1 /* Target-dependent code for NetBSD/powerpc.
2 
3    Copyright (C) 2002-2020 Free Software Foundation, Inc.
4 
5    Contributed by Wasabi Systems, Inc.
6 
7    This file is part of GDB.
8 
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3 of the License, or
12    (at your option) any later version.
13 
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18 
19    You should have received a copy of the GNU General Public License
20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
21 
22 #include "defs.h"
23 #include "gdbtypes.h"
24 #include "osabi.h"
25 #include "regcache.h"
26 #include "regset.h"
27 #include "trad-frame.h"
28 #include "tramp-frame.h"
29 
30 #include "ppc-tdep.h"
31 #include "nbsd-tdep.h"
32 #include "ppc-nbsd-tdep.h"
33 #include "ppc-tdep.h"
34 #include "solib-svr4.h"
35 
36 /* Register offsets from <machine/reg.h>.  */
37 struct ppc_reg_offsets ppcnbsd_reg_offsets;
38 
39 
40 /* Core file support.  */
41 
42 /* NetBSD/powerpc register sets.  */
43 
44 const struct regset ppcnbsd_gregset =
45 {
46   &ppcnbsd_reg_offsets,
47   ppc_supply_gregset
48 };
49 
50 const struct regset ppcnbsd_fpregset =
51 {
52   &ppcnbsd_reg_offsets,
53   ppc_supply_fpregset
54 };
55 
56 /* Iterate over core file register note sections.  */
57 
58 static void
ppcnbsd_iterate_over_regset_sections(struct gdbarch * gdbarch,iterate_over_regset_sections_cb * cb,void * cb_data,const struct regcache * regcache)59 ppcnbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
60 				      iterate_over_regset_sections_cb *cb,
61 				      void *cb_data,
62 				      const struct regcache *regcache)
63 {
64   cb (".reg", 148, 148, &ppcnbsd_gregset, NULL, cb_data);
65   cb (".reg2", 264, 264, &ppcnbsd_fpregset, NULL, cb_data);
66 }
67 
68 
69 /* NetBSD is confused.  It appears that 1.5 was using the correct SVR4
70    convention but, 1.6 switched to the below broken convention.  For
71    the moment use the broken convention.  Ulgh!  */
72 
73 static enum return_value_convention
ppcnbsd_return_value(struct gdbarch * gdbarch,struct value * function,struct type * valtype,struct regcache * regcache,gdb_byte * readbuf,const gdb_byte * writebuf)74 ppcnbsd_return_value (struct gdbarch *gdbarch, struct value *function,
75 		      struct type *valtype, struct regcache *regcache,
76 		      gdb_byte *readbuf, const gdb_byte *writebuf)
77 {
78 #if 0
79   if ((valtype->code () == TYPE_CODE_STRUCT
80        || valtype->code () == TYPE_CODE_UNION)
81       && !((TYPE_LENGTH (valtype) == 16 || TYPE_LENGTH (valtype) == 8)
82 	    && TYPE_VECTOR (valtype))
83       && !(TYPE_LENGTH (valtype) == 1
84 	   || TYPE_LENGTH (valtype) == 2
85 	   || TYPE_LENGTH (valtype) == 4
86 	   || TYPE_LENGTH (valtype) == 8))
87     return RETURN_VALUE_STRUCT_CONVENTION;
88   else
89 #endif
90     return ppc_sysv_abi_broken_return_value (gdbarch, function, valtype,
91 					     regcache, readbuf, writebuf);
92 }
93 
94 
95 /* Signal trampolines.  */
96 
97 extern const struct tramp_frame ppcnbsd2_sigtramp;
98 
99 static void
ppcnbsd_sigtramp_cache_init(const struct tramp_frame * self,struct frame_info * this_frame,struct trad_frame_cache * this_cache,CORE_ADDR func)100 ppcnbsd_sigtramp_cache_init (const struct tramp_frame *self,
101 			     struct frame_info *this_frame,
102 			     struct trad_frame_cache *this_cache,
103 			     CORE_ADDR func)
104 {
105   struct gdbarch *gdbarch = get_frame_arch (this_frame);
106   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
107   CORE_ADDR addr, base;
108   int i;
109 
110   base = get_frame_register_unsigned (this_frame,
111 				      gdbarch_sp_regnum (gdbarch));
112   if (self == &ppcnbsd2_sigtramp)
113     addr = base + 0x10 + 2 * tdep->wordsize;
114   else
115     addr = base + 0x18 + 2 * tdep->wordsize;
116   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
117     {
118       int regnum = i + tdep->ppc_gp0_regnum;
119       trad_frame_set_reg_addr (this_cache, regnum, addr);
120     }
121   trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
122   addr += tdep->wordsize;
