On 19 September 2018 at 11:19, Cédric Le Goater <c...@kaod.org> wrote: > These are the number of read operations done on the flash memory region : > > 922478 ~ 3.5 MBytes OpenBMC U-Boot > 20569977 ~ 80 MBytes Mainline U-Boot > > > So we are trashing the TBs I would say. Is there a way to increase the > TB size ? or some other TB parameter ? Is that directly linked to the > instruction cache size ?
Well, execution direct from MMIO means we read each instruction as we execute it -- there's no caching of TBs. (We generate a temporary TB with a single insn and throw it away after executing from it.) This is because we can't be sure that we would get the same data value the next time we read from the address. So we definitely expect things to go slower -- I'm just a little surprised that we spend so much time executing from flash devices that aren't in "romd" mode. thanks -- PMM
