1 /* Xtensa ELF support for BFD.
2    Copyright (C) 2003-2016 Free Software Foundation, Inc.
3    Contributed by Bob Wilson (bwilson@tensilica.com) at Tensilica.
4 
5    This file is part of BFD, the Binary File Descriptor library.
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, write to the Free Software
19    Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301,
20    USA.  */
21 
22 /* This file holds definitions specific to the Xtensa ELF ABI.  */
23 
24 #ifndef _ELF_XTENSA_H
25 #define _ELF_XTENSA_H
26 
27 #include "elf/reloc-macros.h"
28 
29 #ifdef __cplusplus
30 extern "C" {
31 #endif
32 
33 /* Relocations.  */
34 START_RELOC_NUMBERS (elf_xtensa_reloc_type)
35      RELOC_NUMBER (R_XTENSA_NONE, 0)
36      RELOC_NUMBER (R_XTENSA_32, 1)
37      RELOC_NUMBER (R_XTENSA_RTLD, 2)
38      RELOC_NUMBER (R_XTENSA_GLOB_DAT, 3)
39      RELOC_NUMBER (R_XTENSA_JMP_SLOT, 4)
40      RELOC_NUMBER (R_XTENSA_RELATIVE, 5)
41      RELOC_NUMBER (R_XTENSA_PLT, 6)
42      RELOC_NUMBER (R_XTENSA_OP0, 8)
43      RELOC_NUMBER (R_XTENSA_OP1, 9)
44      RELOC_NUMBER (R_XTENSA_OP2, 10)
45      RELOC_NUMBER (R_XTENSA_ASM_EXPAND, 11)
46      RELOC_NUMBER (R_XTENSA_ASM_SIMPLIFY, 12)
47      RELOC_NUMBER (R_XTENSA_32_PCREL, 14)
48      RELOC_NUMBER (R_XTENSA_GNU_VTINHERIT, 15)
49      RELOC_NUMBER (R_XTENSA_GNU_VTENTRY, 16)
50      RELOC_NUMBER (R_XTENSA_DIFF8, 17)
51      RELOC_NUMBER (R_XTENSA_DIFF16, 18)
52      RELOC_NUMBER (R_XTENSA_DIFF32, 19)
53      RELOC_NUMBER (R_XTENSA_SLOT0_OP, 20)
54      RELOC_NUMBER (R_XTENSA_SLOT1_OP, 21)
55      RELOC_NUMBER (R_XTENSA_SLOT2_OP, 22)
56      RELOC_NUMBER (R_XTENSA_SLOT3_OP, 23)
57      RELOC_NUMBER (R_XTENSA_SLOT4_OP, 24)
58      RELOC_NUMBER (R_XTENSA_SLOT5_OP, 25)
59      RELOC_NUMBER (R_XTENSA_SLOT6_OP, 26)
60      RELOC_NUMBER (R_XTENSA_SLOT7_OP, 27)
61      RELOC_NUMBER (R_XTENSA_SLOT8_OP, 28)
62      RELOC_NUMBER (R_XTENSA_SLOT9_OP, 29)
63      RELOC_NUMBER (R_XTENSA_SLOT10_OP, 30)
64      RELOC_NUMBER (R_XTENSA_SLOT11_OP, 31)
65      RELOC_NUMBER (R_XTENSA_SLOT12_OP, 32)
66      RELOC_NUMBER (R_XTENSA_SLOT13_OP, 33)
67      RELOC_NUMBER (R_XTENSA_SLOT14_OP, 34)
68      RELOC_NUMBER (R_XTENSA_SLOT0_ALT, 35)
69      RELOC_NUMBER (R_XTENSA_SLOT1_ALT, 36)
70      RELOC_NUMBER (R_XTENSA_SLOT2_ALT, 37)
71      RELOC_NUMBER (R_XTENSA_SLOT3_ALT, 38)
72      RELOC_NUMBER (R_XTENSA_SLOT4_ALT, 39)
