Hi Peter, On 19.09.21 09:50, Peter Rosin wrote: > On 2021-09-19 09:06, Rouven Czerwinski wrote: >> Hi Peter, >> >> while this may break for your board, it fundamentally introduces the >> possibility to speculate out of the RAM area on speculation happy > > I'm aware of that. For me, speculation is not an issue since *any* > rogue code running on the embedded device in question is a major fail. We have seen Cortex-A7 CPUs speculatively executing I/O memory. That's why we mar everything eXecute-Never except for known memory banks and expect board code to mark any further regions that are safe to execute manually. > Also, from the cover letter: > > "I'm going to follow up with patches. I very much realize that > these patches are most likely not acceptable as-is, but I do > include them since they are probably the best description of > where the problems are." > >> processors. Are you calling into SAMA5D3 ROM code somewhere? If so an > > *I* am not calling anything. Maybe the board code for sama5d3xek is, > but I have no idea as it's not "my" code. How can I figure out if it > does? If you don't revert this patch. Do you get any output at all? If not, enable DEBUG_LL and see how far you get before hanging. Cheers, Ahad > > Cheers, > Peter > >> exception can be added similar to the handling for the HAB code >> (arch/arm/cpu/mmu_early.c): >> >> if (IS_ENABLED(CONFIG_HABV4) && IS_ENABLED(CONFIG_ARCH_IMX6)) >> map_region(0x0, SZ_1M, PMD_SECT_DEF_CACHED); >> >> which allows calls into the NXP boot ROM to retrieve the HAB status. > > _______________________________________________ > barebox mailing list > barebox@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/barebox > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
