On 3/21/2024 9:49 PM, Jeffrey Hugo wrote:
The AIC100 secondary bootloader uses the Sahara protocol for two purposes - loading the runtime firmware images from the host, and offloading crashdumps to the host. The crashdump functionality is only invoked when the AIC100 device encounters a crash and dumps are enabled. Also the collection of the dump is optional - the host can reject collecting the dump. The Sahara protocol contains many features and modes including firmware upload, crashdump download, and client commands. For simplicity, implement the parts of the protocol needed for loading firmware to the device. Fundamentally, the Sahara protocol is an embedded file transfer protocol. Both sides negotiate a connection through a simple exchange of hello messages. After handshaking through a hello message, the device either sends a message requesting images, or a message advertising the memory dump available for the host. For image transfer, the remote device issues a read data request that provides an image (by ID), an offset, and a length. The host has an internal mapping of image IDs to filenames. The host is expected to access the image and transfer the requested chunk to the device. The device can issue additional read requests, or signal that it has consumed enough data from this image with an end of image message. The host confirms the end of image, and the device can proceed with another image by starting over with the hello exchange again. Some images may be optional, and only provided as part of a provisioning flow. The host is not aware of this information, and thus should report an error to the device when an image is not available. The device will evaluate if the image is required or not, and take the appropriate action. Signed-off-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx> Reviewed-by: Carl Vanderlip <quic_carlv@xxxxxxxxxxx> Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@xxxxxxxxxxx>
Pushed to drm-misc-next -Jeff
