1 2 #include <linux/kernel.h> 3 #include <linux/fs.h> 4 #include <linux/minix_fs.h> 5 #include <linux/ext2_fs.h> 6 #include <linux/romfs_fs.h> 7 #include <linux/cramfs_fs.h> 8 #include <linux/initrd.h> 9 #include <linux/string.h> 10 #include <linux/slab.h> 11 12 #include "do_mounts.h" 13 #include "../fs/squashfs/squashfs_fs.h" 14 15 #include <linux/decompress/generic.h> 16 17 18 int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */ 19 20 static int __init prompt_ramdisk(char *str) 21 { 22 rd_prompt = simple_strtol(str,NULL,0) & 1; 23 return 1; 24 } 25 __setup("prompt_ramdisk=", prompt_ramdisk); 26 27 int __initdata rd_image_start; /* starting block # of image */ 28 29 static int __init ramdisk_start_setup(char *str) 30 { 31 rd_image_start = simple_strtol(str,NULL,0); 32 return 1; 33 } 34 __setup("ramdisk_start=", ramdisk_start_setup); 35 36 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco); 37 38 /* 39 * This routine tries to find a RAM disk image to load, and returns the 40 * number of blocks to read for a non-compressed image, 0 if the image 41 * is a compressed image, and -1 if an image with the right magic 42 * numbers could not be found. 43 * 44 * We currently check for the following magic numbers: 45 * minix 46 * ext2 47 * romfs 48 * cramfs 49 * squashfs 50 * gzip 51 */ 52 static int __init 53 identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) 54 { 55 const int size = 512; 56 struct minix_super_block *minixsb; 57 struct romfs_super_block *romfsb; 58 struct cramfs_super *cramfsb; 59 struct squashfs_super_block *squashfsb; 60 int nblocks = -1; 61 unsigned char *buf; 62 const char *compress_name; 63 unsigned long n; 64 65 buf = kmalloc(size, GFP_KERNEL); 66 if (!buf) 67 return -ENOMEM; 68 69 minixsb = (struct minix_super_block *) buf; 70 romfsb = (struct romfs_super_block *) buf; 71 cramfsb = (struct cramfs_super *) buf; 72 squashfsb = (struct squashfs_super_block *) buf; 73 memset(buf, 0xe5, size); 74 75 /* 76 * Read block 0 to test for compressed kernel 77 */ 78 sys_lseek(fd, start_block * BLOCK_SIZE, 0); 79 sys_read(fd, buf, size); 80 81 *decompressor = decompress_method(buf, size, &compress_name); 82 if (compress_name) { 83 printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n", 84 compress_name, start_block); 85 if (!*decompressor) 86 printk(KERN_EMERG 87 "RAMDISK: %s decompressor not configured!\n", 88 compress_name); 89 nblocks = 0; 90 goto done; 91 } 92 93 /* romfs is at block zero too */ 94 if (romfsb->word0 == ROMSB_WORD0 && 95 romfsb->word1 == ROMSB_WORD1) { 96 printk(KERN_NOTICE 97 "RAMDISK: romfs filesystem found at block %d\n", 98 start_block); 99 nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS; 100 goto done; 101 } 102 103 if (cramfsb->magic == CRAMFS_MAGIC) { 104 printk(KERN_NOTICE 105 "RAMDISK: cramfs filesystem found at block %d\n", 106 start_block); 107 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; 108 goto done; 109 } 110 111 /* squashfs is at block zero too */ 112 if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) { 113 printk(KERN_NOTICE 114 "RAMDISK: squashfs filesystem found at block %d\n", 115 start_block); 116 nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1) 117 >> BLOCK_SIZE_BITS; 118 goto done; 119 } 120 121 /* 122 * Read 512 bytes further to check if cramfs is padded 123 */ 124 sys_lseek(fd, start_block * BLOCK_SIZE + 0x200, 0); 125 sys_read(fd, buf, size); 126 127 if (cramfsb->magic == CRAMFS_MAGIC) { 128 printk(KERN_NOTICE 129 "RAMDISK: cramfs filesystem found at block %d\n", 130 start_block); 131 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; 132 goto done; 133 } 134 135 /* 136 * Read block 1 to test for minix and ext2 superblock 137 */ 138 sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0); 139 sys_read(fd, buf, size); 140 141 /* Try minix */ 142 if (minixsb->s_magic == MINIX_SUPER_MAGIC || 143 minixsb->s_magic == MINIX_SUPER_MAGIC2) { 144 printk(KERN_NOTICE 145 "RAMDISK: Minix filesystem found at block %d\n", 146 start_block); 147 nblocks = minixsb->s_nzones << minixsb->s_log_zone_size; 148 goto done; 149 } 150 151 /* Try ext2 */ 152 n = ext2_image_size(buf); 153 if (n) { 154 printk(KERN_NOTICE 155 "RAMDISK: ext2 filesystem found at block %d\n", 156 start_block); 157 nblocks = n; 158 goto done; 159 } 160 161 printk(KERN_NOTICE 162 "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n", 163 start_block); 164 165 done: 166 sys_lseek(fd, start_block * BLOCK_SIZE, 0); 167 kfree(buf); 168 return nblocks; 169 } 