1 | #ifdef TARGET_DEFS_ONLY
|
---|
2 |
|
---|
3 | #define EM_TCC_TARGET EM_ARM
|
---|
4 |
|
---|
5 | /* relocation type for 32 bit data relocation */
|
---|
6 | #define R_DATA_32 R_ARM_ABS32
|
---|
7 | #define R_DATA_PTR R_ARM_ABS32
|
---|
8 | #define R_JMP_SLOT R_ARM_JUMP_SLOT
|
---|
9 | #define R_GLOB_DAT R_ARM_GLOB_DAT
|
---|
10 | #define R_COPY R_ARM_COPY
|
---|
11 | #define R_RELATIVE R_ARM_RELATIVE
|
---|
12 |
|
---|
13 | #define R_NUM R_ARM_NUM
|
---|
14 |
|
---|
15 | #define ELF_START_ADDR 0x00008000
|
---|
16 | #define ELF_PAGE_SIZE 0x1000
|
---|
17 |
|
---|
18 | #define PCRELATIVE_DLLPLT 1
|
---|
19 | #define RELOCATE_DLLPLT 0
|
---|
20 |
|
---|
21 | enum float_abi {
|
---|
22 | ARM_SOFTFP_FLOAT,
|
---|
23 | ARM_HARD_FLOAT,
|
---|
24 | };
|
---|
25 |
|
---|
26 | #else /* !TARGET_DEFS_ONLY */
|
---|
27 |
|
---|
28 | #include "tcc.h"
|
---|
29 |
|
---|
30 | /* Returns 1 for a code relocation, 0 for a data relocation. For unknown
|
---|
31 | relocations, returns -1. */
|
---|
32 | int code_reloc (int reloc_type)
|
---|
33 | {
|
---|
34 | switch (reloc_type) {
|
---|
35 | case R_ARM_MOVT_ABS:
|
---|
36 | case R_ARM_MOVW_ABS_NC:
|
---|
37 | case R_ARM_THM_MOVT_ABS:
|
---|
38 | case R_ARM_THM_MOVW_ABS_NC:
|
---|
39 | case R_ARM_ABS32:
|
---|
40 | case R_ARM_REL32:
|
---|
41 | case R_ARM_GOTPC:
|
---|
42 | case R_ARM_GOTOFF:
|
---|
43 | case R_ARM_GOT32:
|
---|
44 | case R_ARM_COPY:
|
---|
45 | case R_ARM_GLOB_DAT:
|
---|
46 | case R_ARM_NONE:
|
---|
47 | return 0;
|
---|
48 |
|
---|
49 | case R_ARM_PC24:
|
---|
50 | case R_ARM_CALL:
|
---|
51 | case R_ARM_JUMP24:
|
---|
52 | case R_ARM_PLT32:
|
---|
53 | case R_ARM_THM_PC22:
|
---|
54 | case R_ARM_THM_JUMP24:
|
---|
55 | case R_ARM_PREL31:
|
---|
56 | case R_ARM_V4BX:
|
---|
57 | case R_ARM_JUMP_SLOT:
|
---|
58 | return 1;
|
---|
59 | }
|
---|
60 |
|
---|
61 | tcc_error ("Unknown relocation type: %d", reloc_type);
|
---|
62 | return -1;
|
---|
63 | }
|
---|
64 |
|
---|
65 | /* Returns an enumerator to describe whether and when the relocation needs a
|
---|
66 | GOT and/or PLT entry to be created. See tcc.h for a description of the
|
---|
67 | different values. */
|
---|
68 | int gotplt_entry_type (int reloc_type)
|
---|
69 | {
|
---|
70 | switch (reloc_type) {
|
---|
71 | case R_ARM_NONE:
|
---|
72 | case R_ARM_COPY:
|
---|
73 | case R_ARM_GLOB_DAT:
|
---|
74 | case R_ARM_JUMP_SLOT:
|
---|
75 | return NO_GOTPLT_ENTRY;
|
---|
76 |
|
---|
77 | case R_ARM_PC24:
|
---|
78 | case R_ARM_CALL:
|
---|
79 | case R_ARM_JUMP24:
|
---|
80 | case R_ARM_PLT32:
|
---|
81 | case R_ARM_THM_PC22:
|
---|
82 | case R_ARM_THM_JUMP24:
|
---|
83 | case R_ARM_MOVT_ABS:
|
---|
84 | case R_ARM_MOVW_ABS_NC:
|
---|
85 | case R_ARM_THM_MOVT_ABS:
|
---|
86 | case R_ARM_THM_MOVW_ABS_NC:
|
---|
87 | case R_ARM_PREL31:
|
---|
88 | case R_ARM_ABS32:
|
---|
89 | case R_ARM_REL32:
|
---|
90 | case R_ARM_V4BX:
|
---|
91 | return AUTO_GOTPLT_ENTRY;
|
