/* GNU/Linux on ARM native support.
   Copyright 1999, 2000 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.  */

#include "defs.h"
#include "inferior.h"
#include "gdbcore.h"
#include "gdb_string.h"

#include <sys/user.h>
#include <sys/ptrace.h>
#include <sys/utsname.h>
#include <sys/procfs.h>

extern int arm_apcs_32;

#define		typeNone		0x00
#define		typeSingle		0x01
#define		typeDouble		0x02
#define		typeExtended		0x03
#define 	FPWORDS			28
#define		CPSR_REGNUM		16

typedef union tagFPREG
  {
    unsigned int fSingle;
    unsigned int fDouble[2];
    unsigned int fExtended[3];
  }
FPREG;

typedef struct tagFPA11
  {
    FPREG fpreg[8];		/* 8 floating point registers */
    unsigned int fpsr;		/* floating point status register */
    unsigned int fpcr;		/* floating point control register */
    unsigned char fType[8];	/* type of floating point value held in
				   floating point registers.  */
    int initflag;		/* NWFPE initialization flag.  */
  }
FPA11;

/* The following variables are used to determine the version of the
   underlying Linux operating system.  Examples:

   Linux 2.0.35                 Linux 2.2.12
   os_version = 0x00020023      os_version = 0x0002020c
   os_major = 2                 os_major = 2
   os_minor = 0                 os_minor = 2
   os_release = 35              os_release = 12

   Note: os_version = (os_major << 16) | (os_minor << 8) | os_release

   These are initialized using get_linux_version() from
   _initialize_arm_linux_nat().  */

static unsigned int os_version, os_major, os_minor, os_release;

/* On Linux, threads are implemented as pseudo-processes, in which
   case we may be tracing more than one process at a time.  In that
   case, inferior_pid will contain the main process ID and the
   individual thread (process) ID mashed together.  These macros are
   used to separate them out.  These definitions should be overridden
   if thread support is included.  */

#if !defined (PIDGET)	/* Default definition for PIDGET/TIDGET.  */
#define PIDGET(PID)	PID
#define TIDGET(PID)	0
#endif

int
get_thread_id (int inferior_pid)
{
  int tid = TIDGET (inferior_pid);
  if (0 == tid) tid = inferior_pid;
  return tid;
}
#define GET_THREAD_ID(PID)	get_thread_id ((PID));

static void
fetch_nwfpe_single (unsigned int fn, FPA11 * fpa11)
{
  unsigned int mem[3];

  mem[0] = fpa11->fpreg[fn].fSingle;
  mem[1] = 0;
  mem[2] = 0;
  supply_register (F0_REGNUM + fn, (char *) &mem[0]);
}

static void
fetch_nwfpe_double (unsigned int fn, FPA11 * fpa11)
{
  unsigned int mem[3];

  mem[0] = fpa11->fpreg[fn].fDouble[1];
  mem[1] = fpa11->fpreg[fn].fDouble[0];
  mem[2] = 0;
  supply_register (F0_REGNUM + fn, (char *) &mem[0]);
}

static void
fetch_nwfpe_none (unsigned int fn)
{
  unsigned int mem[3] =
  {0, 0, 0};

  supply_register (F0_REGNUM + fn, (char *) &mem[0]);
}

static void
fetch_nwfpe_extended (unsigned int fn, FPA11 * fpa11)
{
  unsigned int mem[3];

  mem[0] = fpa11->fpreg[fn].fExtended[0];	/* sign & exponent */
  mem[1] = fpa11->fpreg[fn].fExtended[2];	/* ls bits */
  mem[2] = fpa11->fpreg[fn].fExtended[1];	/* ms bits */
  supply_register (F0_REGNUM + fn, (char *) &mem[0]);
}

static void
fetch_nwfpe_register (int regno, FPA11 * fpa11)
{
   int fn = regno - F0_REGNUM;

