mirror of
https://github.com/xemu-project/xemu.git
synced 2024-11-24 03:59:52 +00:00
4b74fe1f00
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@19 c046a42c-6fe2-441c-8c8c-71466251a162
522 lines
15 KiB
C
522 lines
15 KiB
C
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <stdarg.h>
|
|
#include <inttypes.h>
|
|
#include <elf.h>
|
|
#include <unistd.h>
|
|
#include <fcntl.h>
|
|
|
|
#include "thunk.h"
|
|
|
|
/* all dynamically generated functions begin with this code */
|
|
#define OP_PREFIX "op"
|
|
|
|
int elf_must_swap(Elf32_Ehdr *h)
|
|
{
|
|
union {
|
|
uint32_t i;
|
|
uint8_t b[4];
|
|
} swaptest;
|
|
|
|
swaptest.i = 1;
|
|
return (h->e_ident[EI_DATA] == ELFDATA2MSB) !=
|
|
(swaptest.b[0] == 0);
|
|
}
|
|
|
|
void swab16s(uint16_t *p)
|
|
{
|
|
*p = bswap16(*p);
|
|
}
|
|
|
|
void swab32s(uint32_t *p)
|
|
{
|
|
*p = bswap32(*p);
|
|
}
|
|
|
|
void swab64s(uint32_t *p)
|
|
{
|
|
*p = bswap64(*p);
|
|
}
|
|
|
|
void elf_swap_ehdr(Elf32_Ehdr *h)
|
|
{
|
|
swab16s(&h->e_type); /* Object file type */
|
|
swab16s(&h-> e_machine); /* Architecture */
|
|
swab32s(&h-> e_version); /* Object file version */
|
|
swab32s(&h-> e_entry); /* Entry point virtual address */
|
|
swab32s(&h-> e_phoff); /* Program header table file offset */
|
|
swab32s(&h-> e_shoff); /* Section header table file offset */
|
|
swab32s(&h-> e_flags); /* Processor-specific flags */
|
|
swab16s(&h-> e_ehsize); /* ELF header size in bytes */
|
|
swab16s(&h-> e_phentsize); /* Program header table entry size */
|
|
swab16s(&h-> e_phnum); /* Program header table entry count */
|
|
swab16s(&h-> e_shentsize); /* Section header table entry size */
|
|
swab16s(&h-> e_shnum); /* Section header table entry count */
|
|
swab16s(&h-> e_shstrndx); /* Section header string table index */
|
|
}
|
|
|
|
void elf_swap_shdr(Elf32_Shdr *h)
|
|
{
|
|
swab32s(&h-> sh_name); /* Section name (string tbl index) */
|
|
swab32s(&h-> sh_type); /* Section type */
|
|
swab32s(&h-> sh_flags); /* Section flags */
|
|
swab32s(&h-> sh_addr); /* Section virtual addr at execution */
|
|
swab32s(&h-> sh_offset); /* Section file offset */
|
|
swab32s(&h-> sh_size); /* Section size in bytes */
|
|
swab32s(&h-> sh_link); /* Link to another section */
|
|
swab32s(&h-> sh_info); /* Additional section information */
|
|
swab32s(&h-> sh_addralign); /* Section alignment */
|
|
swab32s(&h-> sh_entsize); /* Entry size if section holds table */
|
|
}
|
|
|
|
void elf_swap_phdr(Elf32_Phdr *h)
|
|
{
|
|
swab32s(&h->p_type); /* Segment type */
|
|
swab32s(&h->p_offset); /* Segment file offset */
|
|
swab32s(&h->p_vaddr); /* Segment virtual address */
|
|
swab32s(&h->p_paddr); /* Segment physical address */
|
|
swab32s(&h->p_filesz); /* Segment size in file */
|
|
swab32s(&h->p_memsz); /* Segment size in memory */
|
|
swab32s(&h->p_flags); /* Segment flags */
|
|
swab32s(&h->p_align); /* Segment alignment */
|
|
}
|
|
|
|
int do_swap;
|
|
int e_machine;
|
|
|
|
uint16_t get16(uint16_t *p)
|
|
{
|
|
uint16_t val;
|
|
val = *p;
|
|
if (do_swap)
|
|
val = bswap16(val);
|
|
return val;
|
|
}
|
|
|
|
uint32_t get32(uint32_t *p)
|
|
{
|
|
uint32_t val;
|
|
val = *p;
|
|
if (do_swap)
|
|
val = bswap32(val);
|
|
return val;
|
|
}
|
|
|
|
void put16(uint16_t *p, uint16_t val)
|
|
{
|
|
if (do_swap)
|
|
val = bswap16(val);
|
|
*p = val;
|
|
}
|
|
|
|
void put32(uint32_t *p, uint32_t val)
|
|
{
|
|
if (do_swap)
|
|
val = bswap32(val);
|
|
*p = val;
|
|
}
|
|
|
|
void __attribute__((noreturn)) error(const char *fmt, ...)
