xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/aarch64-netbsd-tdep.c (revision f8cf1a9151c7af1cb0bd8b09c13c66bca599c027)
1 /* Target-dependent code for NetBSD/aarch64.
2 
3    Copyright (C) 2017-2018 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 3 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, see <http://www.gnu.org/licenses/>.  */
19 
20 #include "defs.h"
21 
22 #include "gdbarch.h"
23 #include "netbsd-tdep.h"
24 #include "aarch64-tdep.h"
25 #include "aarch64-netbsd-tdep.h"
26 #include "osabi.h"
27 #include "solib-svr4.h"
28 #include "target.h"
29 #include "tramp-frame.h"
30 #include "trad-frame.h"
31 
32 /* In a signal frame, sp points to a 'struct sigframe' which is
33    defined as:
34 
35    struct sigframe {
36 	   siginfo_t	sf_si;
37 	   ucontext_t	sf_uc;
38    };
39 
40    ucontext_t is defined as:
41 
42    struct __ucontext {
43 	   sigset_t	uc_sigmask;
44 	   mcontext_t	uc_mcontext;
45 	   ...
46    };
47 
48    The mcontext_t contains the general purpose register set followed
49    by the floating point register set.  The floating point register
50    set is only valid if the _MC_FP_VALID flag is set in mc_flags.  */
51 
52 #define AARCH64_MCONTEXT_REG_SIZE               8
53 #define AARCH64_MCONTEXT_FPREG_SIZE             16
54 #define AARCH64_SIGFRAME_UCONTEXT_OFFSET	80
55 #define AARCH64_UCONTEXT_MCONTEXT_OFFSET	16
56 #define	AARCH64_MCONTEXT_FPREGS_OFFSET		272
57 #define	AARCH64_MCONTEXT_FLAGS_OFFSET		800
58 #define AARCH64_MCONTEXT_FLAG_FP_VALID		0x1
59 
60 /* Implement the "init" method of struct tramp_frame.  */
61 
62 static void
63 aarch64_nbsd_sigframe_init (const struct tramp_frame *self,
64 			     frame_info_ptr this_frame,
65 			     struct trad_frame_cache *this_cache,
66 			     CORE_ADDR func)
67 {
68   struct gdbarch *gdbarch = get_frame_arch (this_frame);
69   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
70   CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
71   CORE_ADDR mcontext_addr =
72     sp
73     + AARCH64_SIGFRAME_UCONTEXT_OFFSET
74     + AARCH64_UCONTEXT_MCONTEXT_OFFSET;
75   gdb_byte buf[4];
76   int i;
77 
78   for (i = 0; i < 30; i++)
79     {
80       trad_frame_set_reg_addr (this_cache,
81 			       AARCH64_X0_REGNUM + i,
82 			       mcontext_addr + i * AARCH64_MCONTEXT_REG_SIZE);
83     }
84   trad_frame_set_reg_addr (this_cache, AARCH64_LR_REGNUM,
85 			   mcontext_addr + 30 * AARCH64_MCONTEXT_REG_SIZE);
86   trad_frame_set_reg_addr (this_cache, AARCH64_SP_REGNUM,
87 			   mcontext_addr + 31 * AARCH64_MCONTEXT_REG_SIZE);
88   trad_frame_set_reg_addr (this_cache, AARCH64_PC_REGNUM,
89 			   mcontext_addr + 32 * AARCH64_MCONTEXT_REG_SIZE);
90   trad_frame_set_reg_addr (this_cache, AARCH64_CPSR_REGNUM,
91 			   mcontext_addr + 33 * AARCH64_MCONTEXT_REG_SIZE);
92 
93   if (target_read_memory (mcontext_addr + AARCH64_MCONTEXT_FLAGS_OFFSET, buf,
94 			  4) == 0
95       && (extract_unsigned_integer (buf, 4, byte_order)
96 	  & AARCH64_MCONTEXT_FLAG_FP_VALID))
97     {
98       for (i = 0; i < 32; i++)
99 	{
100 	  trad_frame_set_reg_addr (this_cache, AARCH64_V0_REGNUM + i,
101 				   mcontext_addr
102 				   + AARCH64_MCONTEXT_FPREGS_OFFSET
103 				   + i * AARCH64_MCONTEXT_FPREG_SIZE);
