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/* Definitions to make GDB run on a mips box under Mach 3.0

   Copyright 1992, 1993, 1998, 2000, 2001 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.  */

/* Mach specific routines for little endian mips (e.g. pmax)

 * running Mach 3.0

 *

 * Author: Jukka Virtanen <jtv@hut.fi>

 */

#include "defs.h"

#include "inferior.h"

#include "regcache.h"

#include <stdio.h>

#include <mach.h>

#include <mach/message.h>

#include <mach/exception.h>

#include <mach_error.h>

/* Find offsets to thread states at compile time.

 * If your compiler does not grok this, check the hand coded

 * offsets and use them.

 */

#if 1

#define  REG_OFFSET(reg) (int)(&((struct mips_thread_state *)0)->reg)

#define CREG_OFFSET(reg) (int)(&((struct mips_float_state *)0)->reg)

#define EREG_OFFSET(reg) (int)(&((struct mips_exc_state *)0)->reg)

/* at reg_offset[i] is the offset to the mips_thread_state

 * location where the gdb registers[i] is stored.

 *

 * -1 means mach does not save it anywhere.

 */

static int reg_offset[] =

{

  /*  zero              at                v0                v1       */

  -1, REG_OFFSET (r1), REG_OFFSET (r2), REG_OFFSET (r3),

  /*  a0                a1                a2                a3       */

  REG_OFFSET (r4), REG_OFFSET (r5), REG_OFFSET (r6), REG_OFFSET (r7),

  /*  t0                t1                t2                t3       */

  REG_OFFSET (r8), REG_OFFSET (r9), REG_OFFSET (r10), REG_OFFSET (r11),

  /*  t4                t5                t6                t7       */

  REG_OFFSET (r12), REG_OFFSET (r13), REG_OFFSET (r14), REG_OFFSET (r15),

  /*  s0                s1                s2                s3       */

  REG_OFFSET (r16), REG_OFFSET (r17), REG_OFFSET (r18), REG_OFFSET (r19),

  /*  s4                s5                s6                s7       */

  REG_OFFSET (r20), REG_OFFSET (r21), REG_OFFSET (r22), REG_OFFSET (r23),

  /*  t8                t9                k0                k1       */

  REG_OFFSET (r24), REG_OFFSET (r25), REG_OFFSET (r26), REG_OFFSET (r27),

  /*  gp                sp            s8(30) == fp(72)      ra       */

  REG_OFFSET (r28), REG_OFFSET (r29), REG_OFFSET (r30), REG_OFFSET (r31),

  /*  sr(32) PS_REGNUM   */

  EREG_OFFSET (coproc_state),

  /*  lo(33)            hi(34)    */

  REG_OFFSET (mdlo), REG_OFFSET (mdhi),

  /*  bad(35)                 cause(36)          pc(37)  */

  EREG_OFFSET (address), EREG_OFFSET (cause), REG_OFFSET (pc),

  /*  f0(38)             f1(39)             f2(40)             f3(41)   */

  CREG_OFFSET (r0), CREG_OFFSET (r1), CREG_OFFSET (r2), CREG_OFFSET (r3),

  CREG_OFFSET (r4), CREG_OFFSET (r5), CREG_OFFSET (r6), CREG_OFFSET (r7),

  CREG_OFFSET (r8), CREG_OFFSET (r9), CREG_OFFSET (r10), CREG_OFFSET (r11),

  CREG_OFFSET (r12), CREG_OFFSET (r13), CREG_OFFSET (r14), CREG_OFFSET (r15),

  CREG_OFFSET (r16), CREG_OFFSET (r17), CREG_OFFSET (r18), CREG_OFFSET (r19),

  CREG_OFFSET (r20), CREG_OFFSET (r21), CREG_OFFSET (r22), CREG_OFFSET (r23),

  CREG_OFFSET (r24), CREG_OFFSET (r25), CREG_OFFSET (r26), CREG_OFFSET (r27),

  CREG_OFFSET (r28), CREG_OFFSET (r29), CREG_OFFSET (r30), CREG_OFFSET (r31),

  /*  fsr(70)           fir(71)         fp(72) == s8(30) */

  CREG_OFFSET (csr), CREG_OFFSET (esr), REG_OFFSET (r30)

};

#else

/* If the compiler does not grok the above defines */

static int reg_offset[] =

{

/* mach_thread_state offsets: */

  -1, 0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56,

  60, 64, 68, 72, 76, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120,

/*sr, lo, hi,addr,cause,pc   */

  8, 124, 128, 4, 0, 132,

/* mach_float_state offsets: */

  0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 60,

  64, 68, 72, 76, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120, 124,

/*fsr,fir */

  128, 132,

/* FP_REGNUM pseudo maps to s8==r30 in mach_thread_state */

  116

};

#endif

/* Fetch COUNT contiguous registers from thread STATE starting from REGNUM

 * Caller knows that the regs handled in one transaction are of same size.