|
|
{
|
|
va_list ap;
|
|
va_start(ap, fmt);
|
|
fprintf(stderr, "dyngen: ");
|
|
vfprintf(stderr, fmt, ap);
|
|
fprintf(stderr, "\n");
|
|
va_end(ap);
|
|
exit(1);
|
|
}
|
|
|
|
|
|
Elf32_Shdr *find_elf_section(Elf32_Shdr *shdr, int shnum, const char *shstr,
|
|
const char *name)
|
|
{
|
|
int i;
|
|
const char *shname;
|
|
Elf32_Shdr *sec;
|
|
|
|
for(i = 0; i < shnum; i++) {
|
|
sec = &shdr[i];
|
|
if (!sec->sh_name)
|
|
continue;
|
|
shname = shstr + sec->sh_name;
|
|
if (!strcmp(shname, name))
|
|
return sec;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
void *load_data(int fd, long offset, unsigned int size)
|
|
{
|
|
char *data;
|
|
|
|
data = malloc(size);
|
|
if (!data)
|
|
return NULL;
|
|
lseek(fd, offset, SEEK_SET);
|
|
if (read(fd, data, size) != size) {
|
|
free(data);
|
|
return NULL;
|
|
}
|
|
return data;
|
|
}
|
|
|
|
int strstart(const char *str, const char *val, const char **ptr)
|
|
{
|
|
const char *p, *q;
|
|
p = str;
|
|
q = val;
|
|
while (*q != '\0') {
|
|
if (*p != *q)
|
|
return 0;
|
|
p++;
|
|
q++;
|
|
}
|
|
if (ptr)
|
|
*ptr = p;
|
|
return 1;
|
|
}
|
|
|
|
#define MAX_ARGS 3
|
|
|
|
/* generate op code */
|
|
void gen_code(const char *name, unsigned long offset, unsigned long size,
|
|
FILE *outfile, uint8_t *text, void *relocs, int nb_relocs, int reloc_sh_type,
|
|
Elf32_Sym *symtab, char *strtab)
|
|
{
|
|
int copy_size = 0;
|
|
uint8_t *p_start, *p_end;
|
|
int nb_args, i;
|
|
uint8_t args_present[MAX_ARGS];
|
|
const char *sym_name, *p;
|
|
|
|
/* compute exact size excluding return instruction */
|
|
p_start = text + offset;
|
|
p_end = p_start + size;
|
|
switch(e_machine) {
|
|
case EM_386:
|
|
{
|
|
uint8_t *p;
|
|
p = p_end - 1;
|
|
if (p == p_start)
|
|
error("empty code for %s", name);
|
|
if (p[0] != 0xc3)
|
|
error("ret expected at the end of %s", name);
|
|
copy_size = p - p_start;
|
|
}
|
|
break;
|
|
case EM_PPC:
|
|
{
|
|
uint8_t *p;
|
|
p = (void *)(p_end - 4);
|
|
/* find ret */
|
|
while (p > p_start && get32((uint32_t *)p) != 0x4e800020)
|
|
p -= 4;
|
|
/* skip double ret */
|
|
if (p > p_start && get32((uint32_t *)(p - 4)) == 0x4e800020)
|
|
p -= 4;
|
|
if (p == p_start)
|
|
error("empty code for %s", name);
|
|
copy_size = p - p_start;
|
|
}
|
|
break;
|
|
default:
|
|
error("unsupported CPU (%d)", e_machine);
|
|
}
|
|
|
|
/* compute the number of arguments by looking at the relocations */
|
|
for(i = 0;i < MAX_ARGS; i++)
|
|
args_present[i] = 0;
|
|
|
|
if (reloc_sh_type == SHT_REL) {
|
|
Elf32_Rel *rel;
|
|
int n;
|
|
for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
|
|
if (rel->r_offset >= offset && rel->r_offset < offset + copy_size) {
