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Optimizing SPI communication on STM32 MCUs: a comprehensive guide to high-frequency communication
Published at July 28, 2023 · 22 min read
In this blog post, we delve into the fascinating world of Serial Peripheral Interface (SPI) on STM32 microcontrollers (MCUs). Specifically, we explore how SPI is utilized in TPM chips for communication with PC motherboards. We encounter the challenges of achieving high-frequency SPI communication, especially when operating as a slave, and the specific limitations of STM32L476 MCUs. The article further uncovers the limitations of existing approaches in platforms like Zephyr and STM32 HAL. We then embark on a journey to fix SPI issues, improve DMA performance, and optimize the firmware for high-speed SPI communication. Throughout the blog post, we provide in-depth technical insights and share valuable test results. Join us as we push the boundaries of SPI communication and unlock new possibilities in the world of microcontrollers....
Categories: firmware miscellaneous security
Fobnail Token - platform attestation
Published at April 6, 2022 · 6 min read
The Fobnail Token is an open-source hardware USB device that helps to determine the integrity of the system. The purpose of this blog post is to present the development progress of this project. This phase was focused on attestation....
Porting EDK II to an old Allwinner A13 tablet
Published at January 18, 2022 · 7 min read
Most ARM SoC's run U-Boot or some custom bootloader. That was the case with Allwinner SoC's, until I started porting EDK II to my A13 tablet. In this post, I will tell you about the current UEFI support status on Allwinner SoC's, my future plans, and how to test UEFI on a compatible device...
Categories: firmware manufacturing
Enabling Secure Boot on RockChip SoCs
Published at December 3, 2021 · 9 min read
RockChip Secure Boot is an essential security feature that helps tablet, PC, streaming media TV box, and IoT solution vendors secure their devices against malware infecting the firmware. In the following post, we will tell a story about enabling Secure Boot on the RK32xx family, but the lesson learned can be used on other models...