loader.c

   1 /*
   2  * QEMU Executable loader
   3  *
   4  * Copyright (c) 2006 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "vl.h"
  25 #include "disas.h"
  26
  27 /* return the size or -1 if error */
  28 int get_image_size(const char *filename)
  29 {
  30     int fd, size;
  31     fd = open(filename, O_RDONLY | O_BINARY);
  32     if (fd < 0)
  33         return -1;
  34     size = lseek(fd, 0, SEEK_END);
  35     close(fd);
  36     return size;
  37 }
  38
  39 /* return the size or -1 if error */
  40 int load_image(const char *filename, uint8_t *addr)
  41 {
  42     int fd, size;
  43     fd = open(filename, O_RDONLY | O_BINARY);
  44     if (fd < 0)
  45         return -1;
  46     size = lseek(fd, 0, SEEK_END);
  47     lseek(fd, 0, SEEK_SET);
  48     if (read(fd, addr, size) != size) {
  49         close(fd);
  50         return -1;
  51     }
  52     close(fd);
  53     return size;
  54 }
  55
  56 /* A.OUT loader */
  57
  58 struct exec
  59 {
  60   uint32_t a_info;   /* Use macros N_MAGIC, etc for access */
  61   uint32_t a_text;   /* length of text, in bytes */
  62   uint32_t a_data;   /* length of data, in bytes */
  63   uint32_t a_bss;    /* length of uninitialized data area, in bytes */
  64   uint32_t a_syms;   /* length of symbol table data in file, in bytes */
  65   uint32_t a_entry;  /* start address */
  66   uint32_t a_trsize; /* length of relocation info for text, in bytes */
  67   uint32_t a_drsize; /* length of relocation info for data, in bytes */
  68 };
  69
  70 #ifdef BSWAP_NEEDED
  71 static void bswap_ahdr(struct exec *e)
  72 {
  73     bswap32s(&e->a_info);
  74     bswap32s(&e->a_text);
  75     bswap32s(&e->a_data);
  76     bswap32s(&e->a_bss);
  77     bswap32s(&e->a_syms);
  78     bswap32s(&e->a_entry);
  79     bswap32s(&e->a_trsize);
  80     bswap32s(&e->a_drsize);
  81 }
  82 #else
  83 #define bswap_ahdr(x) do { } while (0)
  84 #endif
  85
  86 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
  87 #define OMAGIC 0407
  88 #define NMAGIC 0410
  89 #define ZMAGIC 0413
  90 #define QMAGIC 0314
  91 #define _N_HDROFF(x) (1024 - sizeof (struct exec))
  92 #define N_TXTOFF(x)                                                     \
  93     (N_MAGIC(x) == ZMAGIC ? _N_HDROFF((x)) + sizeof (struct exec) :     \
  94      (N_MAGIC(x) == QMAGIC ? 0 : sizeof (struct exec)))
  95 #define N_TXTADDR(x) (N_MAGIC(x) == QMAGIC ? TARGET_PAGE_SIZE : 0)
  96 #define N_DATOFF(x) (N_TXTOFF(x) + (x).a_text)
  97 #define _N_SEGMENT_ROUND(x) (((x) + TARGET_PAGE_SIZE - 1) & ~(TARGET_PAGE_SIZE - 1))
  98
  99 #define _N_TXTENDADDR(x) (N_TXTADDR(x)+(x).a_text)
 100
 101 #define N_DATADDR(x) \
 102     (N_MAGIC(x)==OMAGIC? (_N_TXTENDADDR(x)) \
 103      : (_N_SEGMENT_ROUND (_N_TXTENDADDR(x))))
 104
 105
 106 int load_aout(const char *filename, uint8_t *addr)
 107 {
 108     int fd, size, ret;
 109     struct exec e;
 110     uint32_t magic;
 111
 112     fd = open(filename, O_RDONLY | O_BINARY);
 113     if (fd < 0)
 114         return -1;
 115
 116     size = read(fd, &e, sizeof(e));
 117     if (size < 0)
 118         goto fail;
 119
 120     bswap_ahdr(&e);
