1 /* Target-dependent code for NetBSD/sparc.
2 
3    Copyright 2002, 2003, 2004 Free Software Foundation, Inc.
4    Contributed by Wasabi Systems, Inc.
5 
6    This file is part of GDB.
7 
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 2 of the License, or
11    (at your option) any later version.
12 
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with this program; if not, write to the Free Software
20    Foundation, Inc., 59 Temple Place - Suite 330,
21    Boston, MA 02111-1307, USA.  */
22 
23 #include "defs.h"
24 #include "floatformat.h"
25 #include "frame.h"
26 #include "frame-unwind.h"
27 #include "gdbcore.h"
28 #include "osabi.h"
29 #include "regcache.h"
30 #include "regset.h"
31 #include "solib-svr4.h"
32 #include "symtab.h"
33 #include "trad-frame.h"
34 
35 #include "gdb_assert.h"
36 #include "gdb_string.h"
37 
38 #include "sparc-tdep.h"
39 #include "nbsd-tdep.h"
40 
41 const struct sparc_gregset sparc32nbsd_gregset =
42 {
43   0 * 4,			/* %psr */
44   1 * 4,			/* %pc */
45   2 * 4,			/* %npc */
46   3 * 4,			/* %y */
47   -1,				/* %wim */
48   -1,				/* %tbr */
49   5 * 4,			/* %g1 */
50   -1				/* %l0 */
51 };
52 
53 static void
sparc32nbsd_supply_gregset(const struct regset * regset,struct regcache * regcache,int regnum,const void * gregs,size_t len)54 sparc32nbsd_supply_gregset (const struct regset *regset,
55 			    struct regcache *regcache,
56 			    int regnum, const void *gregs, size_t len)
57 {
58   sparc32_supply_gregset (&sparc32nbsd_gregset, regcache, regnum, gregs);
59 
60   /* Traditional NetBSD core files don't use multiple register sets.
61      Instead, the general-purpose and floating-point registers are
62      lumped together in a single section.  */
63   if (len >= 212)
64     sparc32_supply_fpregset (regcache, regnum, (const char *) gregs + 80);
65 }
66 
67 static void
sparc32nbsd_supply_fpregset(const struct regset * regset,struct regcache * regcache,int regnum,const void * fpregs,size_t len)68 sparc32nbsd_supply_fpregset (const struct regset *regset,
69 			     struct regcache *regcache,
70 			     int regnum, const void *fpregs, size_t len)
71 {
72   sparc32_supply_fpregset (regcache, regnum, fpregs);
73 }
74 
75 
76 /* Signal trampolines.  */
77 
78 /* The following variables describe the location of an on-stack signal
79    trampoline.  The current values correspond to the memory layout for
80    NetBSD 1.3 and up.  These shouldn't be necessary for NetBSD 2.0 and
81    up, since NetBSD uses signal trampolines provided by libc now.  */
82 
83 static const CORE_ADDR sparc32nbsd_sigtramp_start = 0xeffffef0;
84 static const CORE_ADDR sparc32nbsd_sigtramp_end = 0xeffffff0;
85 
86 static int
sparc32nbsd_pc_in_sigtramp(CORE_ADDR pc,char * name)87 sparc32nbsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
88 {
89   if (pc >= sparc32nbsd_sigtramp_start && pc < sparc32nbsd_sigtramp_end)
90     return 1;
91 
92   return nbsd_pc_in_sigtramp (pc, name);
93 }
94 
95 struct trad_frame_saved_reg *
sparc32nbsd_sigcontext_saved_regs(struct frame_info * next_frame)96 sparc32nbsd_sigcontext_saved_regs (struct frame_info *next_frame)
97 {
98   struct trad_frame_saved_reg *saved_regs;
99   CORE_ADDR addr, sigcontext_addr;
100   int regnum, delta;
101   ULONGEST psr;
102 
103   saved_regs = trad_frame_alloc_saved_regs (next_frame);
104 
105   /* We find the appropriate instance of `struct sigcontext' at a
106      fixed offset in the signal frame.  */
107   addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM);
108   sigcontext_addr = addr + 64 + 16;
109 
110   /* The registers are saved in bits and pieces scattered all over the
111      place.  The code below records their location on the assumption
112      that the part of the signal trampoline that saves the state has
113      been executed.  */
114 
115   saved_regs[SPARC_SP_REGNUM].addr = sigcontext_addr + 8;
116   saved_regs[SPARC32_PC_REGNUM].addr = sigcontext_addr + 12;
117   saved_regs[SPARC32_NPC_REGNUM].addr = sigcontext_addr + 16;
118   saved_regs[SPARC32_PSR_REGNUM].addr = sigcontext_addr + 20;
119   saved_regs[SPARC_G1_REGNUM].addr = sigcontext_addr + 24;
120   saved_regs[SPARC_O0_REGNUM].addr = sigcontext_addr + 28;
121 
122   /* The remaining `global' registers and %y are saved in the `local'
123      registers.  */
124   delta = SPARC_L0_REGNUM - SPARC_G0_REGNUM;