   switch (fpa11->fType[fn])
     {
     case typeSingle:
       fetch_nwfpe_single (fn, fpa11);
       break;

     case typeDouble:
       fetch_nwfpe_double (fn, fpa11);
       break;

     case typeExtended:
       fetch_nwfpe_extended (fn, fpa11);
       break;

     default:
       fetch_nwfpe_none (fn);
     }
}

static void
store_nwfpe_single (unsigned int fn, FPA11 * fpa11)
{
  unsigned int mem[3];

  read_register_gen (F0_REGNUM + fn, (char *) &mem[0]);
  fpa11->fpreg[fn].fSingle = mem[0];
  fpa11->fType[fn] = typeSingle;
}

static void
store_nwfpe_double (unsigned int fn, FPA11 * fpa11)
{
  unsigned int mem[3];

  read_register_gen (F0_REGNUM + fn, (char *) &mem[0]);
  fpa11->fpreg[fn].fDouble[1] = mem[0];
  fpa11->fpreg[fn].fDouble[0] = mem[1];
  fpa11->fType[fn] = typeDouble;
}

void
store_nwfpe_extended (unsigned int fn, FPA11 * fpa11)
{
  unsigned int mem[3];

  read_register_gen (F0_REGNUM + fn, (char *) &mem[0]);
  fpa11->fpreg[fn].fExtended[0] = mem[0];	/* sign & exponent */
  fpa11->fpreg[fn].fExtended[2] = mem[1];	/* ls bits */
  fpa11->fpreg[fn].fExtended[1] = mem[2];	/* ms bits */
  fpa11->fType[fn] = typeDouble;
}

void
store_nwfpe_register (int regno, FPA11 * fpa11)
{
  if (register_valid[regno])
    {
       unsigned int fn = regno - F0_REGNUM;
       switch (fpa11->fType[fn])
         {
	 case typeSingle:
	   store_nwfpe_single (fn, fpa11);
	   break;

	 case typeDouble:
	   store_nwfpe_double (fn, fpa11);
	   break;

	 case typeExtended:
	   store_nwfpe_extended (fn, fpa11);
	   break;
	 }
    }
}


/* Get the value of a particular register from the floating point
   state of the process and store it into registers[].  */

static void
fetch_fpregister (int regno)
{
  int ret, tid;
  FPA11 fp;
  
  /* Get the thread id for the ptrace call.  */
  tid = GET_THREAD_ID (inferior_pid);

  /* Read the floating point state.  */
  ret = ptrace (PT_GETFPREGS, tid, 0, &fp);
  if (ret < 0)
    {
      warning ("Unable to fetch floating point register.");
      return;
    }

  /* Fetch fpsr.  */
  if (FPS_REGNUM == regno)
    supply_register (FPS_REGNUM, (char *) &fp.fpsr);

  /* Fetch the floating point register.  */
  if (regno >= F0_REGNUM && regno <= F7_REGNUM)
    {
      int fn = regno - F0_REGNUM;

      switch (fp.fType[fn])
	{
	case typeSingle:
	  fetch_nwfpe_single (fn, &fp);
	  break;

	case typeDouble:
	    fetch_nwfpe_double (fn, &fp);
	  break;

	case typeExtended:
	    fetch_nwfpe_extended (fn, &fp);
	  break;

	default:
	    fetch_nwfpe_none (fn);
	}
    }
}

/* Get the whole floating point state of the process and store it
   into registers[].  */

static void
fetch_fpregs (void)
{
  int ret, regno, tid;
  FPA11 fp;

  /* Get the thread id for the ptrace call.  */
  tid = GET_THREAD_ID (inferior_pid);
  
  /* Read the floating point state.  */
  ret = ptrace (PT_GETFPREGS, tid, 0, &fp);
  if (ret < 0)
    {
      warning ("Unable to fetch the floating point registers.");
      return;
    }

  /* Fetch fpsr.  */
  supply_register (FPS_REGNUM, (char *) &fp.fpsr);

