1 /* $NetBSD: frame_regs.h,v 1.4 2008/02/06 22:02:17 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