]>
git.proxmox.com Git - mirror_qemu.git/blob - dyngen.c
11 /* all dynamically generated functions begin with this code */
12 #define OP_PREFIX "op"
14 int elf_must_swap(Elf32_Ehdr
*h
)
22 return (h
->e_ident
[EI_DATA
] == ELFDATA2MSB
) !=
26 void swab16s(uint16_t *p
)
31 void swab32s(uint32_t *p
)
36 void swab64s(uint32_t *p
)
41 void elf_swap_ehdr(Elf32_Ehdr
*h
)
43 swab16s(&h
->e_type
); /* Object file type */
44 swab16s(&h
-> e_machine
); /* Architecture */
45 swab32s(&h
-> e_version
); /* Object file version */
46 swab32s(&h
-> e_entry
); /* Entry point virtual address */
47 swab32s(&h
-> e_phoff
); /* Program header table file offset */
48 swab32s(&h
-> e_shoff
); /* Section header table file offset */
49 swab32s(&h
-> e_flags
); /* Processor-specific flags */
50 swab16s(&h
-> e_ehsize
); /* ELF header size in bytes */
51 swab16s(&h
-> e_phentsize
); /* Program header table entry size */
52 swab16s(&h
-> e_phnum
); /* Program header table entry count */
53 swab16s(&h
-> e_shentsize
); /* Section header table entry size */
54 swab16s(&h
-> e_shnum
); /* Section header table entry count */
55 swab16s(&h
-> e_shstrndx
); /* Section header string table index */
58 void elf_swap_shdr(Elf32_Shdr
*h
)
60 swab32s(&h
-> sh_name
); /* Section name (string tbl index) */
61 swab32s(&h
-> sh_type
); /* Section type */
62 swab32s(&h
-> sh_flags
); /* Section flags */
63 swab32s(&h
-> sh_addr
); /* Section virtual addr at execution */
64 swab32s(&h
-> sh_offset
); /* Section file offset */
65 swab32s(&h
-> sh_size
); /* Section size in bytes */
66 swab32s(&h
-> sh_link
); /* Link to another section */
67 swab32s(&h
-> sh_info
); /* Additional section information */
68 swab32s(&h
-> sh_addralign
); /* Section alignment */
69 swab32s(&h
-> sh_entsize
); /* Entry size if section holds table */
72 void elf_swap_phdr(Elf32_Phdr
*h
)
74 swab32s(&h
->p_type
); /* Segment type */
75 swab32s(&h
->p_offset
); /* Segment file offset */
76 swab32s(&h
->p_vaddr
); /* Segment virtual address */
77 swab32s(&h
->p_paddr
); /* Segment physical address */
78 swab32s(&h
->p_filesz
); /* Segment size in file */
79 swab32s(&h
->p_memsz
); /* Segment size in memory */
80 swab32s(&h
->p_flags
); /* Segment flags */
81 swab32s(&h
->p_align
); /* Segment alignment */
87 uint16_t get16(uint16_t *p
)
96 uint32_t get32(uint32_t *p
)
105 void put16(uint16_t *p
, uint16_t val
)
112 void put32(uint32_t *p
, uint32_t val
)
119 void __attribute__((noreturn
)) error(const char *fmt
, ...)
123 fprintf(stderr
, "dyngen: ");
124 vfprintf(stderr
, fmt
, ap
);
125 fprintf(stderr
, "\n");
131 Elf32_Shdr
*find_elf_section(Elf32_Shdr
*shdr
, int shnum
, const char *shstr
,
138 for(i
= 0; i
< shnum
; i
++) {
142 shname
= shstr
+ sec
->sh_name
;
143 if (!strcmp(shname
, name
))
149 void *load_data(int fd
, long offset
, unsigned int size
)
156 lseek(fd
, offset
, SEEK_SET
);
157 if (read(fd
, data
, size
) != size
) {
164 int strstart(const char *str
, const char *val
, const char **ptr
)
182 /* generate op code */
183 void gen_code(const char *name
, unsigned long offset
, unsigned long size
,
184 FILE *outfile
, uint8_t *text
, void *relocs
, int nb_relocs
, int reloc_sh_type
,
185 Elf32_Sym
*symtab
, char *strtab
)
188 uint8_t *p_start
, *p_end
;
190 uint8_t args_present
[MAX_ARGS
];
191 const char *sym_name
, *p
;
193 /* compute exact size excluding return instruction */
194 p_start
= text
+ offset
;
195 p_end
= p_start
+ size
;
202 while (p
> p_start
&& *p
!= 0xc3)
