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frame_regs.h revision 1.3 
      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) PTHREAD_UCONTEXT_TO_REG (src/lib/libpthread/arch/?*?/pthread_md.h)
     20  *    assumes that something matches the __greg_t layout, but there
     21  *    are no (obvious) references.
     22  * 4) There might be other code out there that relies on the ordering.
     23  *
     24  * The first entries below match the registers used for syscall arguments
     25  * (%rcx is destroyed by the syscall instruction, to the libc stubs copy
     26  * the value to %r10).
     27  * arg6-arg9 are copied from the user stack for system calls with more
     28  * than 6 args (SYS_MAXSYSARGS is 8, + 2 entries for SYS___SYSCALL).
     29  */
     30 #define _FRAME_REG(greg, freg) 	\
     31 	greg(rdi, RDI, 0)	\
     32 	greg(rsi, RSI, 1)	\
     33 	greg(rdx, RDX, 2)	\
     34 	greg(r10, R10, 6)	\
     35 	greg(r8,  R8,  4)	\
     36 	greg(r9,  R9,  5)	\
     37 	freg(arg6, @,  @)	/* syscall arg from stack */ \
     38 	freg(arg7, @,  @)	/* syscall arg from stack */ \
     39 	freg(arg8, @,  @)	/* syscall arg from stack */ \
     40 	freg(arg9, @,  @)	/* syscall arg from stack */ \
     41 	greg(rcx, RCX, 3)	\
     42 	greg(r11, R11, 7)	\
     43 	greg(r12, R12, 8)	\
     44 	greg(r13, R13, 9)	\
     45 	greg(r14, R14, 10)	\
     46 	greg(r15, R15, 11)	\
     47 	greg(rbp, RBP, 12)	\
     48 	greg(rbx, RBX, 13)	\
     49 	greg(rax, RAX, 14)	\
     50 	greg(gs,  GS,  15)	\
     51 	greg(fs,  FS,  16)	\
     52 	greg(es,  ES,  17)	\
     53 	greg(ds,  DS,  18)	\
     54 	greg(trapno, TRAPNO, 19)	\
     55 	/* below portion defined in hardware */ \
     56 	greg(err, ERR, 20)	/* Dummy inserted if not defined */ \
     57 	greg(rip, RIP, 21)	\
     58 	greg(cs,  CS,  22)	\
     59 	greg(rflags, RFLAGS, 23)	\
     60 	/* These are pushed unconditionally on the x86-64 */ \
     61 	greg(rsp, RSP, 24)	\
     62 	greg(ss,  SS,  25)
     63 
     64 #define _FRAME_NOREG(reg, REG, idx)
     65 
     66 #define _FRAME_GREG(greg) _FRAME_REG(greg, _FRAME_NOREG)
     67 
     68 #endif
     69