diff options
Diffstat (limited to 'init/do_mounts_rd.c')
| -rw-r--r-- | init/do_mounts_rd.c | 429 |
1 files changed, 429 insertions, 0 deletions
diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c new file mode 100644 index 000000000000..c10b08a80982 --- /dev/null +++ b/init/do_mounts_rd.c @@ -0,0 +1,429 @@ + +#include <linux/kernel.h> +#include <linux/fs.h> +#include <linux/minix_fs.h> +#include <linux/ext2_fs.h> +#include <linux/romfs_fs.h> +#include <linux/cramfs_fs.h> +#include <linux/initrd.h> +#include <linux/string.h> + +#include "do_mounts.h" + +#define BUILD_CRAMDISK + +int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */ + +static int __init prompt_ramdisk(char *str) +{ + rd_prompt = simple_strtol(str,NULL,0) & 1; + return 1; +} +__setup("prompt_ramdisk=", prompt_ramdisk); + +int __initdata rd_image_start; /* starting block # of image */ + +static int __init ramdisk_start_setup(char *str) +{ + rd_image_start = simple_strtol(str,NULL,0); + return 1; +} +__setup("ramdisk_start=", ramdisk_start_setup); + +static int __init crd_load(int in_fd, int out_fd); + +/* + * This routine tries to find a RAM disk image to load, and returns the + * number of blocks to read for a non-compressed image, 0 if the image + * is a compressed image, and -1 if an image with the right magic + * numbers could not be found. + * + * We currently check for the following magic numbers: + * minix + * ext2 + * romfs + * cramfs + * gzip + */ +static int __init +identify_ramdisk_image(int fd, int start_block) +{ + const int size = 512; + struct minix_super_block *minixsb; + struct ext2_super_block *ext2sb; + struct romfs_super_block *romfsb; + struct cramfs_super *cramfsb; + int nblocks = -1; + unsigned char *buf; + + buf = kmalloc(size, GFP_KERNEL); + if (buf == 0) + return -1; + + minixsb = (struct minix_super_block *) buf; + ext2sb = (struct ext2_super_block *) buf; + romfsb = (struct romfs_super_block *) buf; + cramfsb = (struct cramfs_super *) buf; + memset(buf, 0xe5, size); + + /* + * Read block 0 to test for gzipped kernel + */ + sys_lseek(fd, start_block * BLOCK_SIZE, 0); + sys_read(fd, buf, size); + + /* + * If it matches the gzip magic numbers, return -1 + */ + if (buf[0] == 037 && ((buf[1] == 0213) || (buf[1] == 0236))) { + printk(KERN_NOTICE + "RAMDISK: Compressed image found at block %d\n", + start_block); + nblocks = 0; + goto done; + } + + /* romfs is at block zero too */ + if (romfsb->word0 == ROMSB_WORD0 && + romfsb->word1 == ROMSB_WORD1) { + printk(KERN_NOTICE + "RAMDISK: romfs filesystem found at block %d\n", + start_block); + nblocks = (ntohl(romfsb->size)+BLOCK_SIZE-1)>>BLOCK_SIZE_BITS; + goto done; + } + + if (cramfsb->magic == CRAMFS_MAGIC) { + printk(KERN_NOTICE + "RAMDISK: cramfs filesystem found at block %d\n", + start_block); + nblocks = (cramfsb->size + BLOCK_SIZE - 1) >> BLOCK_SIZE_BITS; + goto done; + } + + /* + * Read block 1 to test for minix and ext2 superblock + */ + sys_lseek(fd, (start_block+1) * BLOCK_SIZE, 0); + sys_read(fd, buf, size); + + /* Try minix */ + if (minixsb->s_magic == MINIX_SUPER_MAGIC || + minixsb->s_magic == MINIX_SUPER_MAGIC2) { + printk(KERN_NOTICE + "RAMDISK: Minix filesystem found at block %d\n", + start_block); + nblocks = minixsb->s_nzones << minixsb->s_log_zone_size; + goto done; + } + + /* Try ext2 */ + if (ext2sb->s_magic == cpu_to_le16(EXT2_SUPER_MAGIC)) { + printk(KERN_NOTICE + "RAMDISK: ext2 filesystem found at block %d\n", + start_block); + nblocks = le32_to_cpu(ext2sb->s_blocks_count) << + le32_to_cpu(ext2sb->s_log_block_size); + goto done; + } + + printk(KERN_NOTICE + "RAMDISK: Couldn't find valid RAM disk image starting at %d.