|
|
sym_name = strtab + symtab[ELF32_R_SYM(rel->r_info)].st_name;
|
|
if (strstart(sym_name, "__op_param", &p)) {
|
|
n = strtoul(p, NULL, 10);
|
|
if (n >= MAX_ARGS)
|
|
error("too many arguments in %s", name);
|
|
args_present[n - 1] = 1;
|
|
} else {
|
|
fprintf(outfile, "extern char %s;\n", sym_name);
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
Elf32_Rela *rel;
|
|
int n;
|
|
for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
|
|
if (rel->r_offset >= offset && rel->r_offset < offset + copy_size) {
|
|
sym_name = strtab + symtab[ELF32_R_SYM(rel->r_info)].st_name;
|
|
if (strstart(sym_name, "__op_param", &p)) {
|
|
n = strtoul(p, NULL, 10);
|
|
if (n >= MAX_ARGS)
|
|
error("too many arguments in %s", name);
|
|
args_present[n - 1] = 1;
|
|
} else {
|
|
fprintf(outfile, "extern char %s;\n", sym_name);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
nb_args = 0;
|
|
while (nb_args < MAX_ARGS && args_present[nb_args])
|
|
nb_args++;
|
|
for(i = nb_args; i < MAX_ARGS; i++) {
|
|
if (args_present[i])
|
|
error("inconsistent argument numbering in %s", name);
|
|
}
|
|
|
|
/* output C code */
|
|
fprintf(outfile, "extern void %s();\n", name);
|
|
fprintf(outfile, "static inline void gen_%s(", name);
|
|
if (nb_args == 0) {
|
|
fprintf(outfile, "void");
|
|
} else {
|
|
for(i = 0; i < nb_args; i++) {
|
|
if (i != 0)
|
|
fprintf(outfile, ", ");
|
|
fprintf(outfile, "long param%d", i + 1);
|
|
}
|
|
}
|
|
fprintf(outfile, ")\n");
|
|
fprintf(outfile, "{\n");
|
|
fprintf(outfile, " memcpy(gen_code_ptr, &%s, %d);\n", name, copy_size);
|
|
|
|
/* patch relocations */
|
|
switch(e_machine) {
|
|
case EM_386:
|
|
{
|
|
Elf32_Rel *rel;
|
|
char name[256];
|
|
int type;
|
|
long addend;
|
|
for(i = 0, rel = relocs;i < nb_relocs; i++, rel++) {
|
|
if (rel->r_offset >= offset && rel->r_offset < offset + copy_size) {
|
|
sym_name = strtab + symtab[ELF32_R_SYM(rel->r_info)].st_name;
|
|
if (strstart(sym_name, "__op_param", &p)) {
|
|
snprintf(name, sizeof(name), "param%s", p);
|
|
} else {
|
|
snprintf(name, sizeof(name), "(long)(&%s)", sym_name);
|
|
}
|
|
type = ELF32_R_TYPE(rel->r_info);
|
|
addend = get32((uint32_t *)(text + rel->r_offset));
|
|
switch(type) {
|
|
case R_386_32:
|
|
fprintf(outfile, " *(uint32_t *)(gen_code_ptr + %ld) = %s + %ld;\n",
|
|
rel->r_offset - offset, name, addend);
|
|
break;
|
|
case R_386_PC32:
|
|
fprintf(outfile, " *(uint32_t *)(gen_code_ptr + %ld) = %s - (long)(gen_code_ptr + %ld) + %ld;\n",
|
|
rel->r_offset - offset, name, rel->r_offset - offset, addend);
|
|
break;
|
|
default:
|
|
