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 11 #include "do_mounts.h" 12 #include "../fs/squashfs/squashfs_fs.h" 13 14 #include <linux/decompress/generic.h> 15 16 17 int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */ 18 19 static int __init prompt_ramdisk(char *str) 20 { 21 rd_prompt = simple_strtol(str,NULL,0) & 1; 22 return 1; 23 } 24 __setup("prompt_ramdisk=", prompt_ramdisk); 25 26 int __initdata rd_image_start; /* starting block # of image */ 27 28 static int __init ramdisk_start_setup(char *str) 29 { 30 rd_image_start = simple_strtol(str,NULL,0); 31 return 1; 32 } 33 __setup("ramdisk_start=", ramdisk_start_setup); 34 35 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco); 36 37 /* 38 * This routine tries to find a RAM disk image to load, and returns the 39 * number of blocks to read for a non-compressed image, 0 if the image 40 * is a compressed image, and -1 if an image with the right magic 41 * numbers could not be found. 42 * 43 * We currently check for the following magic numbers: 44 * minix 45 * ext2 46 * romfs 47 * cramfs 48 * squashfs 49 * gzip 50 */ 51 static int __init 52 identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) 53 { 54 const int size = 512; 55 struct minix_super_block *minixsb; 56 struct ext2_super_block *ext2sb; 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 64 buf = kmalloc(size, GFP_KERNEL); 65 if (!buf) 66 return -1; 67 68 minixsb = (struct minix_super_block *) buf; 69 ext2sb = (struct ext2_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 block 1 to test for minix and ext2 superblock 123 */ 124 sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0); 125 sys_read(fd, buf, size); 126 127 /* Try minix */ 128 if (minixsb->s_magic == MINIX_SUPER_MAGIC || 129 minixsb->s_magic == MINIX_SUPER_MAGIC2) { 130 printk(KERN_NOTICE 131 "RAMDISK: Minix filesystem found at block %d\n", 132 start_block); 133 nblocks = minixsb->s_nzones << minixsb->s_log_zone_size; 134 goto done; 135 } 136 137 /* Try ext2 */ 138 if (ext2sb->s_magic == cpu_to_le16(EXT2_SUPER_MAGIC)) { 139 printk(KERN_NOTICE 140 "RAMDISK: ext2 filesystem found at block %d\n", 141 start_block); 142 nblocks = le32_to_cpu(ext2sb->s_blocks_count) << 143 le32_to_cpu(ext2sb->s_log_block_size); 144 goto done; 145 } 146 147 printk(KERN_NOTICE 148 "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n", 149 start_block); 150 151 done: 152 sys_lseek(fd, start_block * BLOCK_SIZE, 0); 153 kfree(buf); 154 return nblocks; 155 } 156 157 int __init rd_load_image(char *from) 158 { 159 int res = 0; 160 int in_fd, out_fd; 161 unsigned long rd_blocks, devblocks; 162 int nblocks, i, disk; 163 char *buf = NULL; 164 unsigned short rotate = 0; 165 decompress_fn decompressor = NULL; 166 #if !defined(CONFIG_S390) && !defined(CONFIG_PPC_ISERIES) 167 char rotator[4] = { '|' , '/' , '-' , '\\' }; 168 #endif 169 170 out_fd = sys_open("/dev/ram", O_RDWR, 0); 171 if (out_fd < 0) 172 goto out; 173 174 in_fd = sys_open(from, O_RDONLY, 0); 175 if (in_fd < 0) 176 goto noclose_input; 177 178 nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor); 179 if (nblocks < 0) 180 goto done; 181 182 if (nblocks == 0) { 183 if (crd_load(in_fd, out_fd, decompressor) == 0) 184 goto successful_load; 185 goto done; 186 } 187 188 /* 189 * NOTE NOTE: nblocks is not actually blocks but 190 * the number of kibibytes of data to load into a ramdisk. 