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 ext2_super_block *ext2sb; 58 struct romfs_super_block *romfsb; 59 struct cramfs_super *cramfsb; 60 struct squashfs_super_block *squashfsb; 61 int nblocks = -1; 62 unsigned char *buf; 63 const char *compress_name; 64 65 buf = kmalloc(size, GFP_KERNEL); 66 if (!buf) 67 return -ENOMEM; 68 69 minixsb = (struct minix_super_block *) buf; 70 ext2sb = (struct ext2_super_block *) buf; 71 romfsb = (struct romfs_super_block *) buf; 72 cramfsb = (struct cramfs_super *) buf; 73 squashfsb = (struct squashfs_super_block *) buf; 74 memset(buf, 0xe5, size); 75 76 /* 77 * Read block 0 to test for compressed kernel 78 */ 79 sys_lseek(fd, start_block * BLOCK_SIZE, 0); 80 sys_read(fd, buf, size); 81 82 *decompressor = decompress_method(buf, size, &compress_name); 83 if (compress_name) { 84 printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n", 85 compress_name, start_block); 86 if (!*decompressor) 87 printk(KERN_EMERG 88 "RAMDISK: %s decompressor not configured!\n", 89 compress_name); 90 nblocks = 0; 91 goto done; 92 } 93 94 /* romfs is at block zero too */ 95 if (romfsb->word0 == ROMSB_WORD0 && 96 romfsb->word1 == ROMSB_WORD1) { 97 printk(KERN_NOTICE 98 "RAMDISK: romfs filesystem found at block %d\n", 99 start_block); 100 nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS; 101 goto done; 102 } 103 104 if (cramfsb->magic == CRAMFS_MAGIC) { 105 printk(KERN_NOTICE 106 "RAMDISK: cramfs filesystem found at block %d\n", 107 start_block); 108 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; 109 goto done; 110 } 111 112 /* squashfs is at block zero too */ 113 if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) { 114 printk(KERN_NOTICE 115 "RAMDISK: squashfs filesystem found at block %d\n", 116 start_block); 117 nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1) 118 >> BLOCK_SIZE_BITS; 119 goto done; 120 } 121 122 /* 123 * Read 512 bytes further to check if cramfs is padded 124 */ 125 sys_lseek(fd, start_block * BLOCK_SIZE + 0x200, 0); 126 sys_read(fd, buf, size); 127 128 if (cramfsb->magic == CRAMFS_MAGIC) { 129 printk(KERN_NOTICE 130 "RAMDISK: cramfs filesystem found at block %d\n", 131 start_block); 132 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; 133 goto done; 134 } 135 136 /* 137 * Read block 1 to test for minix and ext2 superblock 138 */ 139 sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0); 140 sys_read(fd, buf, size); 141 142 /* Try minix */ 143 if (minixsb->s_magic == MINIX_SUPER_MAGIC || 144 minixsb->s_magic == MINIX_SUPER_MAGIC2) { 145 printk(KERN_NOTICE 146 "RAMDISK: Minix filesystem found at block %d\n", 147 start_block); 148 nblocks = minixsb->s_nzones << minixsb->s_log_zone_size; 149 goto done; 150 } 151 152 /* Try ext2 */ 153 if (ext2sb->s_magic == cpu_to_le16(EXT2_SUPER_MAGIC)) { 154 printk(KERN_NOTICE 155 "RAMDISK: ext2 filesystem found at block %d\n", 156 start_block); 157 nblocks = le32_to_cpu(ext2sb->s_blocks_count) << 158 le32_to_cpu(ext2sb->s_log_block_size); 159 goto done; 160 } 161 162 printk(KERN_NOTICE 163 "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n", 164 start_block); 165 166 done: 167 sys_lseek(fd, start_block * BLOCK_SIZE, 0); 168 kfree(buf); 169 return nblocks; 170 } 171 172 int __init rd_load_image(char *from) 173 { 174 int res = 0; 175 int in_fd, out_fd; 176 unsigned long rd_blocks, devblocks; 177 int nblocks, i, disk; 178 char *buf = NULL; 179 unsigned short rotate = 0; 180 decompress_fn decompressor = NULL; 181 #if !defined(CONFIG_S390) && !defined(CONFIG_PPC_ISERIES) 182 char rotator[4] = { '|' , '/' , '-' , '\\' }; 183 #endif 184 185 out_fd = sys_open((const char __user __force *) "/dev/ram", O_RDWR, 0); 186 if (out_fd < 0) 187 goto out; 188 189 in_fd = sys_open(from, O_RDONLY, 0); 190 if (in_fd < 0) 191 goto noclose_input; 192 193 nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor); 194 if (nblocks < 0) 195 goto done; 196 197 if (nblocks == 0) { 198 if (crd_load(in_fd, out_fd, decompressor) == 0) 199 goto successful_load; 200 goto done; 201 } 202 203 /* 204 * NOTE NOTE: nblocks is not actually blocks but 205 * the number of kibibytes of data to load into a ramdisk. 