  /* Fetch the floating point registers.  */
  for (regno = F0_REGNUM; regno <= F7_REGNUM; regno++)
    {
      int fn = regno - F0_REGNUM;

      switch (fp.fType[fn])
	{
	case typeSingle:
	  fetch_nwfpe_single (fn, &fp);
	  break;

	case typeDouble:
	  fetch_nwfpe_double (fn, &fp);
	  break;

	case typeExtended:
	  fetch_nwfpe_extended (fn, &fp);
	  break;

	default:
	  fetch_nwfpe_none (fn);
	}
    }
}

/* Save a particular register into the floating point state of the
   process using the contents from registers[].  */

static void
store_fpregister (int regno)
{
  int ret, tid;
  FPA11 fp;

  /* Get the thread id for the ptrace call.  */
  tid = GET_THREAD_ID (inferior_pid);
  
  /* Read the floating point state.  */
  ret = ptrace (PT_GETFPREGS, tid, 0, &fp);
  if (ret < 0)
    {
      warning ("Unable to fetch the floating point registers.");
      return;
    }

  /* Store fpsr.  */
  if (FPS_REGNUM == regno && register_valid[FPS_REGNUM])
    read_register_gen (FPS_REGNUM, (char *) &fp.fpsr);

  /* Store the floating point register.  */
  if (regno >= F0_REGNUM && regno <= F7_REGNUM)
    {
      store_nwfpe_register (regno, &fp);
    }

  ret = ptrace (PTRACE_SETFPREGS, tid, 0, &fp);
  if (ret < 0)
    {
      warning ("Unable to store floating point register.");
      return;
    }
}

/* Save the whole floating point state of the process using
   the contents from registers[].  */

static void
store_fpregs (void)
{
  int ret, regno, tid;
  FPA11 fp;

  /* Get the thread id for the ptrace call.  */
  tid = GET_THREAD_ID (inferior_pid);
  
  /* Read the floating point state.  */
  ret = ptrace (PT_GETFPREGS, tid, 0, &fp);
  if (ret < 0)
    {
      warning ("Unable to fetch the floating point registers.");
      return;
    }

  /* Store fpsr.  */
  if (register_valid[FPS_REGNUM])
    read_register_gen (FPS_REGNUM, (char *) &fp.fpsr);

  /* Store the floating point registers.  */
  for (regno = F0_REGNUM; regno <= F7_REGNUM; regno++)
    {
      fetch_nwfpe_register (regno, &fp);
    }

  ret = ptrace (PTRACE_SETFPREGS, tid, 0, &fp);
  if (ret < 0)
    {
      warning ("Unable to store floating point registers.");
      return;
    }
}

/* Fetch a general register of the process and store into
   registers[].  */

static void
fetch_register (int regno)
{
  int ret, tid;
  struct pt_regs regs;

  /* Get the thread id for the ptrace call.  */
  tid = GET_THREAD_ID (inferior_pid);
  
  ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
  if (ret < 0)
    {
      warning ("Unable to fetch general register.");
      return;
    }

  if (regno >= A1_REGNUM && regno < PC_REGNUM)
    supply_register (regno, (char *) &regs.uregs[regno]);

  if (PS_REGNUM == regno)
    {
      if (arm_apcs_32)
        supply_register (PS_REGNUM, (char *) &regs.uregs[CPSR_REGNUM]);
      else
        supply_register (PS_REGNUM, (char *) &regs.uregs[PC_REGNUM]);
    }
    
  if (PC_REGNUM == regno)
    { 
      regs.uregs[PC_REGNUM] = ADDR_BITS_REMOVE (regs.uregs[PC_REGNUM]);
      supply_register (PC_REGNUM, (char *) &regs.uregs[PC_REGNUM]);
    }
}

/* Fetch all general registers of the process and store into
   registers[].  */

static void
fetch_regs (void)
{
  int ret, regno, tid;
  struct pt_regs regs;