204 /* skip double ret */
205 if (p
> p_start
&& p
[-1] == 0xc3)
208 error("empty code for %s", name
);
209 copy_size
= p
- p_start
;
215 p
= (void *)(p_end
- 4);
217 while (p
> p_start
&& get32((uint32_t *)p
) != 0x4e800020)
219 /* skip double ret */
220 if (p
> p_start
&& get32((uint32_t *)(p
- 4)) == 0x4e800020)
223 error("empty code for %s", name
);
224 copy_size
= p
- p_start
;
228 error("unsupported CPU (%d)", e_machine
);
231 /* compute the number of arguments by looking at the relocations */
232 for(i
= 0;i
< MAX_ARGS
; i
++)
235 if (reloc_sh_type
== SHT_REL
) {
238 for(i
= 0, rel
= relocs
;i
< nb_relocs
; i
++, rel
++) {
239 if (rel
->r_offset
>= offset
&& rel
->r_offset
< offset
+ copy_size
) {
240 sym_name
= strtab
+ symtab
[ELF32_R_SYM(rel
->r_info
)].st_name
;
241 if (strstart(sym_name
, "__op_param", &p
)) {
242 n
= strtoul(p
, NULL
, 10);
244 error("too many arguments in %s", name
);
245 args_present
[n
- 1] = 1;
247 fprintf(outfile
, "extern char %s;\n", sym_name
);
254 for(i
= 0, rel
= relocs
;i
< nb_relocs
; i
++, rel
++) {
255 if (rel
->r_offset
>= offset
&& rel
->r_offset
< offset
+ copy_size
) {
256 sym_name
= strtab
+ symtab
[ELF32_R_SYM(rel
->r_info
)].st_name
;
257 if (strstart(sym_name
, "__op_param", &p
)) {
258 n
= strtoul(p
, NULL
, 10);
260 error("too many arguments in %s", name
);
261 args_present
[n
- 1] = 1;
263 fprintf(outfile
, "extern char %s;\n", sym_name
);
270 while (nb_args
< MAX_ARGS
&& args_present
[nb_args
])
272 for(i
= nb_args
; i
< MAX_ARGS
; i
++) {
274 error("inconsistent argument numbering in %s", name
);
278 fprintf(outfile
, "extern void %s();\n", name
);
279 fprintf(outfile
, "static inline void gen_%s(", name
);
281 fprintf(outfile
, "void");
283 for(i
= 0; i
< nb_args
; i
++) {
285 fprintf(outfile
, ", ");
286 fprintf(outfile
, "long param%d", i
+ 1);
289 fprintf(outfile
, ")\n");
290 fprintf(outfile
, "{\n");
291 fprintf(outfile
, " memcpy(gen_code_ptr, &%s, %d);\n", name
, copy_size
);
293 /* patch relocations */
301 for(i
= 0, rel
= relocs
;i
< nb_relocs
; i
++, rel
++) {
302 if (rel
->r_offset
>= offset
&& rel
->r_offset
< offset
+ copy_size
) {
303 sym_name
= strtab
+ symtab
[ELF32_R_SYM(rel
->r_info
)].st_name
;
304 if (strstart(sym_name
, "__op_param", &p
)) {
305 snprintf(name
, sizeof(name
), "param%s", p
);
307 snprintf(name
, sizeof(name
), "(long)(&%s)", sym_name
);
309 type
= ELF32_R_TYPE(rel
->r_info
);
310 addend
= get32((uint32_t *)(text
+ rel
->r_offset
));
313 fprintf(outfile
, " *(uint32_t *)(gen_code_ptr + %ld) = %s + %ld;\n",
314 rel
->r_offset
- offset
, name
, addend
);
317 fprintf(outfile
, " *(uint32_t *)(gen_code_ptr + %ld) = %s - (long)(gen_code_ptr + %ld) + %ld;\n",
318 rel
->r_offset
- offset
, name
, rel
->r_offset
- offset
, addend
);
321 error("unsupported i386 relocation (%d)", type
);
328 error("unsupported CPU for relocations (%d)", e_machine
);
332 fprintf(outfile
, " gen_code_ptr += %d;\n", copy_size
);
333 fprintf(outfile
, "}\n\n");
336 /* load an elf object file */
337 int load_elf(const char *filename
, FILE *outfile
)
341 Elf32_Shdr
*sec
, *shdr
, *symtab_sec
, *strtab_sec
, *text_sec
;
343 Elf32_Sym
*symtab
, *sym
;
344 const char *cpu_name
;
345 char *shstr
, *strtab
;
348 int nb_relocs
, reloc_sh_type
;
350 fd
= open(filename
, O_RDONLY
);
352 error("can't open file '%s'", filename
);
354 /* Read ELF header. */
355 if (read(fd
, &ehdr
, sizeof (ehdr
)) != sizeof (ehdr
))
356 error("unable to read file header");
358 /* Check ELF identification. */
