2 * Generic Dynamic compiler generator
4 * Copyright (c) 2003 Fabrice Bellard
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
31 /* all dynamically generated functions begin with this code */
32 #define OP_PREFIX "op_"
34 int elf_must_swap(Elf32_Ehdr
*h
)
42 return (h
->e_ident
[EI_DATA
] == ELFDATA2MSB
) !=
46 void swab16s(uint16_t *p
)
51 void swab32s(uint32_t *p
)
56 void swab64s(uint32_t *p
)
61 void elf_swap_ehdr(Elf32_Ehdr
*h
)
63 swab16s(&h
->e_type
); /* Object file type */
64 swab16s(&h
-> e_machine
); /* Architecture */
65 swab32s(&h
-> e_version
); /* Object file version */
66 swab32s(&h
-> e_entry
); /* Entry point virtual address */
67 swab32s(&h
-> e_phoff
); /* Program header table file offset */
68 swab32s(&h
-> e_shoff
); /* Section header table file offset */
69 swab32s(&h
-> e_flags
); /* Processor-specific flags */
70 swab16s(&h
-> e_ehsize
); /* ELF header size in bytes */
71 swab16s(&h
-> e_phentsize
); /* Program header table entry size */
72 swab16s(&h
-> e_phnum
); /* Program header table entry count */
73 swab16s(&h
-> e_shentsize
); /* Section header table entry size */
74 swab16s(&h
-> e_shnum
); /* Section header table entry count */
75 swab16s(&h
-> e_shstrndx
); /* Section header string table index */
78 void elf_swap_shdr(Elf32_Shdr
*h
)
80 swab32s(&h
-> sh_name
); /* Section name (string tbl index) */
81 swab32s(&h
-> sh_type
); /* Section type */
82 swab32s(&h
-> sh_flags
); /* Section flags */
83 swab32s(&h
-> sh_addr
); /* Section virtual addr at execution */
84 swab32s(&h
-> sh_offset
); /* Section file offset */
85 swab32s(&h
-> sh_size
); /* Section size in bytes */
86 swab32s(&h
-> sh_link
); /* Link to another section */
87 swab32s(&h
-> sh_info
); /* Additional section information */
88 swab32s(&h
-> sh_addralign
); /* Section alignment */
89 swab32s(&h
-> sh_entsize
); /* Entry size if section holds table */
92 void elf_swap_phdr(Elf32_Phdr
*h
)
94 swab32s(&h
->p_type
); /* Segment type */
95 swab32s(&h
->p_offset
); /* Segment file offset */
96 swab32s(&h
->p_vaddr
); /* Segment virtual address */
97 swab32s(&h
->p_paddr
); /* Segment physical address */
98 swab32s(&h
->p_filesz
); /* Segment size in file */
99 swab32s(&h
->p_memsz
); /* Segment size in memory */
100 swab32s(&h
->p_flags
); /* Segment flags */
101 swab32s(&h
->p_align
); /* Segment alignment */
107 uint16_t get16(uint16_t *p
)
116 uint32_t get32(uint32_t *p
)
125 void put16(uint16_t *p
, uint16_t val
)
132 void put32(uint32_t *p
, uint32_t val
)
139 void __attribute__((noreturn
)) error(const char *fmt
, ...)
