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 */