跟住SEARCH ARM 既CALLING CONVENTION。
The meaning of this register is defined by the platform standard.
The role of register r9 is platform specific. A virtual platform may assign any role to this register and must document this usage. For example, it may designate it as the static base (SB) in a position-independent data model, or it may designate it as the thread register (TR) in an environment with thread-local storage. The usage of this register may require that the value held is persistent across all calls. A virtual platform that has no need for such a special register may designate r9 as an additional callee-saved variable register, v6.
有無人玩過LINUX SOURCE CODE？
COMPILE LINUX KERNEL都會是這樣嗎？