Changes between Version 43 and Version 44 of library_stdio

Timestamp:

Jan 23, 2015, 7:22:34 PM (10 years ago)

Author:

alain

Comment:

--

library_stdio

@@ -117 +117 @@
  == Network related system call ==
 
-The GIET_VM allows a user task to access a private NIC channel, using the CMA component (chained buffers DMA).
+The GIET_VM allows a user task to get and use a private NIC channel, using the CMA component (chained buffers DMA) to transfer packets to or an user buffer.
 The NIC channel and the CMA channel are registered in the task context.
 
- === 1) unsigned int '''giet_nic_tx_alloc'''( ) ===
-This function allocates a private NIC_TX channel (coming with the associated kernel NIC_TX chbuf), and a private CMA channel  to the calling task. It registers both indexes in the calling task context, and returns the NIC channel index, as this channel can be shared by severals tasks of a parallel multi-tasks application. 
-The calling task exit if no available NIC_TX channel, or no available CMA channel.
+ === 1) unsigned int '''giet_nic_tx_alloc'''( unsigned int x_size,  unsigned int y_size) ===
+This function allocates a private NIC_TX channel (coming with the associated kernel NIC_TX chbuf), and a private CMA channel  to the calling task. It registers both indexes in the calling task context, and returns the NIC channel index. This channel can be shared by severals tasks of a parallel multi-tasks application. 
+The packets are transfered by the hardware to the NIC from a distributed kernel chbuf (one 4 Kbytes container per cluster), where the involved clusters are defined by the (x_size / y_size) parameters. 
+The calling task exit if no available NIC_TX channel,  if no available CMA channel, if (x_size / y_size) are too large, or if there is not enough memory for the distributed kernel containers in one selected cluster.
 
  === 2) unsigned int '''giet_nic_rx_alloc'''( ) ===
-This function allocates a private NIC_RX channel (coming with the associated kernel NIC_RX chbuf), and a private CMA channel  to the calling task. It registers both indexes
-in the calling task context, and returns the NIC channel index, as this channel can be shared by severals tasks of a parallel multi-tasks application.
-The calling task exit if no available NIC_RX channel, or no available CMA channel.
+This function allocates a private NIC_RX channel (coming with the associated kernel NIC_RX chbuf), and a private CMA channel  to the calling task. It registers both indexes in the calling task context, and returns the NIC channel index. This channel can be shared by severals tasks of a parallel multi-tasks application.
+The packets are transfered by the hardware from the NIC to a distributed kernel chbuf (one 4 Kbytes container per cluster), where the involved clusters are defined by the (x_size / y_size) parameters. 
+The calling task exit if no available NIC_TX channel,  if no available CMA channel, if (x_size / y_size) are too large, or if there is not enough memory for the distributed kernel containers in one selected cluster.
 
  === 3) void '''giet_nic_tx_start'''( unsigned int channel ) ===
-This function activates both the NIC_TX channel, and the CMA channel allocated to the calling task.
+This function activates both the NIC_TX channel, and the CMA channel allocated to the calling task to transfer packets from the distributed kernel chbuf to the NIC.
 The calling task exit if no allocated NIC_TX channel or no allocated CMA channel, or if the NIC channel argument does not fit the channel allocated to the calling task. 
 
  === 4) void '''giet_nic_rx_start'''( unsigned int channel ) ===
-This function activates both the NIC_RX channel, and the CMA channel allocated to the calling task.
+This function activates both the NIC_RX channel, and the CMA channel allocated to the calling task to transfer packets from the NIC to the distributed kernel chbuf.
 The calling task exit if no allocated NIC_RX channel or no allocated CMA channel.