptoCell-312 security subsystem, one of the most critical yet often overlooked aspects is the development of robust boot code and startup code. The boot code is responsible for initializing the hardware, setting up the memory map, and preparing…
ARM Cortex-A76 and Cortex-A55 DynamIQ Topology Representation Challenges The ARM Cortex-A76 and Cortex-A55 processors, when paired using ARM’s DynamIQ technology, present unique challenges in terms of topology representation within the Linux kernel, particularly in version 4.14. The DynamIQ shared unit (DSU) allows for heterogeneous multi-core configurations, enabling a mix of high-performance cores (Cortex-A76) and power-efficient…
ARM Cortex-M0 vs. Cortex-M0+ Feature Set and Upgrade Considerations The decision to upgrade from an ARM Cortex-M0 to a Cortex-M0+ processor in an industrial automation system, such as a Programmable Logic Controller (PLC), involves a detailed analysis of the feature sets, performance improvements, and compatibility considerations. Both processors are based on the ARMv6-M architecture, which…
ARM Cortex-A78 Instruction Fetch and Decode Pipeline Mechanics The ARM Cortex-A78 is a high-performance processor core designed for efficiency and scalability, commonly used in mobile and embedded systems. One of the key aspects of its performance is the instruction fetch and decode pipeline, which involves the conversion of assembly instructions into Macro-Operations (MOPs) and further…
Uboot’s Access to TZPC Registers During Startup vs. Command Line Environment The core issue revolves around the behavior of Uboot when accessing TrustZone Protection Controller (TZPC) registers on an Exynos 4412 board. During the startup process, Uboot initializes the TZPC registers through a routine called tzpc_init in the lowlevel_init_SCP.S file. This initialization suggests that Uboot…
MPU Enforcement Failure in ITM Address Space (0xE0000000 – 0xE0010000) The Memory Protection Unit (MPU) on the ARM Cortex-M4 is designed to enforce memory access permissions and attributes for different regions of the address space. However, when configuring the MPU to restrict access to the Instrumentation Trace Macrocell (ITM) address range (0xE0000000 – 0xE0010000), unprivileged…