Category Archives: Automotive

Development of an ISO 21434 Based Secure Bootloader for an Automotive Tier-1

About the Customer

Our customer is an automotive tier-1 specializing in innovative solutions around mechatronics of automobiles. Some of the leading OEMs around the globe trust them for their sophisticated solutions.

As the industry is fast embracing automotive cybersecurity, our customer has been one of the earliest adopters of cybersecurity standards and practices. Partnering with us takes their commitment to automotive cybersecurity to newer heights.

Business Challenge

The primary challenge for our customer was to develop a secure bootloader that could flash/reprogram the ECU (control unit). There was a certain level of cybersecurity required for the ECU that entailed numerous security implementations including digital signature.

Here’s a snapshot of the major challenges that needed to be addressed:

• The ECU comprised 2 microcontrollers that required a 1-wire gateway
• Both CAN and LIN based bootloader was required as ECU had both CAN and LIN variant.
• The Hardware Security Module provided by Microchip required drivers to be developed
• Secure Bootloader was needed to be developed with advanced cybersecurity features as per ISO 21434 standard

Since the customer needed a faster time-to-market for their solution, they partnered with us for bootloader development and other solutions. We have a proven track record of delivering secure bootloaders for automotive ECUs.

Embitel’s Solution

Our automotive team was primarily tasked with the development of a secure bootloader that would interact with the Hardware Security Module (HSM) of the ECU and ensure secure ECU flashing. In the process, the image(.hex/.srec) file and the digital signature will be validated with the HSM.

Additionally, the project scope also included developing a ‘gateway’ to facilitate flashing of 2 microcontrollers. Since the ECU had two variants- CAN and LIN, we had to develop bootloaders for both networks.

To facilitate secure ECU flashing, our customer requested us to develop a signing tool that would encrypt the image (.hex/.srec) file based on algorithms required by the customer.

The team started to work parallelly on these three applications.

Details of the solutions built for the customer:

• Secure Bootloader: The secure bootloader comprises of algorithms such as AES- 128, Elliptical Curve Digital Signature algorithm (ECDSA), CRC-32 integrity and data authenticity mechanism. We developed the secure bootloader for both CAN and LIN protocols as requested by the customer.
• Low-level drivers required by the microcontroller: Device drivers such as HSM drivers and all other low-level drivers needed by the microcontrollers such as NVM handler, CAN, LIN drivers were developed.
• 1-wire Gateway: The data coming for microcontroller 2 has to be forwarded from microcontroller 1. We developed a secure gateway for that purpose. It is a UART based 1-wire gateway solely for transmitting data from one MCU to another.

  Gateway proved to be a critical piece of solution to build especially in a 2 MCU environment. The gateway must ensure that the number of bytes of data sent to MCU 2 is received without any loss. Also, the data sent to MCU 2 through the gateway must be validated through HSM. Hence, reliability is the key here. We tested the communication rigorously to rule out any discrepancies.

• Signing Tool: We developed the signing tool to solve the problem of encrypting the firmware image file based on secure algorithms of choice. The signing tool accepts .hex or .srec application images, then encrypts and compresses them using algorithms customizable to meet your specific requirements. Finally, it generates a robust signature for the image, ensuring the integrity and authenticity of your software with an algorithm shaped by your unique needs.

Other Deliverables provided to the customer:

• The secure bootloader developed for the customer was based on CAN and LIN. Hence we delivered our ready-to-integrate CAN protocol (CAN interface layer and network management layer) and LIN protocol (LIN interface layer, network management layer and node service).
• For ECU diagnostics, we integrated the UDS stack (ISO 14229 and ISOTP/ISO15765). Fault code memory (FCM) was also integrated.
• Complete ECU reprogramming sequence was tested with VFlash template.
• Documentation for SWRS, high-level design, MISRA C- 2012 report, unit test report, module test report, and functional test report were provided to the customer.
• We have validated the solution with CAPL script at our end. The customer also validated the same using their proprietary tools.

Embitel’s Impact

Due to our expertise in secure bootloader development, we could complete the project in the strict timeline provided by the customer. Our ready-to-integrate network and diagnostics stacks such as CAN, LIN and UDS also helped save considerable amount of time.
 