  /* Get the thread id for the ptrace call.  */
  tid = GET_THREAD_ID (inferior_pid);
  
  ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
  if (ret < 0)
    {
      warning ("Unable to fetch general registers.");
      return;
    }

  for (regno = A1_REGNUM; regno < PC_REGNUM; regno++)
    supply_register (regno, (char *) &regs.uregs[regno]);

  if (arm_apcs_32)
    supply_register (PS_REGNUM, (char *) &regs.uregs[CPSR_REGNUM]);
  else
    supply_register (PS_REGNUM, (char *) &regs.uregs[PC_REGNUM]);

  regs.uregs[PC_REGNUM] = ADDR_BITS_REMOVE (regs.uregs[PC_REGNUM]);
  supply_register (PC_REGNUM, (char *) &regs.uregs[PC_REGNUM]);
}

/* Store all general registers of the process from the values in
   registers[].  */

static void
store_register (int regno)
{
  int ret, tid;
  struct pt_regs regs;
  
  if (!register_valid[regno])
    return;

  /* Get the thread id for the ptrace call.  */
  tid = GET_THREAD_ID (inferior_pid);
  
  /* Get the general registers from the process.  */
  ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
  if (ret < 0)
    {
      warning ("Unable to fetch general registers.");
      return;
    }

  if (regno >= A1_REGNUM && regno <= PC_REGNUM)
    read_register_gen (regno, (char *) &regs.uregs[regno]);

  ret = ptrace (PTRACE_SETREGS, tid, 0, &regs);
  if (ret < 0)
    {
      warning ("Unable to store general register.");
      return;
    }
}

static void
store_regs (void)
{
  int ret, regno, tid;
  struct pt_regs regs;

  /* Get the thread id for the ptrace call.  */
  tid = GET_THREAD_ID (inferior_pid);
  
  /* Fetch the general registers.  */
  ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
  if (ret < 0)
    {
      warning ("Unable to fetch general registers.");
      return;
    }

  for (regno = A1_REGNUM; regno <= PC_REGNUM; regno++)
    {
      if (register_valid[regno])
	read_register_gen (regno, (char *) &regs.uregs[regno]);
    }

  ret = ptrace (PTRACE_SETREGS, tid, 0, &regs);

  if (ret < 0)
    {
      warning ("Unable to store general registers.");
      return;
    }
}

/* Fetch registers from the child process.  Fetch all registers if
   regno == -1, otherwise fetch all general registers or all floating
   point registers depending upon the value of regno.  */

void
fetch_inferior_registers (int regno)
{
  if (-1 == regno)
    {
      fetch_regs ();
      fetch_fpregs ();
    }
  else 
    {
      if (regno < F0_REGNUM || regno > FPS_REGNUM)
        fetch_register (regno);

      if (regno >= F0_REGNUM && regno <= FPS_REGNUM)
        fetch_fpregister (regno);
    }
}

/* Store registers back into the inferior.  Store all registers if
   regno == -1, otherwise store all general registers or all floating
   point registers depending upon the value of regno.  */

void
store_inferior_registers (int regno)
{
  if (-1 == regno)
    {
      store_regs ();
      store_fpregs ();
    }
  else
    {
      if ((regno < F0_REGNUM) || (regno > FPS_REGNUM))
        store_register (regno);

      if ((regno >= F0_REGNUM) && (regno <= FPS_REGNUM))
        store_fpregister (regno);
    }
}

