Arm Cortex-A7

Revision as of 17:45, 22 December 2020 by Registered User (→‎Peripheral overview)

1. Article purpose[edit source]

The purpose of this article is to:

  • briefly introduce the Arm® Cortex®-A7 core and its main features
  • indicate the level of security supported by this processor

2. Peripheral overview[edit source]

The Arm Cortex-A7 can be instanciated several times into a single cluster.

The STM32MP15 main processor is a Cortex-A7 cluster embedding one or two instance(s), depending on the selected line.

2.1. Features[edit source]

Among a wide range of features, the Cortex-A7 includes a memory management unit (MMU), a separate L1 cache and a unified L2 cache in order to efficiently support rich OS such as Linux, with a high level of performance.

Refer to the STM32MP15 reference manuals for the complete list of features, and to the software components, introduced below, to see which features are implemented.

2.2. Security support[edit source]

The Cortex-A7 supports a non-secure and a secure modes that are defining two hardware execution contexts, so called Cortex-A7 non-secure and Cortex-A7 secure.

3. Peripheral usage and associated software[edit source]

3.1. Boot time[edit source]

As soon as the STM32MP1 is powered up, the Cortex-A7 starts to execute the ROM code, that is the first stage of the boot chain.

3.2. Runtime[edit source]

3.2.1. Overview[edit source]

The Cortex-A7 is running Linux, in SMP mode (on the dual core versions, as explained in the above).

3.2.2. Software frameworks[edit source]

Internal peripherals software table template

| Ecosystem
|  Cortex-A7
|  OP-TEE
|  Linux
| 
|
|-
|}

3.2.3. Peripheral configuration[edit source]

The Cortex-A7 configuration is done by the various components running on it, according to build times parameters but also information coming from the device tree.

3.2.4. Peripheral assignment[edit source]

Not applicable.

4. How to go further[edit source]

Refer to Arm website[1] for more detailled information on this core.

5. References[edit source]