Hi! Am 26.07.2010 11:22, schrieb Michael Schnell:
Maybe Win64 uses some "Selector" mechanism (similar as ) so that there are no different Selector-Register values in different threads.
Win64 uses GS instead of FS for the TEB and everything else stays the same. In fact FS and GS (and to some extend CS) are the only selectors actively used by the x86_64 platform, but - if I understand that correctly - they can only be set up from ring 0 code (thus: kernel code), which normally happens during context switches so that the data of the current thread's TEB is available again.
The usage of the FS and GS selectors in 64bit is also described in AMD's manual: e.g http://support.amd.com/us/Processor_TechDocs/24592.pdf 2.1.2 Segment Registers
Regards, Sven _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org http://lists.freepascal.org/mailman/listinfo/fpc-devel