---|
92 |
|
---|
93 | case R_ARM_GOTPC:
|
---|
94 | case R_ARM_GOTOFF:
|
---|
95 | return BUILD_GOT_ONLY;
|
---|
96 |
|
---|
97 | case R_ARM_GOT32:
|
---|
98 | return ALWAYS_GOTPLT_ENTRY;
|
---|
99 | }
|
---|
100 |
|
---|
101 | tcc_error ("Unknown relocation type: %d", reloc_type);
|
---|
102 | return -1;
|
---|
103 | }
|
---|
104 |
|
---|
105 | ST_FUNC unsigned create_plt_entry(TCCState *s1, unsigned got_offset, struct sym_attr *attr)
|
---|
106 | {
|
---|
107 | Section *plt = s1->plt;
|
---|
108 | uint8_t *p;
|
---|
109 | unsigned plt_offset;
|
---|
110 |
|
---|
111 | /* when building a DLL, GOT entry accesses must be done relative to
|
---|
112 | start of GOT (see x86_64 example above) */
|
---|
113 | if (s1->output_type == TCC_OUTPUT_DLL)
|
---|
114 | tcc_error("DLLs unimplemented!");
|
---|
115 |
|
---|
116 | /* empty PLT: create PLT0 entry that push address of call site and
|
---|
117 | jump to ld.so resolution routine (GOT + 8) */
|
---|
118 | if (plt->data_offset == 0) {
|
---|
119 | p = section_ptr_add(plt, 20);
|
---|
120 | write32le(p, 0xe52de004); /* push {lr} */
|
---|
121 | write32le(p+4, 0xe59fe004); /* ldr lr, [pc, #4] */
|
---|
122 | write32le(p+8, 0xe08fe00e); /* add lr, pc, lr */
|
---|
123 | write32le(p+12, 0xe5bef008); /* ldr pc, [lr, #8]! */
|
---|
124 | /* p+16 is set in relocate_plt */
|
---|
125 | }
|
---|
126 | plt_offset = plt->data_offset;
|
---|
127 |
|
---|
128 | if (attr->plt_thumb_stub) {
|
---|
129 | p = section_ptr_add(plt, 4);
|
---|
130 | write32le(p, 0x4778); /* bx pc */
|
---|
131 | write32le(p+2, 0x46c0); /* nop */
|
---|
132 | }
|
---|
133 | p = section_ptr_add(plt, 16);
|
---|
134 | /* Jump to GOT entry where ld.so initially put address of PLT0 */
|
---|
135 | write32le(p, 0xe59fc004); /* ldr ip, [pc, #4] */
|
---|
136 | write32le(p+4, 0xe08fc00c); /* add ip, pc, ip */
|
---|
137 | write32le(p+8, 0xe59cf000); /* ldr pc, [ip] */
|
---|
138 | /* p + 12 contains offset to GOT entry once patched by relocate_plt */
|
---|
139 | write32le(p+12, got_offset);
|
---|
140 | return plt_offset;
|
---|
141 | }
|
---|
142 |
|
---|
143 | /* relocate the PLT: compute addresses and offsets in the PLT now that final
|
---|
144 | address for PLT and GOT are known (see fill_program_header) */
|
---|
145 | ST_FUNC void relocate_plt(TCCState *s1)
|
---|
146 | {
|
---|
147 | uint8_t *p, *p_end;
|
---|
148 |
|
---|
149 | if (!s1->plt)
|
---|
150 | return;
|
---|
151 |
|
---|
152 | p = s1->plt->data;
|
---|
153 | p_end = p + s1->plt->data_offset;
|
---|
154 |
|
---|
155 | if (p < p_end) {
|
---|
156 | int x = s1->got->sh_addr - s1->plt->sh_addr - 12;
|
---|
157 | write32le(s1->plt->data + 16, x - 16);
|
---|
158 | p += 20;
|
---|
159 | while (p < p_end) {
|
---|
160 | if (read32le(p) == 0x46c04778) /* PLT Thumb stub present */
|
---|
161 | p += 4;
|
---|
162 | add32le(p + 12, x + s1->plt->data - p);
|
---|
163 | p += 16;
|
---|
164 | }
|
---|
165 | }
|
---|