170 171 int __init rd_load_image(char *from) 172 { 173 int res = 0; 174 int in_fd, out_fd; 175 unsigned long rd_blocks, devblocks; 176 int nblocks, i, disk; 177 char *buf = NULL; 178 unsigned short rotate = 0; 179 decompress_fn decompressor = NULL; 180 #if !defined(CONFIG_S390) 181 char rotator[4] = { '|' , '/' , '-' , '\\' }; 182 #endif 183 184 out_fd = sys_open((const char __user __force *) "/dev/ram", O_RDWR, 0); 185 if (out_fd < 0) 186 goto out; 187 188 in_fd = sys_open(from, O_RDONLY, 0); 189 if (in_fd < 0) 190 goto noclose_input; 191 192 nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor); 193 if (nblocks < 0) 194 goto done; 195 196 if (nblocks == 0) { 197 if (crd_load(in_fd, out_fd, decompressor) == 0) 198 goto successful_load; 199 goto done; 200 } 201 202 /* 203 * NOTE NOTE: nblocks is not actually blocks but 204 * the number of kibibytes of data to load into a ramdisk. 205 * So any ramdisk block size that is a multiple of 1KiB should 206 * work when the appropriate ramdisk_blocksize is specified 207 * on the command line. 208 * 209 * The default ramdisk_blocksize is 1KiB and it is generally 210 * silly to use anything else, so make sure to use 1KiB 211 * blocksize while generating ext2fs ramdisk-images. 212 */ 213 if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) 214 rd_blocks = 0; 215 else 216 rd_blocks >>= 1; 217 218 if (nblocks > rd_blocks) { 219 printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n", 220 nblocks, rd_blocks); 221 goto done; 222 } 223 224 /* 225 * OK, time to copy in the data 226 */ 227 if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) 228 devblocks = 0; 229 else 230 devblocks >>= 1; 231 232 if (strcmp(from, "/initrd.image") == 0) 233 devblocks = nblocks; 234 235 if (devblocks == 0) { 236 printk(KERN_ERR "RAMDISK: could not determine device size\n"); 237 goto done; 238 } 239 240 buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); 241 if (!buf) { 242 printk(KERN_ERR "RAMDISK: could not allocate buffer\n"); 243 goto done; 244 } 245 246 printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ", 247 nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : ""); 248 for (i = 0, disk = 1; i < nblocks; i++) { 249 if (i && (i % devblocks == 0)) { 250 printk("done disk #%d.\n", disk++); 251 rotate = 0; 252 if (sys_close(in_fd)) { 253 printk("Error closing the disk.\n"); 254 goto noclose_input; 255 } 256 change_floppy("disk #%d", disk); 257 in_fd = sys_open(from, O_RDONLY, 0); 258 if (in_fd < 0) { 259 printk("Error opening disk.\n"); 260 goto noclose_input; 261 } 262 printk("Loading disk #%d... ", disk); 263 } 264 sys_read(in_fd, buf, BLOCK_SIZE); 265 sys_write(out_fd, buf, BLOCK_SIZE); 266 #if !defined(CONFIG_S390) 267 if (!(i % 16)) { 268 printk("%c\b", rotator[rotate & 0x3]); 269 rotate++; 270 } 271 #endif 272 } 273 printk("done.\n"); 274 275 successful_load: 276 res = 1; 277 done: 278 sys_close(in_fd); 279 noclose_input: 280 sys_close(out_fd); 281 out: 282 kfree(buf); 283 sys_unlink((const char __user __force *) "/dev/ram"); 284 return res; 285 } 286 287 int __init rd_load_disk(int n) 288 { 289 if (rd_prompt) 290 change_floppy("root floppy disk to be loaded into RAM disk"); 291 create_dev("/dev/root", ROOT_DEV); 292 create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n)); 293 return rd_load_image("/dev/root"); 294 } 295 296 static int exit_code; 297 static int decompress_error; 298 static int crd_infd, crd_outfd; 299 300 static int __init compr_fill(void *buf, unsigned int len) 301 { 302 int r = sys_read(crd_infd, buf, len); 303 if (r < 0) 304 printk(KERN_ERR "RAMDISK: error while reading compressed data"); 305 else if (r == 0) 306 printk(KERN_ERR "RAMDISK: EOF while reading compressed data"); 307 return r; 308 } 309 310 static int __init compr_flush(void *window, unsigned int outcnt) 311 { 312 int written = sys_write(crd_outfd, window, outcnt); 313 if (written != outcnt) { 314 if (decompress_error == 0) 315 printk(KERN_ERR 316 "RAMDISK: incomplete write (%d != %d)\n", 317 written, outcnt); 318 decompress_error = 1; 319 return -1; 320 } 321 return outcnt; 322 } 323 324 static void __init error(char *x) 325 { 326 printk(KERN_ERR "%s\n", x); 327 exit_code = 1; 328 decompress_error = 1; 329 } 330 331 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco) 332 { 333 int result; 334 crd_infd = in_fd; 335 crd_outfd = out_fd; 336 result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error); 337 if (decompress_error) 338 result = 1; 339 return result; 340 } 341