esp-idf/components/esp_hw_support

esp_hw_support (G1 component)

This component contains hardware-related operations for supporting the system. These operations are one level above that of hal in that:

1. it uses system services such as memory allocation, logging, scheduling
2. it may be multi-step operations involving/affecting multiple parts of the SoC
3. it offers a service for other components vary from multiple layers (G1, G2 and G3) of ESP-IDF

Implementations that don't fit other components cleanly, but are not worth creating a new component for (yet) may also be placed here as long as they don't pull dependencies other than the core system components.

Event-Task Service (esp_etm)

esp_etm driver design

esp_etm driver is divided into two parts:

• The core driver, which focuses on ETM channel allocation and offers APIs to connect the channel with ETM tasks and ETM events that come from other peripherals.
• Peripheral side extensions, e.g. GPTimer support generating different kinds of ETM events, and accept multiple ETM tasks. These extensions are implemented in the peripheral driver, and can be located in different components. Usually, the task and event extensions will simply inherit the interface that defined in the core driver.

See the following class diagram, we take the GPIO and GPTimer as the example to illustrate the architecture of esp_etm driver.