Before addressing the differences between arm64 and aarch64, it is essential to clarify that these terms typically refer to the same concept. Specifically, both arm64 and aarch64 denote the 64-bit extension of the ARM architecture, commonly used to represent the identical architecture. However, these terms are frequently employed in distinct contexts.
Terms of Origin and Usage
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aarch64:
- Definition and Origin: AArch64 represents the 64-bit state of the ARM architecture, a term originating from ARM. It is the Instruction Set Architecture (ISA) specifically designed for 64-bit processing.
- Usage Context: In technical documentation and developer resources, particularly when detailing architectural specifics or programming-related specifications, AArch64 is more commonly utilized.
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arm64:
- Definition and Origin: arm64 is generally regarded as an informal synonym for AArch64. It is predominantly used in software development and operating system contexts.
- Usage Context: At the operating system level, such as during the configuration and compilation of Linux kernels or Android, iOS, and other systems, arm64 is frequently employed to indicate the supported architecture.
Conclusion
Although these terms exhibit subtle contextual differences, they ultimately refer to the same technical concept. Selecting the appropriate terminology based on context is critical; for example, use AArch64 in technical documentation and arm64 in discussions concerning software compatibility or operating systems.
Practical Example
In a previous project, we developed an embedded Linux system for an ARM-based device. When reviewing technical documentation and official ARM architecture specifications, I used AArch64 to ensure a thorough understanding of all architectural details and instruction sets. During Linux kernel configuration and device driver development, we employed arm64 to denote the target architecture, which ensured consistency between our build environment, toolchain, and the target platform.