1 // SPDX-License-Identifier: GPL-2.0 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 <uapi/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 * bzip2 52 * lzma 53 * xz 54 * lzo 55 * lz4 56 */ 57 static int __init 58 identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor) 59 { 60 const int size = 512; 61 struct minix_super_block *minixsb; 62 struct romfs_super_block *romfsb; 63 struct cramfs_super *cramfsb; 64 struct squashfs_super_block *squashfsb; 65 int nblocks = -1; 66 unsigned char *buf; 67 const char *compress_name; 68 unsigned long n; 69 70 buf = kmalloc(size, GFP_KERNEL); 71 if (!buf) 72 return -ENOMEM; 73 74 minixsb = (struct minix_super_block *) buf; 75 romfsb = (struct romfs_super_block *) buf; 76 cramfsb = (struct cramfs_super *) buf; 77 squashfsb = (struct squashfs_super_block *) buf; 78 memset(buf, 0xe5, size); 79 80 /* 81 * Read block 0 to test for compressed kernel 82 */ 83 ksys_lseek(fd, start_block * BLOCK_SIZE, 0); 84 ksys_read(fd, buf, size); 85 86 *decompressor = decompress_method(buf, size, &compress_name); 87 if (compress_name) { 88 printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n", 89 compress_name, start_block); 90 if (!*decompressor) 91 printk(KERN_EMERG 92 "RAMDISK: %s decompressor not configured!\n", 93 compress_name); 94 nblocks = 0; 95 goto done; 96 } 97 98 /* romfs is at block zero too */ 99 if (romfsb->word0 == ROMSB_WORD0 && 100 romfsb->word1 == ROMSB_WORD1) { 101 printk(KERN_NOTICE 102 "RAMDISK: romfs filesystem found at block %d\n", 103 start_block); 104 nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS; 105 goto done; 106 } 107 108 if (cramfsb->magic == CRAMFS_MAGIC) { 109 printk(KERN_NOTICE 110 "RAMDISK: cramfs filesystem found at block %d\n", 111 start_block); 112 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; 113 goto done; 114 } 115 116 /* squashfs is at block zero too */ 117 if (le32_to_cpu(squashfsb->s_magic) == SQUASHFS_MAGIC) { 118 printk(KERN_NOTICE 119 "RAMDISK: squashfs filesystem found at block %d\n", 120 start_block); 121 nblocks = (le64_to_cpu(squashfsb->bytes_used) + BLOCK_SIZE - 1) 122 >> BLOCK_SIZE_BITS; 123 goto done; 124 } 125 126 /* 127 * Read 512 bytes further to check if cramfs is padded 128 */ 129 ksys_lseek(fd, start_block * BLOCK_SIZE + 0x200, 0); 130 ksys_read(fd, buf, size); 131 132 if (cramfsb->magic == CRAMFS_MAGIC) { 133 printk(KERN_NOTICE 134 "RAMDISK: cramfs filesystem found at block %d\n", 135 start_block); 136 nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; 137 goto done; 138 } 139 140 /* 141 * Read block 1 to test for minix and ext2 superblock 142 */ 143 ksys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0); 144 ksys_read(fd, buf, size); 145 146 /* Try minix */ 147 if (minixsb->s_magic == MINIX_SUPER_MAGIC || 148 minixsb->s_magic == MINIX_SUPER_MAGIC2) { 149 printk(KERN_NOTICE 150 "RAMDISK: Minix filesystem found at block %d\n", 151 start_block); 152 nblocks = minixsb->s_nzones << minixsb->s_log_zone_size; 153 goto done; 154 } 155 156 /* Try ext2 */ 157 n = ext2_image_size(buf); 158 if (n) { 159 printk(KERN_NOTICE 160 "RAMDISK: ext2 filesystem found at block %d\n", 161 start_block); 162 nblocks = n; 163 goto done; 164 } 165 166 printk(KERN_NOTICE 167 "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n", 168 start_block); 169 170 done: 171 ksys_lseek(fd, start_block * BLOCK_SIZE, 0); 172 kfree(buf); 173 return nblocks; 174 } 175 176 int __init rd_load_image(char *from) 177 { 178 int res = 0; 179 int in_fd, out_fd; 180 unsigned long rd_blocks, devblocks; 181 int nblocks, i, disk; 182 char *buf = NULL; 183 unsigned short rotate = 0; 184 decompress_fn decompressor = NULL; 185 #if !defined(CONFIG_S390) 186 char rotator[4] = { '|' , '/' , '-' , '\\' }; 187 #endif 188 189 out_fd = ksys_open("/dev/ram", O_RDWR, 0); 190 if (out_fd < 0) 191 goto out; 192 193 in_fd = ksys_open(from, O_RDONLY, 0); 194 if (in_fd < 0) 195 goto noclose_input; 196 197 nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor); 198 if (nblocks < 0) 199 goto done; 200 201 if (nblocks == 0) { 202 if (crd_load(in_fd, out_fd, decompressor) == 0) 203 goto successful_load; 204 goto done; 205 } 206 207 /* 208 * NOTE NOTE: nblocks is not actually blocks but 209 * the number of kibibytes of data to load into a ramdisk. 