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FreeBSD port in progress

Stanislav Silnicki
Associate III

Hello! Although, the OS is not supported, I'd be happy to get any clues on my relatively generic question.

I have realized, that TEX remapping registers  (PRRR and NMRR) values are hardcoded in Linux kernel source.

.equ	NMRR,	0x40e040e0

I'm particularly interested in the value for the first class of memory access. Lowest two bits  (b00) describe  Non-Cachable access for Normal memory. FreeBSD kernel uses Write-Back+Write-Alloc. type and it seems to cause problems. When it programs prrr&nmrr and then tries to flush entire unified TLB (p15, 0, r0, c8, c7, 0), I witness distortion of stack memory (zeroes) with lose of return address, etc.

Is it kinda implementation dependent behavior of STM32MP157CAC or I shall investigate some OTP/Security settings, preprogrammed by vendor of my board?

Thanks in advance for any clues!