error("unsupported i386 relocation (%d)", type);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
default:
|
|
error("unsupported CPU for relocations (%d)", e_machine);
|
|
}
|
|
|
|
|
|
fprintf(outfile, " gen_code_ptr += %d;\n", copy_size);
|
|
fprintf(outfile, "}\n\n");
|
|
}
|
|
|
|
/* load an elf object file */
|
|
int load_elf(const char *filename, FILE *outfile)
|
|
{
|
|
int fd;
|
|
Elf32_Ehdr ehdr;
|
|
Elf32_Shdr *sec, *shdr, *symtab_sec, *strtab_sec, *text_sec;
|
|
int i, j, nb_syms;
|
|
Elf32_Sym *symtab, *sym;
|
|
const char *cpu_name;
|
|
char *shstr, *strtab;
|
|
uint8_t *text;
|
|
void *relocs;
|
|
int nb_relocs, reloc_sh_type;
|
|
|
|
fd = open(filename, O_RDONLY);
|
|
if (fd < 0)
|
|
error("can't open file '%s'", filename);
|
|
|
|
/* Read ELF header. */
|
|
if (read(fd, &ehdr, sizeof (ehdr)) != sizeof (ehdr))
|
|
error("unable to read file header");
|
|
|
|
/* Check ELF identification. */
|
|
if (ehdr.e_ident[EI_MAG0] != ELFMAG0
|
|
|| ehdr.e_ident[EI_MAG1] != ELFMAG1
|
|
|| ehdr.e_ident[EI_MAG2] != ELFMAG2
|
|
|| ehdr.e_ident[EI_MAG3] != ELFMAG3
|
|
|| ehdr.e_ident[EI_CLASS] != ELFCLASS32
|
|
|| ehdr.e_ident[EI_VERSION] != EV_CURRENT) {
|
|
error("bad ELF header");
|
|
}
|
|
|
|
do_swap = elf_must_swap(&ehdr);
|
|
if (do_swap)
|
|
elf_swap_ehdr(&ehdr);
|
|
if (ehdr.e_type != ET_REL)
|
|
error("ELF object file expected");
|
|
if (ehdr.e_version != EV_CURRENT)
|
|
error("Invalid ELF version");
|
|
e_machine = ehdr.e_machine;
|
|
|
|
/* read section headers */
|
|
shdr = load_data(fd, ehdr.e_shoff, ehdr.e_shnum * sizeof(Elf32_Shdr));
|
|
if (do_swap) {
|
|
for(i = 0; i < ehdr.e_shnum; i++) {
|
|
elf_swap_shdr(&shdr[i]);
|
|
}
|
|
}
|
|
|
|
sec = &shdr[ehdr.e_shstrndx];
|
|
shstr = load_data(fd, sec->sh_offset, sec->sh_size);
|
|
|
|
/* text section */
|
|
|
|
text_sec = find_elf_section(shdr, ehdr.e_shnum, shstr, ".text");
|
|
if (!text_sec)
|
|
error("could not find .text section");
|
|
text = load_data(fd, text_sec->sh_offset, text_sec->sh_size);
|
|
|
|
/* find text relocations, if any */
|
|
nb_relocs = 0;
|
|
relocs = NULL;
|
|
reloc_sh_type = 0;
|
|
for(i = 0; i < ehdr.e_shnum; i++) {
|
|
sec = &shdr[i];
|
|
if ((sec->sh_type == SHT_REL || sec->sh_type == SHT_RELA) &&
|
|
sec->sh_info == (text_sec - shdr)) {
|
|
reloc_sh_type = sec->sh_type;
|
|
relocs = load_data(fd, sec->sh_offset, sec->sh_size);
|
|
nb_relocs = sec->sh_size / sec->sh_entsize;
|
|
if (do_swap) {
|
|
if (sec->sh_type == SHT_REL) {
|
|
Elf32_Rel *rel = relocs;
|
|
for(j = 0, rel = relocs; j < nb_relocs; j++, rel++) {
|
|
swab32s(&rel->r_offset);
|
|
swab32s(&rel->r_info);
|
|
}
|
|
} else {
|
|
Elf32_Rela *rel = relocs;
|
|
