arm.h

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/* Common target dependent code for GDB on ARM systems.
   Copyright (C) 1988-2018 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_H
#define ARM_H

/* 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_FPSCR_REGNUM,

  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
};

/* Enum describing the different kinds of breakpoints.  */
enum arm_breakpoint_kinds
{
   ARM_BP_KIND_THUMB = 2,
   ARM_BP_KIND_THUMB2 = 3,
   ARM_BP_KIND_ARM = 4,
};

/* 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

#define XPSR_T      0x01000000

/* Size of integer registers.  */
#define INT_REGISTER_SIZE       4

/* Addresses for calling Thumb functions have the bit 0 set.
   Here are some macros to test, set, or clear bit 0 of addresses.  */
#define IS_THUMB_ADDR(addr)    ((addr) & 1)
#define MAKE_THUMB_ADDR(addr)  ((addr) | 1)
#define UNMAKE_THUMB_ADDR(addr) ((addr) & ~1)

/* Support routines for instruction parsing.  */
#define submask(x) ((1L << ((x) + 1)) - 1)
#define bits(obj,st,fn) (((obj) >> (st)) & submask ((fn) - (st)))
#define bit(obj,st) (((obj) >> (st)) & 1)
#define sbits(obj,st,fn) \
  ((long) (bits(obj,st,fn) | ((long) bit(obj,fn) * ~ submask (fn - st))))
#define BranchDest(addr,instr) \
  ((CORE_ADDR) (((unsigned long) (addr)) + 8 + (sbits (instr, 0, 23) << 2)))

/* Forward declaration.  */
struct regcache;

/* Return the size in bytes of the complete Thumb instruction whose
   first halfword is INST1.  */
int thumb_insn_size (unsigned short inst1);

/* Returns true if the condition evaluates to true.  */
int condition_true (unsigned long cond, unsigned long status_reg);

/* Return number of 1-bits in VAL.  */
int bitcount (unsigned long val);

/* Return 1 if THIS_INSTR might change control flow, 0 otherwise.  */
int arm_instruction_changes_pc (uint32_t this_instr);

/* Return 1 if the 16-bit Thumb instruction INST might change
   control flow, 0 otherwise.  */
int thumb_instruction_changes_pc (unsigned short inst);

/* Return 1 if the 32-bit Thumb instruction in INST1 and INST2
   might change control flow, 0 otherwise.  */
int thumb2_instruction_changes_pc (unsigned short inst1, unsigned short inst2);

/* Advance the state of the IT block and return that state.  */
int thumb_advance_itstate (unsigned int itstate);

/* Decode shifted register value.  */

unsigned long shifted_reg_val (struct regcache *regcache,
                   unsigned long inst,
                   int carry,
                   unsigned long pc_val,
                   unsigned long status_reg);

#endif