sergiotarxz/nuttx
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

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

Browse Source 
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@2909 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2010-09-01 23:52:38 +00:00
parent b4559a2fcb
commit 7c4b74e4f6
2 changed files with 12 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/arm/src/arm/pg_macros.h
View File

@ -93,6 +93,7 @@
# define MMU_L2_TEXTFLAGS (PTE_TYPE_TINY|PTE_EXT_AP_UNO_SRO|PTE_CACHEABLE)
# define MMU_L1_DATAFLAGS (PMD_TYPE_FINE|PMD_BIT4)
# define MMU_L2_DATAFLAGS (PTE_TYPE_TINY|PTE_EXT_AP_UNO_SRW|PTE_CACHEABLE|PTE_BUFFERABLE)
# define MMU_L2_ALLOCFLAGS (PTE_TYPE_TINY|PTE_EXT_AP_UNO_SRW)
# define MMU_L1_PGTABFLAGS (PMD_TYPE_FINE|PMD_BIT4)
# define MMU_L2_PGTABFLAGS (PTE_TYPE_TINY|PTE_EXT_AP_UNO_SRW)

14
arch/arm/src/arm/up_allocpage.c
View File

@ -133,12 +133,19 @@ static bool g_pgwrap;
* available pages are in-use (the typical case), then this function will
* select a page in-use, un-map it, and make it available.
*
* NOTE 2: Allocating and filling a page is a two step process. up_allocpage()
* NOTE 2: If an in-use page is un-mapped, it may be necessary to flush the
* instruction cache in some architectures.
*
* NOTE 3: 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 4: The initial mapping of vpage should be read-able and write-
* able (but not cached). No special actions will be required of
* up_fillpage() in order to write into this allocated page.
*
* 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
@ -210,11 +217,12 @@ int up_allocpage(FAR _TCB *tcb, FAR void **vpage)
/* Now setup up the new mapping. Get a pointer to the L2 entry
* corresponding to the new mapping. Then set it map to the newly
* allocated page address.
* allocated page address. The inital mapping is read/write but
* non-cached (MMU_L2_ALLOCFLAGS)
*/
pte = up_va2pte(vaddr);
*pte = (paddr | MMU_L2_TEXTFLAGS);
*pte = (paddr | MMU_L2_ALLOCFLAGS);
/* And save the new L1 index */