104 	}
105       trad_frame_set_reg_addr (this_cache, AARCH64_FPSR_REGNUM,
106 			       mcontext_addr + AARCH64_MCONTEXT_FPREGS_OFFSET
107 			       + 32 * AARCH64_MCONTEXT_FPREG_SIZE);
108       trad_frame_set_reg_addr (this_cache, AARCH64_FPCR_REGNUM,
109 			       mcontext_addr + AARCH64_MCONTEXT_FPREGS_OFFSET
110 			       + 32 * AARCH64_MCONTEXT_FPREG_SIZE + 4);
111     }
112 
113   trad_frame_set_id (this_cache, frame_id_build (sp, func));
114 }
115 
116 static const struct tramp_frame aarch64_nbsd_sigframe =
117 {
118   SIGTRAMP_FRAME,
119   4,
120   {
121     {0x910003e0, ULONGEST_MAX},		/* mov  x0, sp  */
122     {0x91014000, ULONGEST_MAX},		/* add  x0, x0, #SF_UC  */
123     {0xd2803428, ULONGEST_MAX},		/* mov  x8, #SYS_sigreturn  */
124     {0xd4000001, ULONGEST_MAX},		/* svc  0x0  */
125     {(ULONGEST)TRAMP_SENTINEL_INSN, ULONGEST_MAX}
126   },
127   aarch64_nbsd_sigframe_init
128 };
129 
130 /* Register maps.  */
131 
132 static const struct regcache_map_entry aarch64_nbsd_gregmap[] =
133   {
134     { 30, AARCH64_X0_REGNUM, 8 }, /* x0 ... x29 */
135     { 1, AARCH64_LR_REGNUM, 8 },
136     { 1, AARCH64_SP_REGNUM, 8 },
137     { 1, AARCH64_PC_REGNUM, 8 },
138     { 1, AARCH64_CPSR_REGNUM, 4 },
139     { 0 }
140   };
141 
142 static const struct regcache_map_entry aarch64_nbsd_fpregmap[] =
143   {
144     { 32, AARCH64_V0_REGNUM, 16 }, /* v0 ... v31 */
145     { 1, AARCH64_FPSR_REGNUM, 4 },
146     { 1, AARCH64_FPCR_REGNUM, 4 },
147     { 0 }
148   };
149 
150 /* Register set definitions.  */
151 
152 const struct regset aarch64_nbsd_gregset =
153   {
154     aarch64_nbsd_gregmap,
155     regcache_supply_regset, regcache_collect_regset
156   };
157 
158 const struct regset aarch64_nbsd_fpregset =
159   {
160     aarch64_nbsd_fpregmap,
161     regcache_supply_regset, regcache_collect_regset
162   };
163 
164 /* Implement the "regset_from_core_section" gdbarch method.  */
165 
166 static void
167 aarch64_nbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
168 					   iterate_over_regset_sections_cb *cb,
169 					   void *cb_data,
170 					   const struct regcache *regcache)
171 {
172   cb (".reg", AARCH64_NBSD_SIZEOF_GREGSET, AARCH64_NBSD_SIZEOF_GREGSET,
173       &aarch64_nbsd_gregset, NULL, cb_data);
174   cb (".reg2", AARCH64_NBSD_SIZEOF_FPREGSET, AARCH64_NBSD_SIZEOF_FPREGSET,
175       &aarch64_nbsd_fpregset, NULL, cb_data);
176 }
177 
178 /* Implement the 'init_osabi' method of struct gdb_osabi_handler.  */
179 
180 static void
181 aarch64_nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
182 {
183   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep>(gdbarch);
184 
185   nbsd_init_abi (info, gdbarch);
186 
187   set_solib_svr4_fetch_link_map_offsets (gdbarch,
188 					 svr4_lp64_fetch_link_map_offsets);
189 
190   tramp_frame_prepend_unwinder (gdbarch, &aarch64_nbsd_sigframe);
191 
192   /* Enable longjmp.  */
193   tdep->jb_pc = 13;
194 
195   set_gdbarch_iterate_over_regset_sections
196     (gdbarch, aarch64_nbsd_iterate_over_regset_sections);
197 }
198 
199 void
200 _initialize_aarch64_nbsd_tdep ()
201 {
202   gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_NETBSD,
203 			  aarch64_nbsd_init_abi);
204 }
205