143 fprintf(stderr
, "dyngen: ");
144 vfprintf(stderr
, fmt
, ap
);
145 fprintf(stderr
, "\n");
151 Elf32_Shdr
*find_elf_section(Elf32_Shdr
*shdr
, int shnum
, const char *shstr
,
158 for(i
= 0; i
< shnum
; i
++) {
162 shname
= shstr
+ sec
->sh_name
;
163 if (!strcmp(shname
, name
))
169 void *load_data(int fd
, long offset
, unsigned int size
)
176 lseek(fd
, offset
, SEEK_SET
);
177 if (read(fd
, data
, size
) != size
) {
184 int strstart(const char *str
, const char *val
, const char **ptr
)
202 /* generate op code */
203 void gen_code(const char *name
, unsigned long offset
, unsigned long size
,
204 FILE *outfile
, uint8_t *text
, void *relocs
, int nb_relocs
, int reloc_sh_type
,
205 Elf32_Sym
*symtab
, char *strtab
, int gen_switch
)
208 uint8_t *p_start
, *p_end
;
210 uint8_t args_present
[MAX_ARGS
];
211 const char *sym_name
, *p
;
213 /* compute exact size excluding return instruction */
214 p_start
= text
+ offset
;
215 p_end
= p_start
+ size
;
222 error("empty code for %s", name
);
224 error("ret expected at the end of %s", name
);
225 copy_size
= p
- p_start
;
231 p
= (void *)(p_end
- 4);
233 error("empty code for %s", name
);
234 if (get32((uint32_t *)p
) != 0x4e800020)
235 error("blr expected at the end of %s", name
);
236 copy_size
= p
- p_start
;
240 error("unsupported CPU (%d)", e_machine
);
243 /* compute the number of arguments by looking at the relocations */
244 for(i
= 0;i
< MAX_ARGS
; i
++)
247 if (reloc_sh_type
== SHT_REL
) {
250 for(i
= 0, rel
= relocs
;i
< nb_relocs
; i
++, rel
++) {
251 if (rel
->r_offset
>= offset
&& rel
->r_offset
< offset
+ copy_size
) {
252 sym_name
= strtab
+ symtab
[ELF32_R_SYM(rel
->r_info
)].st_name
;
253 if (strstart(sym_name
, "__op_param", &p
)) {
254 n
= strtoul(p
, NULL
, 10);
256 error("too many arguments in %s", name
);
257 args_present
[n
- 1] = 1;
264 for(i
= 0, rel
= relocs
;i
< nb_relocs
; i
++, rel
++) {
265 if (rel
->r_offset
>= offset
&& rel
->r_offset
< offset
+ copy_size
) {
266 sym_name
= strtab
+ symtab
[ELF32_R_SYM(rel
->r_info
)].st_name
;
267 if (strstart(sym_name
, "__op_param", &p
)) {
268 n
= strtoul(p
, NULL
, 10);
270 error("too many arguments in %s", name
);
271 args_present
[n
- 1] = 1;
278 while (nb_args
< MAX_ARGS
&& args_present
[nb_args
])
280 for(i
= nb_args
; i
< MAX_ARGS
; i
++) {
282 error("inconsistent argument numbering in %s", name
);
288 fprintf(outfile
, "case INDEX_%s: {\n", name
);
290 fprintf(outfile
, " long ");
291 for(i
= 0; i
< nb_args
; i
++) {
293 fprintf(outfile
, ", ");
294 fprintf(outfile
, "param%d", i
+ 1);
296 fprintf(outfile
, ";\n");
298 fprintf(outfile
, " extern void %s();\n", name
);
300 if (reloc_sh_type
== SHT_REL
) {
302 for(i
= 0, rel
= relocs
;i
< nb_relocs
; i
++, rel
++) {
303 if (rel
->r_offset
>= offset
&& rel
->r_offset
< offset
+ copy_size
) {
304 sym_name
= strtab
+ symtab
[ELF32_R_SYM(rel
->r_info
)].st_name
;
305 if (!strstart(sym_name
, "__op_param", &p
)) {
