xref: /netbsd-src/external/gpl3/gdb.old/dist/gdb/m68k-bsd-nat.c (revision 867d70fc718005c0918b8b8b2f9d7f2d52d0a0db)
1 /* Native-dependent code for Motorola 68000 BSD's.
2 
3    Copyright (C) 2004-2019 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 "gdbcore.h"
22 #include "inferior.h"
23 #include "regcache.h"
24 
25 #include <sys/types.h>
26 #include <sys/ptrace.h>
27 #include <machine/reg.h>
28 
29 #include "m68k-tdep.h"
30 #include "inf-ptrace.h"
31 
32 #ifdef __NetBSD__
33 #include "nbsd-nat.h"
34 struct m68k_bsd_nat_target final : public nbsd_nat_target
35 #else
36 struct m68k_bsd_nat_target final : public inf_ptrace_target
37 #endif
38 {
39   void fetch_registers (struct regcache *, int) override;
40   void store_registers (struct regcache *, int) override;
41 };
42 
43 static m68k_bsd_nat_target the_m68k_bsd_nat_target;
44 
45 static int
46 m68kbsd_gregset_supplies_p (int regnum)
47 {
48   return (regnum >= M68K_D0_REGNUM && regnum <= M68K_PC_REGNUM);
49 }
50 
51 static int
52 m68kbsd_fpregset_supplies_p (int regnum)
53 {
54   return (regnum >= M68K_FP0_REGNUM && regnum <= M68K_FPI_REGNUM);
55 }
56 
57 /* Supply the general-purpose registers stored in GREGS to REGCACHE.  */
58 
59 static void
60 m68kbsd_supply_gregset (struct regcache *regcache, const void *gregs)
61 {
62   const gdb_byte *regs = (const gdb_byte *)gregs;
63   int regnum;
64 
65   for (regnum = M68K_D0_REGNUM; regnum <= M68K_PC_REGNUM; regnum++)
66     regcache->raw_supply (regnum, regs + regnum * 4);
67 }
68 
69 /* Supply the floating-point registers stored in FPREGS to REGCACHE.  */
70 
71 static void
72 m68kbsd_supply_fpregset (struct regcache *regcache, const void *fpregs)
73 {
74   struct gdbarch *gdbarch = regcache->arch ();
75   const gdb_byte *regs = (const gdb_byte *)fpregs;
76   int regnum;
77 
78   for (regnum = M68K_FP0_REGNUM; regnum <= M68K_FPI_REGNUM; regnum++)
79     regcache->raw_supply (regnum,
80 			  regs + m68kbsd_fpreg_offset (gdbarch, regnum));
81 }
82 
83 /* Collect the general-purpose registers from REGCACHE and store them
84    in GREGS.  */
85 
86 static void
87 m68kbsd_collect_gregset (const struct regcache *regcache,
88 			 void *gregs, int regnum)
89 {
90   gdb_byte *regs = (gdb_byte *)gregs;
91   int i;
92 
93   for (i = M68K_D0_REGNUM; i <= M68K_PC_REGNUM; i++)
94     {
95       if (regnum == -1 || regnum == i)
96 	regcache->raw_collect (i, regs + i * 4);
97     }
98 }
99 
100 /* Collect the floating-point registers from REGCACHE and store them
101    in FPREGS.  */
102 
103 static void
104 m68kbsd_collect_fpregset (struct regcache *regcache,
105 			  void *fpregs, int regnum)
106 {
107   struct gdbarch *gdbarch = regcache->arch ();
108   gdb_byte *regs = (gdb_byte *)fpregs;
109   int i;
110 
111   for (i = M68K_FP0_REGNUM; i <= M68K_FPI_REGNUM; i++)
112     {
113       if (regnum == -1 || regnum == i)
114 	regcache->raw_collect (i, regs + m68kbsd_fpreg_offset (gdbarch, i));
115     }
116 }
117 
118 
119 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
120    for all registers (including the floating-point registers).  */
121 
122 void
123 m68k_bsd_nat_target::fetch_registers (struct regcache *regcache, int regnum)
124 {
125   pid_t pid = regcache->ptid ().pid ();
126 
127   if (regnum == -1 || m68kbsd_gregset_supplies_p (regnum))
128     {
129       struct reg regs;
130 
131       if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs,  inferior_ptid.lwp ()) == -1)
