228 lines
9.3 KiB
C
228 lines
9.3 KiB
C
/* Definitions to target GDB on an ISI Optimum V (3.05) under 4.3bsd.
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Copyright (C) 1987, 1989 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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/* This has not been tested on ISI's running BSD 4.2, but it will probably
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work. */
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/* Define this if the C compiler puts an underscore at the front
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of external names before giving them to the linker. */
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#define NAMES_HAVE_UNDERSCORE
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/* Debugger information will be in DBX format. */
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#define READ_DBX_FORMAT
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/*#define STACK_END_ADDR 0x10000000*/
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#define STACK_END_ADDR 0xfffe000
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/* Data segment starts at etext rounded up to DATAROUND in {N,Z}MAGIC files */
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#define DATAROUND 0x20000
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#define N_DATADDR(hdr) (hdr.a_magic != OMAGIC ? \
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(hdr.a_text + DATAROUND) & ~(DATAROUND-1) : hdr.a_text)
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/* Text segment starts at sizeof (struct exec) in {N,Z}MAGIC files */
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#define N_TXTADDR(hdr) (hdr.a_magic != OMAGIC ? sizeof (struct exec) : 0)
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/* Amount PC must be decremented by after a breakpoint.
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This is often the number of bytes in BREAKPOINT
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but not always.
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On the ISI, the kernel resets the pc to the trap instr */
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#define DECR_PC_AFTER_BREAK 0
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/* Return number of args passed to a frame.
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Can return -1, meaning no way to tell. */
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#define FRAME_NUM_ARGS(val, fi) \
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{ register CORE_ADDR pc = FRAME_SAVED_PC (fi); \
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register int insn = 0177777 & read_memory_integer (pc, 2); \
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val = 0; \
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if (insn == 0047757 || insn == 0157374) /* lea W(sp),sp or addaw #W,sp */ \
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val = read_memory_integer (pc + 2, 2); \
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else if ((insn & 0170777) == 0050217 /* addql #N, sp */ \
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|| (insn & 0170777) == 0050117) /* addqw */ \
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{ val = (insn >> 9) & 7; if (val == 0) val = 8; } \
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else if (insn == 0157774) /* addal #WW, sp */ \
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val = read_memory_integer (pc + 2, 4); \
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val >>= 2; }
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/* Put here the code to store, into a struct frame_saved_regs,
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the addresses of the saved registers of frame described by FRAME_INFO.
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This includes special registers such as pc and fp saved in special
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ways in the stack frame. sp is even more special:
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the address we return for it IS the sp for the next frame. */
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#define FRAME_FIND_SAVED_REGS(frame_info, frame_saved_regs) \
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{ register int regnum; \
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register int regmask; \
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register CORE_ADDR next_addr; \
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register CORE_ADDR pc; \
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register int insn; \
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register int offset; \
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bzero (&frame_saved_regs, sizeof frame_saved_regs); \
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if ((frame_info)->pc >= (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM*4 - 8*12 - 4 \
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&& (frame_info)->pc <= (frame_info)->frame) \
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{ next_addr = (frame_info)->frame; \
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pc = (frame_info)->frame - CALL_DUMMY_LENGTH - FP_REGNUM * 4 - 8*12 - 4; }\
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else \
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{ pc = get_pc_function_start ((frame_info)->pc); \
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/* Verify we have a link a6 instruction next, \
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or a branch followed by a link a6 instruction; \
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if not we lose. If we win, find the address above the saved \
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regs using the amount of storage from the link instruction. */\
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retry: \
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insn = read_memory_integer (pc, 2); \
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if (insn == 044016) \
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next_addr = (frame_info)->frame - read_memory_integer (pc += 2, 4), pc+=4; \
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else if (insn == 047126) \
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next_addr = (frame_info)->frame - read_memory_integer (pc += 2, 2), pc+=2; \
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else if ((insn & 0177400) == 060000) /* bra insn */ \
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{ offset = insn & 0377; \
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pc += 2; /* advance past bra */ \
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if (offset == 0) /* bra #word */ \
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offset = read_memory_integer (pc, 2), pc += 2; \
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else if (offset == 0377) /* bra #long */ \
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offset = read_memory_integer (pc, 4), pc += 4; \
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pc += offset; \
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goto retry; \
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} else goto lose; \
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/* If have an addal #-n, sp next, adjust next_addr. */ \
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if ((0177777 & read_memory_integer (pc, 2)) == 0157774) \
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next_addr += read_memory_integer (pc += 2, 4), pc += 4; \
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} \
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/* next should be a moveml to (sp) or -(sp) or a movl r,-(sp) */ \
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insn = read_memory_integer (pc, 2), pc += 2; \
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regmask = read_memory_integer (pc, 2); \
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if ((insn & 0177760) == 022700) /* movl rn, (sp) */ \
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(frame_saved_regs).regs[(insn&7) + ((insn&010)?8:0)] = next_addr; \
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else if ((insn & 0177760) == 024700) /* movl rn, -(sp) */ \
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(frame_saved_regs).regs[(insn&7) + ((insn&010)?8:0)] = next_addr-=4; \
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else if (insn == 0044327) /* moveml mask, (sp) */ \
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{ pc += 2; \
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/* Regmask's low bit is for register 0, the first written */ \
