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 -1; 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 block 1 to test for minix and ext2 superblock 124 */ 125 sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0); 126 sys_read(fd, buf, size); 127 128 /* Try minix */ 129 if (minixsb->s_magic == MINIX_SUPER_MAGIC || 130 minixsb->s_magic == MINIX_SUPER_MAGIC2) { 131 printk(KERN_NOTICE 132 "RAMDISK: Minix filesystem found at block %d\n", 133 start_block); 134 nblocks = minixsb->s_nzones << minixsb->s_log_zone_size; 135 goto done; 136 } 137 138 /* Try ext2 */ 139 if (ext2sb->s_magic == cpu_to_le16(EXT2_SUPER_MAGIC)) { 140 printk(KERN_NOTICE 141 "RAMDISK: ext2 filesystem found at block %d\n", 142 start_block); 143 nblocks = le32_to_cpu(ext2sb->s_blocks_count) << 144 le32_to_cpu(ext2sb->s_log_block_size); 145 goto done; 146 } 147 148 printk(KERN_NOTICE 149 "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n", 150 start_block); 151 152 done: 153 sys_lseek(fd, start_block * BLOCK_SIZE, 0); 154 kfree(buf); 155 return nblocks; 156 } 157 158 int __init rd_load_image(char *from) 159 { 160 int res = 0; 161 int in_fd, out_fd; 162 unsigned long rd_blocks, devblocks; 163 int nblocks, i, disk; 164 char *buf = NULL; 165 unsigned short rotate = 0; 166 decompress_fn decompressor = NULL; 167 #if !defined(CONFIG_S390) && !defined(CONFIG_PPC_ISERIES) 168 char rotator[4] = { '|' , '/' , '-' , '\\' }; 169 #endif 170 171 out_fd = sys_open("/dev/ram", O_RDWR, 0); 172 if (out_fd < 0) 173 goto out; 174 175 in_fd = sys_open(from, O_RDONLY, 0); 176 if (in_fd < 0) 177 goto noclose_input; 178 179 nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor); 180 if (nblocks < 0) 181 goto done; 182 183 if (nblocks == 0) { 184 if (crd_load(in_fd, out_fd, decompressor) == 0) 185 goto successful_load; 186 goto done; 187 } 188 189 /* 190 * NOTE NOTE: nblocks is not actually blocks but 191 * the number of kibibytes of data to load into a ramdisk. 192 * So any ramdisk block size that is a multiple of 1KiB should 193 * work when the appropriate ramdisk_blocksize is specified 194 * on the command line. 195 * 196 * The default ramdisk_blocksize is 1KiB and it is generally 197 * silly to use anything else, so make sure to use 1KiB 198 * blocksize while generating ext2fs ramdisk-images. 199 */ 200 if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) 201 rd_blocks = 0; 202 else 203 rd_blocks >>= 1; 204 205 if (nblocks > rd_blocks) { 206 printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n", 207 nblocks, rd_blocks); 208 goto done; 209 } 210 211 /* 212 * OK, time to copy in the data 213 */ 214 if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) 215 devblocks = 0; 216 else 217 devblocks >>= 1; 218 219 if (strcmp(from, "/initrd.image") == 0) 220 devblocks = nblocks; 221 222 if (devblocks == 0) { 223 printk(KERN_ERR "RAMDISK: could not determine device size\n"); 224 goto done; 225 } 226 227 buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); 228 if (!buf) { 229 printk(KERN_ERR "RAMDISK: could not allocate buffer\n"); 230 goto done; 231 } 232 233 printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ", 234 nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : ""); 235 for (i = 0, disk = 1; i < nblocks; i++) { 236 if (i && (i % devblocks == 0)) { 237 printk("done disk #%d.\n", disk++); 238 rotate = 0; 239 if (sys_close(in_fd)) { 240 printk("Error closing the disk.\n"); 241 goto noclose_input; 242 } 243 change_floppy("disk #%d", disk); 244 in_fd = sys_open(from, O_RDONLY, 0); 245 if (in_fd < 0) { 246 printk("Error opening disk.\n"); 247 goto noclose_input; 248 } 249 printk("Loading disk #%d... ", disk); 250 } 251 sys_read(in_fd, buf, BLOCK_SIZE); 252 sys_write(out_fd, buf, BLOCK_SIZE); 253 #if !defined(CONFIG_S390) && !defined(CONFIG_PPC_ISERIES) 254 if (!(i % 16)) { 255 printk("%c\b", rotator[rotate & 0x3]); 256 rotate++; 257 } 258 #endif 259 } 260 printk("done.\n"); 261 262 successful_load: 263 res = 1; 264 done: 265 sys_close(in_fd); 266 noclose_input: 267 sys_close(out_fd); 268 out: 269 kfree(buf); 270 sys_unlink("/dev/ram"); 271 return res; 272 } 273 274 int __init rd_load_disk(int n) 275 { 276 if (rd_prompt) 277 change_floppy("root floppy disk to be loaded into RAM disk"); 278 create_dev("/dev/root", ROOT_DEV); 279 create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n)); 280 return rd_load_image("/dev/root"); 281 } 282 283 static int exit_code; 284 static int decompress_error; 285 static int crd_infd, crd_outfd; 286 287 static int __init compr_fill(void *buf, unsigned int len) 288 { 289 int r = sys_read(crd_infd, buf, len); 290 if (r < 0) 291 printk(KERN_ERR "RAMDISK: error while reading compressed data"); 292 else if (r == 0) 293 printk(KERN_ERR "RAMDISK: EOF while reading compressed data"); 294 return r; 295 } 296 297 static int __init compr_flush(void *window, unsigned int outcnt) 298 { 299 int written = sys_write(crd_outfd, window, outcnt); 300 if (written != outcnt) { 301 if (decompress_error == 0) 302 printk(KERN_ERR 303 "RAMDISK: incomplete write (%d != %d)\n", 304 written, outcnt); 305 decompress_error = 1; 306 return -1; 307 } 308 return outcnt; 309 } 310 311 static void __init error(char *x) 312 { 313 printk(KERN_ERR "%s\n", x); 314 exit_code = 1; 315 decompress_error = 1; 316 } 317 318 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco) 319 { 320 int result; 321 crd_infd = in_fd; 322 crd_outfd = out_fd; 323 result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error); 324 if (decompress_error) 325 result = 1; 326 return result; 327 } 328