306 fprintf(outfile
, "extern char %s;\n", sym_name
);
312 for(i
= 0, rel
= relocs
;i
< nb_relocs
; i
++, rel
++) {
313 if (rel
->r_offset
>= offset
&& rel
->r_offset
< offset
+ copy_size
) {
314 sym_name
= strtab
+ symtab
[ELF32_R_SYM(rel
->r_info
)].st_name
;
315 if (!strstart(sym_name
, "__op_param", &p
)) {
316 fprintf(outfile
, "extern char %s;\n", sym_name
);
322 fprintf(outfile
, " memcpy(gen_code_ptr, &%s, %d);\n", name
, copy_size
);
323 for(i
= 0; i
< nb_args
; i
++) {
324 fprintf(outfile
, " param%d = *opparam_ptr++;\n", i
+ 1);
327 /* patch relocations */
335 for(i
= 0, rel
= relocs
;i
< nb_relocs
; i
++, rel
++) {
336 if (rel
->r_offset
>= offset
&& rel
->r_offset
< offset
+ copy_size
) {
337 sym_name
= strtab
+ symtab
[ELF32_R_SYM(rel
->r_info
)].st_name
;
338 if (strstart(sym_name
, "__op_param", &p
)) {
339 snprintf(name
, sizeof(name
), "param%s", p
);
341 snprintf(name
, sizeof(name
), "(long)(&%s)", sym_name
);
343 type
= ELF32_R_TYPE(rel
->r_info
);
344 addend
= get32((uint32_t *)(text
+ rel
->r_offset
));
347 fprintf(outfile
, " *(uint32_t *)(gen_code_ptr + %ld) = %s + %ld;\n",
348 rel
->r_offset
- offset
, name
, addend
);
351 fprintf(outfile
, " *(uint32_t *)(gen_code_ptr + %ld) = %s - (long)(gen_code_ptr + %ld) + %ld;\n",
352 rel
->r_offset
- offset
, name
, rel
->r_offset
- offset
, addend
);
355 error("unsupported i386 relocation (%d)", type
);
367 for(i
= 0, rel
= relocs
;i
< nb_relocs
; i
++, rel
++) {
368 if (rel
->r_offset
>= offset
&& rel
->r_offset
< offset
+ copy_size
) {
369 sym_name
= strtab
+ symtab
[ELF32_R_SYM(rel
->r_info
)].st_name
;
370 if (strstart(sym_name
, "__op_param", &p
)) {
371 snprintf(name
, sizeof(name
), "param%s", p
);
373 snprintf(name
, sizeof(name
), "(long)(&%s)", sym_name
);
375 type
= ELF32_R_TYPE(rel
->r_info
);
376 addend
= rel
->r_addend
;
379 fprintf(outfile
, " *(uint32_t *)(gen_code_ptr + %ld) = %s + %ld;\n",
380 rel
->r_offset
- offset
, name
, addend
);
382 case R_PPC_ADDR16_LO
:
383 fprintf(outfile
, " *(uint16_t *)(gen_code_ptr + %ld) = (%s + %ld);\n",
384 rel
->r_offset
- offset
, name
, addend
);
386 case R_PPC_ADDR16_HI
:
387 fprintf(outfile
, " *(uint16_t *)(gen_code_ptr + %ld) = (%s + %ld) >> 16;\n",
388 rel
->r_offset
- offset
, name
, addend
);
390 case R_PPC_ADDR16_HA
:
391 fprintf(outfile
, " *(uint16_t *)(gen_code_ptr + %ld) = (%s + %ld + 0x8000) >> 16;\n",
392 rel
->r_offset
- offset
, name
, addend
);
395 /* warning: must be at 32 MB distancy */
396 fprintf(outfile
, " *(uint32_t *)(gen_code_ptr + %ld) = (*(uint32_t *)(gen_code_ptr + %ld) & ~0x03fffffc) | ((%s - (long)(gen_code_ptr + %ld) + %ld) & 0x03fffffc);\n",
397 rel
->r_offset
- offset
, rel
->r_offset
- offset
, name
, rel
->r_offset
- offset
, addend
);
400 error("unsupported powerpc relocation (%d)", type
);
407 error("unsupported CPU for relocations (%d)", e_machine
);
409 fprintf(outfile
, " gen_code_ptr += %d;\n", copy_size
);
410 fprintf(outfile
, "}\n");