 121
 122     magic = N_MAGIC(e);
 123     switch (magic) {
 124     case ZMAGIC:
 125     case QMAGIC:
 126     case OMAGIC:
 127         lseek(fd, N_TXTOFF(e), SEEK_SET);
 128         size = read(fd, addr, e.a_text + e.a_data);
 129         if (size < 0)
 130             goto fail;
 131         break;
 132     case NMAGIC:
 133         lseek(fd, N_TXTOFF(e), SEEK_SET);
 134         size = read(fd, addr, e.a_text);
 135         if (size < 0)
 136             goto fail;
 137         ret = read(fd, addr + N_DATADDR(e), e.a_data);
 138         if (ret < 0)
 139             goto fail;
 140         size += ret;
 141         break;
 142     default:
 143         goto fail;
 144     }
 145     close(fd);
 146     return size;
 147  fail:
 148     close(fd);
 149     return -1;
 150 }
 151
 152 /* ELF loader */
 153
 154 static void *load_at(int fd, int offset, int size)
 155 {
 156     void *ptr;
 157     if (lseek(fd, offset, SEEK_SET) < 0)
 158         return NULL;
 159     ptr = qemu_malloc(size);
 160     if (!ptr)
 161         return NULL;
 162     if (read(fd, ptr, size) != size) {
 163         qemu_free(ptr);
 164         return NULL;
 165     }
 166     return ptr;
 167 }
 168
 169
 170 #define ELF_CLASS   ELFCLASS32
 171 #include "elf.h"
 172
 173 #define SZ              32
 174 #define elf_word        uint32_t
 175 #define bswapSZs        bswap32s
 176 #include "elf_ops.h"
 177
 178 #undef elfhdr
 179 #undef elf_phdr
 180 #undef elf_shdr
 181 #undef elf_sym
 182 #undef elf_note
 183 #undef elf_word
 184 #undef bswapSZs
 185 #undef SZ
 186 #define elfhdr          elf64_hdr
 187 #define elf_phdr        elf64_phdr
 188 #define elf_note        elf64_note
 189 #define elf_shdr        elf64_shdr
 190 #define elf_sym         elf64_sym
 191 #define elf_word        uint64_t
 192 #define bswapSZs        bswap64s
 193 #define SZ              64
 194 #include "elf_ops.h"
 195
 196 /* return < 0 if error, otherwise the number of bytes loaded in memory */
 197 int load_elf(const char *filename, int64_t virt_to_phys_addend,
 198              uint64_t *pentry)
 199 {
 200     int fd, data_order, must_swab, ret;
 201     uint8_t e_ident[EI_NIDENT];
 202
 203     fd = open(filename, O_RDONLY | O_BINARY);
 204     if (fd < 0) {
 205         perror(filename);
 206         return -1;
 207     }
 208     if (read(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))
 209         goto fail;
 210     if (e_ident[0] != ELFMAG0 ||
 211         e_ident[1] != ELFMAG1 ||
 212         e_ident[2] != ELFMAG2 ||
 213         e_ident[3] != ELFMAG3)
 214         goto fail;
 215 #ifdef WORDS_BIGENDIAN
 216     data_order = ELFDATA2MSB;
 217 #else
 218     data_order = ELFDATA2LSB;
 219 #endif
 220     must_swab = data_order != e_ident[EI_DATA];
 221
 222     lseek(fd, 0, SEEK_SET);
 223     if (e_ident[EI_CLASS] == ELFCLASS64) {
 224         ret = load_elf64(fd, virt_to_phys_addend, must_swab, pentry);
 225     } else {
 226         ret = load_elf32(fd, virt_to_phys_addend, must_swab, pentry);
 227     }
 228
 229     close(fd);
 230     return ret;
 231
 232  fail:
 233     close(fd);
 234     return -1;
 235 }