Non-oETP DMA

These functions require advertised non-oETP DMA support. Frames include Ethernet header and payload, excluding preamble, SFD, and FCS. TX and RX maintain separate commands, byte counts, and sticky error records.

openenoc_endpoint_status_t openenoc_endpoint_non_oetp_dma_tx_request(volatile csr__endpoint_interface_t *endpoint, uint32_t buffer_address, uint32_t frame_length_bytes)

Submit one raw Ethernet frame for TX DMA.

Parameters:

  • endpoint – In; required mapped, word-aligned endpoint-interface pointer.

  • buffer_address – In; first-byte address on the local 32-bit memory bus.

  • frame_length_bytes – In; nonzero complete-frame length, at most the advertised raw-frame limit.

Returns:

OK; INVALID_ARGUMENT for an invalid endpoint pointer; UNSUPPORTED when raw DMA is absent; OUT_OF_RANGE for length or address-space overflow; NOT_READY for pending TX commands or active TX DMA.

Preconditions:

Capture previous status/count first. Keep the buffer accessible and synchronized until completion.

Side effects:

Writes the TX address and length, then submits request without waiting.

openenoc_endpoint_status_t openenoc_endpoint_non_oetp_dma_rx_arm(volatile csr__endpoint_interface_t *endpoint, uint32_t buffer_address, uint32_t buffer_capacity_bytes)

Submit a one-frame receive buffer for RX DMA.

Parameters:

  • endpoint – In; required mapped, word-aligned endpoint-interface pointer.

  • buffer_address – In; first-byte address on the local 32-bit memory bus.

  • buffer_capacity_bytes – In; nonzero capacity, at most the advertised raw-frame limit.

Returns:

OK; INVALID_ARGUMENT for an invalid endpoint pointer; UNSUPPORTED when raw DMA is absent; OUT_OF_RANGE for capacity or address-space overflow; NOT_READY for pending RX commands or active/armed RX DMA.

Preconditions:

Capture previous status/count first. Keep the receive buffer accessible and synchronize it after completion.

Side effects:

Writes the RX address and capacity, then submits arm without waiting. Once accepted and armed, eligible non-oETP traffic is routed to DMA.

openenoc_endpoint_status_t openenoc_endpoint_non_oetp_dma_get_status(volatile const csr__endpoint_interface_t *endpoint, openenoc_endpoint_dma_channel_t channel, openenoc_endpoint_non_oetp_dma_status_t *status)

Read a selected raw DMA channel status.

Parameters:

  • endpoint – In; required mapped, word-aligned endpoint-interface pointer.

  • channel – In; OPENENOC_ENDPOINT_DMA_TX or OPENENOC_ENDPOINT_DMA_RX.

  • status – Out; required channel-status destination. transferred_bytes is TX bytes or RX bytes written; armed is false for TX.

Returns:

OK; INVALID_ARGUMENT for invalid endpoint pointer/channel/output; UNSUPPORTED when raw DMA is absent.

Side effects:

Reads command/status and byte-count CSRs; preserves their state.

openenoc_endpoint_status_t openenoc_endpoint_non_oetp_dma_request_clear_errors(volatile csr__endpoint_interface_t *endpoint, openenoc_endpoint_dma_channel_t channel)

Submit error clearing for one raw DMA channel.

Parameters:

  • endpoint – In; required mapped, word-aligned endpoint-interface pointer.

  • channel – In; OPENENOC_ENDPOINT_DMA_TX or OPENENOC_ENDPOINT_DMA_RX.

Returns:

OK; INVALID_ARGUMENT for invalid endpoint pointer/channel; UNSUPPORTED when raw DMA is absent; NOT_READY while a channel request or clear command is pending.

Side effects:

Submits clear without waiting. Hardware preserves active/armed work, done, byte count, and IRQ claims; new failures win a simultaneous clear.

Public declarations

The maintained header below provides the exact public type and enum definitions.

DMA types
 1typedef enum {
 2    OPENENOC_ENDPOINT_DMA_TX = 0,
 3    OPENENOC_ENDPOINT_DMA_RX = 1
 4} openenoc_endpoint_dma_channel_t;
 5
 6typedef struct {
 7    bool request_pending;
 8    bool clear_errors_pending;
 9    bool idle;
10    bool armed;
11    bool done;
12    bool error;
13    openenoc_endpoint_error_t error_code;
14    uint32_t transferred_bytes;
15} openenoc_endpoint_non_oetp_dma_status_t;
16