#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)
                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_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_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);
        create_dev("/dev/ram", MKDEV(RAMDISK_MAJOR, n));
        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) {
                printk(KERN_ERR "RAMDISK: Couldn't allocate gzip buffer\n");
                return -1;
        }
        window = kmalloc(WSIZE, GFP_KERNEL);
        if (!window) {
                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 */