diff options
Diffstat (limited to 'gdb/z8k-tdep.c')
| -rw-r--r-- | gdb/z8k-tdep.c | 453 |
1 files changed, 453 insertions, 0 deletions
diff --git a/gdb/z8k-tdep.c b/gdb/z8k-tdep.c new file mode 100644 index 0000000..0b5c1c2 --- /dev/null +++ b/gdb/z8k-tdep.c @@ -0,0 +1,453 @@ +/* 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" + + +/* 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) + 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); +} + +int +read_memory_pointer (x) + CORE_ADDR x; +{ + return read_memory_integer (ADDR_BITS_REMOVE (x), BIG ? 4 : 2); +} + +CORE_ADDR +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 +saved_pc_after_call () +{ + 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 +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, 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; + } + _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); + +} |