191 * So any ramdisk block size that is a multiple of 1KiB should 192 * work when the appropriate ramdisk_blocksize is specified 193 * on the command line. 194 * 195 * The default ramdisk_blocksize is 1KiB and it is generally 196 * silly to use anything else, so make sure to use 1KiB 197 * blocksize while generating ext2fs ramdisk-images. 198 */ 199 if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) 200 rd_blocks = 0; 201 else 202 rd_blocks >>= 1; 203 204 if (nblocks > rd_blocks) { 205 printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n", 206 nblocks, rd_blocks); 207 goto done; 208 } 209 210 /* 211 * OK, time to copy in the data 212 */ 213 if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) 214 devblocks = 0; 215 else 216 devblocks >>= 1; 217 218 if (strcmp(from, "/initrd.image") == 0) 219 devblocks = nblocks; 220 221 if (devblocks == 0) { 222 printk(KERN_ERR "RAMDISK: could not determine device size\n"); 223 goto done; 224 } 225 226 buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); 227 if (!buf) { 228 printk(KERN_ERR "RAMDISK: could not allocate buffer\n"); 229 goto done; 230 } 231 232 printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ", 233 nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : ""); 234 for (i = 0, disk = 1; i < nblocks; i++) { 235 if (i && (i % devblocks == 0)) { 236 printk("done disk #%d.\n", disk++); 237 rotate = 0; 238 if (sys_close(in_fd)) { 239 printk("Error closing the disk.\n"); 240 goto noclose_input; 241 } 242 change_floppy("disk #%d", disk); 243 in_fd = sys_open(from, O_RDONLY, 0); 244 if (in_fd < 0) { 245 printk("Error opening disk.\n"); 246 goto noclose_input; 247 } 248 printk("Loading disk #%d... ", disk); 249 } 250 sys_read(in_fd, buf, BLOCK_SIZE); 251 sys_write(out_fd, buf, BLOCK_SIZE); 252 #if !defined(CONFIG_S390) && !defined(CONFIG_PPC_ISERIES) 253 if (!(i % 16)) { 254 printk("%c\b", rotator[rotate & 0x3]); 255 rotate++; 256 } 257 #endif 258 } 259 printk("done.\n"); 260 261 successful_load: 262 res = 1; 263 done: 264 sys_close(in_fd); 265 noclose_input: 266 sys_close(out_fd); 267 out: 268 kfree(buf); 269 sys_unlink("/dev/ram"); 270 return res; 271 } 272 273 int __init rd_load_disk(int n) 274 { 275 if (rd_prompt) 276 change_floppy("root floppy disk to be loaded into RAM disk"); 277 create_dev("/dev/root", ROOT_DEV); 278 create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n)); 279 return rd_load_image("/dev/root"); 280 } 281 282 static int exit_code; 283 static int decompress_error; 284 static int crd_infd, crd_outfd; 285 286 static int __init compr_fill(void *buf, unsigned int len) 287 { 288 int r = sys_read(crd_infd, buf, len); 289 if (r < 0) 290 printk(KERN_ERR "RAMDISK: error while reading compressed data"); 291 else if (r == 0) 292 printk(KERN_ERR "RAMDISK: EOF while reading compressed data"); 293 return r; 294 } 295 296 static int __init compr_flush(void *window, unsigned int outcnt) 297 { 298 int written = sys_write(crd_outfd, window, outcnt); 299 if (written != outcnt) { 300 if (decompress_error == 0) 301 printk(KERN_ERR 302 "RAMDISK: incomplete write (%d != %d)\n", 303 written, outcnt); 304 decompress_error = 1; 305 return -1; 306 } 307 return outcnt; 308 } 309 310 static void __init error(char *x) 311 { 312 printk(KERN_ERR "%s\n", x); 313 exit_code = 1; 314 decompress_error = 1; 315 } 316 317 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco) 318 { 319 int result; 320 crd_infd = in_fd; 321 crd_outfd = out_fd; 322 result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error); 323 if (decompress_error) 324 result = 1; 325 return result; 326 } 327