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/* Common target dependent code for GDB on ARM systems.

   Copyright (C) 2002, 2003, 2007, 2008, 2009, 2010

   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 3 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, see <http://www.gnu.org/licenses/>.  */

#ifndef ARM_TDEP_H

#define ARM_TDEP_H

/* Forward declarations.  */

struct gdbarch;

struct regset;

/* Register numbers of various important registers.  */

enum gdb_regnum {

  ARM_A1_REGNUM = 0,             /* first integer-like argument */

  ARM_A4_REGNUM = 3,            /* last integer-like argument */

  ARM_AP_REGNUM = 11,

  ARM_IP_REGNUM = 12,

  ARM_SP_REGNUM = 13,           /* Contains address of top of stack */

  ARM_LR_REGNUM = 14,           /* address to return to from a function call */

  ARM_PC_REGNUM = 15,           /* Contains program counter */

  ARM_F0_REGNUM = 16,           /* first floating point register */

  ARM_F3_REGNUM = 19,           /* last floating point argument register */

  ARM_F7_REGNUM = 23,           /* last floating point register */

  ARM_FPS_REGNUM = 24,          /* floating point status register */

  ARM_PS_REGNUM = 25,           /* Contains processor status */

  ARM_WR0_REGNUM,               /* WMMX data registers.  */

  ARM_WR15_REGNUM = ARM_WR0_REGNUM + 15,

  ARM_WC0_REGNUM,               /* WMMX control registers.  */

  ARM_WCSSF_REGNUM = ARM_WC0_REGNUM + 2,

  ARM_WCASF_REGNUM = ARM_WC0_REGNUM + 3,

  ARM_WC7_REGNUM = ARM_WC0_REGNUM + 7,

  ARM_WCGR0_REGNUM,             /* WMMX general purpose registers.  */

  ARM_WCGR3_REGNUM = ARM_WCGR0_REGNUM + 3,

  ARM_WCGR7_REGNUM = ARM_WCGR0_REGNUM + 7,

  ARM_D0_REGNUM,                /* VFP double-precision registers.  */

  ARM_D31_REGNUM = ARM_D0_REGNUM + 31,

  ARM_NUM_REGS,

  /* Other useful registers.  */

  ARM_FP_REGNUM = 11,           /* Frame register in ARM code, if used.  */

  THUMB_FP_REGNUM = 7,          /* Frame register in Thumb code, if used.  */

  ARM_NUM_ARG_REGS = 4,

  ARM_LAST_ARG_REGNUM = ARM_A4_REGNUM,

  ARM_NUM_FP_ARG_REGS = 4,

  ARM_LAST_FP_ARG_REGNUM = ARM_F3_REGNUM

};

/* Size of integer registers.  */

#define INT_REGISTER_SIZE               4

/* Say how long FP registers are.  Used for documentation purposes and

   code readability in this header.  IEEE extended doubles are 80

   bits.  DWORD aligned they use 96 bits.  */

#define FP_REGISTER_SIZE        12

/* Number of machine registers.  The only define actually required

   is gdbarch_num_regs.  The other definitions are used for documentation

   purposes and code readability.  */

/* For 26 bit ARM code, a fake copy of the PC is placed in register 25 (PS)