166 | }
|
---|
167 |
|
---|
168 | void relocate_init(Section *sr) {}
|
---|
169 |
|
---|
170 | void relocate(TCCState *s1, ElfW_Rel *rel, int type, unsigned char *ptr, addr_t addr, addr_t val)
|
---|
171 | {
|
---|
172 | ElfW(Sym) *sym;
|
---|
173 | int sym_index;
|
---|
174 |
|
---|
175 | sym_index = ELFW(R_SYM)(rel->r_info);
|
---|
176 | sym = &((ElfW(Sym) *)symtab_section->data)[sym_index];
|
---|
177 |
|
---|
178 | switch(type) {
|
---|
179 | case R_ARM_PC24:
|
---|
180 | case R_ARM_CALL:
|
---|
181 | case R_ARM_JUMP24:
|
---|
182 | case R_ARM_PLT32:
|
---|
183 | {
|
---|
184 | int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko;
|
---|
185 | x = (*(int *) ptr) & 0xffffff;
|
---|
186 | #ifdef DEBUG_RELOC
|
---|
187 | printf ("reloc %d: x=0x%x val=0x%x ", type, x, val);
|
---|
188 | #endif
|
---|
189 | (*(int *)ptr) &= 0xff000000;
|
---|
190 | if (x & 0x800000)
|
---|
191 | x -= 0x1000000;
|
---|
192 | x <<= 2;
|
---|
193 | blx_avail = (TCC_CPU_VERSION >= 5);
|
---|
194 | is_thumb = val & 1;
|
---|
195 | is_bl = (*(unsigned *) ptr) >> 24 == 0xeb;
|
---|
196 | is_call = (type == R_ARM_CALL || (type == R_ARM_PC24 && is_bl));
|
---|
197 | x += val - addr;
|
---|
198 | #ifdef DEBUG_RELOC
|
---|
199 | printf (" newx=0x%x name=%s\n", x,
|
---|
200 | (char *) symtab_section->link->data + sym->st_name);
|
---|
201 | #endif
|
---|
202 | h = x & 2;
|
---|
203 | th_ko = (x & 3) && (!blx_avail || !is_call);
|
---|
204 | if (th_ko || x >= 0x2000000 || x < -0x2000000)
|
---|
205 | tcc_error("can't relocate value at %x,%d",addr, type);
|
---|
206 | x >>= 2;
|
---|
207 | x &= 0xffffff;
|
---|
208 | /* Only reached if blx is avail and it is a call */
|
---|
209 | if (is_thumb) {
|
---|
210 | x |= h << 24;
|
---|
211 | (*(int *)ptr) = 0xfa << 24; /* bl -> blx */
|
---|
212 | }
|
---|
213 | (*(int *) ptr) |= x;
|
---|
214 | }
|
---|
215 | return;
|
---|
216 | /* Since these relocations only concern Thumb-2 and blx instruction was
|
---|
217 | introduced before Thumb-2, we can assume blx is available and not
|
---|
218 | guard its use */
|
---|
219 | case R_ARM_THM_PC22:
|
---|
220 | case R_ARM_THM_JUMP24:
|
---|
221 | {
|
---|
222 | int x, hi, lo, s, j1, j2, i1, i2, imm10, imm11;
|
---|
223 | int to_thumb, is_call, to_plt, blx_bit = 1 << 12;
|
---|
224 | Section *plt;
|
---|
225 |
|
---|
226 | /* weak reference */
|
---|
227 | if (sym->st_shndx == SHN_UNDEF &&
|
---|
228 | ELFW(ST_BIND)(sym->st_info) == STB_WEAK)
|
---|
229 | return;
|
---|
230 |
|
---|
231 | /* Get initial offset */
|
---|
232 | hi = (*(uint16_t *)ptr);
|
---|
233 | lo = (*(uint16_t *)(ptr+2));
|
---|
234 | s = (hi >> 10) & 1;
|
---|
235 | j1 = (lo >> 13) & 1;
|
---|
236 | j2 = (lo >> 11) & 1;
|
---|
237 | i1 = (j1 ^ s) ^ 1;
|
---|
238 | i2 = (j2 ^ s) ^ 1;
|
---|
239 | imm10 = hi & 0x3ff;
|
---|
240 | imm11 = lo & 0x7ff;
|
---|
241 | x = (s << 24) | (i1 << 23) | (i2 << 22) |
|
---|
242 | (imm10 << 12) | (imm11 << 1);
