/* Target-machine dependent code for Hitachi H8/300, for GDB. Copyright (C) 1988, 1990, 1991 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* Contributed by Steve Chamberlain sac@cygnus.com */ #include "defs.h" #include "frame.h" #include "obstack.h" #include "symtab.h" #undef NUM_REGS #define NUM_REGS 11 #define UNSIGNED_SHORT(X) ((X) & 0xffff) /* an easy to debug H8 stack frame looks like: 0x6df6 push r6 0x0d76 mov.w r7,r6 0x6dfn push reg 0x7905 nnnn mov.w #n,r5 or 0x1b87 subs #2,sp 0x1957 sub.w r5,sp */ #define IS_PUSH(x) ((x & 0xff00)==0x6d00) #define IS_PUSH_FP(x) (x == 0x6df6) #define IS_MOVE_FP(x) (x == 0x0d76) #define IS_MOV_SP_FP(x) (x == 0x0d76) #define IS_SUB2_SP(x) (x==0x1b87) #define IS_MOVK_R5(x) (x==0x7905) #define IS_SUB_R5SP(x) (x==0x1957) CORE_ADDR examine_prologue (); void frame_find_saved_regs (); CORE_ADDR h8300_skip_prologue (start_pc) CORE_ADDR start_pc; { short int w; w = read_memory_short (start_pc); /* Skip past all push insns */ while (IS_PUSH_FP (w)) { start_pc += 2; w = read_memory_short (start_pc); } /* Skip past a move to FP */ if (IS_MOVE_FP (w)) { start_pc += 2; w = read_memory_short (start_pc); } /* Skip the stack adjust */ if (IS_MOVK_R5 (w)) { start_pc += 2; w = read_memory_short (start_pc); } if (IS_SUB_R5SP (w)) { start_pc += 2; w = read_memory_short (start_pc); } while (IS_SUB2_SP (w)) { start_pc += 2; w = read_memory_short (start_pc); } return start_pc; } int print_insn (memaddr, stream) CORE_ADDR memaddr; FILE *stream; { /* Nothing is bigger than 8 bytes */ char data[8]; read_memory (memaddr, data, sizeof (data)); return print_insn_h8300 (memaddr, data, stream); } /* Given a GDB frame, determine the address of the calling function's frame. This will be used to create a new GDB frame struct, and then INIT_EXTRA_FRAME_INFO and INIT_FRAME_PC will be called for the new frame. For us, the frame address is its stack pointer value, so we look up the function prologue to determine the caller's sp value, and return it. */ FRAME_ADDR FRAME_CHAIN (thisframe) FRAME thisframe; { frame_find_saved_regs (thisframe, (struct frame_saved_regs *) 0); return thisframe->fsr->regs[SP_REGNUM]; } /* Put here the code to store, into a struct frame_saved_regs, the addresses of the saved registers of frame described by FRAME_INFO. This includes special registers such as pc and fp saved in special ways in the stack frame. sp is even more special: the address we return for it IS the sp for the next frame. We cache the result of doing this in the frame_cache_obstack, since it is fairly expensive. */ void frame_find_saved_regs (fi, fsr) struct frame_info *fi; struct frame_saved_regs *fsr; { register CORE_ADDR next_addr; register CORE_ADDR *saved_regs; register int regnum; register struct frame_saved_regs *cache_fsr; extern struct obstack frame_cache_obstack; CORE_ADDR ip; struct symtab_and_line sal; CORE_ADDR limit; if (!fi->fsr) { cache_fsr = (struct frame_saved_regs *) obstack_alloc (&frame_cache_obstack, sizeof (struct frame_saved_regs)); bzero (cache_fsr, sizeof (struct frame_saved_regs)); fi->fsr = cache_fsr; /* Find the start and end of the function prologue. If the PC is in the function prologue, we only consider the part that has executed already. */ ip = get_pc_function_start (fi->pc); sal = find_pc_line (ip, 0); limit = (sal.end && sal.end < fi->pc) ? sal.end : fi->pc; /* This will fill in fields in *fi as well as in cache_fsr. */ examine_prologue (ip, limit, fi->frame, cache_fsr, fi); } if (fsr) *fsr = *fi->fsr; } /* Fetch the instruction at ADDR, returning 0 if ADDR is beyond LIM or is not the address of a valid instruction, the address of the next instruction beyond ADDR otherwise. *PWORD1 receives the first word of the instruction.*/ CORE_ADDR NEXT_PROLOGUE_INSN (addr, lim, pword1) CORE_ADDR addr; CORE_ADDR lim; short *pword1; { if (addr < lim + 8) { read_memory (addr, pword1, sizeof (*pword1)); SWAP_TARGET_AND_HOST (pword1, sizeof (short)); return addr + 2; } return 0; } /* Examine the prologue of a function. `ip' points to the first instruction. `limit' is the limit of the prologue (e.g. the addr of the first linenumber, or perhaps the program counter if we're stepping through). `frame_sp' is the stack pointer value in use in this frame. `fsr' is a pointer to a frame_saved_regs structure into which we put info about the registers saved by this frame. `fi' is a struct frame_info pointer; we fill in various fields in it to reflect the offsets of the arg pointer and the locals pointer. */ static CORE_ADDR examine_prologue (ip, limit, after_prolog_fp, fsr, fi) register CORE_ADDR ip; register CORE_ADDR limit; FRAME_ADDR after_prolog_fp; struct frame_saved_regs *fsr; struct frame_info *fi; { register CORE_ADDR next_ip; int r; int i; int have_fp = 0; register int src; register struct pic_prologue_code *pcode; INSN_WORD insn_word; int size, offset; unsigned int reg_save_depth = 2; /* Number of things pushed onto stack, starts at 2, 'cause the PC is already there */ unsigned int auto_depth = 0; /* Number of bytes of autos */ char in_frame[8]; /* One for each reg */ memset (in_frame, 1, 8); for (r = 0; r < 8; r++) { fsr->regs[r] = 0; } if (after_prolog_fp == 0) { after_prolog_fp = read_register (SP_REGNUM); } if (ip == 0 || ip & ~0xffff) return 0; next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); /* Skip over any fp push instructions */ fsr->regs[6] = after_prolog_fp; while (next_ip && IS_PUSH_FP (insn_word)) { ip = next_ip; in_frame[insn_word & 0x7] = reg_save_depth; next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); reg_save_depth += 2; } /* Is this a move into the fp */ if (next_ip && IS_MOV_SP_FP (insn_word)) { ip = next_ip; next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); have_fp = 1; } /* Skip over any stack adjustment, happens either with a number of sub#2,sp or a mov #x,r5 sub r5,sp */ if (next_ip && IS_SUB2_SP (insn_word)) { while (next_ip && IS_SUB2_SP (insn_word)) { auto_depth += 2; ip = next_ip; next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); } } else { if (next_ip && IS_MOVK_R5 (insn_word)) { ip = next_ip; next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); auto_depth += insn_word; next_ip = NEXT_PROLOGUE_INSN (next_ip, limit, &insn_word); auto_depth += insn_word; } } /* Work out which regs are stored where */ while (next_ip && IS_PUSH (insn_word)) { ip = next_ip; next_ip = NEXT_PROLOGUE_INSN (ip, limit, &insn_word); fsr->regs[r] = after_prolog_fp + auto_depth; auto_depth += 2; } /* The args are always reffed based from the stack pointer */ fi->args_pointer = after_prolog_fp; /* Locals are always reffed based from the fp */ fi->locals_pointer = after_prolog_fp; /* The PC is at a known place */ fi->from_pc = read_memory_short (after_prolog_fp + 2); /* Rememeber any others too */ in_frame[PC_REGNUM] = 0; if (have_fp) /* We keep the old FP in the SP spot */ fsr->regs[SP_REGNUM] = (read_memory_short (fsr->regs[6])); else fsr->regs[SP_REGNUM] = after_prolog_fp + auto_depth; return (ip); } void init_extra_frame_info (fromleaf, fi) int fromleaf; struct frame_info *fi; { fi->fsr = 0; /* Not yet allocated */ fi->args_pointer = 0; /* Unknown */ fi->locals_pointer = 0; /* Unknown */ fi->from_pc = 0; } /* Return the saved PC from this frame. If the frame has a memory copy of SRP_REGNUM, use that. If not, just use the register SRP_REGNUM itself. */ CORE_ADDR frame_saved_pc (frame) FRAME frame; { return frame->from_pc; } CORE_ADDR frame_locals_address (fi) struct frame_info *fi; { if (!fi->locals_pointer) { struct frame_saved_regs ignore; get_frame_saved_regs (fi, &ignore); } return fi->locals_pointer; } /* Return the address of the argument block for the frame described by FI. Returns 0 if the address is unknown. */ CORE_ADDR frame_args_address (fi) struct frame_info *fi; { if (!fi->args_pointer) { struct frame_saved_regs ignore; get_frame_saved_regs (fi, &ignore); } return fi->args_pointer; } void h8300_pop_frame () { unsigned regnum; struct frame_saved_regs fsr; struct frame_info *fi; FRAME frame = get_current_frame (); fi = get_frame_info (frame); get_frame_saved_regs (fi, &fsr); for (regnum = 0; regnum < 8; regnum++) { if (fsr.regs[regnum]) { write_register (regnum, read_memory_short (fsr.regs[regnum])); } flush_cached_frames (); set_current_frame (create_new_frame (read_register (FP_REGNUM), read_pc ())); } } void print_register_hook (regno) { if (regno == 8) { /* CCR register */ int C, Z, N, V; unsigned char b[2]; unsigned char l; read_relative_register_raw_bytes (regno, b); l = b[1]; printf ("\t"); printf ("I-%d - ", (l & 0x80) != 0); printf ("H-%d - ", (l & 0x20) != 0); N = (l & 0x8) != 0; Z = (l & 0x4) != 0; V = (l & 0x2) != 0; C = (l & 0x1) != 0; printf ("N-%d ", N); printf ("Z-%d ", Z); printf ("V-%d ", V); printf ("C-%d ", C); if ((C | Z) == 0) printf ("u> "); if ((C | Z) == 1) printf ("u<= "); if ((C == 0)) printf ("u>= "); if (C == 1) printf ("u< "); if (Z == 0) printf ("!= "); if (Z == 1) printf ("== "); if ((N ^ V) == 0) printf (">= "); if ((N ^ V) == 1) printf ("< "); if ((Z | (N ^ V)) == 0) printf ("> "); if ((Z | (N ^ V)) == 1) printf ("<= "); } }