new x86 CPU core

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@14 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 521 insertions, 0 deletions

diff --git a/dyngen.c b/dyngen.c
new file mode 100644
index 0000000..ff10891
--- /dev/null
+++ b/dyngen.c
@@ -0,0 +1,521 @@
+#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;
+            /* find ret */
+            while (p > p_start && *p != 0xc3)
+                p--;
+            /* skip double ret */
+            if (p > p_start && p[-1] == 0xc3)
+                p--;
+            if (p == p_start)
+                error("empty code for %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 {
+        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;
+                }
+            }
+        }
+    }
+    
+    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;
+}