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/* Target dependent code for the Motorola 68000 series. Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1999, 2000, 2001 Free Software Foundation, Inc. This file is part of GDB. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ #include "defs.h" #include "frame.h" #include "symtab.h" #include "gdbcore.h" #include "value.h" #include "gdb_string.h" #include "inferior.h" #include "regcache.h" #define P_LINKL_FP 0x480e #define P_LINKW_FP 0x4e56 #define P_PEA_FP 0x4856 #define P_MOVL_SP_FP 0x2c4f #define P_MOVL 0x207c #define P_JSR 0x4eb9 #define P_BSR 0x61ff #define P_LEAL 0x43fb #define P_MOVML 0x48ef #define P_FMOVM 0xf237 #define P_TRAP 0x4e40 /* The only reason this is here is the tm-altos.h reference below. It was moved back here from tm-m68k.h. FIXME? */ extern CORE_ADDR altos_skip_prologue (CORE_ADDR pc) { register int op = read_memory_integer (pc, 2); if (op == P_LINKW_FP) pc += 4; /* Skip link #word */ else if (op == P_LINKL_FP) pc += 6; /* Skip link #long */ /* Not sure why branches are here. */ /* From tm-altos.h */ else if (op == 0060000) pc += 4; /* Skip bra #word */ else if (op == 00600377) pc += 6; /* skip bra #long */ else if ((op & 0177400) == 0060000) pc += 2; /* skip bra #char */ return pc; } /* The only reason this is here is the tm-isi.h reference below. It was moved back here from tm-m68k.h. FIXME? */ /* OBSOLETE extern CORE_ADDR */ /* OBSOLETE isi_skip_prologue (CORE_ADDR pc) */ /* OBSOLETE { */ /* OBSOLETE register int op = read_memory_integer (pc, 2); */ /* OBSOLETE if (op == P_LINKW_FP) */ /* OBSOLETE pc += 4; *//* Skip link #word */ /* OBSOLETE else if (op == P_LINKL_FP) */ /* OBSOLETE pc += 6; *//* Skip link #long */ /* OBSOLETE *//* Not sure why branches are here. */ /* OBSOLETE *//* From tm-isi.h, tm-altos.h */ /* OBSOLETE else if (op == 0060000) */ /* OBSOLETE pc += 4; *//* Skip bra #word */ /* OBSOLETE else if (op == 00600377) */ /* OBSOLETE pc += 6; *//* skip bra #long */ /* OBSOLETE else if ((op & 0177400) == 0060000) */ /* OBSOLETE pc += 2; *//* skip bra #char */ /* OBSOLETE return pc; */ /* OBSOLETE } */ int delta68_in_sigtramp (CORE_ADDR pc, char *name) { if (name != NULL) return strcmp (name, "_sigcode") == 0; else return 0; } CORE_ADDR delta68_frame_args_address (struct frame_info *frame_info) { /* we assume here that the only frameless functions are the system calls or other functions who do not put anything on the stack. */ if (frame_info->signal_handler_caller) return frame_info->frame + 12; else if (frameless_look_for_prologue (frame_info)) { /* Check for an interrupted system call */ if (frame_info->next && frame_info->next->signal_handler_caller) return frame_info->next->frame + 16; else return frame_info->frame + 4; } else return frame_info->frame; } CORE_ADDR delta68_frame_saved_pc (struct frame_info *frame_info) { return read_memory_integer (delta68_frame_args_address (frame_info) + 4, 4); } /* Return number of args passed to a frame. Can return -1, meaning no way to tell. */ int isi_frame_num_args (struct frame_info *fi) { int val; CORE_ADDR pc = FRAME_SAVED_PC (fi); int insn = 0177777 & read_memory_integer (pc, 2); val = 0; if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */ val = read_memory_integer (pc + 2, 2); else if ((insn & 0170777) == 0050217 /* addql #N, sp */ || (insn & 0170777) == 0050117) /* addqw */ { val = (insn >> 9) & 7; if (val == 0) val = 8; } else if (insn == 0157774) /* addal #WW, sp */ val = read_memory_integer (pc + 2, 4); val >>= 2; return val; } int delta68_frame_num_args (struct frame_info *fi) { int val; CORE_ADDR pc = FRAME_SAVED_PC (fi); int insn = 0177777 & read_memory_integer (pc, 2); val = 0; if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */ val = read_memory_integer (pc + 2, 2); else if ((insn & 0170777) == 0050217 /* addql #N, sp */ || (insn & 0170777) == 0050117) /* addqw */ { val = (insn >> 9) & 7; if (val == 0) val = 8; } else if (insn == 0157774) /* addal #WW, sp */ val = read_memory_integer (pc + 2, 4); val >>= 2; return val; } int news_frame_num_args (struct frame_info *fi) { int val; CORE_ADDR pc = FRAME_SAVED_PC (fi); int insn = 0177777 & read_memory_integer (pc, 2); val = 0; if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */ val = read_memory_integer (pc + 2, 2); else if ((insn & 0170777) == 0050217 /* addql #N, sp */ || (insn & 0170777) == 0050117) /* addqw */ { val = (insn >> 9) & 7; if (val == 0) val = 8; } else if (insn == 0157774) /* addal #WW, sp */ val = read_memory_integer (pc + 2, 4); val >>= 2; return val; } /* Push an empty stack frame, to record the current PC, etc. */ void m68k_push_dummy_frame (void) { register CORE_ADDR sp = read_register (SP_REGNUM); register int regnum; char raw_buffer[12]; sp = push_word (sp, read_register (PC_REGNUM)); sp = push_word (sp, read_register (FP_REGNUM)); write_register (FP_REGNUM, sp); /* Always save the floating-point registers, whether they exist on this target or not. */ for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--) { read_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12); sp = push_bytes (sp, raw_buffer, 12); } for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--) { sp = push_word (sp, read_register (regnum)); } sp = push_word (sp, read_register (PS_REGNUM)); write_register (SP_REGNUM, sp); } /* Discard from the stack the innermost frame, restoring all saved registers. */ void m68k_pop_frame (void) { register struct frame_info *frame = get_current_frame (); register CORE_ADDR fp; register int regnum; struct frame_saved_regs fsr; char raw_buffer[12]; fp = FRAME_FP (frame); get_frame_saved_regs (frame, &fsr); for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--) { if (fsr.regs[regnum]) { read_memory (fsr.regs[regnum], raw_buffer, 12); write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12); } } for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--) { if (fsr.regs[regnum]) { write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); } } if (fsr.regs[PS_REGNUM]) { write_register (PS_REGNUM, read_memory_integer (fsr.regs[PS_REGNUM], 4)); } write_register (FP_REGNUM, read_memory_integer (fp, 4)); write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); write_register (SP_REGNUM, fp + 8); flush_cached_frames (); } /* Given an ip value corresponding to the start of a function, return the ip of the first instruction after the function prologue. This is the generic m68k support. Machines which require something different can override the SKIP_PROLOGUE macro to point elsewhere. Some instructions which typically may appear in a function prologue include: A link instruction, word form: link.w %a6,&0 4e56 XXXX A link instruction, long form: link.l %fp,&F%1 480e XXXX XXXX A movm instruction to preserve integer regs: movm.l &M%1,(4,%sp) 48ef XXXX XXXX A fmovm instruction to preserve float regs: fmovm &FPM%1,(FPO%1,%sp) f237 XXXX XXXX XXXX XXXX Some profiling setup code (FIXME, not recognized yet): lea.l (.L3,%pc),%a1 43fb XXXX XXXX XXXX bsr _mcount 61ff XXXX