1/* Target-dependent code for the IA-64 for GDB, the GNU debugger.
2
3   Copyright 2000, 2004 Free Software Foundation, Inc.
4
5   This file is part of GDB.
6
7   This program is free software; you can redistribute it and/or modify
8   it under the terms of the GNU General Public License as published by
9   the Free Software Foundation; either version 2 of the License, or
10   (at your option) any later version.
11
12   This program is distributed in the hope that it will be useful,
13   but WITHOUT ANY WARRANTY; without even the implied warranty of
14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   GNU General Public License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with this program; if not, write to the Free Software
19   Foundation, Inc., 59 Temple Place - Suite 330,
20   Boston, MA 02111-1307, USA.  */
21
22#include "defs.h"
23#include "ia64-tdep.h"
24#include "arch-utils.h"
25#include "gdbcore.h"
26#include "regcache.h"
27
28/* The sigtramp code is in a non-readable (executable-only) region
29   of memory called the ``gate page''.  The addresses in question
30   were determined by examining the system headers.  They are
31   overly generous to allow for different pages sizes. */
32
33#define GATE_AREA_START 0xa000000000000100LL
34#define GATE_AREA_END   0xa000000000020000LL
35
36/* Offset to sigcontext structure from frame of handler */
37#define IA64_LINUX_SIGCONTEXT_OFFSET 192
38
39int
40ia64_linux_in_sigtramp (CORE_ADDR pc, char *func_name)
41{
42  return (pc >= (CORE_ADDR) GATE_AREA_START && pc < (CORE_ADDR) GATE_AREA_END);
43}
44
45/* IA-64 GNU/Linux specific function which, given a frame address and
46   a register number, returns the address at which that register may be
47   found.  0 is returned for registers which aren't stored in the the
48   sigcontext structure. */
49
50CORE_ADDR
51ia64_linux_sigcontext_register_address (CORE_ADDR sp, int regno)
52{
53  char buf[8];
54  CORE_ADDR sigcontext_addr = 0;
55
56  /* The address of the sigcontext area is found at offset 16 in the sigframe.  */
57  read_memory (sp + 16, buf, 8);
58  sigcontext_addr = extract_unsigned_integer (buf, 8);
59
60  if (IA64_GR0_REGNUM <= regno && regno <= IA64_GR31_REGNUM)
61    return sigcontext_addr + 200 + 8 * (regno - IA64_GR0_REGNUM);
62  else if (IA64_BR0_REGNUM <= regno && regno <= IA64_BR7_REGNUM)
63    return sigcontext_addr + 136 + 8 * (regno - IA64_BR0_REGNUM);
64  else if (IA64_FR0_REGNUM <= regno && regno <= IA64_FR127_REGNUM)
65    return sigcontext_addr + 464 + 16 * (regno - IA64_FR0_REGNUM);
66  else
67    switch (regno)
68      {
69      case IA64_IP_REGNUM :
70	return sigcontext_addr + 40;
71      case IA64_CFM_REGNUM :
72	return sigcontext_addr + 48;
73      case IA64_PSR_REGNUM :
74	return sigcontext_addr + 56;		/* user mask only */
75      /* sc_ar_rsc is provided, from which we could compute bspstore, but
76	 I don't think it's worth it.  Anyway, if we want it, it's at offset
77	 64 */
78      case IA64_BSP_REGNUM :
79	return sigcontext_addr + 72;
80      case IA64_RNAT_REGNUM :
81	return sigcontext_addr + 80;
82      case IA64_CCV_REGNUM :
83	return sigcontext_addr + 88;
84      case IA64_UNAT_REGNUM :
85	return sigcontext_addr + 96;
86      case IA64_FPSR_REGNUM :
87	return sigcontext_addr + 104;
88      case IA64_PFS_REGNUM :
89	return sigcontext_addr + 112;
90      case IA64_LC_REGNUM :
91	return sigcontext_addr + 120;
92      case IA64_PR_REGNUM :
93	return sigcontext_addr + 128;
94      default :
95	return 0;
96      }
97}
98
99void
100ia64_linux_write_pc (CORE_ADDR pc, ptid_t ptid)
101{
102  ia64_write_pc (pc, ptid);
103
104  /* We must be careful with modifying the instruction-pointer: if we
105     just interrupt a system call, the kernel would ordinarily try to
106     restart it when we resume the inferior, which typically results
107     in SIGSEGV or SIGILL.  We prevent this by clearing r10, which
108     will tell the kernel that r8 does NOT contain a valid error code
109     and hence it will skip system-call restart.
110
111     The clearing of r10 is safe as long as ia64_write_pc() is only
112     called as part of setting up an inferior call.  */
113  write_register_pid (IA64_GR10_REGNUM, 0, ptid);
114}
115