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/* Target-dependent code for GNU/Linux on MIPS processors.

   Copyright 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.  */

#include "defs.h"

#include "gdbcore.h"

#include "target.h"

#include "solib-svr4.h"

/* Copied from <asm/elf.h>.  */

#define ELF_NGREG       45

#define ELF_NFPREG      33

typedef unsigned char elf_greg_t[4];

typedef elf_greg_t elf_gregset_t[ELF_NGREG];

typedef unsigned char elf_fpreg_t[8];

typedef elf_fpreg_t elf_fpregset_t[ELF_NFPREG];

/* 0 - 31 are integer registers, 32 - 63 are fp registers.  */

#define FPR_BASE        32

#define PC              64

#define CAUSE           65

#define BADVADDR        66

#define MMHI            67

#define MMLO            68

#define FPC_CSR         69

#define FPC_EIR         70

#define EF_REG0                 6

#define EF_REG31                37

#define EF_LO                   38

#define EF_HI                   39

#define EF_CP0_EPC              40

#define EF_CP0_BADVADDR         41

#define EF_CP0_STATUS           42

#define EF_CP0_CAUSE            43

#define EF_SIZE                 180

/* Figure out where the longjmp will land.

   We expect the first arg to be a pointer to the jmp_buf structure from

   which we extract the pc (MIPS_LINUX_JB_PC) that we will land at.  The pc

   is copied into PC.  This routine returns 1 on success.  */

int

mips_linux_get_longjmp_target (CORE_ADDR *pc)

{

  CORE_ADDR jb_addr;

  char buf[TARGET_PTR_BIT / TARGET_CHAR_BIT];

  jb_addr = read_register (A0_REGNUM);

  if (target_read_memory (jb_addr

                          + MIPS_LINUX_JB_PC * MIPS_LINUX_JB_ELEMENT_SIZE,

                          buf, TARGET_PTR_BIT / TARGET_CHAR_BIT))

    return 0;

  *pc = extract_address (buf, TARGET_PTR_BIT / TARGET_CHAR_BIT);

  return 1;

}

/* Unpack an elf_gregset_t into GDB's register cache.  */

void

supply_gregset (elf_gregset_t *gregsetp)

{

  int regi;

  elf_greg_t *regp = *gregsetp;

  char *zerobuf = alloca (MAX_REGISTER_RAW_SIZE);

  memset (zerobuf, 0, MAX_REGISTER_RAW_SIZE);

  for (regi = EF_REG0; regi <= EF_REG31; regi++)

    supply_register ((regi - EF_REG0), (char *)(regp + regi));

  supply_register (LO_REGNUM, (char *)(regp + EF_LO));

  supply_register (HI_REGNUM, (char *)(regp + EF_HI));

  supply_register (PC_REGNUM, (char *)(regp + EF_CP0_EPC));

  supply_register (BADVADDR_REGNUM, (char *)(regp + EF_CP0_BADVADDR));

  supply_register (PS_REGNUM, (char *)(regp + EF_CP0_STATUS));

  supply_register (CAUSE_REGNUM, (char *)(regp + EF_CP0_CAUSE));

  /* Fill inaccessible registers with zero.  */

  supply_register (FP_REGNUM, zerobuf);

  supply_register (UNUSED_REGNUM, zerobuf);

  for (regi = FIRST_EMBED_REGNUM; regi < LAST_EMBED_REGNUM; regi++)

    supply_register (regi, zerobuf);

}

/* Pack our registers (or one register) into an elf_gregset_t.  */

void

fill_gregset (elf_gregset_t *gregsetp, int regno)

{

  int regaddr, regi;

  elf_greg_t *regp = *gregsetp;

  void *src, *dst;

  if (regno == -1)

    {

      memset (regp, 0, sizeof (elf_gregset_t));

      for (regi = 0; regi < 32; regi++)

        fill_gregset (gregsetp, regi);

      fill_gregset (gregsetp, LO_REGNUM);

      fill_gregset (gregsetp, HI_REGNUM);

      fill_gregset (gregsetp, PC_REGNUM);

      fill_gregset (gregsetp, BADVADDR_REGNUM);

      fill_gregset (gregsetp, PS_REGNUM);

      fill_gregset (gregsetp, CAUSE_REGNUM);

      return;

   }

  if (regno < 32)

    {

      src = &registers[REGISTER_BYTE (regno)];

      dst = regp + regno + EF_REG0;

      memcpy (dst, src, sizeof (elf_greg_t));

      return;

    }

  regaddr = -1;

  switch (regno)

    {

      case LO_REGNUM:

        regaddr = EF_LO;

        break;

      case HI_REGNUM:

        regaddr = EF_HI;

        break;

      case PC_REGNUM:

        regaddr = EF_CP0_EPC;

        break;

      case BADVADDR_REGNUM:

        regaddr = EF_CP0_BADVADDR;

        break;

      case PS_REGNUM:

        regaddr = EF_CP0_STATUS;

        break;

      case CAUSE_REGNUM:

        regaddr = EF_CP0_CAUSE;

        break;

    }

  if (regaddr != -1)

    {

      src = &registers[REGISTER_BYTE (regno)];

      dst = regp + regaddr;

      memcpy (dst, src, sizeof (elf_greg_t));

    }

}

/* Likewise, unpack an elf_fpregset_t.  */

void

supply_fpregset (elf_fpregset_t *fpregsetp)