125   for (regnum = SPARC_G2_REGNUM; regnum <= SPARC_G7_REGNUM; regnum++)
126     saved_regs[regnum].realreg = regnum + delta;
127   saved_regs[SPARC32_Y_REGNUM].realreg = SPARC_L1_REGNUM;
128 
129   /* The remaining `out' registers can be found in the current frame's
130      `in' registers.  */
131   delta = SPARC_I0_REGNUM - SPARC_O0_REGNUM;
132   for (regnum = SPARC_O1_REGNUM; regnum <= SPARC_O5_REGNUM; regnum++)
133     saved_regs[regnum].realreg = regnum + delta;
134   saved_regs[SPARC_O7_REGNUM].realreg = SPARC_I7_REGNUM;
135 
136   /* The `local' and `in' registers have been saved in the register
137      save area.  */
138   addr = saved_regs[SPARC_SP_REGNUM].addr;
139   addr = get_frame_memory_unsigned (next_frame, addr, 4);
140   for (regnum = SPARC_L0_REGNUM;
141        regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
142     saved_regs[regnum].addr = addr;
143 
144   /* Handle StackGhost.  */
145   {
146     ULONGEST wcookie = sparc_fetch_wcookie ();
147 
148     if (wcookie != 0)
149       {
150 	ULONGEST i7;
151 
152 	addr = saved_regs[SPARC_I7_REGNUM].addr;
153 	i7 = get_frame_memory_unsigned (next_frame, addr, 4);
154 	trad_frame_set_value (saved_regs, SPARC_I7_REGNUM, i7 ^ wcookie);
155       }
156   }
157 
158   /* The floating-point registers are only saved if the EF bit in %prs
159      has been set.  */
160 
161 #define PSR_EF	0x00001000
162 
163   addr = saved_regs[SPARC32_PSR_REGNUM].addr;
164   psr = get_frame_memory_unsigned (next_frame, addr, 4);
165   if (psr & PSR_EF)
166     {
167       CORE_ADDR sp;
168 
169       sp = frame_unwind_register_unsigned (next_frame, SPARC_SP_REGNUM);
170       saved_regs[SPARC32_FSR_REGNUM].addr = sp + 96;
171       for (regnum = SPARC_F0_REGNUM, addr = sp + 96 + 8;
172 	   regnum <= SPARC_F31_REGNUM; regnum++, addr += 4)
173 	saved_regs[regnum].addr = addr;
174     }
175 
176   return saved_regs;
177 }
178 
179 static struct sparc_frame_cache *
sparc32nbsd_sigcontext_frame_cache(struct frame_info * next_frame,void ** this_cache)180 sparc32nbsd_sigcontext_frame_cache (struct frame_info *next_frame,
181 				    void **this_cache)
182 {
183   struct sparc_frame_cache *cache;
184   CORE_ADDR addr;
185 
186   if (*this_cache)
187     return *this_cache;
188 
189   cache = sparc_frame_cache (next_frame, this_cache);
190   gdb_assert (cache == *this_cache);
191 
192   /* If we couldn't find the frame's function, we're probably dealing
193      with an on-stack signal trampoline.  */
194   if (cache->pc == 0)
195     {
196       cache->pc = sparc32nbsd_sigtramp_start;
197 
198       /* Since we couldn't find the frame's function, the cache was
199          initialized under the assumption that we're frameless.  */
200       cache->frameless_p = 0;
201       addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM);
202       cache->base = addr;
203     }
204 
205   cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (next_frame);
206 
207   return cache;
208 }
209 
210 static void
sparc32nbsd_sigcontext_frame_this_id(struct frame_info * next_frame,void ** this_cache,struct frame_id * this_id)211 sparc32nbsd_sigcontext_frame_this_id (struct frame_info *next_frame,
212 				      void **this_cache,
213 				      struct frame_id *this_id)
214 {
215   struct sparc_frame_cache *cache =
216     sparc32nbsd_sigcontext_frame_cache (next_frame, this_cache);
217 
218   (*this_id) = frame_id_build (cache->base, cache->pc);
219 }
220 
221 static void
sparc32nbsd_sigcontext_frame_prev_register(struct frame_info * next_frame,void ** this_cache,int regnum,int * optimizedp,enum lval_type * lvalp,CORE_ADDR * addrp,int * realnump,void * valuep)222 sparc32nbsd_sigcontext_frame_prev_register (struct frame_info *next_frame,
223 					    void **this_cache,
224 					    int regnum, int *optimizedp,
225 					    enum lval_type *lvalp,
226 					    CORE_ADDR *addrp,
227 					    int *realnump, void *valuep)
228 {
229   struct sparc_frame_cache *cache =
230     sparc32nbsd_sigcontext_frame_cache (next_frame, this_cache);
231 
232   trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum,
233 				optimizedp, lvalp, addrp, realnump, valuep);
234 }
235 
236 static const struct frame_unwind sparc32nbsd_sigcontext_frame_unwind =
237 {
238   SIGTRAMP_FRAME,
239   sparc32nbsd_sigcontext_frame_this_id,
