static void prvENET_Send(void)
{
portBASE_TYPE i;
static unsigned portCHAR *pcTxData;
/* Get a DMA buffer into which we can write the data to send. */
for( i = 0; i < uipBUFFER_WAIT_ATTEMPTS; i++ )
{
pcTxData = pcGetNextBuffer();
if( pcTxData )
{
break;
}
else
{
vTaskDelay( uipBUFFER_WAIT_DELAY );
}
}
if( pcTxData )
{
/* Copy the header into the Tx buffer. */
memcpy( ( void * ) pcTxData, ( void * ) uip_buf, uipTOTAL_FRAME_HEADER_SIZE );
if( uip_len > uipTOTAL_FRAME_HEADER_SIZE )
{
memcpy( ( void * ) &( pcTxData[ uipTOTAL_FRAME_HEADER_SIZE ] ), ( void * ) uip_appdata, ( uip_len - uipTOTAL_FRAME_HEADER_SIZE ) );
}
ENET_TxPkt( &pcTxData, uip_len );
}
}
/**
* This function should do the actual transmission of the packet. The packet is
* contained in the pbuf that is passed to the function. This pbuf
* might be chained.
*
* @param netif the lwip network interface structure for this ethernetif
* @param p the MAC packet to send (e.g. IP packet including MAC addresses and type)
* @return ERR_OK if the packet could be sent
* an err_t value if the packet couldn't be sent
*
* @note Returning ERR_MEM here if a DMA queue of your MAC is full can lead to
* strange results. You might consider waiting for space in the DMA queue
* to become availale since the stack doesn't retry to send a packet
* dropped because of memory failure (except for the TCP timers).
*/
static err_t low_level_output(struct netif *netif, struct pbuf *p)
{
struct pbuf *q;
u32_t l = 0;
unsigned char *pcTxData;
#if ETH_PAD_SIZE
pbuf_header(p, -ETH_PAD_SIZE); /* drop the padding word */
#endif
/* Get a DMA buffer into which we can write the data to send. */
for( int i = 0; i < netifBUFFER_WAIT_ATTEMPTS; i++ ) {
pcTxData = pcGetNextBuffer();
if( pcTxData ) {
break;
} else {
vTaskDelay( netifBUFFER_WAIT_DELAY );
}
}
if (pcTxData == NULL) {
portNOP();
return ERR_BUF;
} else {
for(q = p; q != NULL; q = q->next) {
/* Send the data from the pbuf to the interface, one pbuf at a
time. The size of the data in each pbuf is kept in the ->len
variable. */
vTaskSuspendAll();
memcpy(&pcTxData[l], (u8_t*)q->payload, q->len);
xTaskResumeAll();
l += q->len;
}
}
ENET_TxPkt( &pcTxData, l );
#if ETH_PAD_SIZE
pbuf_header(p, ETH_PAD_SIZE); /* reclaim the padding word */
#endif
LINK_STATS_INC(link.xmit);
return ERR_OK;
}