RPi3B+ Drivers¶

TRENTOS includes drivers for accessing the peripheral devices of the Raspberry Pi 3 Model B+ (RPi3B+).

Timer¶

The timer driver of the RPi3B+ is implemented in the seL4 libplatsupport library. Timer functionalities in TRENTOS are provided through the TimeServer component.

Ethernet¶

The Raspberry Pi uses an onboard USB-based Ethernet device. The USB (and Ethernet) support on the RPi3B+ is based on a chain of different HW IPs, tightly connected together.

The ethernet driver is based on the project USPi found in https://github.com/rsta2/uspi licensed under GNU General Public License v3.0.

Within TRENTOS the ethernet driver functionality is encapsulated in the NIC_RPi component.

GPIO¶

Support for accessing and manipulating GPIOs on the RPi3B+ is provided by seL4 libplatsupport.

A user can use the following includes to access GPIO related functions.

#include <platsupport/gpio.h>
#include <platsupport/plat/gpio.h>

As an example, GPIO support is used in the SdHostController component for the RPi3B+.

Mailbox¶

Support for writing to and reading from the RPi3B+ mailbox is provided by seL4 libplatsupport.

A user can use the following includes to access mailbox-related functions.

#include <platsupport/mach/mailbox_util.h>

As an example, mailbox support is used in the NIC_RPi and SdHostController component for the RPi3B+.

SD Host Controller¶

The host controller functionalities for interfacing with an SD card in TRENTOS are provided through the SdHostController component that implements the generic TRENTOS CAmkES storage interface.

On the RPi3B+, the ports of the host controller are mapped as follows:

Port	MMC
SDHC1 (Default Port on TRENTOS)	microSD Slot

SPI / Flash¶

To enable flash access via SPI on the RPi3B+ TRENTOS provides the RPi_SPI_Flash component.

It encapsulates drivers for the SPI found onboard the RPi3B+ together with drivers for flash connected via SPI.

The included SPI driver is based on: https://www.airspayce.com/mikem/bcm2835/ under GNU General Public License v3.0.

The included SPI flash driver is based on: https://github.com/pellepl/spiflash_driver under MIT License.