   (and called PS for processor status) so the status bits can be cleared

   from the PC (register 15).  For 32 bit ARM code, a copy of CPSR is placed

   in PS.  */

#define NUM_FREGS       8       /* Number of floating point registers.  */

#define NUM_SREGS       2       /* Number of status registers.  */

#define NUM_GREGS       16      /* Number of general purpose registers.  */

/* Instruction condition field values.  */

#define INST_EQ         0x0

#define INST_NE         0x1

#define INST_CS         0x2

#define INST_CC         0x3

#define INST_MI         0x4

#define INST_PL         0x5

#define INST_VS         0x6

#define INST_VC         0x7

#define INST_HI         0x8

#define INST_LS         0x9

#define INST_GE         0xa

#define INST_LT         0xb

#define INST_GT         0xc

#define INST_LE         0xd

#define INST_AL         0xe

#define INST_NV         0xf

#define FLAG_N          0x80000000

#define FLAG_Z          0x40000000

#define FLAG_C          0x20000000

#define FLAG_V          0x10000000

#define CPSR_T          0x20

/* Type of floating-point code in use by inferior.  There are really 3 models

   that are traditionally supported (plus the endianness issue), but gcc can

   only generate 2 of those.  The third is APCS_FLOAT, where arguments to

   functions are passed in floating-point registers.

   In addition to the traditional models, VFP adds two more.

   If you update this enum, don't forget to update fp_model_strings in

   arm-tdep.c.  */

enum arm_float_model

{

  ARM_FLOAT_AUTO,       /* Automatic detection.  Do not set in tdep.  */

  ARM_FLOAT_SOFT_FPA,   /* Traditional soft-float (mixed-endian on LE ARM).  */

  ARM_FLOAT_FPA,        /* FPA co-processor.  GCC calling convention.  */

  ARM_FLOAT_SOFT_VFP,   /* Soft-float with pure-endian doubles.  */

  ARM_FLOAT_VFP,        /* Full VFP calling convention.  */

  ARM_FLOAT_LAST        /* Keep at end.  */

};

/* ABI used by the inferior.  */

enum arm_abi_kind

{

  ARM_ABI_AUTO,

  ARM_ABI_APCS,

  ARM_ABI_AAPCS,

  ARM_ABI_LAST

};

/* Convention for returning structures.  */

enum struct_return

{

  pcc_struct_return,            /* Return "short" structures in memory.  */

  reg_struct_return             /* Return "short" structures in registers.  */

};

/* Target-dependent structure in gdbarch.  */

struct gdbarch_tdep

{

  /* The ABI for this architecture.  It should never be set to

     ARM_ABI_AUTO.  */

  enum arm_abi_kind arm_abi;

  enum arm_float_model fp_model; /* Floating point calling conventions.  */

  int have_fpa_registers;       /* Does the target report the FPA registers?  */

  int have_vfp_registers;       /* Does the target report the VFP registers?  */

  int have_vfp_pseudos;         /* Are we synthesizing the single precision

                                   VFP registers?  */

  int have_neon_pseudos;        /* Are we synthesizing the quad precision

                                   NEON registers?  Requires

                                   have_vfp_pseudos.  */

  int have_neon;                /* Do we have a NEON unit?  */

  CORE_ADDR lowest_pc;          /* Lowest address at which instructions

                                   will appear.  */

  const char *arm_breakpoint;   /* Breakpoint pattern for an ARM insn.  */

  int arm_breakpoint_size;      /* And its size.  */

  const char *thumb_breakpoint; /* Breakpoint pattern for a Thumb insn.  */

  int thumb_breakpoint_size;    /* And its size.  */

  /* If the Thumb breakpoint is an undefined instruction (which is

     affected by IT blocks) rather than a BKPT instruction (which is

     not), then we need a 32-bit Thumb breakpoint to preserve the

     instruction count in IT blocks.  */

  const char *thumb2_breakpoint;

  int thumb2_breakpoint_size;

  int jb_pc;                    /* Offset to PC value in jump buffer.

