1/* Target-dependent code for Analog Devices Blackfin processor, for GDB.
2
3   Copyright (C) 2005-2020 Free Software Foundation, Inc.
4
5   Contributed by Analog Devices, Inc.
6
7   This file is part of GDB.
8
9   This program is free software; you can redistribute it and/or modify
10   it under the terms of the GNU General Public License as published by
11   the Free Software Foundation; either version 3 of the License, or
12   (at your option) any later version.
13
14   This program is distributed in the hope that it will be useful,
15   but WITHOUT ANY WARRANTY; without even the implied warranty of
16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17   GNU General Public License for more details.
18
19   You should have received a copy of the GNU General Public License
20   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
21
22#include "defs.h"
23#include "arch-utils.h"
24#include "regcache.h"
25#include "tramp-frame.h"
26#include "trad-frame.h"
27#include "osabi.h"
28#include "xml-syscall.h"
29#include "linux-tdep.h"
30#include "bfin-tdep.h"
31
32/* From <asm/sigcontext.h>.  */
33
34#define SIGCONTEXT_OFFSET	168
35
36static const int bfin_linux_sigcontext_reg_offset[BFIN_NUM_REGS] =
37{
38  0 * 4,	/* %r0 */
39  1 * 4,	/* %r1 */
40  2 * 4,	/* %r2 */
41  3 * 4,	/* %r3 */
42  4 * 4,	/* %r4 */
43  5 * 4,	/* %r5 */
44  6 * 4,	/* %r6 */
45  7 * 4,	/* %r7 */
46  8 * 4,	/* %p0 */
47  9 * 4,	/* %p1 */
48  10 * 4,	/* %p2 */
49  11 * 4,	/* %p3 */
50  12 * 4,	/* %p4 */
51  13 * 4,	/* %p5 */
52  14 * 4,	/* %sp */
53  23 * 4,	/* %fp */
54  24 * 4,	/* %i0 */
55  25 * 4,	/* %i1 */
56  26 * 4,	/* %i2 */
57  27 * 4,	/* %i3 */
58  28 * 4,	/* %m0 */
59  29 * 4,	/* %m1 */
60  30 * 4,	/* %m2 */
61  31 * 4,	/* %m3 */
62  36 * 4,	/* %b0 */
63  37 * 4,	/* %b1 */
64  38 * 4,	/* %b2 */
65  39 * 4,	/* %b3 */
66  32 * 4,	/* %l0 */
67  33 * 4,	/* %l1 */
68  34 * 4,	/* %l2 */
69  35 * 4,	/* %l3 */
70  17 * 4,	/* %a0x */
71  15 * 4,	/* %a0w */
72  18 * 4,	/* %a1x */
73  16 * 4,	/* %a1w */
74  19 * 4,	/* %astat */
75  20 * 4,	/* %rets */
76  40 * 4,	/* %lc0 */
77  42 * 4,	/* %lt0 */
78  44 * 4,	/* %lb0 */
79  41 * 4,	/* %lc1 */
80  43 * 4,	/* %lt1 */
81  45 * 4,	/* %lb1 */
82  -1,		/* %cycles */
83  -1,		/* %cycles2 */
84  -1,		/* %usp */
85  46 * 4,	/* %seqstat */
86  -1,		/* syscfg */
87  21 * 4,	/* %reti */
88  22 * 4,	/* %retx */
89  -1,		/* %retn */
90  -1,		/* %rete */
91  21 * 4,	/* %pc */
92};
93
94/* Signal trampolines.  */
95
96static void
97bfin_linux_sigframe_init (const struct tramp_frame *self,
98			  struct frame_info *this_frame,
99			  struct trad_frame_cache *this_cache,
100			  CORE_ADDR func)
101{
102  CORE_ADDR sp = get_frame_sp (this_frame);
103  CORE_ADDR pc = get_frame_pc (this_frame);
104  CORE_ADDR sigcontext = sp + SIGCONTEXT_OFFSET;
105  const int *reg_offset = bfin_linux_sigcontext_reg_offset;
106  int i;
107
108  for (i = 0; i < BFIN_NUM_REGS; i++)
109    if (reg_offset[i] != -1)
110      trad_frame_set_reg_addr (this_cache, i, sigcontext + reg_offset[i]);
111
112  /* This would come after the LINK instruction in the ret_from_signal
113     function, hence the frame id would be SP + 8.  */
114  trad_frame_set_id (this_cache, frame_id_build (sp + 8, pc));
115}
116
117static const struct tramp_frame bfin_linux_sigframe =
118{
119  SIGTRAMP_FRAME,
120  4,
121  {
122    { 0x00ADE128, 0xffffffff },	/* P0 = __NR_rt_sigreturn; */
123    { 0x00A0, 0xffff },		/* EXCPT 0; */
124    { TRAMP_SENTINEL_INSN, ULONGEST_MAX },
125  },
126  bfin_linux_sigframe_init,
127};
128
129static LONGEST
130bfin_linux_get_syscall_number (struct gdbarch *gdbarch,
131			       thread_info *thread)
132{
133  struct regcache *regcache = get_thread_regcache (thread);
134  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
135  /* The content of a register.  */
136  gdb_byte buf[4];
137  /* The result.  */
138  LONGEST ret;
139
140  /* Getting the system call number from the register.
141     When dealing with Blackfin architecture, this information
142     is stored at %p0 register.  */
143  regcache->cooked_read (BFIN_P0_REGNUM, buf);
144
145  ret = extract_signed_integer (buf, 4, byte_order);
146
147  return ret;
148}
149
150static void
151bfin_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
152{
153  linux_init_abi (info, gdbarch);
154
155  /* Set the sigtramp frame sniffer.  */
156  tramp_frame_prepend_unwinder (gdbarch, &bfin_linux_sigframe);
157
158  /* Functions for 'catch syscall'.  */
159  set_xml_syscall_file_name (gdbarch, "syscalls/bfin-linux.xml");
160  set_gdbarch_get_syscall_number (gdbarch,
161                                  bfin_linux_get_syscall_number);
162}
163
164void _initialize_bfin_linux_tdep ();
165void
166_initialize_bfin_linux_tdep ()
167{
168  gdbarch_register_osabi (bfd_arch_bfin, 0, GDB_OSABI_LINUX,
169                          bfin_linux_init_abi);
170}
171