xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/m32r-linux-nat.c (revision c9496f6b604074a9451a67df576a5b423068e71e)
1 /* Native-dependent code for GNU/Linux m32r.
2 
3    Copyright (C) 2004-2016 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 
30 /* Prototypes for supply_gregset etc.  */
31 #include "gregset.h"
32 
33 #include "m32r-tdep.h"
34 
35 
36 
37 
38 /* Since EVB register is not available for native debug, we reduce
39    the number of registers.  */
40 #define M32R_LINUX_NUM_REGS (M32R_NUM_REGS - 1)
41 
42 /* Mapping between the general-purpose registers in `struct user'
43    format and GDB's register array layout.  */
44 static int regmap[] = {
45   4, 5, 6, 7, 0, 1, 2, 8,
46   9, 10, 11, 12, 13, 24, 25, 23,
47   19, 19, 26, 23, 22, 20, 16, 15
48 };
49 
50 #define PSW_REGMAP 19
51 #define BBPSW_REGMAP 21
52 #define SPU_REGMAP 23
53 #define SPI_REGMAP 26
54 
55 /* Doee (??) apply to the corresponding SET requests as well.  */
56 #define GETREGS_SUPPLIES(regno) (0 <= (regno) \
57 				 && (regno) <= M32R_LINUX_NUM_REGS)
58 
59 
60 
61 /* Transfering the general-purpose registers between GDB, inferiors
62    and core files.  */
63 
64 /* Fill GDB's register array with the general-purpose register values
65    in *GREGSETP.  */
66 
67 void
68 supply_gregset (struct regcache *regcache, const elf_gregset_t * gregsetp)
69 {
70   const elf_greg_t *regp = (const elf_greg_t *) gregsetp;
71   int i;
72   unsigned long psw, bbpsw;
73 
74   psw = *(regp + PSW_REGMAP);
75   bbpsw = *(regp + BBPSW_REGMAP);
76 
77   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
78     {
79       elf_greg_t regval;
80 
81       switch (i)
82 	{
83 	case PSW_REGNUM:
84 	  regval = ((0x00c1 & bbpsw) << 8) | ((0xc100 & psw) >> 8);
85 	  break;
86 	case CBR_REGNUM:
87 	  regval = ((psw >> 8) & 1);
88 	  break;
89 	default:
90 	  regval = *(regp + regmap[i]);
91 	  break;
92 	}
93 
94       if (i != M32R_SP_REGNUM)
95 	regcache_raw_supply (regcache, i, &regval);
96       else if (psw & 0x8000)
97 	regcache_raw_supply (regcache, i, regp + SPU_REGMAP);
98       else
99 	regcache_raw_supply (regcache, i, regp + SPI_REGMAP);
100     }
101 }
102 
103 /* Fetch all general-purpose registers from process/thread TID and
104    store their values in GDB's register array.  */
105 
106 static void
107 fetch_regs (struct regcache *regcache, int tid)
108 {
109   elf_gregset_t regs;
110 
111   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
112     perror_with_name (_("Couldn't get registers"));
113 
114   supply_gregset (regcache, (const elf_gregset_t *) &regs);
115 }
116 
117 /* Fill register REGNO (if it is a general-purpose register) in
118    *GREGSETPS with the value in GDB's register array.  If REGNO is -1,
119    do this for all registers.  */
120 
121 void
122 fill_gregset (const struct regcache *regcache,
123 	      elf_gregset_t * gregsetp, int regno)
124 {
125   elf_greg_t *regp = (elf_greg_t *) gregsetp;
126   int i;
127   unsigned long psw, bbpsw, tmp;
128 
129   psw = *(regp + PSW_REGMAP);
130   bbpsw = *(regp + BBPSW_REGMAP);
131 
132   for (i = 0; i < M32R_LINUX_NUM_REGS; i++)
133     {
134       if (regno != -1 && regno != i)
135 	continue;
136 
137       if (i == CBR_REGNUM || i == PSW_REGNUM)
138 	continue;
139 
140       if (i == SPU_REGNUM || i == SPI_REGNUM)
141 	continue;
142 
143       if (i != M32R_SP_REGNUM)
144 	regcache_raw_collect (regcache, i, regp + regmap[i]);
145       else if (psw & 0x8000)
146 	regcache_raw_collect (regcache, i, regp + SPU_REGMAP);
147       else
148 	regcache_raw_collect (regcache, i, regp + SPI_REGMAP);
149     }
150 }
151 
152 /* Store all valid general-purpose registers in GDB's register array
153    into the process/thread specified by TID.  */
154 
155 static void
156 store_regs (const struct regcache *regcache, int tid, int regno)
157 {
158   elf_gregset_t regs;
159 
160   if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
161     perror_with_name (_("Couldn't get registers"));
162 
163   fill_gregset (regcache, &regs, regno);
164 
165   if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
166     perror_with_name (_("Couldn't write registers"));
167 }
168 
169 
170 
171 /* Transfering floating-point registers between GDB, inferiors and cores.
