pybricks/support

AI Summary: The task involves migrating the EV3's ASYNC3 clock domain from PLL0 to PLL1 to ensure compatibility with potential future CPU frequency changes. This requires auditing drivers using peripherals in the ASYNC3 domain (TIMER 2/3, UART, McASP, eHRPWM, eCAP, SPI1) to verify no assumptions about the clock frequency are broken. The goal is to align Pybricks with the official LEGO firmware and ev3dev configurations.

AI Summary: Implement the missing functionality in the EV3 clock driver to provide sub-millisecond time readings, specifically the `pbdrv_clock_get_100us` function. This involves completing the 'TODO' items in the existing clock driver code and potentially implementing other related clock hooks. The task also indirectly relates to providing timer functionality for a PRU example.

AI Summary: The task involves enabling PRU1 on the EV3 brick to control LED brightness using PWM. This requires building and integrating the ev3dev PRU1 firmware, modifying it to remove unnecessary components, and completing the Pybricks LED PWM driver. It may involve exploring alternative build tools and ensuring no memory conflicts with existing code.

AI Summary: Implement an SPI flash block device driver for the LEGO MINDSTORMS EV3 brick to enable program loading on boot and saving during shutdown. This involves adapting an existing SPIKE Prime implementation to use different SPI commands and leveraging existing SPI and DMA code for the EV3. The necessary SPI commands and parameters are available in the original EV3 firmware and u-boot, or from the flash memory datasheet.