Messages in this thread | | | Date | Fri, 7 May 1999 10:41:19 -0400 (EDT) | From | "Richard B. Johnson" <> | Subject | Re: mmap from 0xFFFF0000 -> 0xFFFFFFFF does not work, why?! |
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On Fri, 7 May 1999, Matti Aarnio wrote: [SNIPPED] > > > > Because the pentium processors have caches it is required to disable them > > before access the flash memory (you know, time critical access). So i include > > some assembler code that use the %cr0 pentium processor register but i get > > segfaults while executing this source line :( How can i disable the cpu cache > > withou using the assembler code within the user application ?! Of > > course, only root can do that. > > "root" isn't powerfull enough, those must be executed > in the supervisor mode -- within the kernel, that is. > Another reason to go via device driver kernel module. > Will iopl(3) work for this? Certainly a device-driver is the final solution, but he may be able to test most things this way.
Cheers, Dick Johnson ***** FILE SYSTEM WAS MODIFIED ***** Penguin : Linux version 2.2.6 on an i686 machine (400.59 BogoMips). Warning : It's hard to remain at the trailing edge of technology.
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