Hardware Abstraction Layer (HAL) is a set of written codes and programs which allows the operating system of a computer to communicate with the hardware plugged in with the computer. It is a layer of program bundle which is more generic in nature and thus works at an abstract level. This layer can be fed either from the device’s driver or in the operating system’s kernel. This enables the computer to communicate with the hardware in more generalized way paving way for standard programs for similar hardware.

Bytesplay’s HAL Designing team consists of experienced and knowledgeable programmers who have been designing similar layers for various operating systems and other systems. This process of designing a Hardware Abstraction Layer is the first step in developing a hardware-independent firmware which is also reusable. The HAL provides a set of pre-written codes to the application developer which he uses to access the hardware without taking the pain to write the codes and programs for the hardware.

HAL is like an API which can interact with the hardware. HAL has many advantages as it is portable, abstract, reusable and come in less cost. A well designed HAL eases the problems manifolds and has minimum bugs which can be fixed easily.

How we design the HAL?

A well designed HAL can be swift in functioning and will have minimum bugs whereas an inefficient HAL would not only make the program bulky but also render it incompatible with many hardware products. We follow a specific pattern to design HAL for our clients that has minimum bugs and is smooth in functioning and highly compatible with a range of hardware products.

• HAL has to be used on multiple hardware platforms. We examine all the standard microcontroller peripherals to ascertain their key features. All the microcontrollers that fulfil our requirements are segregated.
• We design separate HAL for every microcontroller as every microcontroller is built to fulfil its niche specifications and cannot be incorporated within a single program. This reduces the chances of bugs and helps to reduce the cost and ensures optimum utilization.
• Our programmers use Doxygen to design the HAL. Doxygen can be used to create documents like HTML and PDF and it can also be used to fill the HAL functions in the blank template as per the requirements, which originates because the comments of the HAL are automatically developed.
• Our engineers ensure that the HAL is used for longer period to maximize code usage and minimize the cost. They develop multiple monitoring programs to keep the HAL running without the bugs.
• Designing a bug-free and perfect HAL is unrealistic and impossible. We can only try to minimize the bugs and upgrade it from time to time so that it functions smoothly.
• The HAL interface developed by Bytesplay has simple interface and it can be easily understood by even the novice user.
• The HAL designed here are standard and have consistent interface to aid the multiple hardware functionality.
• The programmers here use mnemonic codes while writing the codes which make it easier for other developers to understand. The most reliable interface used here is ANSI-C compliant. It allows multiple compilers and tool chains portability.
• We keep in mind to pass the pointer to provide greater portability and reuse value to the HAL.
• After the design is complete and the HAL is designed, it is tested by deploying multiple microcontrollers from different brands to check its compatibility and portability.

One of the best advantages of HAL is having one set of commands that is well defined to allow all other application codes to get easily switched from one microcontroller to the other. Other advantages are its reusability, less cost and abstractness of the hardware. However, the HAL may sometimes decrease the efficiency and delay the execution process by increasing the code length. But the latest microcontrollers and compilers have put these issues to grave with their impeccable architecture and enhanced optimization.