/* Fill register regno (if it is a general-purpose register) in
   *gregsetp with the appropriate value from GDB's register array.
   If regno is -1, do this for all registers.  */

void
fill_gregset (gregset_t *gregsetp, int regno)
{
  if (-1 == regno)
    {
      int regnum;
      for (regnum = A1_REGNUM; regnum <= PC_REGNUM; regnum++) 
        if (register_valid[regnum])
	  read_register_gen (regnum, (char *) &(*gregsetp)[regnum]);
    }
  else if (regno >= A1_REGNUM && regno <= PC_REGNUM)
    {
      if (register_valid[regno])
	read_register_gen (regno, (char *) &(*gregsetp)[regno]);
    }

  if (PS_REGNUM == regno || -1 == regno)
    {
      if (register_valid[regno] || -1 == regno)
        {
          if (arm_apcs_32)
	    read_register_gen (PS_REGNUM, (char *) &(*gregsetp)[CPSR_REGNUM]);
	  else
	    read_register_gen (PC_REGNUM, (char *) &(*gregsetp)[PC_REGNUM]);
	}
    }
        
}

/* Fill GDB's register array with the general-purpose register values
   in *gregsetp.  */

void
supply_gregset (gregset_t *gregsetp)
{
  int regno, reg_pc;

  for (regno = A1_REGNUM; regno < PC_REGNUM; regno++)
    supply_register (regno, (char *) &(*gregsetp)[regno]);

  if (arm_apcs_32)
    supply_register (PS_REGNUM, (char *) &(*gregsetp)[CPSR_REGNUM]);
  else
    supply_register (PS_REGNUM, (char *) &(*gregsetp)[PC_REGNUM]);

  reg_pc = ADDR_BITS_REMOVE ((CORE_ADDR)(*gregsetp)[PC_REGNUM]);
  supply_register (PC_REGNUM, (char *) &reg_pc);
}

/* Fill register regno (if it is a floating-point register) in
   *fpregsetp with the appropriate value from GDB's register array.
   If regno is -1, do this for all registers.  */

void
fill_fpregset (fpregset_t *fpregsetp, int regno)
{
  FPA11 *fp = (FPA11 *) fpregsetp;
  
  if (-1 == regno)
    {
       int regnum;
       for (regnum = F0_REGNUM; regnum <= F7_REGNUM; regnum++)
         store_nwfpe_register (regnum, fp);
    }
  else if (regno >= F0_REGNUM && regno <= F7_REGNUM)
    {
      store_nwfpe_register (regno, fp);
      return;
    }

  /* Store fpsr.  */
  if (register_valid[FPS_REGNUM])
    if (FPS_REGNUM == regno || -1 == regno)
      read_register_gen (FPS_REGNUM, (char *) &fp->fpsr);
}

/* Fill GDB's register array with the floating-point register values
   in *fpregsetp.  */

void
supply_fpregset (fpregset_t *fpregsetp)
{
  int regno;
  FPA11 *fp = (FPA11 *) fpregsetp;

  /* Fetch fpsr.  */
  supply_register (FPS_REGNUM, (char *) &fp->fpsr);

  /* Fetch the floating point registers.  */
  for (regno = F0_REGNUM; regno <= F7_REGNUM; regno++)
    {
      fetch_nwfpe_register (regno, fp);
    }
}

int
arm_linux_kernel_u_size (void)
{
  return (sizeof (struct user));
}

static unsigned int
get_linux_version (unsigned int *vmajor,
		   unsigned int *vminor,
		   unsigned int *vrelease)
{
  struct utsname info;
  char *pmajor, *pminor, *prelease, *tail;

  if (-1 == uname (&info))
    {
      warning ("Unable to determine Linux version.");
      return -1;
    }

  pmajor = strtok (info.release, ".");
  pminor = strtok (NULL, ".");
  prelease = strtok (NULL, ".");

  *vmajor = (unsigned int) strtoul (pmajor, &tail, 0);
  *vminor = (unsigned int) strtoul (pminor, &tail, 0);
  *vrelease = (unsigned int) strtoul (prelease, &tail, 0);

  return ((*vmajor << 16) | (*vminor << 8) | *vrelease);
}

void
_initialize_arm_linux_nat (void)
{
  os_version = get_linux_version (&os_major, &os_minor, &os_release);
}