 */

#define FETCH_REGS(state, regnum, count) \

  memcpy (&registers[REGISTER_BYTE (regnum)], \

          (char *)state+reg_offset[ regnum ], \

          count*REGISTER_SIZE)

/* Store COUNT contiguous registers to thread STATE starting from REGNUM */

#define STORE_REGS(state, regnum, count) \

  memcpy ((char *)state+reg_offset[ regnum ], \

          &registers[REGISTER_BYTE (regnum)], \

          count*REGISTER_SIZE)

#define REGS_ALL    -1

#define REGS_NORMAL  1

#define REGS_EXC     2

#define REGS_COP1    4

/* Hardware regs that matches FP_REGNUM */

#define MACH_FP_REGNUM 30

/* Fech thread's registers. if regno == -1, fetch all regs */

void

fetch_inferior_registers (int regno)

{

  kern_return_t ret;

  thread_state_data_t state;

  struct mips_exc_state exc_state;

  int stateCnt = MIPS_THREAD_STATE_COUNT;

  int which_regs = 0;            /* A bit mask */

  if (!MACH_PORT_VALID (current_thread))

    error ("fetch inferior registers: Invalid thread");

  if (regno < -1 || regno >= NUM_REGS)

    error ("invalid register %d supplied to fetch_inferior_registers", regno);

  if (regno == -1)

    which_regs = REGS_ALL;

  else if (regno == ZERO_REGNUM)

    {

      int zero = 0;

      supply_register (ZERO_REGNUM, &zero);

      return;

    }

  else if ((ZERO_REGNUM < regno && regno < PS_REGNUM)

           || regno == FP_REGNUM

           || regno == LO_REGNUM

           || regno == HI_REGNUM

           || regno == PC_REGNUM)

    which_regs = REGS_NORMAL;

  else if (FP0_REGNUM <= regno && regno <= FCRIR_REGNUM)

    which_regs = REGS_COP1 | REGS_EXC;

  else

    which_regs = REGS_EXC;

  /* fetch regs saved to mips_thread_state */

  if (which_regs & REGS_NORMAL)

    {

      ret = thread_get_state (current_thread,

                              MIPS_THREAD_STATE,

                              state,

                              &stateCnt);

      CHK ("fetch inferior registers: thread_get_state", ret);

      if (which_regs == REGS_NORMAL)

        {

          /* Fetch also FP_REGNUM if fetching MACH_FP_REGNUM and vice versa */

          if (regno == MACH_FP_REGNUM || regno == FP_REGNUM)

            {

              supply_register (FP_REGNUM,

                               (char *) state + reg_offset[MACH_FP_REGNUM]);

              supply_register (MACH_FP_REGNUM,

                               (char *) state + reg_offset[MACH_FP_REGNUM]);

            }

          else

            supply_register (regno,

                             (char *) state + reg_offset[regno]);

          return;

        }

      /* ZERO_REGNUM is always zero */

      *(int *) registers = 0;

      /* Copy thread saved regs 1..31 to gdb's reg value array

       * Luckily, they are contiquous

       */

      FETCH_REGS (state, 1, 31);

      /* Copy mdlo and mdhi */

      FETCH_REGS (state, LO_REGNUM, 2);

      /* Copy PC */

      FETCH_REGS (state, PC_REGNUM, 1);

      /* Mach 3.0 saves FP to MACH_FP_REGNUM.

       * For some reason gdb wants to assign a pseudo register for it.

       */

      FETCH_REGS (state, FP_REGNUM, 1);

    }

  /* Read exc state. Also read if need to fetch floats */

  if (which_regs & REGS_EXC)

    {

      stateCnt = MIPS_EXC_STATE_COUNT;

      ret = thread_get_state (current_thread,

                              MIPS_EXC_STATE,

                              (thread_state_t) & exc_state,

                              &stateCnt);

      CHK ("fetch inferior regs (exc): thread_get_state", ret);

      /* We need to fetch exc_state to see if the floating

       * state is valid for the thread.