210 */ 211 if (ksys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) 212 rd_blocks = 0; 213 else 214 rd_blocks >>= 1; 215 216 if (nblocks > rd_blocks) { 217 printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n", 218 nblocks, rd_blocks); 219 goto done; 220 } 221 222 /* 223 * OK, time to copy in the data 224 */ 225 if (ksys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) 226 devblocks = 0; 227 else 228 devblocks >>= 1; 229 230 if (strcmp(from, "/initrd.image") == 0) 231 devblocks = nblocks; 232 233 if (devblocks == 0) { 234 printk(KERN_ERR "RAMDISK: could not determine device size\n"); 235 goto done; 236 } 237 238 buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); 239 if (!buf) { 240 printk(KERN_ERR "RAMDISK: could not allocate buffer\n"); 241 goto done; 242 } 243 244 printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ", 245 nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : ""); 246 for (i = 0, disk = 1; i < nblocks; i++) { 247 if (i && (i % devblocks == 0)) { 248 pr_cont("done disk #%d.\n", disk++); 249 rotate = 0; 250 if (ksys_close(in_fd)) { 251 printk("Error closing the disk.\n"); 252 goto noclose_input; 253 } 254 change_floppy("disk #%d", disk); 255 in_fd = ksys_open(from, O_RDONLY, 0); 256 if (in_fd < 0) { 257 printk("Error opening disk.\n"); 258 goto noclose_input; 259 } 260 printk("Loading disk #%d... ", disk); 261 } 262 ksys_read(in_fd, buf, BLOCK_SIZE); 263 ksys_write(out_fd, buf, BLOCK_SIZE); 264 #if !defined(CONFIG_S390) 265 if (!(i % 16)) { 266 pr_cont("%c\b", rotator[rotate & 0x3]); 267 rotate++; 268 } 269 #endif 270 } 271 pr_cont("done.\n"); 272 273 successful_load: 274 res = 1; 275 done: 276 ksys_close(in_fd); 277 noclose_input: 278 ksys_close(out_fd); 279 out: 280 kfree(buf); 281 ksys_unlink("/dev/ram"); 282 return res; 283 } 284 285 int __init rd_load_disk(int n) 286 { 287 if (rd_prompt) 288 change_floppy("root floppy disk to be loaded into RAM disk"); 289 create_dev("/dev/root", ROOT_DEV); 290 create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n)); 291 return rd_load_image("/dev/root"); 292 } 293 294 static int exit_code; 295 static int decompress_error; 296 static int crd_infd, crd_outfd; 297 298 static long __init compr_fill(void *buf, unsigned long len) 299 { 300 long r = ksys_read(crd_infd, buf, len); 301 if (r < 0) 302 printk(KERN_ERR "RAMDISK: error while reading compressed data"); 303 else if (r == 0) 304 printk(KERN_ERR "RAMDISK: EOF while reading compressed data"); 305 return r; 306 } 307 308 static long __init compr_flush(void *window, unsigned long outcnt) 309 { 310 long written = ksys_write(crd_outfd, window, outcnt); 311 if (written != outcnt) { 312 if (decompress_error == 0) 313 printk(KERN_ERR 314 "RAMDISK: incomplete write (%ld != %ld)\n", 315 written, outcnt); 316 decompress_error = 1; 317 return -1; 318 } 319 return outcnt; 320 } 321 322 static void __init error(char *x) 323 { 324 printk(KERN_ERR "%s\n", x); 325 exit_code = 1; 326 decompress_error = 1; 327 } 328 329 static int __init crd_load(int in_fd, int out_fd, decompress_fn deco) 330 { 331 int result; 332 crd_infd = in_fd; 333 crd_outfd = out_fd; 334 335 if (!deco) { 336 pr_emerg("Invalid ramdisk decompression routine. " 337 "Select appropriate config option.\n"); 338 panic("Could not decompress initial ramdisk image."); 339 } 340 341 result = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error); 342 if (decompress_error) 343 result = 1; 344 return result; 345 } 346