static unsigned char *prvGetNextBuffer( void )
{
long x;
unsigned char *pucReturn = NULL;
unsigned long ulAttempts = 0;
while( pucReturn == NULL ) {
/* Look through the buffers to find one that is not in use by
anything else. */
for( x = 0; x < ETH_NUM_BUFFERS; x++ ) {
if( ucBufferInUse[ x ] == pdFALSE ) {
ucBufferInUse[ x ] = pdTRUE;
pucReturn = ( unsigned char * ) ETH_BUF( x );
break;
}
}
/* Was a buffer found? */
if( pucReturn == NULL ) {
ulAttempts++;
if( ulAttempts >= emacBUFFER_WAIT_ATTEMPTS ) {
break;
}
/* Wait then look again. */
vTaskDelay( emacBUFFER_WAIT_DELAY );
}
}
return pucReturn;
}
static void prvReturnBuffer( unsigned char *pucBuffer )
{
unsigned long ul;
/* Return a buffer to the pool of free buffers. */
for( ul = 0; ul < ETH_NUM_BUFFERS; ul++ ) {
if( ETH_BUF( ul ) == ( unsigned long ) pucBuffer ) {
ucBufferInUse[ ul ] = pdFALSE;
break;
}
}
}
static void prevRxDescriptor(void)
{
int x;
//デスクリプタの設定
for( x = 0; x < NUM_RX_FRAG; x++ )
{
/* Allocate the next Ethernet buffer to this descriptor. */
RX_DESC_PACKET(x) = ETH_BUF(x);
RX_DESC_CTRL(x) = RCTRL_INT | ( ETH_FRAG_SIZE - 1 );
RX_STAT_INFO(x) = 0;
RX_STAT_HASHCRC(x) = 0;
}
/* Set LPC_EMAC Receive Descriptor Registers. */
LPC_EMAC->RxDescriptor = RX_DESC_BASE;
LPC_EMAC->RxStatus = RX_STAT_BASE;
LPC_EMAC->RxDescriptorNumber = NUM_RX_FRAG - 1;
}
static void prvInitDescriptors( void )
{
long x, lNextBuffer = 0;
for( x = 0; x < NUM_RX_FRAG; x++ )
{
/* Allocate the next Ethernet buffer to this descriptor. */
RX_DESC_PACKET( x ) = ETH_BUF( lNextBuffer );
RX_DESC_CTRL( x ) = RCTRL_INT | ( ETH_FRAG_SIZE - 1 );
RX_STAT_INFO( x ) = 0;
RX_STAT_HASHCRC( x ) = 0;
/* The Ethernet buffer is now in use. */
ucBufferInUse[ lNextBuffer ] = pdTRUE;
lNextBuffer++;
}
/* Set EMAC Receive Descriptor Registers. */
EMAC->RxDescriptor = RX_DESC_BASE;
EMAC->RxStatus = RX_STAT_BASE;
EMAC->RxDescriptorNumber = NUM_RX_FRAG - 1;
/* Rx Descriptors Point to 0 */
EMAC->RxConsumeIndex = 0;
/* A buffer is not allocated to the Tx descriptors until they are actually
used. */
for( x = 0; x < NUM_TX_FRAG; x++ )
{
TX_DESC_PACKET( x ) = ( unsigned long ) NULL;
TX_DESC_CTRL( x ) = 0;
TX_STAT_INFO( x ) = 0;
}
/* Set EMAC Transmit Descriptor Registers. */
EMAC->TxDescriptor = TX_DESC_BASE;
EMAC->TxStatus = TX_STAT_BASE;
EMAC->TxDescriptorNumber = NUM_TX_FRAG - 1;
/* Tx Descriptors Point to 0 */
EMAC->TxProduceIndex = 0;
}