       */

      /* cproc_state: Which coprocessors the thread uses */

      supply_register (PS_REGNUM,

                       (char *) &exc_state + reg_offset[PS_REGNUM]);

      if (which_regs == REGS_EXC || which_regs == REGS_ALL)

        {

          supply_register (BADVADDR_REGNUM,

                         (char *) &exc_state + reg_offset[BADVADDR_REGNUM]);

          supply_register (CAUSE_REGNUM,

                           (char *) &exc_state + reg_offset[CAUSE_REGNUM]);

          if (which_regs == REGS_EXC)

            return;

        }

    }

  if (which_regs & REGS_COP1)

    {

      /* If the thread does not have saved COPROC1, set regs to zero */

      if (!(exc_state.coproc_state & MIPS_STATUS_USE_COP1))

        bzero (&registers[REGISTER_BYTE (FP0_REGNUM)],

               sizeof (struct mips_float_state));

      else

        {

          stateCnt = MIPS_FLOAT_STATE_COUNT;

          ret = thread_get_state (current_thread,

                                  MIPS_FLOAT_STATE,

                                  state,

                                  &stateCnt);

          CHK ("fetch inferior regs (floats): thread_get_state", ret);

          if (regno != -1)

            {

              supply_register (regno,

                               (char *) state + reg_offset[regno]);

              return;

            }

          FETCH_REGS (state, FP0_REGNUM, 34);

        }

    }

  /* All registers are valid, if not returned yet */

  registers_fetched ();

}

/* Store gdb's view of registers to the thread.

 * All registers are always valid when entering here.

 * @@ ahem, maybe that is too strict, we could validate the necessary ones

 *    here.

 *

 * Hmm. It seems that gdb set $reg=value command first reads everything,

 * then sets the reg and then stores everything. -> we must make sure

 * that the immutable registers are not changed by reading them first.

 */

void

store_inferior_registers (register int regno)

{

  thread_state_data_t state;

  kern_return_t ret;

  if (!MACH_PORT_VALID (current_thread))

    error ("store inferior registers: Invalid thread");

  /* Check for read only regs.

   * @@ If some of these is can be changed, fix this

   */

  if (regno == ZERO_REGNUM ||

      regno == PS_REGNUM ||

      regno == BADVADDR_REGNUM ||

      regno == CAUSE_REGNUM ||

      regno == FCRIR_REGNUM)

    {

      message ("You can not alter read-only register `%s'",

               REGISTER_NAME (regno));

      fetch_inferior_registers (regno);

      return;

    }

  if (regno == -1)

    {

      /* Don't allow these to change */

      /* ZERO_REGNUM */

      *(int *) registers = 0;

      fetch_inferior_registers (PS_REGNUM);

      fetch_inferior_registers (BADVADDR_REGNUM);

      fetch_inferior_registers (CAUSE_REGNUM);

      fetch_inferior_registers (FCRIR_REGNUM);

    }

  if (regno == -1 || (ZERO_REGNUM < regno && regno <= PC_REGNUM))

    {

#if 1

      /* Mach 3.0 saves thread's FP to MACH_FP_REGNUM.

       * GDB wants assigns a pseudo register FP_REGNUM for frame pointer.

       *

       * @@@ Here I assume (!) that gdb's FP has the value that

       *     should go to threads frame pointer. If not true, this

       *     fails badly!!!!!

       */

      memcpy (&registers[REGISTER_BYTE (MACH_FP_REGNUM)],

              &registers[REGISTER_BYTE (FP_REGNUM)],

              REGISTER_RAW_SIZE (FP_REGNUM));

#endif

      /* Save gdb's regs 1..31 to thread saved regs 1..31

       * Luckily, they are contiquous

       */

      STORE_REGS (state, 1, 31);

      /* Save mdlo, mdhi */

      STORE_REGS (state, LO_REGNUM, 2);

      /* Save PC */

      STORE_REGS (state, PC_REGNUM, 1);

      ret = thread_set_state (current_thread,

                              MIPS_THREAD_STATE,

                              state,

                              MIPS_FLOAT_STATE_COUNT);

      CHK ("store inferior regs : thread_set_state", ret);

    }

  if (regno == -1 || regno >= FP0_REGNUM)

    {

      /* If thread has floating state, save it */

      if (read_register (PS_REGNUM) & MIPS_STATUS_USE_COP1)

        {

          /* Do NOT save FCRIR_REGNUM */

          STORE_REGS (state, FP0_REGNUM, 33);

          ret = thread_set_state (current_thread,

                                  MIPS_FLOAT_STATE,

                                  state,

                                  MIPS_FLOAT_STATE_COUNT);

          CHK ("store inferior registers (floats): thread_set_state", ret);

        }

      else if (regno != -1)

        message

          ("Thread does not use floating point unit, floating regs not saved");

    }

}