| /* Target-machine dependent code for Zilog Z8000, for GDB. |
| Copyright (C) 1992, 1993, 1994 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. */ |
| |
| /* |
| Contributed by Steve Chamberlain |
| sac@cygnus.com |
| */ |
| |
| #include "defs.h" |
| #include "frame.h" |
| #include "obstack.h" |
| #include "symtab.h" |
| #include "gdbcmd.h" |
| #include "gdbtypes.h" |
| #include "dis-asm.h" |
| #include "gdbcore.h" |
| |
| #include "value.h" /* For read_register() */ |
| |
| |
| static int read_memory_pointer (CORE_ADDR x); |
| |
| /* 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 |
| z8k_frame_saved_pc (frame) |
| struct frame_info *frame; |
| { |
| return read_memory_pointer (frame->frame + (BIG ? 4 : 2)); |
| } |
| |
| #define IS_PUSHL(x) (BIG ? ((x & 0xfff0) == 0x91e0):((x & 0xfff0) == 0x91F0)) |
| #define IS_PUSHW(x) (BIG ? ((x & 0xfff0) == 0x93e0):((x & 0xfff0)==0x93f0)) |
| #define IS_MOVE_FP(x) (BIG ? x == 0xa1ea : x == 0xa1fa) |
| #define IS_MOV_SP_FP(x) (BIG ? x == 0x94ea : x == 0x0d76) |
| #define IS_SUB2_SP(x) (x==0x1b87) |
| #define IS_MOVK_R5(x) (x==0x7905) |
| #define IS_SUB_SP(x) ((x & 0xffff) == 0x020f) |
| #define IS_PUSH_FP(x) (BIG ? (x == 0x93ea) : (x == 0x93fa)) |
| |
| /* work out how much local space is on the stack and |
| return the pc pointing to the first push */ |
| |
| static CORE_ADDR |
| skip_adjust (pc, size) |
| CORE_ADDR pc; |
| int *size; |
| { |
| *size = 0; |
| |
| if (IS_PUSH_FP (read_memory_short (pc)) |
| && IS_MOV_SP_FP (read_memory_short (pc + 2))) |
| { |
| /* This is a function with an explict frame pointer */ |
| pc += 4; |
| *size += 2; /* remember the frame pointer */ |
| } |
| |
| /* remember any stack adjustment */ |
| if (IS_SUB_SP (read_memory_short (pc))) |
| { |
| *size += read_memory_short (pc + 2); |
| pc += 4; |
| } |
| return pc; |
| } |
| |
| static CORE_ADDR examine_frame PARAMS ((CORE_ADDR, CORE_ADDR * regs, CORE_ADDR)); |
| static CORE_ADDR |
| examine_frame (pc, regs, sp) |
| CORE_ADDR pc; |
| CORE_ADDR *regs; |
| CORE_ADDR sp; |
| { |
| int w = read_memory_short (pc); |
| int offset = 0; |
| int regno; |
| |
| for (regno = 0; regno < NUM_REGS; regno++) |
| regs[regno] = 0; |
| |
| while (IS_PUSHW (w) || IS_PUSHL (w)) |
| { |
| /* work out which register is being pushed to where */ |
| if (IS_PUSHL (w)) |
| { |
| regs[w & 0xf] = offset; |
| regs[(w & 0xf) + 1] = offset + 2; |
| offset += 4; |
| } |
| else |
| { |
| regs[w & 0xf] = offset; |
| offset += 2; |
| } |
| pc += 2; |
| w = read_memory_short (pc); |
| } |
| |
| if (IS_MOVE_FP (w)) |
| { |
| /* We know the fp */ |
| |
| } |
| else if (IS_SUB_SP (w)) |
| { |
| /* Subtracting a value from the sp, so were in a function |
| which needs stack space for locals, but has no fp. We fake up |
| the values as if we had an fp */ |
| regs[FP_REGNUM] = sp; |
| } |
| else |
| { |
| /* This one didn't have an fp, we'll fake it up */ |
| regs[SP_REGNUM] = sp; |
| } |
| /* stack pointer contains address of next frame */ |
| /* regs[fp_regnum()] = fp; */ |
| regs[SP_REGNUM] = sp; |
| return pc; |
| } |
| |
| CORE_ADDR |
| z8k_skip_prologue (start_pc) |
| CORE_ADDR start_pc; |
