binutils-gdb/gdb/mips-linux-tdep.c

345 lines
8.7 KiB
C

/* Target-dependent code for Linux/MIPS.
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 (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 + JB_PC * 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;
static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};
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;
static char zerobuf[MAX_REGISTER_RAW_SIZE] = {0};
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 Linux/MIPS targets using the struct offsets
defined in link.h (but without actual reference to that file).
This makes it possible to access Linux/MIPS shared libraries from a
GDB that was not built on an Linux/MIPS host (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);
}