1 /* C6X EABI compliant unwinding routines.
2 Copyright (C) 2011-2023 Free Software Foundation, Inc.
3
4 This file is free software; you can redistribute it and/or modify it
5 under the terms of the GNU General Public License as published by the
6 Free Software Foundation; either version 3, or (at your option) any
7 later version.
8
9 This file is distributed in the hope that it will be useful, but
10 WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 General Public License for more details.
13
14 Under Section 7 of GPL version 3, you are granted additional
15 permissions described in the GCC Runtime Library Exception, version
16 3.1, as published by the Free Software Foundation.
17
18 You should have received a copy of the GNU General Public License and
19 a copy of the GCC Runtime Library Exception along with this program;
20 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
21 <http://www.gnu.org/licenses/>. */
22
23 #include "unwind.h"
24
25 /* Misc constants. */
26 #define NUM_SAVED_REGS 32
27 #define R_B0 16
28 #define R_B3 (R_B0 + 3)
29 #define R_B15 (R_B0 + 15)
30 #define R_SP R_B15
31 #define R_LR R_B3
32 #define R_PC 33
33
34 #define VRS_PC(vrs) ((vrs)->core.pc)
35 #define VRS_SP(vrs) ((vrs)->core.reg[R_SP])
36 #define VRS_RETURN(vrs) ((vrs)->core.reg[R_B3])
37
38 struct core_regs
39 {
40 _uw reg[NUM_SAVED_REGS];
41 _uw pc;
42 };
43
44 typedef struct
45 {
46 /* The first fields must be the same as a phase2_vrs. */
47 _uw demand_save_flags; /* Currently always zero. */
48 struct core_regs core;
49 _uw prev_sp; /* Only valid during forced unwinding. */
50 } phase1_vrs;
51
52 /* This must match the structure created by the assembly wrappers. */
53 typedef struct
54 {
55 _uw demand_save_flags;
56 struct core_regs core;
57 } phase2_vrs;
58
59 /* Coprocessor register state manipulation functions. */
60
61 /* Restore coprocessor state after phase1 unwinding. */
62 static void
63 restore_non_core_regs (phase1_vrs * vrs __attribute__((unused)))
64 {
65 }
66
67 #include "unwind-arm-common.inc"
68
69 /* ABI defined personality routines. */
70 extern _Unwind_Reason_Code __c6xabi_unwind_cpp_pr0 (_Unwind_State,
71 _Unwind_Control_Block *, _Unwind_Context *);// __attribute__((weak));
72 extern _Unwind_Reason_Code __c6xabi_unwind_cpp_pr1 (_Unwind_State,
73 _Unwind_Control_Block *, _Unwind_Context *) __attribute__((weak));
74 extern _Unwind_Reason_Code __c6xabi_unwind_cpp_pr2 (_Unwind_State,
75 _Unwind_Control_Block *, _Unwind_Context *) __attribute__((weak));
76 extern _Unwind_Reason_Code __c6xabi_unwind_cpp_pr3 (_Unwind_State,
77 _Unwind_Control_Block *, _Unwind_Context *) __attribute__((weak));
78 extern _Unwind_Reason_Code __c6xabi_unwind_cpp_pr4 (_Unwind_State,
79 _Unwind_Control_Block *, _Unwind_Context *) __attribute__((weak));
80
81 /* ABI defined routine to store a virtual register to memory. */
82
83 _Unwind_VRS_Result _Unwind_VRS_Get (_Unwind_Context *context,
84 _Unwind_VRS_RegClass regclass,
85 _uw regno,
86 _Unwind_VRS_DataRepresentation representation,
