Fiasco.OC x86 IO port permission bitmap
d.waddington at samsung.com
Fri Jan 27 22:38:39 CET 2012
After further experimentation and learning - I can confirm it does work
as you say (at least on x86 32bit).
On 01/25/2012 05:29 AM, Adam Lackorzynski wrote:
> On Tue Jan 24, 2012 at 13:12:03 -0800, Daniel Waddington wrote:
>> I see. So it seems that you have to map all of the IO port space
>> before getting IOPL raised to 3 (assuming Kconfig IO_PROT&
>> !IO_PROT_3) and therefore the default mode of operation is a driver
>> will map the whole space if it wants to use IO instructions
>> directly. Is it right that you currently don't use the TSS IO
>> bitmap to allow access to only specific IO ports with CPL> IOPL?
> 'in' and 'out' are supposed to work just fine on single ports, no need
> to request all 64k ports for that and no iopl3 required.
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the l4-hackers