XXXX */ CORE_ADDR m68k_skip_prologue (CORE_ADDR ip) { register CORE_ADDR limit; struct symtab_and_line sal; register int op; /* Find out if there is a known limit for the extent of the prologue. If so, ensure we don't go past it. If not, assume "infinity". */ sal = find_pc_line (ip, 0); limit = (sal.end) ? sal.end : (CORE_ADDR) ~ 0; while (ip < limit) { op = read_memory_integer (ip, 2); op &= 0xFFFF; if (op == P_LINKW_FP) ip += 4; /* Skip link.w */ else if (op == P_PEA_FP) ip += 2; /* Skip pea %fp */ else if (op == P_MOVL_SP_FP) ip += 2; /* Skip move.l %sp, %fp */ else if (op == P_LINKL_FP) ip += 6; /* Skip link.l */ else if (op == P_MOVML) ip += 6; /* Skip movm.l */ else if (op == P_FMOVM) ip += 10; /* Skip fmovm */ else break; /* Found unknown code, bail out. */ } return (ip); } void m68k_find_saved_regs (struct frame_info *frame_info, struct frame_saved_regs *saved_regs) { register int regnum; register int regmask; register CORE_ADDR next_addr; register CORE_ADDR pc; /* First possible address for a pc in a call dummy for this frame. */ CORE_ADDR possible_call_dummy_start = (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM * 4 - 4 - 8 * 12; int nextinsn; memset (saved_regs, 0, sizeof (*saved_regs)); if ((frame_info)->pc >= possible_call_dummy_start && (frame_info)->pc <= (frame_info)->frame) { /* It is a call dummy. We could just stop now, since we know what the call dummy saves and where. But this code proceeds to parse the "prologue" which is part of the call dummy. This is needlessly complex and confusing. FIXME. */ next_addr = (frame_info)->frame; pc = possible_call_dummy_start; } else { pc = get_pc_function_start ((frame_info)->pc); nextinsn = read_memory_integer (pc, 2); if (P_PEA_FP == nextinsn && P_MOVL_SP_FP == read_memory_integer (pc + 2, 2)) { /* pea %fp move.l %sp, %fp */ next_addr = frame_info->frame; pc += 4; } else if (P_LINKL_FP == nextinsn) /* link.l %fp */ /* Find the address above the saved regs using the amount of storage from the link instruction. */ { next_addr = (frame_info)->frame + read_memory_integer (pc + 2, 4); pc += 6; } else if (P_LINKW_FP == nextinsn) /* link.w %fp */ /* Find the address above the saved regs using the amount of storage from the link instruction. */ { next_addr = (frame_info)->frame + read_memory_integer (pc + 2, 2); pc += 4; } else goto lose; /* If have an addal #-n, sp next, adjust next_addr. */ if ((0177777 & read_memory_integer (pc, 2)) == 0157774) next_addr += read_memory_integer (pc += 2, 4), pc += 4; } for ( ; ; ) { nextinsn = 0xffff & read_memory_integer (pc, 2); regmask = read_memory_integer (pc + 2, 2); /* fmovemx to -(sp) */ if (0xf227 == nextinsn && (regmask & 0xff00) == 0xe000) { /* Regmask's low bit is for register fp7, the first pushed */ for (regnum = FP0_REGNUM + 8; --regnum >= FP0_REGNUM; regmask >>= 1) if (regmask & 1) saved_regs->regs[regnum] = (next_addr -= 12); pc += 4; } /* fmovemx to (fp + displacement) */ else if (0171056 == nextinsn && (regmask & 0xff00) == 0xf000) { register CORE_ADDR addr; addr = (frame_info)->frame + read_memory_integer (pc + 4, 2); /* Regmask's low bit is for register fp7, the first pushed */ for (regnum = FP0_REGNUM + 8; --regnum >= FP0_REGNUM; regmask >>= 1) if (regmask & 1) { saved_regs->regs[regnum] = addr; addr += 12; } pc += 6; } /* moveml to (sp) */ else if (0044327 == nextinsn) { /* Regmask's low bit is for register 0, the first written */ for (regnum = 0; regnum < 16; regnum++, regmask >>= 1) if (regmask & 1) { saved_regs->regs[regnum] = next_addr; next_addr += 4; } pc += 4; } /* moveml to (fp + displacement) */ else if (0044356 == nextinsn) { register CORE_ADDR addr; addr = (frame_info)->frame + read_memory_integer (pc + 4, 2); /* Regmask's low bit is for register 0, the first written */ for (regnum = 0; regnum < 16; regnum++, regmask >>= 1) if (regmask & 1) { saved_regs->regs[regnum] = addr; addr += 4; } pc += 6; } /* moveml to -(sp) */ else if (0044347 == nextinsn) { /* Regmask's low bit is for register 15, the first pushed */ for (regnum = 16; --regnum >= 0; regmask >>= 1) if (regmask & 1) saved_regs->regs[regnum] = (next_addr -= 4); pc += 4; } /* movl r,-(sp) */ else if (0x2f00 == (0xfff0 & nextinsn)) { regnum = 0xf & nextinsn; saved_regs->regs[regnum] = (next_addr -= 4); pc += 2; } /* fmovemx to index of sp */ else if (0xf236 == nextinsn && (regmask & 0xff00) == 0xf000) { /* Regmask's low bit is for register fp0, the first written */ for (regnum = FP0_REGNUM + 8; --regnum >= FP0_REGNUM; regmask >>= 1) if (regmask & 1) { saved_regs->regs[regnum] = next_addr; next_addr += 12; } pc += 10; } /* clrw -(sp); movw ccr,-(sp) */ else if (0x4267 == nextinsn && 0x42e7 == regmask) { saved_regs->regs[PS_REGNUM] = (next_addr -= 4); pc += 4; } else break; } lose:; saved_regs->regs[SP_REGNUM] = (frame_info)->frame + 8; saved_regs->regs[FP_REGNUM] = (frame_info)->frame; saved_regs->regs[PC_REGNUM] = (frame_info)->frame + 4; #ifdef SIG_SP_FP_OFFSET /* Adjust saved SP_REGNUM for fake _sigtramp frames. */ if (frame_info->signal_handler_caller && frame_info->next) saved_regs->regs[SP_REGNUM] = frame_info->next->frame + SIG_SP_FP_OFFSET; #endif } #ifdef USE_PROC_FS /* Target dependent support for /proc */ #include <sys/procfs.h> /* Prototypes for supply_gregset etc. */ #include "gregset.h" /* The /proc interface divides the target machine's register set up into two different sets, the general register set (gregset) and the floating point register set (fpregset). For each set, there is an ioctl to get the current register set and another ioctl to set the current values. The actual structure passed through the ioctl interface is, of course, naturally machine dependent, and is different for each set of registers. For the m68k for example, the general register set is typically defined by: typedef int gregset_t[18]; #define R_D0 0 ... #define R_PS 17 and the floating point set by: typedef struct fpregset { int f_pcr; int f_psr; int f_fpiaddr; int f_fpregs[8][3]; (8 regs, 96 bits each) } fpregset_t; These routines provide the packing and unpacking of gregset_t and fpregset_t formatted data. */ /* Atari SVR4 has R_SR but not R_PS */ #if !defined (R_PS) && defined (R_SR) #define R_PS R_SR #endif /* Given a pointer to a general register set in /proc format (gregset_t *), unpack the register contents and supply them as gdb's idea of the current register values. */ void supply_gregset (gregset_t *gregsetp) { register int regi; register greg_t *regp = (greg_t *) gregsetp; for (regi = 0; regi < R_PC; regi++) { supply_register (regi, (char *) (regp + regi)); } supply_register (PS_REGNUM, (char *) (regp + R_PS)); supply_register (PC_REGNUM, (char *) (regp + R_PC)); } void fill_gregset (gregset_t *gregsetp, int regno) { register int regi; register greg_t *regp = (greg_t *) gregsetp; for (regi = 0; regi < R_PC; regi++) { if ((regno == -1) || (regno == regi)) { *(regp + regi) = *(int *) ®isters[REGISTER_BYTE (regi)]; } } if ((regno == -1) || (regno == PS_REGNUM)) { *(regp + R_PS) = *(int *) ®isters[REGISTER_BYTE (PS_REGNUM)]; } if ((regno == -1) || (regno == PC_REGNUM)) { *(regp + R_PC) = *(int *) ®isters[REGISTER_BYTE (PC_REGNUM)]; } } #if defined (FP0_REGNUM) /* Given a pointer to a floating point register set in /proc format (fpregset_t *), unpack the register contents and supply them as gdb's idea of the current floating point register values. */ void supply_fpregset (fpregset_t *fpregsetp) { register int regi; char *from; for (regi = FP0_REGNUM; regi < FPC_REGNUM; regi++) { from = (char *) &(fpregsetp->f_fpregs[regi - FP0_REGNUM][0]); supply_register (regi, from); } supply_register (FPC_REGNUM, (char *) &(fpregsetp->f_pcr)); supply_register (FPS_REGNUM, (char *) &(fpregsetp->f_psr)); supply_register (FPI_REGNUM, (char *) &(fpregsetp->f_fpiaddr)); } /* Given a pointer to a floating point register set in /proc format (fpregset_t *), update the register specified by REGNO from gdb's idea of the current floating point register set. If REGNO is -1, update them all. */ void fill_fpregset (fpregset_t *fpregsetp, int regno) { int regi; char *to; char *from; for (regi = FP0_REGNUM; regi < FPC_REGNUM; regi++) { if ((regno == -1) || (regno == regi)) { from = (char *) ®isters[REGISTER_BYTE (regi)]; to = (char *) &(fpregsetp->f_fpregs[regi - FP0_REGNUM][0]); memcpy (to, from, REGISTER_RAW_SIZE (regi)); } } if ((regno == -1) || (regno == FPC_REGNUM)) { fpregsetp->f_pcr = *(int *) ®isters[REGISTER_BYTE (FPC_REGNUM)]; } if ((regno == -1) || (regno == FPS_REGNUM)) { fpregsetp->f_psr = *(int *) ®isters[REGISTER_BYTE (FPS_REGNUM)]; } if ((regno == -1) || (regno == FPI_REGNUM)) { fpregsetp->f_fpiaddr = *(int *) ®isters[REGISTER_BYTE (FPI_REGNUM)]; } } #endif /* defined (FP0_REGNUM) */ #endif /* USE_PROC_FS */ /* Figure out where the longjmp will land. Slurp the args out of the stack. We expect the first arg to be a pointer to the jmp_buf structure from which we extract the pc (JB_PC) that we will land at. The pc is copied into PC. This routine returns true on success. */ /* NOTE: cagney/2000-11-08: For this function to be fully multi-arched the macro's JB_PC and JB_ELEMENT_SIZE would need to be moved into the ``struct gdbarch_tdep'' object and then set on a target ISA/ABI dependant basis. */ int m68k_get_longjmp_target (CORE_ADDR *pc) { #if defined (JB_PC) && defined (JB_ELEMENT_SIZE) char *buf; CORE_ADDR sp, jb_addr; buf = alloca (TARGET_PTR_BIT / TARGET_CHAR_BIT); sp = read_register (SP_REGNUM); if (target_read_memory (sp + SP_ARG0, /* Offset of first arg on stack */ buf, TARGET_PTR_BIT / TARGET_CHAR_BIT)) return 0; jb_addr = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); if (target_read_memory (jb_addr + JB_PC * JB_ELEMENT_SIZE, buf, TARGET_PTR_BIT / TARGET_CHAR_BIT)) return 0; *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT); return 1; #else internal_error (__FILE__, __LINE__, "m68k_get_longjmp_target: not implemented"); return 0; #endif } /* Immediately after a function call, return the saved pc before the frame is setup. For sun3's, we check for the common case of being inside of a system call, and if so, we know that Sun pushes the call # on the stack prior to doing the trap. */ CORE_ADDR m68k_saved_pc_after_call (struct frame_info *frame) { #ifdef SYSCALL_TRAP int op; op = read_memory_integer (frame->pc - SYSCALL_TRAP_OFFSET, 2); if (op == SYSCALL_TRAP) return read_memory_integer (read_register (SP_REGNUM) + 4, 4); else #endif /* SYSCALL_TRAP */ return read_memory_integer (read_register (SP_REGNUM), 4); } void _initialize_m68k_tdep (void) { tm_print_insn = print_insn_m68k; }