* Fixed checking for DR6 bits after a debug exception (we were and'ing

with the bit number, not the respective mask).
* Added a small hack to allow single stepping to work in qemu.
  Apparently the BS bit in DR6 is not set when the debug exception
  is handled. So we always assume that a single step event occurred,
  when we couldn't recognize any other event, if the hack is enabled.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@11998 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/arch/x86/arch_user_debugger.h

@@ -5,6 +5,8 @@
 #ifndef _KERNEL_ARCH_X86_USER_DEBUGGER_H
 #define _KERNEL_ARCH_X86_USER_DEBUGGER_H
 
+#define ARCH_INIT_USER_DEBUG i386_init_user_debug
+
 // number of breakpoints the CPU supports
 // Actually it supports 4, but DR3 is used to hold the struct thread*.
 enum {
@@ -127,6 +129,8 @@ extern void i386_reinit_user_debug_after_context_switch(struct thread *thread);
 extern int i386_handle_debug_exception(struct iframe *frame);
 extern int i386_handle_breakpoint_exception(struct iframe *frame);
 
+extern void i386_init_user_debug();
+
 #ifdef __cplusplus
 }
 #endif