Hi, experts.
I'm developing pagetable on exynos5250 and exynos5433.
But i have very strange problem....
when i mapping secure-memory-area as section with attributes that is
S = 1, TEX= 001, C =1, B = 1 => Outer and Inner Write-Back, Write-Allocate, Normal memory type.
or
S = 1, TEX= 000, C =1, B = 1 => Outer and Inner Write-Back, no Write-Allocate, Normal memory type,
it occurs Spurious interrupt (1023).. and i'cant process anymore.
But when i set that area with attributes that is
S = 1, TEX= 000, C =1, B = 0 ==> Outer and Inner Write-Through, no Write-Allocate, Normal memory type.
it works well..
However, when i try to map secure-memory-area with attributes which happen Interrupt on exynos5250, it work very well at exynos5433.
I don't know why this happens, and secure-memory-area isn't shared with Non-Secure.
also i map secure-memory-area as Section.
the memory address where interrupt happens when i try to set Outer and Inner Write-Back, write-Allocate, Normal memory type are
0xBF000000 ~ 0xC0000000. ( will be used in secure mode - DRAM ) and
0x02000000 ~ 0x02100000 (IRAM).
Could share your experience and knowledge for this beginner please?
Thanks.
On the Cortex-A15, write-through regions are treated as non-cacheable. Therefore your change is effectively changing the address from cacheable (not working) to non-cacheable (working).
Which region(s) are you changing the attributes for? Just secure memories (flash, ram...)?
Sanity check, the virtual address that maps to the GIC, it is marked as Device? What do the GICC_HPPIR report? Does it change if your turn the MMU off?
For background, here is the TRM section which explains the Cortex-A15 treatment of write-through regions:
ARM Cortex-A15 MPCore Processor Technical Reference Manual: 6.4.1. Behavior for different memory types
GICC_HPPIR reports 1023... When i reset it.. And secure memory is the memory that will be used in secure mode. that's why i give ns bit as 0 to related section..;
Thank you for ur answer.
Though late, Thank you for information!.
Thx experts.. But i have one more question...
then when i set cache policy as write-through, is it become "Non-Cachable"?.
or only disable write cache, and is read cache available?
Thank you.