Win 64 register usage

http://www.mouseos.com/win64/registers.html

Seems UEFI using rcx, rdx, r8, r9, r10, r11, r12 to store argv

下面是摘自 MSDN 的文章，在 Win64 下的 registers 用途

Register	Status	Use
RAX	Volatile	Return value register
RCX	Volatile	First integer argument
RDX	Volatile	Second integer argument
R8	Volatile	Third integer argument
R9	Volatile	Fourth integer argument
R10:R11	Volatile	Must be preserved as needed by caller; used in syscall/sysret   instructions
R12:R15	Nonvolatile	Must be preserved by callee
RDI	Nonvolatile	Must be preserved by callee
RSI	Nonvolatile	Must be preserved by callee
RBX	Nonvolatile	Must be preserved by callee
RBP	Nonvolatile	May be used as a frame pointer; must be preserved by   callee
RSP	Nonvolatile	Stack pointer
XMM0	Volatile	First FP argument
XMM1	Volatile	Second FP argument
XMM2	Volatile	Third FP argument
XMM3	Volatile	Fourth FP argument
XMM4:XMM5	Volatile	Must be preserved as needed by caller
XMM6:XMM15	Nonvolatile	Must be preserved as needed by callee.

1. 传递参数

在 Win64 里使用下面寄存器来传递参数：

• rcx - 第 1 个参数
• rdx - 第 2 个参数
• r8 - 第 3 个参数
• r9 - 第 4 个参数

其它多出来的参数通过 stack 传递。

使用下面寄存器来传递浮数数：

• xmm0 - 第 1 个参数
• xmm1 - 第 2 个参数
• xmm2 - 第 3 个参数
• xmm3 - 第 4 个参数