Tools and Technologies

Vector CANoe: Used for validation of the secure bootloader

Vflash tool: ECU reprogramming sequence was validated using Vflash tool

Microchip Compiler Environment MPLab IDE- Used for development and debugging

Tessy Tool: Used for unit testing

Building a Customizable LED Automotive Lighting Solution for an Automotive Tier-1

About the Customer

Our customer is an automotive tier-1 supplier specializing in developing microcontroller-based automotive solutions. With innovation embedded deeply in their products, they wish to create safer, greener and more comfortable mobility.

Business Challenge

The emergence of LED (Light-Emitting Diode) technology has had a significant impact on automotive lighting. In terms of efficiency, longevity, design flexibility, adaptive capabilities and diverse use-cases, LED lighting has been a game changer.

Since our customer has been at the forefront of semiconductor-based innovations in the automotive domain, they wished to extend this to automotive lighting solutions as well. Their team was keen on developing an ASPICE compliant RGBW (Red Green Blue White) LED solution that can be customized as per the end-customer’s requirements.

An automotive grade solution is required to adhere to certain automotive standards such as MISRA C 2012, HIS Matrix etc. The customer’s software team faced certain challenges in following such automotive standards and coding practices specific to the automotive domain.

Following the ASPICE process came across as another challenge as it required ASPICE compliance at an organization level. Since most OEMs now require ASPICE compliance, our customer was looking for a partner with expertise in ASPICE level 2 compliance. We met all such requirements of the customer, and the seed of a new partnership was sown.

The customer’s team performed the system analysis and came up with a set of system requirements. These requirements were the foundation for us to develop the intended LED automotive lighting solution.
 

Embitel’s Solution

In a nutshell, our task was to build a base software (BSW) with all the components required for LIN-based control of the RGBW LED using a PWM generator. In addition to the PWM generator, there were several other components required for the lighting solution to work in the intended manner.

Our LED-based automotive lighting solution involved the development of the base software, incorporating key components such as ADC, VIC, watchdog timer, sleep/wakeup, and GPIO. These components were carefully integrated to ensure efficient and reliable functioning.
 

 
The Hardware Abstraction Layer (HAL) was utilized to provide a standardized interface between the software and hardware, enabling seamless interaction with the microcontroller and peripheral devices. A scheduler was implemented to manage tasks and optimize resource allocation, ensuring efficient execution of software functions.

One of the major highlights of our project was the integration of LIN-based control for LED lighting using a PWM generator. Through LIN frames, the duty cycle of the PWM can be changed, enabling precise control over the LED lights. This functionality allows for dynamic adjustments, facilitating various lighting effects, brightness levels, and customized lighting patterns.

In addition to the base software, we developed applications to showcase the capabilities of our LED-based lighting solution. An example is the LED blinking application, which demonstrates the functionality of our solution by controlling the LED’s on/off states.

To facilitate the configuration of various components of the solution, we have provided a comprehensive user manual. The manual guides customers through essential configurations, such as PWM generator and driver configuration, output current configuration, duty cycle configuration, and more. This documentation ensures that customers can easily adapt the solution to their specific needs, enhancing usability and flexibility.

Additionally, we have extended support to customers in aligning and integrating their LIN node services within our architecture, enabling seamless integration and full utilization of our LED-based lighting solution.

Throughout the development process, we adhered to ASPICE guidelines to ensure high-quality software. Our dedicated ASPICE team was actively involved in the development and testing phases (SW 1 to SW 6) conducting module testing, integration testing, and qualification testing (white box and black box). Regular audits, including work product audits and process audits, were performed to verify compliance with the correct processes.

Embitel’s Impact

Through our ASPICE competence and deep understanding of automotive lighting domain, we were able to grasp the requirements very well. And that translated into a robust solution with all bugs and error contained at the right stage.

We also developed unique test cases that helped make the solution even more robust and reliable.
 

Tools and Technologies

IAR Workbench: Code development and debugging, Compilation and Flashing of software

Evaluation kit: Base for testing the solution

Unit Testing: Tessy tool

Polyspace: MISRA C check and static analysis