172    Since M32R has no floating-point registers, these functions do nothing.  */
173 
174 void
175 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregs)
176 {
177 }
178 
179 void
180 fill_fpregset (const struct regcache *regcache,
181 	       gdb_fpregset_t *fpregs, int regno)
182 {
183 }
184 
185 
186 
187 /* Transferring arbitrary registers between GDB and inferior.  */
188 
189 /* Fetch register REGNO from the child process.  If REGNO is -1, do
190    this for all registers (including the floating point and SSE
191    registers).  */
192 
193 static void
194 m32r_linux_fetch_inferior_registers (struct target_ops *ops,
195 				     struct regcache *regcache, int regno)
196 {
197   int tid;
198 
199   /* GNU/Linux LWP ID's are process ID's.  */
200   tid = ptid_get_lwp (inferior_ptid);
201   if (tid == 0)
202     tid = ptid_get_pid (inferior_ptid);	/* Not a threaded program.  */
203 
204   /* Use the PTRACE_GETREGS request whenever possible, since it
205      transfers more registers in one system call, and we'll cache the
206      results.  */
207   if (regno == -1 || GETREGS_SUPPLIES (regno))
208     {
209       fetch_regs (regcache, tid);
210       return;
211     }
212 
213   internal_error (__FILE__, __LINE__,
214 		  _("Got request for bad register number %d."), regno);
215 }
216 
217 /* Store register REGNO back into the child process.  If REGNO is -1,
218    do this for all registers (including the floating point and SSE
219    registers).  */
220 static void
221 m32r_linux_store_inferior_registers (struct target_ops *ops,
222 				     struct regcache *regcache, int regno)
223 {
224   int tid;
225 
226   /* GNU/Linux LWP ID's are process ID's.  */
227   if ((tid = ptid_get_lwp (inferior_ptid)) == 0)
228     tid = ptid_get_pid (inferior_ptid);	/* Not a threaded program.  */
229 
230   /* Use the PTRACE_SETREGS request whenever possible, since it
231      transfers more registers in one system call.  */
232   if (regno == -1 || GETREGS_SUPPLIES (regno))
233     {
234       store_regs (regcache, tid, regno);
235       return;
236     }
237 
238   internal_error (__FILE__, __LINE__,
239 		  _("Got request to store bad register number %d."), regno);
240 }
241 
242 void _initialize_m32r_linux_nat (void);
243 
244 void
245 _initialize_m32r_linux_nat (void)
246 {
247   struct target_ops *t;
248 
249   /* Fill in the generic GNU/Linux methods.  */
250   t = linux_target ();
251 
252   /* Add our register access methods.  */
253   t->to_fetch_registers = m32r_linux_fetch_inferior_registers;
254   t->to_store_registers = m32r_linux_store_inferior_registers;
255 
256   /* Register the target.  */
257   linux_nat_add_target (t);
258 }
259