| { |
| CORE_ADDR dummy[NUM_REGS]; |
| |
| return examine_frame (start_pc, dummy, 0); |
| } |
| |
| CORE_ADDR |
| z8k_addr_bits_remove (addr) |
| CORE_ADDR addr; |
| { |
| return (addr & PTR_MASK); |
| } |
| |
| static int |
| read_memory_pointer (CORE_ADDR x) |
| { |
| return read_memory_integer (ADDR_BITS_REMOVE (x), BIG ? 4 : 2); |
| } |
| |
| CORE_ADDR |
| z8k_frame_chain (thisframe) |
| struct frame_info *thisframe; |
| { |
| if (thisframe->prev == 0) |
| { |
| /* This is the top of the stack, let's get the sp for real */ |
| } |
| if (!inside_entry_file (thisframe->pc)) |
| { |
| return read_memory_pointer (thisframe->frame); |
| } |
| return 0; |
| } |
| |
| void |
| init_frame_pc () |
| { |
| abort (); |
| } |
| |
| /* 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. */ |
| |
| void |
| z8k_frame_init_saved_regs (frame_info) |
| struct frame_info *frame_info; |
| { |
| CORE_ADDR pc; |
| int w; |
| |
| frame_saved_regs_zalloc (frame_info); |
| pc = get_pc_function_start (frame_info->pc); |
| |
| /* wander down the instruction stream */ |
| examine_frame (pc, frame_info->saved_regs, frame_info->frame); |
| |
| } |
| |
| void |
| z8k_push_dummy_frame () |
| { |
| abort (); |
| } |
| |
| int |
| gdb_print_insn_z8k (memaddr, info) |
| bfd_vma memaddr; |
| disassemble_info *info; |
| { |
| if (BIG) |
| return print_insn_z8001 (memaddr, info); |
| else |
| return print_insn_z8002 (memaddr, info); |
| } |
| |
| /* 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; |
| { |
| char buf[2]; |
| if (addr < lim + 8) |
| { |
| read_memory (addr, buf, 2); |
| *pword1 = extract_signed_integer (buf, 2); |
| |
| return addr + 2; |
| } |
| return 0; |
| } |
| |
| #if 0 |
| /* 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 (fip, fsrp) |
| struct frame_info *fip; |
| struct frame_saved_regs *fsrp; |
| { |
| int locals; |
| CORE_ADDR pc; |
| CORE_ADDR adr; |
| int i; |
| |
| memset (fsrp, 0, sizeof *fsrp); |
| |
| pc = skip_adjust (get_pc_function_start (fip->pc), &locals); |
| |
| { |
| adr = FRAME_FP (fip) - locals; |
| for (i = 0; i < 8; i++) |
| { |
| int word = read_memory_short (pc); |
| |
| pc += 2; |
| if (IS_PUSHL (word)) |
| { |
| fsrp->regs[word & 0xf] = adr; |
| fsrp->regs[(word & 0xf) + 1] = adr - 2; |
| adr -= 4; |
| } |
| else if (IS_PUSHW (word)) |
| { |
| fsrp->regs[word & 0xf] = adr; |
| adr -= 2; |
| } |
| else |
| break; |
| } |
| |
| } |
| |
| fsrp->regs[PC_REGNUM] = fip->frame + 4; |
| fsrp->regs[FP_REGNUM] = fip->frame; |
| |
| } |
| #endif |
| |
| int |
| z8k_saved_pc_after_call (struct frame_info *frame) |
| { |
| return ADDR_BITS_REMOVE |
| (read_memory_integer (read_register (SP_REGNUM), PTR_SIZE)); |
| } |
| |
| |
| void |
| extract_return_value (type, regbuf, valbuf) |
| struct type *type; |
| char *regbuf; |
| char *valbuf; |
| { |
| int b; |
| int len = TYPE_LENGTH (type); |
| |
| for (b = 0; b < len; b += 2) |
| { |
| int todo = len - b; |
| |
| if (todo > 2) |
| todo = 2; |
| memcpy (valbuf + b, regbuf + b, todo); |
| } |
| } |
| |
| void |
| write_return_value (type, valbuf) |
| struct type *type; |
| char *valbuf; |
| { |
| int reg; |
