Initial allocated page must be read/write/non-cacheable

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2909 42af7a65-404d-4744-a932-0658087f49c3

1 files changed, 8 insertions, 1 deletions

diff --git a/nuttx/configs/ea3131/src/up_fillpage.c b/nuttx/configs/ea3131/src/up_fillpage.c
index b9a97f684..2c238c9a1 100755
--- a/nuttx/configs/ea3131/src/up_fillpage.c
+++ b/nuttx/configs/ea3131/src/up_fillpage.c
@@ -77,12 +77,19 @@
  *  This callback is assumed to occur from an interrupt level when the
  *  device driver completes the fill operation.
  *
- *  NOTE: Allocating and filling a page is a two step process.  up_allocpage()
+ *  NOTE 1: Allocating and filling a page is a two step process.  up_allocpage()
  *  allocates the page, and up_fillpage() fills it with data from some non-
  *  volatile storage device.  This distinction is made because up_allocpage()
  *  can probably be implemented in board-independent logic whereas up_fillpage()
  *  probably must be implemented as board-specific logic.
  *
+ *  NOTE 2: The initial mapping of vpage will be read-able, write-able,
+ *  but non-cacheable.  No special actions will be required of
+ *  up_fillpage() in order to write into this allocated page.  If the
+ *  virtual address maps to a text region, however, this function should
+ *  remap the region so that is is read/execute only.  It should be made
+ *  cache-able in any case.
+
  * Input Parameters:
  *   tcb - A reference to the task control block of the task that needs to
  *         have a page fill.  Architecture-specific logic can retrieve page