for(j = 0, rel = relocs; j < nb_relocs; j++, rel++) {
|
|
swab32s(&rel->r_offset);
|
|
swab32s(&rel->r_info);
|
|
swab32s(&rel->r_addend);
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
symtab_sec = find_elf_section(shdr, ehdr.e_shnum, shstr, ".symtab");
|
|
if (!symtab_sec)
|
|
error("could not find .symtab section");
|
|
strtab_sec = &shdr[symtab_sec->sh_link];
|
|
|
|
symtab = load_data(fd, symtab_sec->sh_offset, symtab_sec->sh_size);
|
|
strtab = load_data(fd, strtab_sec->sh_offset, strtab_sec->sh_size);
|
|
|
|
nb_syms = symtab_sec->sh_size / sizeof(Elf32_Sym);
|
|
if (do_swap) {
|
|
for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
|
|
swab32s(&sym->st_name);
|
|
swab32s(&sym->st_value);
|
|
swab32s(&sym->st_size);
|
|
swab16s(&sym->st_shndx);
|
|
}
|
|
}
|
|
|
|
switch(e_machine) {
|
|
case EM_386:
|
|
cpu_name = "i386";
|
|
break;
|
|
case EM_PPC:
|
|
cpu_name = "ppc";
|
|
break;
|
|
case EM_MIPS:
|
|
cpu_name = "mips";
|
|
break;
|
|
case EM_ARM:
|
|
cpu_name = "arm";
|
|
break;
|
|
case EM_SPARC:
|
|
cpu_name = "sparc";
|
|
break;
|
|
default:
|
|
error("unsupported CPU (e_machine=%d)", e_machine);
|
|
}
|
|
|
|
fprintf(outfile, "#include \"gen-%s.h\"\n\n", cpu_name);
|
|
|
|
for(i = 0, sym = symtab; i < nb_syms; i++, sym++) {
|
|
const char *name;
|
|
name = strtab + sym->st_name;
|
|
if (strstart(name, "op_", NULL) ||
|
|
strstart(name, "op1_", NULL) ||
|
|
strstart(name, "op2_", NULL) ||
|
|
strstart(name, "op3_", NULL)) {
|
|
#if 0
|
|
printf("%4d: %s pos=0x%08x len=%d\n",
|
|
i, name, sym->st_value, sym->st_size);
|
|
#endif
|
|
if (sym->st_shndx != (text_sec - shdr))
|
|
error("invalid section for opcode (0x%x)", sym->st_shndx);
|
|
gen_code(name, sym->st_value, sym->st_size, outfile,
|
|
text, relocs, nb_relocs, reloc_sh_type, symtab, strtab);
|
|
}
|
|
}
|
|
|
|
close(fd);
|
|
return 0;
|
|
}
|
|
|
|
void usage(void)
|
|
{
|
|
printf("dyngen (c) 2003 Fabrice Bellard\n"
|
|
"usage: dyngen [-o outfile] objfile\n"
|
|
"Generate a dynamic code generator from an object file\n");
|
|
exit(1);
|
|
}
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
int c;
|
|
const char *filename, *outfilename;
|
|
FILE *outfile;
|
|
|
|
outfilename = "out.c";
|
|
for(;;) {
|
|
c = getopt(argc, argv, "ho:");
|
|
if (c == -1)
|
|
break;
|
|
switch(c) {
|
|
case 'h':
|
|
usage();
|
|
break;
|
|
case 'o':
|
|
outfilename = optarg;
|
|
break;
|
|
}
|
|
}
|
|
if (optind >= argc)
|
|
usage();
|
|
filename = argv[optind];
|
|
outfile = fopen(outfilename, "w");
|
|
if (!outfile)
|
|
error("could not open '%s'", outfilename);
|
|
load_elf(filename, outfile);
|
|
fclose(outfile);
|
|
return 0;
|
|
}
|