240   sparc32nbsd_sigcontext_frame_prev_register
241 };
242 
243 static const struct frame_unwind *
sparc32nbsd_sigtramp_frame_sniffer(struct frame_info * next_frame)244 sparc32nbsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
245 {
246   CORE_ADDR pc = frame_pc_unwind (next_frame);
247   char *name;
248 
249   find_pc_partial_function (pc, &name, NULL, NULL);
250   if (sparc32nbsd_pc_in_sigtramp (pc, name))
251     {
252       if (name == NULL || strncmp (name, "__sigtramp_sigcontext", 21))
253 	return &sparc32nbsd_sigcontext_frame_unwind;
254     }
255 
256   return NULL;
257 }
258 
259 
260 /* Return non-zero if we are in a shared library trampoline code stub.  */
261 
262 static int
sparcnbsd_aout_in_solib_call_trampoline(CORE_ADDR pc,char * name)263 sparcnbsd_aout_in_solib_call_trampoline (CORE_ADDR pc, char *name)
264 {
265   return (name && !strcmp (name, "_DYNAMIC"));
266 }
267 
268 static void
sparc32nbsd_init_abi(struct gdbarch_info info,struct gdbarch * gdbarch)269 sparc32nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
270 {
271   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
272 
273   /* NetBSD doesn't support the 128-bit `long double' from the psABI.  */
274   set_gdbarch_long_double_bit (gdbarch, 64);
275   set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big);
276 
277   tdep->gregset = regset_alloc (gdbarch, sparc32nbsd_supply_gregset, NULL);
278   tdep->sizeof_gregset = 20 * 4;
279 
280   tdep->fpregset = regset_alloc (gdbarch, sparc32nbsd_supply_fpregset, NULL);
281   tdep->sizeof_fpregset = 33 * 4;
282 
283   frame_unwind_append_sniffer (gdbarch, sparc32nbsd_sigtramp_frame_sniffer);
284 }
285 
286 static void
sparc32nbsd_aout_init_abi(struct gdbarch_info info,struct gdbarch * gdbarch)287 sparc32nbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
288 {
289   sparc32nbsd_init_abi (info, gdbarch);
290 
291   set_gdbarch_in_solib_call_trampoline
292     (gdbarch, sparcnbsd_aout_in_solib_call_trampoline);
293 }
294 
295 void
sparc32nbsd_elf_init_abi(struct gdbarch_info info,struct gdbarch * gdbarch)296 sparc32nbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
297 {
298   sparc32nbsd_init_abi (info, gdbarch);
299 
300   set_solib_svr4_fetch_link_map_offsets
301     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
302 }
303 
304 static enum gdb_osabi
sparcnbsd_aout_osabi_sniffer(bfd * abfd)305 sparcnbsd_aout_osabi_sniffer (bfd *abfd)
306 {
307   if (strcmp (bfd_get_target (abfd), "a.out-sparc-netbsd") == 0)
308     return GDB_OSABI_NETBSD_AOUT;
309 
310   return GDB_OSABI_UNKNOWN;
311 }
312 
313 /* OpenBSD uses the traditional NetBSD core file format, even for
314    ports that use ELF.  Therefore, if the default OS ABI is OpenBSD
315    ELF, we return that instead of NetBSD a.out.  This is mainly for
316    the benfit of OpenBSD/sparc64, which inherits the sniffer below
317    since we include this file for an OpenBSD/sparc64 target.  For
318    OpenBSD/sparc, the NetBSD a.out OS ABI is probably similar enough
319    to both the OpenBSD a.out and the OpenBSD ELF OS ABI.  */
320 #if defined (GDB_OSABI_DEFAULT) && (GDB_OSABI_DEFAULT == GDB_OSABI_OPENBSD_ELF)
321 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
322 #else
323 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_NETBSD_AOUT
324 #endif
325 
326 static enum gdb_osabi
sparcnbsd_core_osabi_sniffer(bfd * abfd)327 sparcnbsd_core_osabi_sniffer (bfd *abfd)
328 {
329   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
330     return GDB_OSABI_NETBSD_CORE;
331 
332   return GDB_OSABI_UNKNOWN;
333 }
334 
335 
336 /* Provide a prototype to silence -Wmissing-prototypes.  */
337 void _initialize_sparcnbsd_tdep (void);
338 
339 void
_initialize_sparnbsd_tdep(void)340 _initialize_sparnbsd_tdep (void)
341 {
342   gdbarch_register_osabi_sniffer (bfd_arch_sparc, bfd_target_aout_flavour,
343 				  sparcnbsd_aout_osabi_sniffer);
344 
345   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
346   gdbarch_register_osabi_sniffer (bfd_arch_sparc, bfd_target_unknown_flavour,
347                                   sparcnbsd_core_osabi_sniffer);
348 
349   gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD_AOUT,
350 			  sparc32nbsd_aout_init_abi);
351   gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD_ELF,
352 			  sparc32nbsd_elf_init_abi);
353 }
354