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next_addr -= 4; \
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for (regnum = 0; regnum < 16; regnum++, regmask >>= 1) \
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if (regmask & 1) \
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(frame_saved_regs).regs[regnum] = (next_addr += 4); \
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} else if (insn == 0044347) /* moveml mask, -(sp) */ \
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{ pc += 2; \
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/* Regmask's low bit is for register 15, the first pushed */ \
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for (regnum = 15; regnum >= 0; regnum--, regmask >>= 1) \
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if (regmask & 1) \
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(frame_saved_regs).regs[regnum] = (next_addr -= 4); } \
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/* clrw -(sp); movw ccr,-(sp) may follow. */ \
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if (read_memory_integer (pc, 2) == 041147 \
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&& read_memory_integer (pc+2, 2) == 042347) \
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(frame_saved_regs).regs[PS_REGNUM] = (next_addr -= 4); \
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lose: ; \
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(frame_saved_regs).regs[SP_REGNUM] = (frame_info)->frame + 8; \
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(frame_saved_regs).regs[FP_REGNUM] = (frame_info)->frame; \
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(frame_saved_regs).regs[PC_REGNUM] = (frame_info)->frame + 4; \
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}
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/* Things needed for making the inferior call functions. */
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/* Push an empty stack frame, to record the current PC, etc. */
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#define PUSH_DUMMY_FRAME \
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{ register CORE_ADDR sp = read_register (SP_REGNUM); \
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register int regnum; \
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char raw_buffer[12]; \
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sp = push_word (sp, read_register (PC_REGNUM)); \
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sp = push_word (sp, read_register (FP_REGNUM)); \
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write_register (FP_REGNUM, sp); \
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for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--) \
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{ read_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12); \
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sp = push_bytes (sp, raw_buffer, 12); } \
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for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--) \
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sp = push_word (sp, read_register (regnum)); \
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sp = push_word (sp, read_register (PS_REGNUM)); \
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write_register (SP_REGNUM, sp); }
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/* Discard from the stack the innermost frame, restoring all registers. */
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#define POP_FRAME \
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{ register FRAME frame = get_current_frame (); \
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register CORE_ADDR fp; \
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register int regnum; \
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struct frame_saved_regs fsr; \
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struct frame_info *fi; \
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char raw_buffer[12]; \
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fi = get_frame_info (frame); \
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fp = fi->frame; \
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get_frame_saved_regs (fi, &fsr); \
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for (regnum = FP0_REGNUM + 7; regnum >= FP0_REGNUM; regnum--) \
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if (fsr.regs[regnum]) \
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{ read_memory (fsr.regs[regnum], raw_buffer, 12); \
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write_register_bytes (REGISTER_BYTE (regnum), raw_buffer, 12); }\
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for (regnum = FP_REGNUM - 1; regnum >= 0; regnum--) \
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if (fsr.regs[regnum]) \
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write_register (regnum, read_memory_integer (fsr.regs[regnum], 4)); \
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if (fsr.regs[PS_REGNUM]) \
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write_register (PS_REGNUM, read_memory_integer (fsr.regs[PS_REGNUM], 4)); \
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write_register (FP_REGNUM, read_memory_integer (fp, 4)); \
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write_register (PC_REGNUM, read_memory_integer (fp + 4, 4)); \
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write_register (SP_REGNUM, fp + 8); \
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flush_cached_frames (); \
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set_current_frame ( create_new_frame (read_register (FP_REGNUM), \
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read_pc ())); }
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/* This sequence of words is the instructions
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fmovem #<f0-f7>,-(sp)
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moveml 0xfffc,-(sp)
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clrw -(sp)
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movew ccr,-(sp)
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/..* The arguments are pushed at this point by GDB;
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no code is needed in the dummy for this.
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The CALL_DUMMY_START_OFFSET gives the position of
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the following jsr instruction. *../
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jsr @#32323232
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addl #69696969,sp
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bpt
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nop
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Note this is 24 bytes.
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We actually start executing at the jsr, since the pushing of the
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registers is done by PUSH_DUMMY_FRAME. If this were real code,
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the arguments for the function called by the jsr would be pushed
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between the moveml and the jsr, and we could allow it to execute through.
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But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
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and we cannot allow the moveml to push the registers again lest they be
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taken for the arguments. */
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#define CALL_DUMMY {0xf227e0ff, 0x48e7fffc, 0x426742e7, 0x4eb93232, 0x3232dffc, 0x69696969, 0x4e4f4e71}
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#define CALL_DUMMY_LENGTH 28
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#define CALL_DUMMY_START_OFFSET 12
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/* Insert the specified number of args and function address
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into a call sequence of the above form stored at DUMMYNAME. */
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#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
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{ *(int *)((char *) dummyname + 20) = nargs * 4; \
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*(int *)((char *) dummyname + 14) = fun; }
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#define HAVE_68881 1
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#include "tm-68k.h"
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