411 fprintf(outfile
, "break;\n\n");
413 fprintf(outfile
, "static inline void gen_%s(", name
);
415 fprintf(outfile
, "void");
417 for(i
= 0; i
< nb_args
; i
++) {
419 fprintf(outfile
, ", ");
420 fprintf(outfile
, "long param%d", i
+ 1);
423 fprintf(outfile
, ")\n");
424 fprintf(outfile
, "{\n");
425 for(i
= 0; i
< nb_args
; i
++) {
426 fprintf(outfile
, " *gen_opparam_ptr++ = param%d;\n", i
+ 1);
428 fprintf(outfile
, " *gen_opc_ptr++ = INDEX_%s;\n", name
);
429 fprintf(outfile
, "}\n\n");
433 /* load an elf object file */
434 int load_elf(const char *filename
, FILE *outfile
, int do_print_enum
)
438 Elf32_Shdr
*sec
, *shdr
, *symtab_sec
, *strtab_sec
, *text_sec
;
440 Elf32_Sym
*symtab
, *sym
;
441 const char *cpu_name
;
442 char *shstr
, *strtab
;
445 int nb_relocs
, reloc_sh_type
;
447 fd
= open(filename
, O_RDONLY
);
449 error("can't open file '%s'", filename
);
451 /* Read ELF header. */
452 if (read(fd
, &ehdr
, sizeof (ehdr
)) != sizeof (ehdr
))
453 error("unable to read file header");
455 /* Check ELF identification. */
456 if (ehdr
.e_ident
[EI_MAG0
] != ELFMAG0
457 || ehdr
.e_ident
[EI_MAG1
] != ELFMAG1
458 || ehdr
.e_ident
[EI_MAG2
] != ELFMAG2
459 || ehdr
.e_ident
[EI_MAG3
] != ELFMAG3
460 || ehdr
.e_ident
[EI_CLASS
] != ELFCLASS32
461 || ehdr
.e_ident
[EI_VERSION
] != EV_CURRENT
) {
462 error("bad ELF header");
465 do_swap
= elf_must_swap(&ehdr
);
467 elf_swap_ehdr(&ehdr
);
468 if (ehdr
.e_type
!= ET_REL
)
469 error("ELF object file expected");
470 if (ehdr
.e_version
!= EV_CURRENT
)
471 error("Invalid ELF version");
472 e_machine
= ehdr
.e_machine
;
474 /* read section headers */
475 shdr
= load_data(fd
, ehdr
.e_shoff
, ehdr
.e_shnum
* sizeof(Elf32_Shdr
));
477 for(i
= 0; i
< ehdr
.e_shnum
; i
++) {
478 elf_swap_shdr(&shdr
[i
]);
482 sec
= &shdr
[ehdr
.e_shstrndx
];
483 shstr
= load_data(fd
, sec
->sh_offset
, sec
->sh_size
);
487 text_sec
= find_elf_section(shdr
, ehdr
.e_shnum
, shstr
, ".text");
489 error("could not find .text section");
490 text
= load_data(fd
, text_sec
->sh_offset
, text_sec
->sh_size
);
492 /* find text relocations, if any */
496 for(i
= 0; i
< ehdr
.e_shnum
; i
++) {
498 if ((sec
->sh_type
== SHT_REL
|| sec
->sh_type
== SHT_RELA
) &&
499 sec
->sh_info
== (text_sec
- shdr
)) {
500 reloc_sh_type
= sec
->sh_type
;
501 relocs
= load_data(fd
, sec
->sh_offset
, sec
->sh_size
);
502 nb_relocs
= sec
->sh_size
/ sec
->sh_entsize
;
504 if (sec
->sh_type
== SHT_REL
) {
505 Elf32_Rel
*rel
= relocs
;
506 for(j
= 0, rel
= relocs
; j
< nb_relocs
; j
++, rel
++) {
507 swab32s(&rel
->r_offset
);
508 swab32s(&rel
->r_info
);
511 Elf32_Rela
*rel
= relocs
;
512 for(j
= 0, rel
= relocs
; j
< nb_relocs
; j
++, rel
++) {
513 swab32s(&rel
->r_offset
);
514 swab32s(&rel
->r_info
);
515 swab32s(&rel
->r_addend
);
523 symtab_sec
= find_elf_section(shdr
, ehdr
.e_shnum
, shstr
, ".symtab");
525 error("could not find .symtab section");
526 strtab_sec
= &shdr
[symtab_sec
->sh_link
