Changes between Version 14 and Version 15 of kernel_syscalls

Timestamp:

Nov 10, 2014, 2:17:13 PM (10 years ago)

Author:

alain

Comment:

--

kernel_syscalls

@@ -1 @@
-= GIET-VM  / Syscall Handler =
+= GIET-VM  / Syscall Handlers =
 
 The [source:soft/giet_vm/giet_kernel/sys_handler.c sys_handler.c] and [source:soft/giet_vm/giet_kernel/sys_handler.h sys_handler.h] files define the kernel data structure and functions that are used to handle the system calls. These functions are prefixed by ''_'' to remind that they can only be executed by a processor in kernel mode.
@@ -51 +51 @@
 == __NIC related syscall handlers__ ==
 
-=== int '''_sys_nic_rx_alloc'''() ===
-This function allocates a private NIC_RX channel, the associated NIC_RX chbuf, and a private CMA channel to the calling task, and register these channel indexes in the task context.
-Return -1 if no NIC_RX channel available, or if no CMA channel available.
+These '4 functions can be used for both a NIC_RX or NIC_TX channel, depending on the '''is_rx''' argument.
 
-=== int '''_sys_nic_tx_alloc'''() ===
-This function allocates a private NIC_TX channel, the associated NIC_TX chbuf, and a private CMA channel to the calling task, and register these channel indexes in the task context.
-Return -1 if no NIC_TX channel available, or if no CMA channel available.
+=== int '''_sys_nic_alloc'''( unsigned int is_rx ) ===
+This function allocates a private NIC_RX or NIC_TX channel, the associated chbuf, and a private CMA channel to the calling task, and register these channel indexes in the task context.
+Returns 0 if success. Return -1 if no NIC channel available, or if no CMA channel available.
 
-=== int '''_sys_nic_rx_start'''() ===
-This function starts the NIC_RX and the CMA channels allocated to the calling task.
-Returns -1 if no NIC_RX channel or no CMA channel allocated to the calling task.
+=== int '''_sys_nic_start'''( unsigned int is_rx ) ===
+This function starts the NIC and the CMA channels allocated to the calling task.
+Returns 0 if success. Returns -1 if no NIC channel or no CMA channel allocated to the calling task.
 
-=== int '''_sys_nic_tx_start'''() ===
-This function starts the NIC_RX and the CMA channels allocated to the calling task.
-Returns -1 if no NIC_RX channel or no CMA channel allocated to the calling task.
-
-=== int '''_sys_nic_rx_move'''( void* buffer ) ===
-This function moves one 4kbytes container from the private kernel NIC_RX chbuf allocated to the calling task, to an user buffer.
+=== int '''_sys_nic_move'''(  unsigned int is_rx,  void* buffer ) ===
+This function moves one 4kbytes container between the kernel chbuf allocated to the calling task, and an user buffer. 
+ * '''is_rx''' defines the transfer direction (user -> kernel for TX / kernel -> user for RX) 
  * '''buffer''' is the user buffer virtual base address.
-It is blocking if the kernel NIC_RX chbuf is empty, with a time-out limit.
+It is blocking if the kernel chbuf is empty (for an RX transfer) or full (for a TX transfer). The bloking situation
+is bounded by a timeout defined by the GIET_NIC_TIMEOUT parameter defined in the ''giet_config.h'' file.
 Returns 0 if success, returns -1 if the user buffer address is illegal, or if there is no  NIC_RX channel allocated to the calling task, or if the timeout is elapsed.
-
-=== int '''_sys_nic_tx_move'''( void* buffer ) ===
-This function moves one 4kbytes container from an user buffer, to the private kernel NIC_TX chbuf allocated to the calling task. 
- * '''buffer''' is the user buffer virtual base address.
-It is blocking if the kernel NIC_TX chbuf is full, with a time-out limit.
-Returns 0 if success, returns -1 if the user buffer address is illegal, or if there is no  NIC_TX channel allocated to the calling task, or if the timeout is elapsed.