Hello Jacky, Hello Ye,
On 21.10.23 18:18, Ahmad Fatoum wrote:
Hello Jacky,
On 21.09.23 12:42, Ahmad Fatoum wrote:
Hello Jacky,
On 21.09.23 12:34, Jacky Bai wrote:
Subject: Re: Cache Maintenance For SiP buffers Could you confirm that the BootROM on i.MX8M does cache maintenance internally as on i.MX6?
Sorry, it seems I missed your previous mail. ^_^.
No problem. Thanks for the prompt response.
From what I know, no need to do cache maintenance. HAB will use cache to fast the authentication, but no cacheable data will be write out to be used by the caller. Do you see any data will be used by the caller?
barebox does cache maintenance around its FSL_SIP_HAB_REPORT_STATUS SMC. If the BootROM didn't do cache maintenance, I'd have expected data loss in barebox, because dirtied cache lines would be discarded and not a lot happens between return from bootrom and return to normal world that would cause cache line writeback.
I don't observe issues though suggesting that the BootROM does cache maintenance, which would be a good thing, because you don't necessarily want to rely on cache attributes between secure and normal world being the same, but it would be good to know this for a fact.
Are you able to confirm that the i.MX8M BootROM does in fact do cache maintenance itself for HAB buffers it writes to?
any news on whether BL33 should do cache maintenance on i.MX8M or not (or if it doesn't matter)?
Cheers, Ahmad
Thanks again, Ahmad
Thanks, Ahmad