xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/m32r-linux-nat.c (revision 200d779b75dbeafa7bc01fd0f60bc61185f6967b)
1 /* Native-dependent code for GNU/Linux m32r.
2 
3    Copyright (C) 2004-2014 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 
27 #include "gdb_assert.h"
28 #include <string.h>
29 #include <sys/ptrace.h>
30 #include <sys/user.h>
31 #include <sys/procfs.h>
32 
33 /* Prototypes for supply_gregset etc.  */
34 #include "gregset.h"
35 
36 #include "m32r-tdep.h"
37 
38 
39 
40 
41 /* Since EVB register is not available for native debug, we reduce
42    the number of registers.  */
43 #define M32R_LINUX_NUM_REGS (M32R_NUM_REGS - 1)
44 
45 /* Mapping between the general-purpose registers in `struct user'
46    format and GDB's register array layout.  */
47 static int regmap[] = {
48   4, 5, 6, 7, 0, 1, 2, 8,
49   9, 10, 11, 12, 13, 24, 25, 23,
50   19, 19, 26, 23, 22, 20, 16, 15
51 };
52 
53 #define PSW_REGMAP 19
54 #define BBPSW_REGMAP 21
55 #define SPU_REGMAP 23
56 #define SPI_REGMAP 26
57 
58 /* Doee (??) apply to the corresponding SET requests as well.  */
59 #define GETREGS_SUPPLIES(regno) (0 <= (regno) \
60 				 && (regno) <= M32R_LINUX_NUM_REGS)
61 
62 
63 
64 /* Transfering the general-purpose registers between GDB, inferiors
65    and core files.  */
66 
67 /* Fill GDB's register array with the general-purpose register values
68    in *GREGSETP.  */
69 
70 void
71 supply_gregset (struct regcache *regcache, const elf_gregset_t * gregsetp)
72 {
73   const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
74   int i;
75   unsigned long psw, bbpsw;
76 
77   psw = *(regp + PSW_REGMAP);
78   bbpsw = *(regp + BBPSW_REGMAP);
79 
80   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
81     {
82       elf_greg_t regval;
83 
84       switch (i)
85 	{
86 	case PSW_REGNUM:
87 	  regval = ((0x00c1 & bbpsw) << 8) | ((0xc100 & psw) >> 8);
88 	  break;
89 	case CBR_REGNUM:
90 	  regval = ((psw >> 8) & 1);
91 	  break;
92 	default:
93 	  regval = *(regp + regmap[i]);
94 	  break;
95 	}
96 
97       if (i != M32R_SP_REGNUM)
98 	regcache_raw_supply (regcache, i, &regval);
99       else if (psw & 0x8000)
100 	regcache_raw_supply (regcache, i, regp + SPU_REGMAP);
101       else
102 	regcache_raw_supply (regcache, i, regp + SPI_REGMAP);
103     }
104 }
105 
106 /* Fetch all general-purpose registers from process/thread TID and
107    store their values in GDB's register array.  */
108 
109 static void
110 fetch_regs (struct regcache *regcache, int tid)
111 {
112   elf_gregset_t regs;
113 
114   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
115     perror_with_name (_("Couldn't get registers"));
116 
117   supply_gregset (regcache, (const elf_gregset_t *) &regs);
118 }
119 
120 /* Fill register REGNO (if it is a general-purpose register) in
121    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
122    do this for all registers.  */
123 
124 void
125 fill_gregset (const struct regcache *regcache,
126 	      elf_gregset_t * gregsetp, int regno)
127 {
128   elf_greg_t *regp = (elf_greg_t *) gregsetp;
129   int i;
130   unsigned long psw, bbpsw, tmp;
131 
132   psw = *(regp + PSW_REGMAP);
133   bbpsw = *(regp + BBPSW_REGMAP);
134 
135   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
136     {
137       if (regno != -1 && regno != i)
138 	continue;
139 
140       if (i == CBR_REGNUM || i == PSW_REGNUM)
141 	continue;
142 
143       if (i == SPU_REGNUM || i == SPI_REGNUM)
144 	continue;
145 
146       if (i != M32R_SP_REGNUM)
147 	regcache_raw_collect (regcache, i, regp + regmap[i]);
148       else if (psw & 0x8000)
149 	regcache_raw_collect (regcache, i, regp + SPU_REGMAP);
150       else
151 	regcache_raw_collect (regcache, i, regp + SPI_REGMAP);
152     }
153 }
154 
155 /* Store all valid general-purpose registers in GDB's register array
156    into the process/thread specified by TID.  */
157 
158 static void
159 store_regs (const struct regcache *regcache, int tid, int regno)
160 {
161   elf_gregset_t regs;
162 
163   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
164     perror_with_name (_("Couldn't get registers"));
165 
166   fill_gregset (regcache, &regs, regno);
167 
168   if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
169     perror_with_name (_("Couldn't write registers"));
170 }
171 
172 
173 
174 /* Transfering floating-point registers between GDB, inferiors and cores.
