summaryrefslogtreecommitdiffstats
path: root/arch/blackfin/lib/module.c
blob: a82d0a913727d7c70d334a6956e7ab28f0ca62e6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
/*
 * File:         arch/blackfin/kernel/module.c
 * Based on:
 * Author:
 *
 * Created:
 * Description:
 *
 * Modified:
 *               Copyright 2004-2006 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <common.h>
#include <elf.h>
#include <module.h>
#include <malloc.h>
#include <errno.h>

/*
 * handle arithmetic relocations.
 * See binutils/bfd/elf32-bfin.c for more details
 */
#define RELOC_STACK_SIZE 100
static uint32_t reloc_stack[RELOC_STACK_SIZE];
static unsigned int reloc_stack_tos;

#define is_reloc_stack_empty() ((reloc_stack_tos > 0)?0:1)

static void reloc_stack_push(uint32_t value)
{
	reloc_stack[reloc_stack_tos++] = value;
}

static uint32_t reloc_stack_pop(void)
{
	return reloc_stack[--reloc_stack_tos];
}

static uint32_t reloc_stack_operate(unsigned int oper, struct module *mod)
{
	uint32_t value;

	switch (oper) {
	case R_add:
		value = reloc_stack[reloc_stack_tos - 2] +
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_sub:
		value = reloc_stack[reloc_stack_tos - 2] -
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_mult:
		value = reloc_stack[reloc_stack_tos - 2] *
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_div:
		value = reloc_stack[reloc_stack_tos - 2] /
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_mod:
		value = reloc_stack[reloc_stack_tos - 2] %
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_lshift:
		value = reloc_stack[reloc_stack_tos - 2] <<
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_rshift:
		value = reloc_stack[reloc_stack_tos - 2] >>
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_and:
		value = reloc_stack[reloc_stack_tos - 2] &
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_or:
		value = reloc_stack[reloc_stack_tos - 2] |
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_xor:
		value = reloc_stack[reloc_stack_tos - 2] ^
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_land:
		value = reloc_stack[reloc_stack_tos - 2] &&
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_lor:
		value = reloc_stack[reloc_stack_tos - 2] ||
			reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 2;
		break;
	case R_neg:
		value = -reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos--;
		break;
	case R_comp:
		value = ~reloc_stack[reloc_stack_tos - 1];
		reloc_stack_tos -= 1;
		break;
	default:
		printf("module %s: unhandled reloction\n",
				mod->name);
		return 0;
	}

	/* now push the new value back on stack */
	reloc_stack_push(value);

	return value;
}

int
apply_relocate(Elf_Shdr * sechdrs, const char *strtab,
	       unsigned int symindex, unsigned int relsec, struct module *me)
{
	printf("module %s: .rel unsupported\n", me->name);
	return -ENOEXEC;
}

/*************************************************************************/
/* FUNCTION : apply_relocate_add                                         */
/* ABSTRACT : Blackfin specific relocation handling for the loadable     */
/*            modules. Modules are expected to be .o files.              */
/*            Arithmetic relocations are handled.                        */
/*            We do not expect LSETUP to be split and hence is not       */
/*            handled.                                                   */
/*            R_byte and R_byte2 are also not handled as the gas         */
/*            does not generate it.                                      */
/*************************************************************************/
int
apply_relocate_add(Elf_Shdr * sechdrs, const char *strtab,
		   unsigned int symindex, unsigned int relsec,
		   struct module *mod)
{
	unsigned int i;
	unsigned short tmp;
	Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
	Elf32_Sym *sym;
	uint32_t *location32;
	uint16_t *location16;
	uint32_t value;

	debug("Applying relocate section %u to %u\n", relsec,
	       sechdrs[relsec].sh_info);
	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
		/* This is where to make the change */
		location16 =
		    (uint16_t *) (sechdrs[sechdrs[relsec].sh_info].sh_addr +
				  rel[i].r_offset);
		location32 = (uint32_t *) location16;
		/* This is the symbol it is referring to. Note that all
		   undefined symbols have been resolved. */
		sym = (Elf32_Sym *) sechdrs[symindex].sh_addr
		    + ELF32_R_SYM(rel[i].r_info);
		if (is_reloc_stack_empty()) {
			value = sym->st_value;
		} else {
			value = reloc_stack_pop();
		}
		value += rel[i].r_addend;
		debug("location is %x, value is %x type is %d \n",
			 (unsigned int) location32, value,
			 ELF32_R_TYPE(rel[i].r_info));