| int len; |
| |
| for (len = 0; len < TYPE_LENGTH (type); len += 2) |
| write_register_bytes (REGISTER_BYTE (len / 2 + 2), valbuf + len, 2); |
| } |
| |
| void |
| store_struct_return (addr, sp) |
| CORE_ADDR addr; |
| CORE_ADDR sp; |
| { |
| write_register (2, addr); |
| } |
| |
| |
| void |
| z8k_print_register_hook (regno) |
| int regno; |
| { |
| if ((regno & 1) == 0 && regno < 16) |
| { |
| unsigned short l[2]; |
| |
| read_relative_register_raw_bytes (regno, (char *) (l + 0)); |
| read_relative_register_raw_bytes (regno + 1, (char *) (l + 1)); |
| printf_unfiltered ("\t"); |
| printf_unfiltered ("%04x%04x", l[0], l[1]); |
| } |
| |
| if ((regno & 3) == 0 && regno < 16) |
| { |
| unsigned short l[4]; |
| |
| read_relative_register_raw_bytes (regno, (char *) (l + 0)); |
| read_relative_register_raw_bytes (regno + 1, (char *) (l + 1)); |
| read_relative_register_raw_bytes (regno + 2, (char *) (l + 2)); |
| read_relative_register_raw_bytes (regno + 3, (char *) (l + 3)); |
| |
| printf_unfiltered ("\t"); |
| printf_unfiltered ("%04x%04x%04x%04x", l[0], l[1], l[2], l[3]); |
| } |
| if (regno == 15) |
| { |
| unsigned short rval; |
| int i; |
| |
| read_relative_register_raw_bytes (regno, (char *) (&rval)); |
| |
| printf_unfiltered ("\n"); |
| for (i = 0; i < 10; i += 2) |
| { |
| printf_unfiltered ("(sp+%d=%04x)", i, |
| (unsigned int)read_memory_short (rval + i)); |
| } |
| } |
| |
| } |
| |
| void |
| z8k_pop_frame () |
| { |
| } |
| |
| struct cmd_list_element *setmemorylist; |
| |
| void |
| z8k_set_pointer_size (newsize) |
| int newsize; |
| { |
| static int oldsize = 0; |
| |
| if (oldsize != newsize) |
| { |
| printf_unfiltered ("pointer size set to %d bits\n", newsize); |
| oldsize = newsize; |
| if (newsize == 32) |
| { |
| BIG = 1; |
| } |
| else |
| { |
| BIG = 0; |
| } |
| /* FIXME: This code should be using the GDBARCH framework to |
| handle changed type sizes. If this problem is ever fixed |
| (the direct reference to _initialize_gdbtypes() below |
| eliminated) then Makefile.in should be updated so that |
| z8k-tdep.c is again compiled with -Werror. */ |
| _initialize_gdbtypes (); |
| } |
| } |
| |
| static void |
| segmented_command (args, from_tty) |
| char *args; |
| int from_tty; |
| { |
| z8k_set_pointer_size (32); |
| } |
| |
| static void |
| unsegmented_command (args, from_tty) |
| char *args; |
| int from_tty; |
| { |
| z8k_set_pointer_size (16); |
| } |
| |
| static void |
| set_memory (args, from_tty) |
| char *args; |
| int from_tty; |
| { |
| printf_unfiltered ("\"set memory\" must be followed by the name of a memory subcommand.\n"); |
| help_list (setmemorylist, "set memory ", -1, gdb_stdout); |
| } |
| |
| void |
| _initialize_z8ktdep () |
| { |
| tm_print_insn = gdb_print_insn_z8k; |
| |
| add_prefix_cmd ("memory", no_class, set_memory, |
| "set the memory model", &setmemorylist, "set memory ", 0, |
| &setlist); |
| add_cmd ("segmented", class_support, segmented_command, |
| "Set segmented memory model.", &setmemorylist); |
| add_cmd ("unsegmented", class_support, unsegmented_command, |
| "Set unsegmented memory model.", &setmemorylist); |
| |
| } |