1/*	$NetBSD: frame_regs.h,v 1.3 2008/01/05 12:08:51 dsl Exp $	*/
2
3#ifndef _AMD64_FRAME_REGS_H_
4#define _AMD64_FRAME_REGS_H_
5
6/*
7 * amd64 registers (and friends) ordered as in a trap/interrupt/syscall frame.
8 * Also the indexes into the 'general register state' (__greg_t) passed to
9 * userland.
10 * Historically they were in the same order, but the order in the frames
11 * has been changed to improve syscall efficiency.
12 *
13 * Notes:
14 * 1) gdb (src/gnu/dist/gdb6/gdb/amd64nbsd-tdep.c) has a lookup table that
15 *    assumes the __greg_t ordering.
16 * 2) src/lib/libc/arch/x86_64/gen/makecontext.c assumes that the first
17 *    6 entries in the __greg_t array match the registers used to pass
18 *    function arguments.
19 * 3) The 'struct reg' from machine/reg.h has to match __greg_t.
20 *    Since they are both arrays and indexed with the same tokens this
21 *    shouldn't be a problem, but is rather confusing.
22 *    This assumption is made in a lot of places!
23 * 4) There might be other code out there that relies on the ordering.
24 *
25 * The first entries below match the registers used for syscall arguments
26 * (%rcx is destroyed by the syscall instruction, the libc system call
27 * stubs copy %rcx to %r10).
28 * arg6-arg9 are copied from the user stack for system calls with more
29 * than 6 args (SYS_MAXSYSARGS is 8, + 2 entries for SYS___SYSCALL).
30 */
31#define _FRAME_REG(greg, freg) 	\
32	greg(rdi, RDI, 0)	\
33	greg(rsi, RSI, 1)	\
34	greg(rdx, RDX, 2)	\
35	greg(r10, R10, 6)	\
36	greg(r8,  R8,  4)	\
37	greg(r9,  R9,  5)	\
38	freg(arg6, @,  @)	/* syscall arg from stack */ \
39	freg(arg7, @,  @)	/* syscall arg from stack */ \
40	freg(arg8, @,  @)	/* syscall arg from stack */ \
41	freg(arg9, @,  @)	/* syscall arg from stack */ \
42	greg(rcx, RCX, 3)	\
43	greg(r11, R11, 7)	\
44	greg(r12, R12, 8)	\
45	greg(r13, R13, 9)	\
46	greg(r14, R14, 10)	\
47	greg(r15, R15, 11)	\
48	greg(rbp, RBP, 12)	\
49	greg(rbx, RBX, 13)	\
50	greg(rax, RAX, 14)	\
51	greg(gs,  GS,  15)	\
52	greg(fs,  FS,  16)	\
53	greg(es,  ES,  17)	\
54	greg(ds,  DS,  18)	\
55	greg(trapno, TRAPNO, 19)	\
56	/* below portion defined in hardware */ \
57	greg(err, ERR, 20)	/* Dummy inserted if not defined */ \
58	greg(rip, RIP, 21)	\
59	greg(cs,  CS,  22)	\
60	greg(rflags, RFLAGS, 23)	\
61	/* These are pushed unconditionally on the x86-64 */ \
62	greg(rsp, RSP, 24)	\
63	greg(ss,  SS,  25)
64
65#define _FRAME_NOREG(reg, REG, idx)
66
67#define _FRAME_GREG(greg) _FRAME_REG(greg, _FRAME_NOREG)
68
69#endif
70