359 if (ehdr
.e_ident
[EI_MAG0
] != ELFMAG0
360 || ehdr
.e_ident
[EI_MAG1
] != ELFMAG1
361 || ehdr
.e_ident
[EI_MAG2
] != ELFMAG2
362 || ehdr
.e_ident
[EI_MAG3
] != ELFMAG3
363 || ehdr
.e_ident
[EI_CLASS
] != ELFCLASS32
364 || ehdr
.e_ident
[EI_VERSION
] != EV_CURRENT
) {
365 error("bad ELF header");
368 do_swap
= elf_must_swap(&ehdr
);
370 elf_swap_ehdr(&ehdr
);
371 if (ehdr
.e_type
!= ET_REL
)
372 error("ELF object file expected");
373 if (ehdr
.e_version
!= EV_CURRENT
)
374 error("Invalid ELF version");
375 e_machine
= ehdr
.e_machine
;
377 /* read section headers */
378 shdr
= load_data(fd
, ehdr
.e_shoff
, ehdr
.e_shnum
* sizeof(Elf32_Shdr
));
380 for(i
= 0; i
< ehdr
.e_shnum
; i
++) {
381 elf_swap_shdr(&shdr
[i
]);
385 sec
= &shdr
[ehdr
.e_shstrndx
];
386 shstr
= load_data(fd
, sec
->sh_offset
, sec
->sh_size
);
390 text_sec
= find_elf_section(shdr
, ehdr
.e_shnum
, shstr
, ".text");
392 error("could not find .text section");
393 text
= load_data(fd
, text_sec
->sh_offset
, text_sec
->sh_size
);
395 /* find text relocations, if any */
399 for(i
= 0; i
< ehdr
.e_shnum
; i
++) {
401 if ((sec
->sh_type
== SHT_REL
|| sec
->sh_type
== SHT_RELA
) &&
402 sec
->sh_info
== (text_sec
- shdr
)) {
403 reloc_sh_type
= sec
->sh_type
;
404 relocs
= load_data(fd
, sec
->sh_offset
, sec
->sh_size
);
405 nb_relocs
= sec
->sh_size
/ sec
->sh_entsize
;
407 if (sec
->sh_type
== SHT_REL
) {
408 Elf32_Rel
*rel
= relocs
;
409 for(j
= 0, rel
= relocs
; j
< nb_relocs
; j
++, rel
++) {
410 swab32s(&rel
->r_offset
);
411 swab32s(&rel
->r_info
);
414 Elf32_Rela
*rel
= relocs
;
415 for(j
= 0, rel
= relocs
; j
< nb_relocs
; j
++, rel
++) {
416 swab32s(&rel
->r_offset
);
417 swab32s(&rel
->r_info
);
418 swab32s(&rel
->r_addend
);
426 symtab_sec
= find_elf_section(shdr
, ehdr
.e_shnum
, shstr
, ".symtab");
428 error("could not find .symtab section");
429 strtab_sec
= &shdr
[symtab_sec
->sh_link
];
431 symtab
= load_data(fd
, symtab_sec
->sh_offset
, symtab_sec
->sh_size
);
432 strtab
= load_data(fd
, strtab_sec
->sh_offset
, strtab_sec
->sh_size
);
434 nb_syms
= symtab_sec
->sh_size
/ sizeof(Elf32_Sym
);
436 for(i
= 0, sym
= symtab
; i
< nb_syms
; i
++, sym
++) {
437 swab32s(&sym
->st_name
);
438 swab32s(&sym
->st_value
);
439 swab32s(&sym
->st_size
);
440 swab16s(&sym
->st_shndx
);
461 error("unsupported CPU (e_machine=%d)", e_machine
);
464 fprintf(outfile
, "#include \"gen-%s.h\"\n\n", cpu_name
);
466 for(i
= 0, sym
= symtab
; i
< nb_syms
; i
++, sym
++) {
468 name
= strtab
+ sym
->st_name
;
469 if (strstart(name
, "op_", NULL
) ||
470 strstart(name
, "op1_", NULL
) ||
471 strstart(name
, "op2_", NULL
) ||
472 strstart(name
, "op3_", NULL
)) {
474 printf("%4d: %s pos=0x%08x len=%d\n",
475 i
, name
, sym
->st_value
, sym
->st_size
);
477 if (sym
->st_shndx
!= (text_sec
- shdr
))
478 error("invalid section for opcode (0x%x)", sym
->st_shndx
);
479 gen_code(name
, sym
->st_value
, sym
->st_size
, outfile
,
480 text
, relocs
, nb_relocs
, reloc_sh_type
, symtab
, strtab
);
490 printf("dyngen (c) 2003 Fabrice Bellard\n"
491 "usage: dyngen [-o outfile] objfile\n"
492 "Generate a dynamic code generator from an object file\n");
496 int main(int argc
, char **argv
)
499 const char *filename
, *outfilename
;
502 outfilename
= "out.c";
504 c
= getopt(argc
, argv
, "ho:");
512 outfilename
= optarg
;
518 filename
= argv
[optind
];
519 outfile
= fopen(outfilename
, "w");
521 error("could not open '%s'", outfilename
);
522 load_elf(filename
, outfile
);