87 void *valuep)
88 {
89 phase1_vrs *vrs = (phase1_vrs *) context;
90
91 switch (regclass)
92 {
93 case _UVRSC_CORE:
94 if (representation != _UVRSD_UINT32)
95 return _UVRSR_FAILED;
96 if (regno == R_PC)
97 {
98 *(_uw *) valuep = vrs->core.pc;
99 return _UVRSR_OK;
100 }
101 if (regno >= NUM_SAVED_REGS)
102 return _UVRSR_FAILED;
103 *(_uw *) valuep = vrs->core.reg[regno];
104 return _UVRSR_OK;
105
106 default:
107 return _UVRSR_FAILED;
108 }
109 }
110
111
112 /* ABI defined function to load a virtual register from memory. */
113
114 _Unwind_VRS_Result _Unwind_VRS_Set (_Unwind_Context *context,
115 _Unwind_VRS_RegClass regclass,
116 _uw regno,
117 _Unwind_VRS_DataRepresentation representation,
118 void *valuep)
119 {
120 phase1_vrs *vrs = (phase1_vrs *) context;
121
122 switch (regclass)
123 {
124 case _UVRSC_CORE:
125 if (representation != _UVRSD_UINT32)
126 return _UVRSR_FAILED;
127 if (regno == R_PC)
128 {
129 vrs->core.pc = *(_uw *) valuep;
130 return _UVRSR_OK;
131 }
132 if (regno >= NUM_SAVED_REGS)
133 return _UVRSR_FAILED;
134
135 vrs->core.reg[regno] = *(_uw *) valuep;
136 return _UVRSR_OK;
137
138 default:
139 return _UVRSR_FAILED;
140 }
141 }
142
143
144 /* Core unwinding functions. */
145
146 /* Calculate the address encoded by a 31-bit self-relative offset at address
147 P. */
148 static inline _uw
149 selfrel_offset31 (const _uw *p)
150 {
151 _uw offset;
152
153 offset = *p << 1;
154 return offset + (_uw) p;
155 }
156
157
158 static _uw
159 __gnu_unwind_get_pr_addr (int idx)
160 {
161 switch (idx)
162 {
163 case 0:
164 return (_uw) &__c6xabi_unwind_cpp_pr0;
165
166 case 1:
167 return (_uw) &__c6xabi_unwind_cpp_pr1;
168
169 case 2:
170 return (_uw) &__c6xabi_unwind_cpp_pr2;
171
172 case 3:
173 return (_uw) &__c6xabi_unwind_cpp_pr3;
174
175 case 4:
176 return (_uw) &__c6xabi_unwind_cpp_pr4;
177
178 default:
179 return 0;
180 }
181 }
182
183
184 /* ABI defined personality routine entry points. */
185
186 _Unwind_Reason_Code
187 __c6xabi_unwind_cpp_pr0 (_Unwind_State state,
188 _Unwind_Control_Block *ucbp,
189 _Unwind_Context *context)
190 {
191 return __gnu_unwind_pr_common (state, ucbp, context, 0);
192 }
193
194 _Unwind_Reason_Code
195 __c6xabi_unwind_cpp_pr1 (_Unwind_State state,
196 _Unwind_Control_Block *ucbp,
197 _Unwind_Context *context)
198 {
199 return __gnu_unwind_pr_common (state, ucbp, context, 1);
200 }
201
202 _Unwind_Reason_Code
203 __c6xabi_unwind_cpp_pr2 (_Unwind_State state,
204 _Unwind_Control_Block *ucbp,
205 _Unwind_Context *context)
206 {
207 return __gnu_unwind_pr_common (state, ucbp, context, 2);
208 }
209
210 _Unwind_Reason_Code
211 __c6xabi_unwind_cpp_pr3 (_Unwind_State state,
212 _Unwind_Control_Block *ucbp,
213 _Unwind_Context *context)
214 {
215 return __gnu_unwind_pr_common (state, ucbp, context, 3);
216 }
217
218 _Unwind_Reason_Code
219 __c6xabi_unwind_cpp_pr4 (_Unwind_State state,
220 _Unwind_Control_Block *ucbp,
221 _Unwind_Context *context)
222 {
223 return __gnu_unwind_pr_common (state, ucbp, context, 4);
224 }