		switch (ELF32_R_TYPE(rel[i].r_info)) {

		case R_pcrel24:
		case R_pcrel24_jump_l:
			/* Add the value, subtract its postition */
			location16 =
			    (uint16_t *) (sechdrs[sechdrs[relsec].sh_info].
					  sh_addr + rel[i].r_offset - 2);
			location32 = (uint32_t *) location16;
			value -= (uint32_t) location32;
			value >>= 1;
			debug("value is %x, before %x-%x after %x-%x\n", value,
			       *location16, *(location16 + 1),
			       (*location16 & 0xff00) | (value >> 16 & 0x00ff),
			       value & 0xffff);
			*location16 =
			    (*location16 & 0xff00) | (value >> 16 & 0x00ff);
			*(location16 + 1) = value & 0xffff;
			break;
		case R_pcrel12_jump:
		case R_pcrel12_jump_s:
			value -= (uint32_t) location32;
			value >>= 1;
			*location16 = (value & 0xfff);
			break;
		case R_pcrel10:
			value -= (uint32_t) location32;
			value >>= 1;
			*location16 = (value & 0x3ff);
			break;
		case R_luimm16:
			debug("before %x after %x\n", *location16,
				       (value & 0xffff));
			tmp = (value & 0xffff);
			*location16 = tmp;
			break;
		case R_huimm16:
			debug("before %x after %x\n", *location16,
				       ((value >> 16) & 0xffff));
			tmp = ((value >> 16) & 0xffff);
			*location16 = tmp;
			break;
		case R_rimm16:
			*location16 = (value & 0xffff);
			break;
		case R_byte4_data:
			debug("before %x after %x\n", *location32, value);
			*location32 = value;
			break;
		case R_push:
			reloc_stack_push(value);
			break;
		case R_const:
			reloc_stack_push(rel[i].r_addend);
			break;
		case R_add:
		case R_sub:
		case R_mult:
		case R_div:
		case R_mod:
		case R_lshift:
		case R_rshift:
		case R_and:
		case R_or:
		case R_xor:
		case R_land:
		case R_lor:
		case R_neg:
		case R_comp:
			reloc_stack_operate(ELF32_R_TYPE(rel[i].r_info), mod);
			break;
		default:
			printf("module %s: Unknown relocation: %u\n",
			       mod->name, ELF32_R_TYPE(rel[i].r_info));
			return -ENOEXEC;
		}
	}
	return 0;
}

#if 0
int
module_finalize(const Elf_Ehdr * hdr,
		const Elf_Shdr * sechdrs, struct module *mod)
{
	unsigned int i, strindex = 0, symindex = 0;
	char *secstrings;

	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;

	for (i = 1; i < hdr->e_shnum; i++) {
		/* Internal symbols and strings. */
		if (sechdrs[i].sh_type == SHT_SYMTAB) {
			symindex = i;
			strindex = sechdrs[i].sh_link;
		}
	}

	for (i = 1; i < hdr->e_shnum; i++) {
		const char *strtab = (char *)sechdrs[strindex].sh_addr;
		unsigned int info = sechdrs[i].sh_info;

		/* Not a valid relocation section? */
		if (info >= hdr->e_shnum)
			continue;

		if ((sechdrs[i].sh_type == SHT_RELA) &&
		    ((strcmp(".rela.l1.text", secstrings + sechdrs[i].sh_name) == 0) ||
		    ((strcmp(".rela.text", secstrings + sechdrs[i].sh_name) == 0) &&
			 (hdr->e_flags & FLG_CODE_IN_L1)))) {
			apply_relocate_add((Elf_Shdr *) sechdrs, strtab,
					   symindex, i, mod);
		}
	}
	return 0;
}
#endif