206 * So any ramdisk block size that is a multiple of 1KiB should 207 * work when the appropriate ramdisk_blocksize is specified 208 * on the command line. 209 * 210 * The default ramdisk_blocksize is 1KiB and it is generally 211 * silly to use anything else, so make sure to use 1KiB 212 * blocksize while generating ext2fs ramdisk-images. 213 */ 214 if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) 215 rd_blocks = 0; 216 else 217 rd_blocks >>= 1; 218 219 if (nblocks > rd_blocks) { 220 printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n", 221 nblocks, rd_blocks); 222 goto done; 223 } 224 225 /* 226 * OK, time to copy in the data 227 */ 228 if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) 229 devblocks = 0; 230 else 231 devblocks >>= 1; 232 233 if (strcmp(from, "/initrd.image") == 0) 234 devblocks = nblocks; 235 236 if (devblocks == 0) { 237 printk(KERN_ERR "RAMDISK: could not determine device size\n"); 238 goto done; 239 } 240 241 buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); 242 if (!buf) { 243 printk(KERN_ERR "RAMDISK: could not allocate buffer\n"); 244 goto done; 245 } 246 247 printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ", 248 nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : ""); 249 for (i = 0, disk = 1; i < nblocks; i++) { 250 if (i && (i % devblocks == 0)) { 251 printk("done disk #%d.\n", disk++); 252 rotate = 0; 253 if (sys_close(in_fd)) { 254 printk("Error closing the disk.\n"); 255 goto noclose_input; 256 } 257 change_floppy("disk #%d", disk); 258 in_fd = sys_open(from, O_RDONLY, 0); 259 if (in_fd < 0) { 260 printk("Error opening disk.\n"); 261 goto noclose_input; 262 } 263 printk("Loading disk #%d... ", disk); 264 } 265 sys_read(in_fd, buf, BLOCK_SIZE); 266 sys_write(out_fd, buf, BLOCK_SIZE); 267 #if !defined(CONFIG_S390) && !defined(CONFIG_PPC_ISERIES) 268 if (!(i % 16)) { 269 printk("%c\b", rotator[rotate & 0x3]); 270 rotate++; 271 } 272 #endif 273 } 274 printk("done.\n"); 275 276 successful_load: 277 res = 1; 278 done: 279 sys_close(in_fd); 280 noclose_input: 281 sys_close(out_fd); 282 out: 283 kfree(buf); 284 sys_unlink((const char __user __force *) "/dev/ram"); 285 return res; 286 } 287 288 int __init rd_load_disk(int n) 289 { 290 if (rd_prompt) 291 change_floppy("root floppy disk to be loaded into RAM disk"); 292 create_dev("/dev/root", ROOT_DEV); 293 create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n)); 294 return rd_load_image("/dev/root"); 295 } 296 297 static int exit_code; 298 static int decompress_error; 299 static int crd_infd, crd_outfd; 300 301 static int __init compr_fill(void *buf, unsigned int len) 302 { 303 int r = sys_read(crd_infd, buf, len); 304 if (r < 0) 305 printk(KERN_ERR "RAMDISK: error while reading compressed data"); 306 else if (r == 0) 307 printk(KERN_ERR "RAMDISK: EOF while reading compressed data"); 308 return r; 309 } 310 311 static int __init compr_flush(void *window, unsigned int outcnt) 312 { 313 int written = sys_write(crd_outfd, window, outcnt); 314 if (written != outcnt) { 315 if (decompress_error == 0) 316 printk(KERN_ERR 317 "RAMDISK: incomplete write (%d != %d)\n", 318 written, outcnt); 319 decompress_error = 1; 320 return -1; 321 } 322 return outcnt; 323 } 324 325 static void __init error(char *x) 326 { 327 printk(KERN_ERR "%s\n", x); 328 exit_code = 1; 329 decompress_error = 1; 330 } 331 332 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco) 333 { 334 int result; 335 crd_infd = in_fd; 336 crd_outfd = out_fd; 337 result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error); 338 if (decompress_error) 339 result = 1; 340 return result; 341 } 342