Changeset 728 for soft/giet_vm/giet_drivers/bdv_driver.h

Timestamp:

Nov 21, 2015, 2:53:00 PM (9 years ago)

Author:

alain

Message:

bloup

File:

• soft/giet_vm/giet_drivers/bdv_driver.h (modified) (1 diff)

soft/giet_vm/giet_drivers/bdv_driver.h

@@ -15 +15 @@
 // - in "synchronous" mode, it uses a polling policy on the BDV STATUS 
 //   register to detect transfer completion, as interrupts are not activated. 
-//   This mode is used by the boot code to load the map.bin file into memory
+//   This mode must be used by the boot code to load the map.bin file into memory
 //   (before MMU activation), or to load the .elf files (after MMU activation). 
+//   As only one processor acces the block device, it doesn't take the _bdv_lock.
+//
 // - In "descheduling" mode, ir uses a descheduling + IRQ policy.
+//   This mode mus be used by the kernel code tho handle system calls.
 //   The ISR executed when transfer completes should restart the calling task,
 //   as the calling task global index has been saved in the _bdv_gtid variable.
-//   
-// As the BDV component can be used by several programs running in parallel,
-// the _bdv_lock variable guaranties exclusive access to the device.
+//   As the BDV component can be used by several programs running in parallel,
+//   it takes the _bdv_lock and registers it in the calling task context.
 //
 // The SEG_IOC_BASE address must be defined in the hard_config.h file.