                                   If this is negative, longjmp support

                                   will be disabled.  */

  size_t jb_elt_size;           /* And the size of each entry in the buf.  */

  /* Convention for returning structures.  */

  enum struct_return struct_return;

  /* Cached core file helpers.  */

  struct regset *gregset, *fpregset;

  /* ISA-specific data types.  */

  struct type *arm_ext_type;

  struct type *neon_double_type;

  struct type *neon_quad_type;

};

/* Structures used for displaced stepping.  */

/* The maximum number of temporaries available for displaced instructions.  */

#define DISPLACED_TEMPS                 16

/* The maximum number of modified instructions generated for one single-stepped

   instruction, including the breakpoint (usually at the end of the instruction

   sequence) and any scratch words, etc.  */

#define DISPLACED_MODIFIED_INSNS        8

struct displaced_step_closure

{

  ULONGEST tmp[DISPLACED_TEMPS];

  int rd;

  int wrote_to_pc;

  union

  {

    struct

    {

      int xfersize;

      int rn;                      /* Writeback register.  */

      unsigned int immed : 1;      /* Offset is immediate.  */

      unsigned int writeback : 1;  /* Perform base-register writeback.  */

      unsigned int restore_r4 : 1; /* Used r4 as scratch.  */

    } ldst;

    struct

    {

      unsigned long dest;

      unsigned int link : 1;

      unsigned int exchange : 1;

      unsigned int cond : 4;

    } branch;

    struct

    {

      unsigned int regmask;

      int rn;

      CORE_ADDR xfer_addr;

      unsigned int load : 1;

      unsigned int user : 1;

      unsigned int increment : 1;

      unsigned int before : 1;

      unsigned int writeback : 1;

      unsigned int cond : 4;

    } block;

    struct

    {

      unsigned int immed : 1;

    } preload;

    struct

    {

      /* If non-NULL, override generic SVC handling (e.g. for a particular

         OS).  */

      int (*copy_svc_os) (struct gdbarch *gdbarch, uint32_t insn, CORE_ADDR to,

                          struct regcache *regs,

                          struct displaced_step_closure *dsc);

    } svc;

  } u;

  unsigned long modinsn[DISPLACED_MODIFIED_INSNS];

  int numinsns;

  CORE_ADDR insn_addr;

  CORE_ADDR scratch_base;

  void (*cleanup) (struct gdbarch *, struct regcache *,

                   struct displaced_step_closure *);

};

/* Values for the WRITE_PC argument to displaced_write_reg.  If the register

   write may write to the PC, specifies the way the CPSR T bit, etc. is

   modified by the instruction.  */

enum pc_write_style

{

  BRANCH_WRITE_PC,

  BX_WRITE_PC,

  LOAD_WRITE_PC,

  ALU_WRITE_PC,

  CANNOT_WRITE_PC

};

extern void

  arm_process_displaced_insn (struct gdbarch *gdbarch, uint32_t insn,

                              CORE_ADDR from, CORE_ADDR to,

                              struct regcache *regs,

                              struct displaced_step_closure *dsc);

extern void

  arm_displaced_init_closure (struct gdbarch *gdbarch, CORE_ADDR from,

                              CORE_ADDR to, struct displaced_step_closure *dsc);

extern ULONGEST

  displaced_read_reg (struct regcache *regs, CORE_ADDR from, int regno);

extern void

  displaced_write_reg (struct regcache *regs,

                       struct displaced_step_closure *dsc, int regno,

                       ULONGEST val, enum pc_write_style write_pc);

CORE_ADDR arm_skip_stub (struct frame_info *, CORE_ADDR);

CORE_ADDR arm_get_next_pc (struct frame_info *, CORE_ADDR);

int arm_software_single_step (struct frame_info *);

extern struct displaced_step_closure *

  arm_displaced_step_copy_insn (struct gdbarch *, CORE_ADDR, CORE_ADDR,

                                struct regcache *);

extern void arm_displaced_step_fixup (struct gdbarch *,

                                      struct displaced_step_closure *,

                                      CORE_ADDR, CORE_ADDR, struct regcache *);

/* Functions exported from armbsd-tdep.h.  */

/* Return the appropriate register set for the core section identified

   by SECT_NAME and SECT_SIZE.  */

extern const struct regset *

  armbsd_regset_from_core_section (struct gdbarch *gdbarch,

                                   const char *sect_name, size_t sect_size);

#endif /* arm-tdep.h */