{

  register int regi;

  char *zerobuf = alloca (MAX_REGISTER_RAW_SIZE);

  memset (zerobuf, 0, MAX_REGISTER_RAW_SIZE);

  for (regi = 0; regi < 32; regi++)

    supply_register (FP0_REGNUM + regi,

                     (char *)(*fpregsetp + regi));

  supply_register (FCRCS_REGNUM, (char *)(*fpregsetp + 32));

  /* FIXME: how can we supply FCRIR_REGNUM?  The ABI doesn't tell us. */

  supply_register (FCRIR_REGNUM, zerobuf);

}

/* Likewise, pack one or all floating point registers into an

   elf_fpregset_t.  */

void

fill_fpregset (elf_fpregset_t *fpregsetp, int regno)

{

  char *from, *to;

  if ((regno >= FP0_REGNUM) && (regno < FP0_REGNUM + 32))

    {

      from = (char *) &registers[REGISTER_BYTE (regno)];

      to = (char *) (*fpregsetp + regno - FP0_REGNUM);

      memcpy (to, from, REGISTER_RAW_SIZE (regno - FP0_REGNUM));

    }

  else if (regno == FCRCS_REGNUM)

    {

      from = (char *) &registers[REGISTER_BYTE (regno)];

      to = (char *) (*fpregsetp + 32);

      memcpy (to, from, REGISTER_RAW_SIZE (regno));

    }

  else if (regno == -1)

    {

      int regi;

      for (regi = 0; regi < 32; regi++)

        fill_fpregset (fpregsetp, FP0_REGNUM + regi);

      fill_fpregset(fpregsetp, FCRCS_REGNUM);

    }

}

/* Map gdb internal register number to ptrace ``address''.

   These ``addresses'' are normally defined in <asm/ptrace.h>.  */

CORE_ADDR

register_addr (int regno, CORE_ADDR blockend)

{

  int regaddr;

  if (regno < 0 || regno >= NUM_REGS)

    error ("Bogon register number %d.", regno);

  if (regno < 32)

    regaddr = regno;

  else if ((regno >= FP0_REGNUM) && (regno < FP0_REGNUM + 32))

    regaddr = FPR_BASE + (regno - FP0_REGNUM);

  else if (regno == PC_REGNUM)

    regaddr = PC;

  else if (regno == CAUSE_REGNUM)

    regaddr = CAUSE;

  else if (regno == BADVADDR_REGNUM)

    regaddr = BADVADDR;

  else if (regno == LO_REGNUM)

    regaddr = MMLO;

  else if (regno == HI_REGNUM)

    regaddr = MMHI;

  else if (regno == FCRCS_REGNUM)

    regaddr = FPC_CSR;

  else if (regno == FCRIR_REGNUM)

    regaddr = FPC_EIR;

  else

    error ("Unknowable register number %d.", regno);

  return regaddr;

}

/*  Use a local version of this function to get the correct types for

    regsets, until multi-arch core support is ready.  */

static void

fetch_core_registers (char *core_reg_sect, unsigned core_reg_size,

                      int which, CORE_ADDR reg_addr)

{

  elf_gregset_t gregset;

  elf_fpregset_t fpregset;

  if (which == 0)

    {

      if (core_reg_size != sizeof (gregset))

        {

          warning ("wrong size gregset struct in core file");

        }

      else

        {

          memcpy ((char *) &gregset, core_reg_sect, sizeof (gregset));

          supply_gregset (&gregset);

        }

    }

  else if (which == 2)

    {

      if (core_reg_size != sizeof (fpregset))

        {

          warning ("wrong size fpregset struct in core file");

        }

      else

        {

          memcpy ((char *) &fpregset, core_reg_sect, sizeof (fpregset));

          supply_fpregset (&fpregset);

        }

    }

}

/* Register that we are able to handle ELF file formats using standard

   procfs "regset" structures.  */

static struct core_fns regset_core_fns =

{

  bfd_target_elf_flavour,               /* core_flavour */

  default_check_format,                 /* check_format */

  default_core_sniffer,                 /* core_sniffer */

  fetch_core_registers,                 /* core_read_registers */

  NULL                                  /* next */

};

/* Fetch (and possibly build) an appropriate link_map_offsets

   structure for native GNU/Linux MIPS targets using the struct offsets

   defined in link.h (but without actual reference to that file).

   This makes it possible to access GNU/Linux MIPS shared libraries from a

   GDB that was built on a different host platform (for cross debugging).  */

struct link_map_offsets *

mips_linux_svr4_fetch_link_map_offsets (void)

{

  static struct link_map_offsets lmo;

  static struct link_map_offsets *lmp = NULL;

  if (lmp == NULL)

    {

      lmp = &lmo;

      lmo.r_debug_size = 8;     /* The actual size is 20 bytes, but

                                   this is all we need.  */

      lmo.r_map_offset = 4;

      lmo.r_map_size   = 4;

      lmo.link_map_size = 20;

      lmo.l_addr_offset = 0;

      lmo.l_addr_size   = 4;

      lmo.l_name_offset = 4;

      lmo.l_name_size   = 4;

      lmo.l_next_offset = 12;

      lmo.l_next_size   = 4;

      lmo.l_prev_offset = 16;

      lmo.l_prev_size   = 4;

    }

  return lmp;

}

void

_initialize_mips_linux_tdep (void)

{

  add_core_fns (&regset_core_fns);

}