73      RELOC_NUMBER (R_XTENSA_SLOT5_ALT, 40)
74      RELOC_NUMBER (R_XTENSA_SLOT6_ALT, 41)
75      RELOC_NUMBER (R_XTENSA_SLOT7_ALT, 42)
76      RELOC_NUMBER (R_XTENSA_SLOT8_ALT, 43)
77      RELOC_NUMBER (R_XTENSA_SLOT9_ALT, 44)
78      RELOC_NUMBER (R_XTENSA_SLOT10_ALT, 45)
79      RELOC_NUMBER (R_XTENSA_SLOT11_ALT, 46)
80      RELOC_NUMBER (R_XTENSA_SLOT12_ALT, 47)
81      RELOC_NUMBER (R_XTENSA_SLOT13_ALT, 48)
82      RELOC_NUMBER (R_XTENSA_SLOT14_ALT, 49)
83      RELOC_NUMBER (R_XTENSA_TLSDESC_FN, 50)
84      RELOC_NUMBER (R_XTENSA_TLSDESC_ARG, 51)
85      RELOC_NUMBER (R_XTENSA_TLS_DTPOFF, 52)
86      RELOC_NUMBER (R_XTENSA_TLS_TPOFF, 53)
87      RELOC_NUMBER (R_XTENSA_TLS_FUNC, 54)
88      RELOC_NUMBER (R_XTENSA_TLS_ARG, 55)
89      RELOC_NUMBER (R_XTENSA_TLS_CALL, 56)
90 END_RELOC_NUMBERS (R_XTENSA_max)
91 
92 /* Processor-specific flags for the ELF header e_flags field.  */
93 
94 /* Four-bit Xtensa machine type field.  */
95 #define EF_XTENSA_MACH			0x0000000f
96 
97 /* Various CPU types.  */
98 #define E_XTENSA_MACH			0x00000000
99 
100 /* Leave bits 0xf0 alone in case we ever have more than 16 cpu types.
101    Highly unlikely, but what the heck.  */
102 
103 #define EF_XTENSA_XT_INSN		0x00000100
104 #define EF_XTENSA_XT_LIT		0x00000200
105 
106 
107 /* Processor-specific dynamic array tags.  */
108 
109 /* Offset of the table that records the GOT location(s).  */
110 #define DT_XTENSA_GOT_LOC_OFF		0x70000000
111 
112 /* Number of entries in the GOT location table.  */
113 #define DT_XTENSA_GOT_LOC_SZ		0x70000001
114 
115 
116 /* Definitions for instruction and literal property tables.  The
117    tables for ".gnu.linkonce.*" sections are placed in the following
118    sections:
119 
120    instruction tables:	.gnu.linkonce.x.*
121    literal tables:	.gnu.linkonce.p.*
122 */
123 
124 #define XTENSA_INSN_SEC_NAME ".xt.insn"
125 #define XTENSA_LIT_SEC_NAME  ".xt.lit"
126 #define XTENSA_PROP_SEC_NAME ".xt.prop"
127 
128 typedef struct property_table_entry_t
129 {
130   bfd_vma address;
131   bfd_vma size;
132   flagword flags;
133 } property_table_entry;
134 
135 /* Flags in the property tables to specify whether blocks of memory are
136    literals, instructions, data, or unreachable.  For instructions,
137    blocks that begin loop targets and branch targets are designated.