\n", + start_block); + +done: + sys_lseek(fd, start_block * BLOCK_SIZE, 0); + kfree(buf); + return nblocks; +} + +int __init rd_load_image(char *from) +{ + int res = 0; + int in_fd, out_fd; + unsigned long rd_blocks, devblocks; + int nblocks, i, disk; + char *buf = NULL; + unsigned short rotate = 0; +#if !defined(CONFIG_ARCH_S390) && !defined(CONFIG_PPC_ISERIES) + char rotator[4] = { '|' , '/' , '-' , '\\' }; +#endif + + out_fd = sys_open("/dev/ram", O_RDWR, 0); + if (out_fd < 0) + goto out; + + in_fd = sys_open(from, O_RDONLY, 0); + if (in_fd < 0) + goto noclose_input; + + nblocks = identify_ramdisk_image(in_fd, rd_image_start); + if (nblocks < 0) + goto done; + + if (nblocks == 0) { +#ifdef BUILD_CRAMDISK + if (crd_load(in_fd, out_fd) == 0) + goto successful_load; +#else + printk(KERN_NOTICE + "RAMDISK: Kernel does not support compressed " + "RAM disk images\n"); +#endif + goto done; + } + + /* + * NOTE NOTE: nblocks is not actually blocks but + * the number of kibibytes of data to load into a ramdisk. + * So any ramdisk block size that is a multiple of 1KiB should + * work when the appropriate ramdisk_blocksize is specified + * on the command line. + * + * The default ramdisk_blocksize is 1KiB and it is generally + * silly to use anything else, so make sure to use 1KiB + * blocksize while generating ext2fs ramdisk-images. + */ + if (sys_ioctl(out_fd, BLKGETSIZE, (unsigned long)&rd_blocks) < 0) + rd_blocks = 0; + else + rd_blocks >>= 1; + + if (nblocks > rd_blocks) { + printk("RAMDISK: image too big! (%dKiB/%ldKiB)\n", + nblocks, rd_blocks); + goto done; + } + + /* + * OK, time to copy in the data + */ + if (sys_ioctl(in_fd, BLKGETSIZE, (unsigned long)&devblocks) < 0) + devblocks = 0; + else + devblocks >>= 1; + + if (strcmp(from, "/initrd.image") == 0) + devblocks = nblocks; + + if (devblocks == 0) { + printk(KERN_ERR "RAMDISK: could not determine device size\n"); + goto done; + } + + buf = kmalloc(BLOCK_SIZE, GFP_KERNEL); + if (buf == 0) { + printk(KERN_ERR "RAMDISK: could not allocate buffer\n"); + goto done; + } + + printk(KERN_NOTICE "RAMDISK: Loading %dKiB [%ld disk%s] into ram disk... ", + nblocks, ((nblocks-1)/devblocks)+1, nblocks>devblocks ? "s" : ""); + for (i = 0, disk = 1; i < nblocks; i++) { + if (i && (i % devblocks == 0)) { + printk("done disk #%d.\n", disk++); + rotate = 0; + if (sys_close(in_fd)) { + printk("Error closing the disk.\n"); + goto noclose_input; + } + change_floppy("disk #%d", disk); + in_fd = sys_open(from, O_RDONLY, 0); + if (in_fd < 0) { + printk("Error opening disk.\n"); + goto noclose_input; + } + printk("Loading disk #%d... ", disk); + } + sys_read(in_fd, buf, BLOCK_SIZE); + sys_write(out_fd, buf, BLOCK_SIZE); +#if !defined(CONFIG_ARCH_S390) && !defined(CONFIG_PPC_ISERIES) + if (!(i % 16)) { + printk("%c\b", rotator[rotate & 0x3]); + rotate++; + } +#endif + } + printk("done.\n"); + +successful_load: + res = 1; +done: + sys_close(in_fd); +noclose_input: + sys_close(out_fd); +out: + kfree(buf); + sys_unlink("/dev/ram"); + return res; +} + +int __init rd_load_disk(int n) +{ + if (rd_prompt) + change_floppy("root floppy disk to be loaded into RAM disk"); + create_dev("/dev/root", ROOT_DEV, root_device_name); + create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n), NULL); + return rd_load_image("/dev/root"); +} + +#ifdef BUILD_CRAMDISK + +/* + * gzip declarations + */ + +#define OF(args) args + +#ifndef memzero +#define memzero(s, n) memset ((s), 0, (n)) +#endif + +typedef unsigned char uch; +typedef unsigned short ush; +typedef unsigned long ulg; + +#define INBUFSIZ 4096 +#define WSIZE 0x8000 /* window size--must be a power of two, and */ + /* at least 32K for zip's deflate method */ + +static uch *inbuf; +static uch *window; + +static unsigned insize; /* valid bytes in inbuf */ +static unsigned inptr; /* index of next byte to be processed in inbuf */ +static unsigned outcnt; /* bytes in output buffer */ +static int exit_code; +static int unzip_error; +static long bytes_out; +static int crd_infd, crd_outfd; + +#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf()) + +/* Diagnostic functions (stubbed out) */ +#define Assert(cond,msg) +#define Trace(x) +#define Tracev(x) +#define Tracevv(x) +#define Tracec(c,x) +#define Tracecv(c,x) + +#define STATIC static +#define INIT __init + +static int __init fill_inbuf(void); +static void __init flush_window(void); +static void __init *malloc(size_t size); +static void __init free(void *where); +static void __init error(char *m); +static void __init gzip_mark(void **); +static void __init gzip_release(void **); + +#include "../lib/inflate.c" + +static void __init *malloc(size_t size) +{ + return kmalloc(size, GFP_KERNEL); +} + +static void __init free(void *where) +{ + kfree(where); +} + +static void __init gzip_mark(void **ptr) +{ +} + +static void __init gzip_release(void **ptr) +{ +} + + +/* =========================================================================== + * Fill the input buffer. This is called only when the buffer is empty + * and at least one byte is really needed. + * Returning -1 does not guarantee that gunzip() will ever return. + */ +static int __init fill_inbuf(void) +{ + if (exit_code) return -1; + + insize = sys_read(crd_infd, inbuf, INBUFSIZ); + if (insize == 0) { + error("RAMDISK: ran out of compressed data"); + return -1; + } + + inptr = 1; + + return inbuf[0]; +} + +/* =========================================================================== + * Write the output window window[0..outcnt-1] and update crc and bytes_out. + * (Used for the decompressed data only.) + */ +static void __init flush_window(void) +{ + ulg c = crc; /* temporary variable */ + unsigned n, written; + uch *in, ch; + + written = sys_write(crd_outfd, window, outcnt); + if (written != outcnt && unzip_error == 0) { + printk(KERN_ERR "RAMDISK: incomplete write (%d != %d) %ld\n", + written, outcnt, bytes_out); + unzip_error = 1; + } + in = window; + for (n = 0; n < outcnt; n++) { + ch = *in++; + c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8); + } + crc = c; + bytes_out += (ulg)outcnt; + outcnt = 0; +} + +static void __init error(char *x) +{ + printk(KERN_ERR "%s\n", x); + exit_code = 1; + unzip_error = 1; +} + +static int __init crd_load(int in_fd, int out_fd) +{ + int result; + + insize = 0; /* valid bytes in inbuf */ + inptr = 0; /* index of next byte to be processed in inbuf */ + outcnt = 0; /* bytes in output buffer */ + exit_code = 0; + bytes_out = 0; + crc = (ulg)0xffffffffL; /* shift register contents */ + + crd_infd = in_fd; + crd_outfd = out_fd; + inbuf = kmalloc(INBUFSIZ, GFP_KERNEL); + if (inbuf == 0) { + printk(KERN_ERR "RAMDISK: Couldn't allocate gzip buffer\n"); + return -1; + } + window = kmalloc(WSIZE, GFP_KERNEL); + if (window == 0) { + printk(KERN_ERR "RAMDISK: Couldn't allocate gzip window\n"); + kfree(inbuf); + return -1; + } + makecrc(); + result = gunzip(); + if (unzip_error) + result = 1; + kfree(inbuf); + kfree(window); + return result; +} + +#endif /* BUILD_CRAMDISK */ |