132 	perror_with_name (_("Couldn't get registers"));
133 
134       m68kbsd_supply_gregset (regcache, &regs);
135     }
136 
137   if (regnum == -1 || m68kbsd_fpregset_supplies_p (regnum))
138     {
139       struct fpreg fpregs;
140 
141       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs,  inferior_ptid.lwp ()) == -1)
142 	perror_with_name (_("Couldn't get floating point status"));
143 
144       m68kbsd_supply_fpregset (regcache, &fpregs);
145     }
146 }
147 
148 /* Store register REGNUM back into the inferior.  If REGNUM is -1, do
149    this for all registers (including the floating-point registers).  */
150 
151 void
152 m68k_bsd_nat_target::store_registers (struct regcache *regcache, int regnum)
153 {
154   pid_t pid = regcache->ptid ().pid ();
155 
156   if (regnum == -1 || m68kbsd_gregset_supplies_p (regnum))
157     {
158       struct reg regs;
159 
160       if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs,  inferior_ptid.lwp ()) == -1)
161         perror_with_name (_("Couldn't get registers"));
162 
163       m68kbsd_collect_gregset (regcache, &regs, regnum);
164 
165       if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs,  inferior_ptid.lwp ()) == -1)
166         perror_with_name (_("Couldn't write registers"));
167     }
168 
169   if (regnum == -1 || m68kbsd_fpregset_supplies_p (regnum))
170     {
171       struct fpreg fpregs;
172 
173       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs,  inferior_ptid.lwp ()) == -1)
174 	perror_with_name (_("Couldn't get floating point status"));
175 
176       m68kbsd_collect_fpregset (regcache, &fpregs, regnum);
177 
178       if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs,  inferior_ptid.lwp ()) == -1)
179 	perror_with_name (_("Couldn't write floating point status"));
180     }
181 }
182 
183 
184 /* Support for debugging kernel virtual memory images.  */
185 
186 #include <machine/pcb.h>
187 
188 #include "bsd-kvm.h"
189 
190 /* OpenBSD doesn't have these.  */
191 #ifndef PCB_REGS_FP
192 #define PCB_REGS_FP 10
193 #endif
194 #ifndef PCB_REGS_SP
195 #define PCB_REGS_SP 11
196 #endif
197 
198 static int
199 m68kbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
200 {
201   int regnum, tmp;
202   int i = 0;
203 
204   /* The following is true for NetBSD 1.6.2:
205 
206      The pcb contains %d2...%d7, %a2...%a7 and %ps.  This accounts for
207      all callee-saved registers.  From this information we reconstruct
208      the register state as it would look when we just returned from
209      cpu_switch().  */
210 
211   /* The stack pointer shouldn't be zero.  */
212   if (pcb->pcb_regs[PCB_REGS_SP] == 0)
213     return 0;
214 
215   for (regnum = M68K_D2_REGNUM; regnum <= M68K_D7_REGNUM; regnum++)
216     regcache->raw_supply (regnum, &pcb->pcb_regs[i++]);
217   for (regnum = M68K_A2_REGNUM; regnum <= M68K_SP_REGNUM; regnum++)
218     regcache->raw_supply (regnum, &pcb->pcb_regs[i++]);
219 
220   tmp = pcb->pcb_ps & 0xffff;
221   regcache->raw_supply (M68K_PS_REGNUM, &tmp);
222 
223   read_memory (pcb->pcb_regs[PCB_REGS_FP] + 4, (gdb_byte *) &tmp, sizeof tmp);
224   regcache->raw_supply (M68K_PC_REGNUM, &tmp);
225 
226   return 1;
227 }
228 
229 void
230 _initialize_m68kbsd_nat (void)
231 {
232   add_inf_child_target (&the_m68k_bsd_nat_target);
233 
234   /* Support debugging kernel virtual memory images.  */
235   bsd_kvm_add_target (m68kbsd_supply_pcb);
236 }
237