Changes between Version 9 and Version 10 of library_stdio

Timestamp:

Aug 7, 2014, 12:07:37 AM (10 years ago)

Author:

alain

Comment:

--

library_stdio

@@ -4 +4 @@
 
 [[PageOutline]]
+
+
+
 
  == __1) Processor related system calls__ ==
@@ -86 +89 @@
  == __6) Frame Buffer related system calls__ ==
 
+ === void giet_fb_sync_read( unsigned int offset, void* buffer, unsigned int length ) ===
+This blocking function use a memcopy strategy to transfer data from the frame buffer to an user buffer: ''offset'' defines the offset (in bytes) in the frame buffer, ''buffer''  is the user buffer base address, ''length''  is the number of bytes to be transfered. In case or error, it makes a giet_exit().
+
+ === void giet_fb_sync_write( unsigned int offset, void* buffer, unsigned int length ) ===
+This blocking function use a memcopy strategy to transfer data from an user buffer to the frame buffer: ''offset'' defines the offset (in bytes) in the frame buffer, ''buffer''  is the user buffer base address, ''length''  is the number of bytes to be transfered. In case or error, it makes a giet_exit().
+
+ === void giet_fb_cma_init( void* buf0, void* buf1, unsigned int length ) === 
+This function initializes the two chained bufffer (sorce and destination)  used by the chained buffer DMA controller (CMA) to transfer a stream of data from the user buffers to the frame buffer. A CMA channel should have been allocated to the calling task in the application mapping. ''buf0'' is the first user buffer base address, ''buf1'' is the second user buffer base address,  ''length'' is the buffer size (bytes). In case or error, it makes a giet_exit().
+
+ === void giet_fb_cma_write( unsigned int buffer_id ) ===
+This function enables the transfer of the buffer specified by the ''buffer_id'' argument (0 or 1).
+
+ === void giet_fb_cma_stop( ) ===
+This function desactivates the CMA channel allocated to the calling task.
+
  == __7) Miscelaneous system calls__ ==