linux-user: Move init_main_thread() prototype to user-internals.h

The init_main_thread() prototype is needed only by code internal to
linux-user/, so it doesn't need to be in qemu.h (which is also pulled
in by various files outside linux-user/).

Move the prototype to user-internals.h, and give it a documentation
comment.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>

linux-user/qemu.h

@@ -371,6 +371,4 @@ void *lock_user_string(abi_ulong guest_addr);
 /* Clone cpu state */
 CPUArchState *cpu_copy(CPUArchState *env);
 
-void init_main_thread(CPUState *cs, struct image_info *info);
-
 #endif /* QEMU_H */

linux-user/user-internals.h

@@ -194,6 +194,21 @@ static inline void begin_parallel_context(CPUState *cs)
     }
 }
 
+/**
+ * init_main_thread: Set CPU state for main thread
+ * @cs: CPU context to set
+ * @info: information about the image being loaded
+ *
+ * This function must be provided by the per-target code. It should
+ * set the initial CPU state based on the information about the
+ * starting binary in @image_info. This will be at a minimum setting
+ * the initial guest program counter and stack pointer; it should
+ * also set up any other guest register values where the Linux ABI
+ * defines that they start set to some other value than what the
+ * guest CPU architecture gives you out of reset.
+ */
+void init_main_thread(CPUState *cs, struct image_info *info);
+
 /*
  * Include target-specific struct and function definitions;
  * they may need access to the target-independent structures