Changes between Initial Version and Version 1 of Component/Vci Fd Access

Timestamp:

Oct 29, 2007, 12:55:10 PM (17 years ago)

Author:

Nicolas Pouillon

Comment:

Fd Access

Component/Vci Fd Access

@@ +1 @@
+[wiki:Component SocLib Components General Index] 
+
+= !VciFdAccess Functional Description =
+
+This VCI component is both a target and an initiator.
+ * Addressing as a target allows to configure it for a transfer.
+ * Initiator will do the transfer
+
+There is only one access context handled at a time, but fd can be changed for each operation, many fd can be open at the same time.
+
+An IRQ is optionally asserted when transfer is finished.
+
+This hardware component checks for segmentation violation, and can be used
+as a default target.
+
+= Memory region layout =
+
+ * `FD_ACCESS_FD` File descriptor for the transfer
+
+ * `FD_ACCESS_BUFFER` Buffer (in SoC memory) for the transfer
+
+ * `FD_ACCESS_SIZE` Size of the transfer
+
+ * `FD_ACCESS_HOW` Type of open() operation
+
+ * `FD_ACCESS_WHENCE` Type of offset when changing file pointer
+
+ * `FD_ACCESS_OP` Type of operation, writing here initiates the operation.[[BR]]
+   This register goes back to FD_ACCESS_NOOP when operation is finished.
+
+ * `FD_ACCESS_RETVAL` Return value
+
+ * `FD_ACCESS_ERRNO` Errno
+
+ * `FD_ACCESS_IRQ_ENABLE` Boolean enabling the IRQ line
+
+ * `FD_ACCESS_MODE` (aliases with WHENCE) Mode for open() with a O_CREAT
+
+= Operations codes =
+
+ * `FD_ACCESS_NOOP` Nothing
+
+ * `FD_ACCESS_OPEN` open()[[BR]]
+   path: `FD_ACCESS_BUFFER`[[BR]]
+   `FD_ACCESS_SIZE` must contain the length of path[[BR]]
+   returned fd is in `FD_ACCESS_RETVAL`
+
+ * `FD_ACCESS_CLOSE` close()
+
+ * `FD_ACCESS_READ` read()
+
+ * `FD_ACCESS_WRITE` write()
+
+ * `FD_ACCESS_LSEEK` lseek()
+
+= Component usage =
+
+For extensibility issues, you should access this component using globally-defined offsets.
+
+You should include file source:trunk/soclib/include/soclib/fd_access.h from your software, it
+defines `FD_ACCESS_FD`, `FD_ACCESS_BUFFER`, ...
+
+Sample code:
+{{{
+#include "soclib/fd_access.h"
+
+static const void* fd_base = 0xc0000000;
+
+int open( const char *path, const int how, const int mode )
+{
+        soclib_io_set(fd_base, FD_ACCESS_BUFFER, (uint32_t)path);
+        soclib_io_set(fd_base, FD_ACCESS_SIZE, strlen(path));
+        soclib_io_set(fd_base, FD_ACCESS_HOW, how);
+        soclib_io_set(fd_base, FD_ACCESS_MODE, mode);
+        soclib_io_set(fd_base, FD_ACCESS_OP, FD_ACCESS_OPEN);
+        while (soclib_io_get(fd_base, FD_ACCESS_OP))
+                ;
+        errno = soclib_io_get(fd_base, FD_ACCESS_ERRNO);
+        return soclib_io_get(fd_base, FD_ACCESS_RETVAL);
+}
+
+int close( const int fd )
+{
+        soclib_io_set(fd_base, FD_ACCESS_FD, fd);
+        soclib_io_set(fd_base, FD_ACCESS_OP, FD_ACCESS_CLOSE);
+        while (soclib_io_get(fd_base, FD_ACCESS_OP))
+                ;
+        errno = soclib_io_get(fd_base, FD_ACCESS_ERRNO);
+        return soclib_io_get(fd_base, FD_ACCESS_RETVAL);
+}
+
+// Beware your caches could contain stale memory image after this call
+int read( const int fd, const void *buffer, const size_t len )
+{
+        soclib_io_set(fd_base, FD_ACCESS_FD, fd);
+        soclib_io_set(fd_base, FD_ACCESS_BUFFER, (uint32_t)buffer);
+        soclib_io_set(fd_base, FD_ACCESS_SIZE, len);
+        soclib_io_set(fd_base, FD_ACCESS_OP, FD_ACCESS_READ);
+        while (soclib_io_get(fd_base, FD_ACCESS_OP))
+                ;
+        errno = soclib_io_get(fd_base, FD_ACCESS_ERRNO);
+        return soclib_io_get(fd_base, FD_ACCESS_RETVAL);
+}
+
+int write( const int fd, const void *buffer, const size_t len )
+{
+        soclib_io_set(fd_base, FD_ACCESS_FD, fd);
+        soclib_io_set(fd_base, FD_ACCESS_BUFFER, (uint32_t)buffer);
+        soclib_io_set(fd_base, FD_ACCESS_SIZE, len);
+        soclib_io_set(fd_base, FD_ACCESS_OP, FD_ACCESS_WRITE);
+        while (soclib_io_get(fd_base, FD_ACCESS_OP))
+                ;
+        errno = soclib_io_get(fd_base, FD_ACCESS_ERRNO);
+        return soclib_io_get(fd_base, FD_ACCESS_RETVAL);
+}
+
+int lseek( const int fd, const off_t offset, int whence )
+{
+        soclib_io_set(fd_base, FD_ACCESS_FD, fd);
+        soclib_io_set(fd_base, FD_ACCESS_SIZE, offset);
+        soclib_io_set(fd_base, FD_ACCESS_WHENCE, whence);
+        soclib_io_set(fd_base, FD_ACCESS_OP, FD_ACCESS_LSEEK);
+        while (soclib_io_get(fd_base, FD_ACCESS_OP))
+                ;
+        errno = soclib_io_get(fd_base, FD_ACCESS_ERRNO);
+        return soclib_io_get(fd_base, FD_ACCESS_RETVAL);
+}
+}}}
+
+(add -I/path/to/soclib/include to your compilation command-line)
+
+= Component definition =
+
+Available in source:trunk/soclib/desc/soclib/vci_fd_access.sd
+
+== Usage ==
+
+!VciFdAccess has no other parameter than VCI ones, it may be used like others, see [wiki:SoclibCc/VciParameters SoclibCc/VciParameters]
+{{{
+Uses( 'vci_fd_access', **vci_parameters )
+}}}
+
+= !VciFdAccess CABA  Implementation =
+
+The caba implementation is in 
+ * source:trunk/soclib/systemc/include/caba/target/vci_fd_access.h
+ * source:trunk/soclib/systemc/src/caba/target/vci_fd_access.cc
+
+== Template parameters: ==
+
+ * The VCI parameters
+
+== Constructor parameters ==
+{{{
+VciFdAccess(
+     sc_module_name name,   //  Component Name
+     const soclib::common::IntTab & index,  // Target index
+     const soclib::common::MappingTable &mt )   // MappingTable
+}}}
+
+== Ports ==
+
+ * sc_in<bool> '''p_resetn''' : Global system reset
+ * sc_in<bool> '''p_clk''' : Global system clock
+ * soclib::caba::!VciTarget<vci_param> '''p_vci_target''' : The VCI target port
+ * soclib::caba::!VciInitiator<vci_param> '''p_vci_initiator''' : The VCI initiator port
+ * sc_out<bool> '''p_irq''' : Interrupt port