| 556b966f | 13-Apr-2015 |
Sandrine Bailleux <sandrine.bailleux@arm.com> |
Detect SCP version incompatibility
There has been a breaking change in the communication protocols used between the AP cores and the SCP on CSS based platforms like Juno. This means both the AP Trus
Detect SCP version incompatibility
There has been a breaking change in the communication protocols used between the AP cores and the SCP on CSS based platforms like Juno. This means both the AP Trusted Firmware and SCP firmware must be updated at the same time.
In case the user forgets to update the SCP ROM firmware, this patch detects when it still uses the previous version of the communication protocol. It will then output a comprehensive error message that helps trouble-shoot the issue.
Change-Id: I7baf8f05ec0b7d8df25e0ee53df61fe7be0207c2
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| e234ba03 | 18-Mar-2015 |
Sandrine Bailleux <sandrine.bailleux@arm.com> |
Move to the new ARM SCP Messaging Interfaces
The communication protocol used between the AP cores and the SCP in CSS-based platforms like Juno has undergone a number of changes. This patch makes the
Move to the new ARM SCP Messaging Interfaces
The communication protocol used between the AP cores and the SCP in CSS-based platforms like Juno has undergone a number of changes. This patch makes the required modifications to the SCP Boot Protocol, SCPI Protocol and MHU driver code in shared CSS platform code so that the AP cores are still able to communicate with the SCP.
This patch focuses on the mandatory changes to make it work. The design of this code needs to be improved but this will come in a subsequent patch.
The main changes are:
- MHU communication protocol
- The command ID and payload size are no longer written into the MHU registers directly. Instead, they are stored in the payload area. The MHU registers are now used only as a doorbell to kick off messages. Same goes for any command result, the AP has to pick it up from the payload area.
- SCP Boot Protocol
- The BL3-0 image is now expected to embed a checksum. This checksum must be passed to the SCP, which uses it to check the integrity of the image it received.
- The BL3-0 image used to be transferred a block (4KB) at a time. The SCP now supports receiving up to 128KB at a time, which is more than the size of the BL3-0 image. Therefore, the image is now sent in one go.
- The command IDs have changed.
- SCPI Protocol
- The size of the SCPI payload has been reduced down from 512 bytes to 256 bytes. This changes the base address of the AP-to-SCP payload area.
- For commands that have a response, the response is the same SCPI header that was sent, except for the size and the status, which both must be updated appropriately. Success/Failure of a command is determined by looking at the updated status code.
- Some command IDs have changed.
NOTE: THIS PATCH BREAKS COMPATIBILITY WITH FORMER VERSIONS OF THE SCP FIRMWARE AND THUS REQUIRES AN UPDATE OF THIS BINARY. THE LATEST SCP BINARY CAN BE OBTAINED FROM THE ARM CONNECTED COMMUNITY WEBSITE.
Change-Id: Ia5f6b95fe32401ee04a3805035748e8ef6718da7
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