123   trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
124   addr += tdep->wordsize;
125   trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
126   addr += tdep->wordsize;
127   trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
128   addr += tdep->wordsize;
129   trad_frame_set_reg_addr (this_cache, gdbarch_pc_regnum (gdbarch),
130 			   addr); /* SRR0?  */
131   addr += tdep->wordsize;
132 
133   /* Construct the frame ID using the function start.  */
134   trad_frame_set_id (this_cache, frame_id_build (base, func));
135 }
136 
137 static const struct tramp_frame ppcnbsd_sigtramp =
138 {
139   SIGTRAMP_FRAME,
140   4,
141   {
142     { 0x3821fff0, ULONGEST_MAX },		/* add r1,r1,-16 */
143     { 0x4e800021, ULONGEST_MAX },		/* blrl */
144     { 0x38610018, ULONGEST_MAX },		/* addi r3,r1,24 */
145     { 0x38000127, ULONGEST_MAX },		/* li r0,295 */
146     { 0x44000002, ULONGEST_MAX },		/* sc */
147     { 0x38000001, ULONGEST_MAX },		/* li r0,1 */
148     { 0x44000002, ULONGEST_MAX },		/* sc */
149     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
150   },
151   ppcnbsd_sigtramp_cache_init
152 };
153 
154 /* NetBSD 2.0 introduced a slightly different signal trampoline.  */
155 
156 const struct tramp_frame ppcnbsd2_sigtramp =
157 {
158   SIGTRAMP_FRAME,
159   4,
160   {
161     { 0x3821fff0, ULONGEST_MAX },		/* add r1,r1,-16 */
162     { 0x4e800021, ULONGEST_MAX },		/* blrl */
163     { 0x38610010, ULONGEST_MAX },		/* addi r3,r1,16 */
164     { 0x38000127, ULONGEST_MAX },		/* li r0,295 */
165     { 0x44000002, ULONGEST_MAX },		/* sc */
166     { 0x38000001, ULONGEST_MAX },		/* li r0,1 */
167     { 0x44000002, ULONGEST_MAX },		/* sc */
168     { TRAMP_SENTINEL_INSN, ULONGEST_MAX }
169   },
170   ppcnbsd_sigtramp_cache_init
171 };
172 
173 
174 static void
ppcnbsd_init_abi(struct gdbarch_info info,struct gdbarch * gdbarch)175 ppcnbsd_init_abi (struct gdbarch_info info,
176                   struct gdbarch *gdbarch)
177 {
178   nbsd_init_abi (info, gdbarch);
179 
180   /* NetBSD doesn't support the 128-bit `long double' from the psABI.  */
181   set_gdbarch_long_double_bit (gdbarch, 64);
182   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
183 
184   /* For NetBSD, this is an on again, off again thing.  Some systems
185      do use the broken struct convention, and some don't.  */
186   set_gdbarch_return_value (gdbarch, ppcnbsd_return_value);
187 
188   /* NetBSD uses SVR4-style shared libraries.  */
189   set_solib_svr4_fetch_link_map_offsets
190     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
191 
192   set_gdbarch_iterate_over_regset_sections
193     (gdbarch, ppcnbsd_iterate_over_regset_sections);
194 
195   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd_sigtramp);
196   tramp_frame_prepend_unwinder (gdbarch, &ppcnbsd2_sigtramp);
197 }
198 
199 void _initialize_ppcnbsd_tdep ();
200 void
_initialize_ppcnbsd_tdep()201 _initialize_ppcnbsd_tdep ()
202 {
203   gdbarch_register_osabi (bfd_arch_powerpc, 0, GDB_OSABI_NETBSD,
204 			  ppcnbsd_init_abi);
205   gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_NETBSD,
206 			  ppcnbsd_init_abi);
207 
208   /* Avoid initializing the register offsets again if they were
209      already initialized by ppcnbsd-nat.c.  */
210   if (ppcnbsd_reg_offsets.pc_offset == 0)
211     {
212       /* General-purpose registers.  */
213       ppcnbsd_reg_offsets.r0_offset = 0;
214       ppcnbsd_reg_offsets.gpr_size = 4;
215       ppcnbsd_reg_offsets.xr_size = 4;
216       ppcnbsd_reg_offsets.lr_offset = 128;
217       ppcnbsd_reg_offsets.cr_offset = 132;
218       ppcnbsd_reg_offsets.xer_offset = 136;
219       ppcnbsd_reg_offsets.ctr_offset = 140;
220       ppcnbsd_reg_offsets.pc_offset = 144;
221       ppcnbsd_reg_offsets.ps_offset = -1;
222       ppcnbsd_reg_offsets.mq_offset = -1;
223 
224       /* Floating-point registers.  */
225       ppcnbsd_reg_offsets.f0_offset = 0;
226       ppcnbsd_reg_offsets.fpscr_offset = 256;
227       ppcnbsd_reg_offsets.fpscr_size = 4;
228 
229     }
230 }
231