175    Since M32R has no floating-point registers, these functions do nothing.  */
176 
177 void
178 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
179 {
180 }
181 
182 void
183 fill_fpregset (const struct regcache *regcache,
184 	       gdb_fpregset_t *fpregs, int regno)
185 {
186 }
187 
188 
189 
190 /* Transferring arbitrary registers between GDB and inferior.  */
191 
192 /* Fetch register REGNO from the child process.  If REGNO is -1, do
193    this for all registers (including the floating point and SSE
194    registers).  */
195 
196 static void
197 m32r_linux_fetch_inferior_registers (struct target_ops *ops,
198 				     struct regcache *regcache, int regno)
199 {
200   int tid;
201 
202   /* GNU/Linux LWP ID's are process ID's.  */
203   tid = ptid_get_lwp (inferior_ptid);
204   if (tid == 0)
205     tid = ptid_get_pid (inferior_ptid);	/* Not a threaded program.  */
206 
207   /* Use the PTRACE_GETREGS request whenever possible, since it
208      transfers more registers in one system call, and we'll cache the
209      results.  */
210   if (regno == -1 || GETREGS_SUPPLIES (regno))
211     {
212       fetch_regs (regcache, tid);
213       return;
214     }
215 
216   internal_error (__FILE__, __LINE__,
217 		  _("Got request for bad register number %d."), regno);
218 }
219 
220 /* Store register REGNO back into the child process.  If REGNO is -1,
221    do this for all registers (including the floating point and SSE
222    registers).  */
223 static void
224 m32r_linux_store_inferior_registers (struct target_ops *ops,
225 				     struct regcache *regcache, int regno)
226 {
227   int tid;
228 
229   /* GNU/Linux LWP ID's are process ID's.  */
230   if ((tid = ptid_get_lwp (inferior_ptid)) == 0)
231     tid = ptid_get_pid (inferior_ptid);	/* Not a threaded program.  */
232 
233   /* Use the PTRACE_SETREGS request whenever possible, since it
234      transfers more registers in one system call.  */
235   if (regno == -1 || GETREGS_SUPPLIES (regno))
236     {
237       store_regs (regcache, tid, regno);
238       return;
239     }
240 
241   internal_error (__FILE__, __LINE__,
242 		  _("Got request to store bad register number %d."), regno);
243 }
244 
245 void _initialize_m32r_linux_nat (void);
246 
247 void
248 _initialize_m32r_linux_nat (void)
249 {
250   struct target_ops *t;
251 
252   /* Fill in the generic GNU/Linux methods.  */
253   t = linux_target ();
254 
255   /* Add our register access methods.  */
256   t->to_fetch_registers = m32r_linux_fetch_inferior_registers;
257   t->to_store_registers = m32r_linux_store_inferior_registers;
258 
259   /* Register the target.  */
260   linux_nat_add_target (t);
261 }
262