|
---|
243 | if (x & 0x01000000)
|
---|
244 | x -= 0x02000000;
|
---|
245 |
|
---|
246 | /* Relocation infos */
|
---|
247 | to_thumb = val & 1;
|
---|
248 | plt = s1->plt;
|
---|
249 | to_plt = (val >= plt->sh_addr) &&
|
---|
250 | (val < plt->sh_addr + plt->data_offset);
|
---|
251 | is_call = (type == R_ARM_THM_PC22);
|
---|
252 |
|
---|
253 | if (!to_thumb && !to_plt && !is_call) {
|
---|
254 | int index;
|
---|
255 | uint8_t *p;
|
---|
256 | char *name, buf[1024];
|
---|
257 | Section *text_section;
|
---|
258 |
|
---|
259 | name = (char *) symtab_section->link->data + sym->st_name;
|
---|
260 | text_section = s1->sections[sym->st_shndx];
|
---|
261 | /* Modify reloc to target a thumb stub to switch to ARM */
|
---|
262 | snprintf(buf, sizeof(buf), "%s_from_thumb", name);
|
---|
263 | index = put_elf_sym(symtab_section,
|
---|
264 | text_section->data_offset + 1,
|
---|
265 | sym->st_size, sym->st_info, 0,
|
---|
266 | sym->st_shndx, buf);
|
---|
267 | to_thumb = 1;
|
---|
268 | val = text_section->data_offset + 1;
|
---|
269 | rel->r_info = ELFW(R_INFO)(index, type);
|
---|
270 | /* Create a thumb stub function to switch to ARM mode */
|
---|
271 | put_elf_reloc(symtab_section, text_section,
|
---|
272 | text_section->data_offset + 4, R_ARM_JUMP24,
|
---|
273 | sym_index);
|
---|
274 | p = section_ptr_add(text_section, 8);
|
---|
275 | write32le(p, 0x4778); /* bx pc */
|
---|
276 | write32le(p+2, 0x46c0); /* nop */
|
---|
277 | write32le(p+4, 0xeafffffe); /* b $sym */
|
---|
278 | }
|
---|
279 |
|
---|
280 | /* Compute final offset */
|
---|
281 | x += val - addr;
|
---|
282 | if (!to_thumb && is_call) {
|
---|
283 | blx_bit = 0; /* bl -> blx */
|
---|
284 | x = (x + 3) & -4; /* Compute offset from aligned PC */
|
---|
285 | }
|
---|
286 |
|
---|
287 | /* Check that relocation is possible
|
---|
288 | * offset must not be out of range
|
---|
289 | * if target is to be entered in arm mode:
|
---|
290 | - bit 1 must not set
|
---|
291 | - instruction must be a call (bl) or a jump to PLT */
|
---|
292 | if (!to_thumb || x >= 0x1000000 || x < -0x1000000)
|
---|
293 | if (to_thumb || (val & 2) || (!is_call && !to_plt))
|
---|
294 | tcc_error("can't relocate value at %x,%d",addr, type);
|
---|
295 |
|
---|
296 | /* Compute and store final offset */
|
---|
297 | s = (x >> 24) & 1;
|
---|
298 | i1 = (x >> 23) & 1;
|
---|
299 | i2 = (x >> 22) & 1;
|
---|
300 | j1 = s ^ (i1 ^ 1);
|
---|
301 | j2 = s ^ (i2 ^ 1);
|
---|
302 | imm10 = (x >> 12) & 0x3ff;
|
---|
303 | imm11 = (x >> 1) & 0x7ff;
|
---|
304 | (*(uint16_t *)ptr) = (uint16_t) ((hi & 0xf800) |
|
---|
305 | (s << 10) | imm10);
|
---|
306 | (*(uint16_t *)(ptr+2)) = (uint16_t) ((lo & 0xc000) |
|
---|
307 | (j1 << 13) | blx_bit | (j2 << 11) |
|
---|
308 | imm11);
|
---|
309 | }
|
---|
310 | return;
|
---|
311 | case R_ARM_MOVT_ABS:
|
---|
312 | case R_ARM_MOVW_ABS_NC:
|
---|
313 | {
|
---|
314 | int x, imm4, imm12;