138    Blocks that do not allow density instructions, instruction reordering
139    or transformation are also specified.  Finally, for branch targets,
140    branch target alignment priority is included.  Alignment of the next
141    block is specified in the current block and the size of the current
142    block does not include any fill required to align to the next
143    block.  */
144 
145 #define XTENSA_PROP_LITERAL		0x00000001
146 #define XTENSA_PROP_INSN		0x00000002
147 #define XTENSA_PROP_DATA		0x00000004
148 #define XTENSA_PROP_UNREACHABLE		0x00000008
149 /* Instruction-only properties at beginning of code. */
150 #define XTENSA_PROP_INSN_LOOP_TARGET	0x00000010
151 #define XTENSA_PROP_INSN_BRANCH_TARGET	0x00000020
152 /* Instruction-only properties about code. */
153 #define XTENSA_PROP_INSN_NO_DENSITY	0x00000040
154 #define XTENSA_PROP_INSN_NO_REORDER	0x00000080
155 /* Historically, NO_TRANSFORM was a property of instructions,
156    but it should apply to literals under certain circumstances.  */
157 #define XTENSA_PROP_NO_TRANSFORM	0x00000100
158 
159 /*  Branch target alignment information.  This transmits information
160     to the linker optimization about the priority of aligning a
161     particular block for branch target alignment: None, low priority,
162     high priority, or required.  These only need to be checked in
163     instruction blocks marked as XTENSA_PROP_INSN_BRANCH_TARGET.
164     Common usage is:
165 
166     switch (GET_XTENSA_PROP_BT_ALIGN(flags))
167     case XTENSA_PROP_BT_ALIGN_NONE:
168     case XTENSA_PROP_BT_ALIGN_LOW:
169     case XTENSA_PROP_BT_ALIGN_HIGH:
170     case XTENSA_PROP_BT_ALIGN_REQUIRE:
171 */
172 #define XTENSA_PROP_BT_ALIGN_MASK       0x00000600
173 
174 /* No branch target alignment.  */
175 #define XTENSA_PROP_BT_ALIGN_NONE       0x0
176 /* Low priority branch target alignment.  */
177 #define XTENSA_PROP_BT_ALIGN_LOW        0x1
178 /* High priority branch target alignment. */
179 #define XTENSA_PROP_BT_ALIGN_HIGH       0x2
180 /* Required branch target alignment.  */
181 #define XTENSA_PROP_BT_ALIGN_REQUIRE    0x3
182 
183 #define GET_XTENSA_PROP_BT_ALIGN(flag) \
184   (((unsigned)((flag) & (XTENSA_PROP_BT_ALIGN_MASK))) >> 9)
185 #define SET_XTENSA_PROP_BT_ALIGN(flag, align) \
186   (((flag) & (~XTENSA_PROP_BT_ALIGN_MASK)) | \
187     (((align) << 9) & XTENSA_PROP_BT_ALIGN_MASK))
188 
189 /* Alignment is specified in the block BEFORE the one that needs
190    alignment.  Up to 5 bits.  Use GET_XTENSA_PROP_ALIGNMENT(flags) to
191    get the required alignment specified as a power of 2.  Use
192    SET_XTENSA_PROP_ALIGNMENT(flags, pow2) to set the required
193    alignment.  Be careful of side effects since the SET will evaluate
194    flags twice.  Also, note that the SIZE of a block in the property
195    table does not include the alignment size, so the alignment fill
196    must be calculated to determine if two blocks are contiguous.
197    TEXT_ALIGN is not currently implemented but is a placeholder for a
198    possible future implementation.  */
199 
200 #define XTENSA_PROP_ALIGN		0x00000800
201 
202 #define XTENSA_PROP_ALIGNMENT_MASK      0x0001f000
203 
204 #define GET_XTENSA_PROP_ALIGNMENT(flag) \
205   (((unsigned)((flag) & (XTENSA_PROP_ALIGNMENT_MASK))) >> 12)
206 #define SET_XTENSA_PROP_ALIGNMENT(flag, align) \
207   (((flag) & (~XTENSA_PROP_ALIGNMENT_MASK)) | \
208     (((align) << 12) & XTENSA_PROP_ALIGNMENT_MASK))
209 
210 #define XTENSA_PROP_INSN_ABSLIT        0x00020000
211 
212 extern asection *xtensa_make_property_section (asection *, const char *);
213 
214 #ifdef __cplusplus
215 }
216 #endif
217 
218 #endif /* _ELF_XTENSA_H */
219