];
528 symtab
= load_data(fd
, symtab_sec
->sh_offset
, symtab_sec
->sh_size
);
529 strtab
= load_data(fd
, strtab_sec
->sh_offset
, strtab_sec
->sh_size
);
531 nb_syms
= symtab_sec
->sh_size
/ sizeof(Elf32_Sym
);
533 for(i
= 0, sym
= symtab
; i
< nb_syms
; i
++, sym
++) {
534 swab32s(&sym
->st_name
);
535 swab32s(&sym
->st_value
);
536 swab32s(&sym
->st_size
);
537 swab16s(&sym
->st_shndx
);
558 error("unsupported CPU (e_machine=%d)", e_machine
);
562 fprintf(outfile
, "DEF(end)\n");
563 for(i
= 0, sym
= symtab
; i
< nb_syms
; i
++, sym
++) {
564 const char *name
, *p
;
565 name
= strtab
+ sym
->st_name
;
566 if (strstart(name
, OP_PREFIX
, &p
)) {
567 fprintf(outfile
, "DEF(%s)\n", p
);
571 /* generate big code generation switch */
573 "int dyngen_code(uint8_t *gen_code_buf,\n"
574 " const uint16_t *opc_buf, const uint32_t *opparam_buf)\n"
576 " uint8_t *gen_code_ptr;\n"
577 " const uint16_t *opc_ptr;\n"
578 " const uint32_t *opparam_ptr;\n"
579 " gen_code_ptr = gen_code_buf;\n"
580 " opc_ptr = opc_buf;\n"
581 " opparam_ptr = opparam_buf;\n"
583 " switch(*opc_ptr++) {\n"
586 for(i
= 0, sym
= symtab
; i
< nb_syms
; i
++, sym
++) {
588 name
= strtab
+ sym
->st_name
;
589 if (strstart(name
, OP_PREFIX
, NULL
)) {
591 printf("%4d: %s pos=0x%08x len=%d\n",
592 i
, name
, sym
->st_value
, sym
->st_size
);
594 if (sym
->st_shndx
!= (text_sec
- shdr
))
595 error("invalid section for opcode (0x%x)", sym
->st_shndx
);
596 gen_code(name
, sym
->st_value
, sym
->st_size
, outfile
,
597 text
, relocs
, nb_relocs
, reloc_sh_type
, symtab
, strtab
, 1);
609 /* generate a return */
612 fprintf(outfile
, "*gen_code_ptr++ = 0xc3; /* ret */\n");
615 fprintf(outfile
, "*((uint32_t *)gen_code_ptr)++ = 0x4e800020; /* blr */\n");
618 error("no return generation for cpu '%s'", cpu_name
);
621 fprintf(outfile
, "return gen_code_ptr - gen_code_buf;\n");
622 fprintf(outfile
, "}\n\n");
624 /* generate gen_xxx functions */
625 /* XXX: suppress the use of these functions to simplify code */
626 for(i
= 0, sym
= symtab
; i
< nb_syms
; i
++, sym
++) {
628 name
= strtab
+ sym
->st_name
;
629 if (strstart(name
, OP_PREFIX
, NULL
)) {
630 if (sym
->st_shndx
!= (text_sec
- shdr
))
631 error("invalid section for opcode (0x%x)", sym
->st_shndx
);
632 gen_code(name
, sym
->st_value
, sym
->st_size
, outfile
,
633 text
, relocs
, nb_relocs
, reloc_sh_type
, symtab
, strtab
, 0);
644 printf("dyngen (c) 2003 Fabrice Bellard\n"
645 "usage: dyngen [-o outfile] [-c] objfile\n"
646 "Generate a dynamic code generator from an object file\n"
647 "-c output enum of operations\n"
652 int main(int argc
, char **argv
)
654 int c
, do_print_enum
;
655 const char *filename
, *outfilename
;
658 outfilename
= "out.c";
661 c
= getopt(argc
, argv
, "ho:c");
669 outfilename
= optarg
;
678 filename
= argv
[optind
];
679 outfile
= fopen(outfilename
, "w");
681 error("could not open '%s'", outfilename
);
682 load_elf(filename
, outfile
, do_print_enum
);