|
---|
315 | if (type == R_ARM_MOVT_ABS)
|
---|
316 | val >>= 16;
|
---|
317 | imm12 = val & 0xfff;
|
---|
318 | imm4 = (val >> 12) & 0xf;
|
---|
319 | x = (imm4 << 16) | imm12;
|
---|
320 | if (type == R_ARM_THM_MOVT_ABS)
|
---|
321 | *(int *)ptr |= x;
|
---|
322 | else
|
---|
323 | *(int *)ptr += x;
|
---|
324 | }
|
---|
325 | return;
|
---|
326 | case R_ARM_THM_MOVT_ABS:
|
---|
327 | case R_ARM_THM_MOVW_ABS_NC:
|
---|
328 | {
|
---|
329 | int x, i, imm4, imm3, imm8;
|
---|
330 | if (type == R_ARM_THM_MOVT_ABS)
|
---|
331 | val >>= 16;
|
---|
332 | imm8 = val & 0xff;
|
---|
333 | imm3 = (val >> 8) & 0x7;
|
---|
334 | i = (val >> 11) & 1;
|
---|
335 | imm4 = (val >> 12) & 0xf;
|
---|
336 | x = (imm3 << 28) | (imm8 << 16) | (i << 10) | imm4;
|
---|
337 | if (type == R_ARM_THM_MOVT_ABS)
|
---|
338 | *(int *)ptr |= x;
|
---|
339 | else
|
---|
340 | *(int *)ptr += x;
|
---|
341 | }
|
---|
342 | return;
|
---|
343 | case R_ARM_PREL31:
|
---|
344 | {
|
---|
345 | int x;
|
---|
346 | x = (*(int *)ptr) & 0x7fffffff;
|
---|
347 | (*(int *)ptr) &= 0x80000000;
|
---|
348 | x = (x * 2) / 2;
|
---|
349 | x += val - addr;
|
---|
350 | if((x^(x>>1))&0x40000000)
|
---|
351 | tcc_error("can't relocate value at %x,%d",addr, type);
|
---|
352 | (*(int *)ptr) |= x & 0x7fffffff;
|
---|
353 | }
|
---|
354 | case R_ARM_ABS32:
|
---|
355 | *(int *)ptr += val;
|
---|
356 | return;
|
---|
357 | case R_ARM_REL32:
|
---|
358 | *(int *)ptr += val - addr;
|
---|
359 | return;
|
---|
360 | case R_ARM_GOTPC:
|
---|
361 | *(int *)ptr += s1->got->sh_addr - addr;
|
---|
362 | return;
|
---|
363 | case R_ARM_GOTOFF:
|
---|
364 | *(int *)ptr += val - s1->got->sh_addr;
|
---|
365 | return;
|
---|
366 | case R_ARM_GOT32:
|
---|
367 | /* we load the got offset */
|
---|
368 | *(int *)ptr += s1->sym_attrs[sym_index].got_offset;
|
---|
369 | return;
|
---|
370 | case R_ARM_COPY:
|
---|
371 | return;
|
---|
372 | case R_ARM_V4BX:
|
---|
373 | /* trade Thumb support for ARMv4 support */
|
---|
374 | if ((0x0ffffff0 & *(int*)ptr) == 0x012FFF10)
|
---|
375 | *(int*)ptr ^= 0xE12FFF10 ^ 0xE1A0F000; /* BX Rm -> MOV PC, Rm */
|
---|
376 | return;
|
---|
377 | case R_ARM_GLOB_DAT:
|
---|
378 | case R_ARM_JUMP_SLOT:
|
---|
379 | *(addr_t *)ptr = val;
|
---|
380 | return;
|
---|
381 | case R_ARM_NONE:
|
---|
382 | /* Nothing to do. Normally used to indicate a dependency
|
---|
383 | on a certain symbol (like for exception handling under EABI). */
|
---|
384 | return;
|
---|
385 | case R_ARM_RELATIVE:
|
---|
386 | #ifdef TCC_TARGET_PE
|
---|
387 | add32le(ptr, val - s1->pe_imagebase);
|
---|
388 | #endif
|
---|
389 | /* do nothing */
|
---|
390 | return;
|
---|
391 | default:
|
---|
392 | fprintf(stderr,"FIXME: handle reloc type %x at %x [%p] to %x\n",
|
---|
393 | type, (unsigned)addr, ptr, (unsigned)val);
|
---|
394 | return;
|
---|
395 | }
|
---|
396 | }
|
---|
397 |
|
---|
398 | #endif /* !TARGET_DEFS_ONLY */
|
---|