On 2013-10-04 11:07, Hesham Moustafa wrote:
On Fri, Oct 4, 2013 at 9:50 AM, Sebastian Huber <sebastian.hu...@embedded-brains.de <mailto:sebastian.hu...@embedded-brains.de>> wrote:On 2013-10-03 14:49, Gedare Bloom wrote: @@ -87,9 +90,9 @@ arm_cp15_start_setup___translation_table_and_enable___mmu_and_cache( arm_cp15_set_domain_access___control(dac); arm_cp15_set_translation___table_base(ttb); - /* Initialize translation table with invalid entries */ + /* Initialize translation table with fixed-map read-write entries */ for (i = 0; i < ARM_MMU_TRANSLATION_TABLE___ENTRY_COUNT; ++i) { - ttb [i] = 0; + ttb [i] = (i << ARM_MMU_SECT_BASE_SHIFT) | ARMV7_MMU_DATA_READ_WRITE; } What is the reason for this change? I don't think that unconditional read-write access is a good idea. I made this change when I was trying to get RaspberryPi MMU initialization to work.
Then it is probably better to fix the memory map description of this particular BSP.
Also I thought the default behavior for RTEMS is the unprotected mode, and the new protection (limitation) attributes are new and should be applied when needed (by configuration table at startup or dynamically).
Allow everything with explicit deny is very bad design. It should be always deny everything with explicit allow.
-- Sebastian Huber, embedded brains GmbH Address : Dornierstr. 4, D-82178 Puchheim, Germany Phone : +49 89 189 47 41-16 Fax : +49 89 189 47 41-09 E-Mail : sebastian.hu...@embedded-brains.de PGP : Public key available on request. Diese Nachricht ist keine geschäftliche Mitteilung im Sinne des EHUG. _______________________________________________ rtems-devel mailing list rtems-devel@rtems.org http://www.rtems.org/mailman/listinfo/rtems-devel
