xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/m32r-linux-nat.c (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /* Native-dependent code for GNU/Linux m32r.
2 
3    Copyright (C) 2004-2017 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 #include "inferior.h"
22 #include "gdbcore.h"
23 #include "regcache.h"
24 #include "linux-nat.h"
25 #include "target.h"
26 #include "nat/gdb_ptrace.h"
27 #include <sys/user.h>
28 #include <sys/procfs.h>
29 #include "inf-ptrace.h"
30 
31 /* Prototypes for supply_gregset etc.  */
32 #include "gregset.h"
33 
34 #include "m32r-tdep.h"
35 
36 
37 
38 
39 /* Since EVB register is not available for native debug, we reduce
40    the number of registers.  */
41 #define M32R_LINUX_NUM_REGS (M32R_NUM_REGS - 1)
42 
43 /* Mapping between the general-purpose registers in `struct user'
44    format and GDB's register array layout.  */
45 static int regmap[] = {
46   4, 5, 6, 7, 0, 1, 2, 8,
47   9, 10, 11, 12, 13, 24, 25, 23,
48   19, 19, 26, 23, 22, 20, 16, 15
49 };
50 
51 #define PSW_REGMAP 19
52 #define BBPSW_REGMAP 21
53 #define SPU_REGMAP 23
54 #define SPI_REGMAP 26
55 
56 /* Doee (??) apply to the corresponding SET requests as well.  */
57 #define GETREGS_SUPPLIES(regno) (0 <= (regno) \
58 				 && (regno) <= M32R_LINUX_NUM_REGS)
59 
60 
61 
62 /* Transfering the general-purpose registers between GDB, inferiors
63    and core files.  */
64 
65 /* Fill GDB's register array with the general-purpose register values
66    in *GREGSETP.  */
67 
68 void
69 supply_gregset (struct regcache *regcache, const elf_gregset_t * gregsetp)
70 {
71   const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
72   int i;
73   unsigned long psw, bbpsw;
74 
75   psw = *(regp + PSW_REGMAP);
76   bbpsw = *(regp + BBPSW_REGMAP);
77 
78   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
79     {
80       elf_greg_t regval;
81 
82       switch (i)
83 	{
84 	case PSW_REGNUM:
85 	  regval = ((0x00c1 & bbpsw) << 8) | ((0xc100 & psw) >> 8);
86 	  break;
87 	case CBR_REGNUM:
88 	  regval = ((psw >> 8) & 1);
89 	  break;
90 	default:
91 	  regval = *(regp + regmap[i]);
92 	  break;
93 	}
94 
95       if (i != M32R_SP_REGNUM)
96 	regcache_raw_supply (regcache, i, &regval);
97       else if (psw & 0x8000)
98 	regcache_raw_supply (regcache, i, regp + SPU_REGMAP);
99       else
100 	regcache_raw_supply (regcache, i, regp + SPI_REGMAP);
101     }
102 }
103 
104 /* Fetch all general-purpose registers from process/thread TID and
105    store their values in GDB's register array.  */
106 
107 static void
108 fetch_regs (struct regcache *regcache, int tid)
109 {
110   elf_gregset_t regs;
111 
112   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
113     perror_with_name (_("Couldn't get registers"));
114 
115   supply_gregset (regcache, (const elf_gregset_t *) &regs);
116 }
117 
118 /* Fill register REGNO (if it is a general-purpose register) in
119    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
120    do this for all registers.  */
121 
122 void
123 fill_gregset (const struct regcache *regcache,
124 	      elf_gregset_t * gregsetp, int regno)
125 {
126   elf_greg_t *regp = (elf_greg_t *) gregsetp;
127   int i;
128   unsigned long psw, bbpsw, tmp;
129 
130   psw = *(regp + PSW_REGMAP);
131   bbpsw = *(regp + BBPSW_REGMAP);
132 
133   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
134     {
135       if (regno != -1 && regno != i)
136 	continue;
137 
138       if (i == CBR_REGNUM || i == PSW_REGNUM)
139 	continue;
140 
141       if (i == SPU_REGNUM || i == SPI_REGNUM)
142 	continue;
143 
144       if (i != M32R_SP_REGNUM)
145 	regcache_raw_collect (regcache, i, regp + regmap[i]);
146       else if (psw & 0x8000)
147 	regcache_raw_collect (regcache, i, regp + SPU_REGMAP);
148       else
149 	regcache_raw_collect (regcache, i, regp + SPI_REGMAP);
150     }
151 }
152 
153 /* Store all valid general-purpose registers in GDB's register array
154    into the process/thread specified by TID.  */
155 
156 static void
157 store_regs (const struct regcache *regcache, int tid, int regno)
158 {
159   elf_gregset_t regs;
160 
161   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
162     perror_with_name (_("Couldn't get registers"));
163 
164   fill_gregset (regcache, &regs, regno);
165 
166   if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
167     perror_with_name (_("Couldn't write registers"));
168 }
169 
170 
171 
172 /* Transfering floating-point registers between GDB, inferiors and cores.
173    Since M32R has no floating-point registers, these functions do nothing.  */
174 
175 void
176 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
177 {
178 }
179 
180 void
181 fill_fpregset (const struct regcache *regcache,
182 	       gdb_fpregset_t *fpregs, int regno)
183 {
184 }
185 
186 
187 
188 /* Transferring arbitrary registers between GDB and inferior.  */
189 
190 /* Fetch register REGNO from the child process.  If REGNO is -1, do
191    this for all registers (including the floating point and SSE
192    registers).  */
193 
194 static void
195 m32r_linux_fetch_inferior_registers (struct target_ops *ops,
196 				     struct regcache *regcache, int regno)
197 {
198   pid_t tid = get_ptrace_pid (regcache_get_ptid (regcache));
199 
200   /* Use the PTRACE_GETREGS request whenever possible, since it
201      transfers more registers in one system call, and we'll cache the
202      results.  */
203   if (regno == -1 || GETREGS_SUPPLIES (regno))
204     {
205       fetch_regs (regcache, tid);
206       return;
207     }
208 
209   internal_error (__FILE__, __LINE__,
210 		  _("Got request for bad register number %d."), regno);
211 }
212 
213 /* Store register REGNO back into the child process.  If REGNO is -1,
214    do this for all registers (including the floating point and SSE
215    registers).  */
216 static void
217 m32r_linux_store_inferior_registers (struct target_ops *ops,
218 				     struct regcache *regcache, int regno)
219 {
220   pid_t tid = get_ptrace_pid (regcache_get_ptid (regcache));
221 
222   /* Use the PTRACE_SETREGS request whenever possible, since it
223      transfers more registers in one system call.  */
224   if (regno == -1 || GETREGS_SUPPLIES (regno))
225     {
226       store_regs (regcache, tid, regno);
227       return;
228     }
229 
230   internal_error (__FILE__, __LINE__,
231 		  _("Got request to store bad register number %d."), regno);
232 }
233 
234 void _initialize_m32r_linux_nat (void);
235 
236 void
237 _initialize_m32r_linux_nat (void)
238 {
239   struct target_ops *t;
240 
241   /* Fill in the generic GNU/Linux methods.  */
242   t = linux_target ();
243 
244   /* Add our register access methods.  */
245   t->to_fetch_registers = m32r_linux_fetch_inferior_registers;
246   t->to_store_registers = m32r_linux_store_inferior_registers;
247 
248   /* Register the target.  */
249   linux_nat_add_target (t);
250 }
251