Thanks I've noticed that bionic uses address 0xffff0ff0 to implement TLS in arm But isn't this address a space of kernel? How can a user space program access that address without a soft-interupt...
Or the memory map in arm is different from x86, so the high 1G mem is not kernel used only? On Wed, Aug 5, 2009 at 3:06 AM, David Turner <di...@android.com> wrote: > > > On Tue, Aug 4, 2009 at 12:24 PM, Neo <zingafri...@yahoo.com> wrote: > >> >> >> >> On Aug 4, 8:17 am, Ouyang Jiannan <jallen....@gmail.com> wrote: >> > hi, everyone, >> > In bionic/libc/Android.mk we can see that >> > x86 uses files pthread.c, pthread-timers.c ptrace.c and __get_tls.c >> > in arm, it uses pthread.c.arm , pthread-timers.c.arm, ptrace.c.arm >> > But I can't find these files or places which generate it >> > >> > So what's the arm support of TLS? Is there a reg uses as gs in x86 as a >> > pointer to tls? >> >> TLS is not supported in android though it is present in armv6 and >> later. > > > TLS is supported in Android (there wouldn't be any pthread implementation > anyway). > > The current ARM implementation doesn't use an ARMv6-specific register but > instead > relies on a small kernel trick (which updates a very specific user virtual > address on each > context switch instead). > > >> >> >> > > > > --~--~---------~--~----~------------~-------~--~----~ unsubscribe: android-porting+unsubscr...@googlegroups.com website: http://groups.google.com/group/android-porting -~----------~----~----~----~------~----~------~--~---
