3 files changed, 124 insertions, 211 deletions

diff --git a/init/Kconfig b/init/Kconfig
index a724a149bf3f..a3e3bf548046 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -101,6 +101,66 @@ config LOCALVERSION_AUTO
 
           which is done within the script "scripts/setlocalversion".)
 
+config HAVE_KERNEL_GZIP
+        bool
+
+config HAVE_KERNEL_BZIP2
+        bool
+
+config HAVE_KERNEL_LZMA
+        bool
+
+choice
+        prompt "Kernel compression mode"
+        default KERNEL_GZIP
+        depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA
+        help
+          The linux kernel is a kind of self-extracting executable.
+          Several compression algorithms are available, which differ
+          in efficiency, compression and decompression speed.
+          Compression speed is only relevant when building a kernel.
+          Decompression speed is relevant at each boot.
+
+          If you have any problems with bzip2 or lzma compressed
+          kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
+          version of this functionality (bzip2 only), for 2.4, was
+          supplied by Christian Ludwig)
+
+          High compression options are mostly useful for users, who
+          are low on disk space (embedded systems), but for whom ram
+          size matters less.
+
+          If in doubt, select 'gzip'
+
+config KERNEL_GZIP
+        bool "Gzip"
+        depends on HAVE_KERNEL_GZIP
+        help
+          The old and tried gzip compression. Its compression ratio is
+          the poorest among the 3 choices; however its speed (both
+          compression and decompression) is the fastest.
+
+config KERNEL_BZIP2
+        bool "Bzip2"
+        depends on HAVE_KERNEL_BZIP2
+        help
+          Its compression ratio and speed is intermediate.
+          Decompression speed is slowest among the three.  The kernel
+          size is about 10% smaller with bzip2, in comparison to gzip.
+          Bzip2 uses a large amount of memory. For modern kernels you
+          will need at least 8MB RAM or more for booting.
+
+config KERNEL_LZMA
+        bool "LZMA"
+        depends on HAVE_KERNEL_LZMA
+        help
+          The most recent compression algorithm.
+          Its ratio is best, decompression speed is between the other
+          two. Compression is slowest.  The kernel size is about 33%
+          smaller with LZMA in comparison to gzip.
+
+endchoice
+
 config SWAP
         bool "Support for paging of anonymous memory (swap)"
         depends on MMU && BLOCK
diff --git a/init/do_mounts_rd.c b/init/do_mounts_rd.c
index 0f0f0cf3ba9a..a015e267fd17 100644
--- a/init/do_mounts_rd.c
+++ b/init/do_mounts_rd.c
@@ -11,6 +11,9 @@
 #include "do_mounts.h"
 #include "../fs/squashfs/squashfs_fs.h"
 
+#include <linux/decompress/generic.h>
+
+
 int __initdata rd_prompt = 1;/* 1 = prompt for RAM disk, 0 = don't prompt */
 
 static int __init prompt_ramdisk(char *str)
@@ -29,7 +32,7 @@ static int __init ramdisk_start_setup(char *str)
 }
 __setup("ramdisk_start=", ramdisk_start_setup);
 
-static int __init crd_load(int in_fd, int out_fd);
+static int __init crd_load(int in_fd, int out_fd, decompress_fn deco);
 
 /*
  * This routine tries to find a RAM disk image to load, and returns the
@@ -38,15 +41,15 @@ static int __init crd_load(int in_fd, int out_fd);
  * numbers could not be found.
  *
  * We currently check for the following magic numbers:
- *      minix
- *      ext2
+ *      minix
+ *      ext2
  *      romfs
  *      cramfs
  *      squashfs
- *      gzip
+ *      gzip
  */
-static int __init 
-identify_ramdisk_image(int fd, int start_block)
+static int __init
+identify_ramdisk_image(int fd, int start_block, decompress_fn *decompressor)
 {
         const int size = 512;
         struct minix_super_block *minixsb;
@@ -56,6 +59,7 @@ identify_ramdisk_image(int fd, int start_block)
         struct squashfs_super_block *squashfsb;
         int nblocks = -1;
         unsigned char *buf;
+        const char *compress_name;
 
         buf = kmalloc(size, GFP_KERNEL);
         if (!buf)
@@ -69,18 +73,15 @@ identify_ramdisk_image(int fd, int start_block)
         memset(buf, 0xe5, size);
 
         /*
-         * Read block 0 to test for gzipped kernel
+         * Read block 0 to test for compressed kernel
          */
         sys_lseek(fd, start_block * BLOCK_SIZE, 0);
         sys_read(fd, buf, size);
 
-        /*
-         * If it matches the gzip magic numbers, return 0
-         */
-        if (buf[0] == 037 && ((buf[1] == 0213) || (buf[1] == 0236))) {
-                printk(KERN_NOTICE
-                       "RAMDISK: Compressed image found at block %d\n",
-                       start_block);
+        *decompressor = decompress_method(buf, size, &compress_name);
+        if (*decompressor) {
+                printk(KERN_NOTICE "RAMDISK: %s image found at block %d\n",
+                       compress_name, start_block);
                 nblocks = 0;
                 goto done;
         }
@@ -142,7 +143,7 @@ identify_ramdisk_image(int fd, int start_block)
         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);
@@ -157,6 +158,7 @@ int __init rd_load_image(char *from)
         int nblocks, i, disk;
         char *buf = NULL;
         unsigned short rotate = 0;
+        decompress_fn decompressor = NULL;
 #if !defined(CONFIG_S390) && !defined(CONFIG_PPC_ISERIES)
         char rotator[4] = { '|' , '/' , '-' , '\\' };
 #endif
@@ -169,12 +171,12 @@ int __init rd_load_image(char *from)
         if (in_fd < 0)
                 goto noclose_input;
 
-        nblocks = identify_ramdisk_image(in_fd, rd_image_start);
+        nblocks = identify_ramdisk_image(in_fd, rd_image_start, &decompressor);
         if (nblocks < 0)
                 goto done;
 
         if (nblocks == 0) {
-                if (crd_load(in_fd, out_fd) == 0)
+                if (crd_load(in_fd, out_fd, decompressor) == 0)
                         goto successful_load;
                 goto done;
         }
@@ -200,7 +202,7 @@ int __init rd_load_image(char *from)
                        nblocks, rd_blocks);
                 goto done;
         }
-                
+
         /*
          * OK, time to copy in the data
          */
@@ -273,138 +275,48 @@ int __init rd_load_disk(int n)
         return rd_load_image("/dev/root");
 }
 
-/*
- * 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 decompress_error;
 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 error(char *m);
-
-#define NO_INFLATE_MALLOC
-
-#include "../lib/inflate.c"
-
-/* ===========================================================================
- * 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)
+static int __init compr_fill(void *buf, unsigned int len)
 {
-        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];
+        int r = sys_read(crd_infd, buf, len);
+        if (r < 0)
+                printk(KERN_ERR "RAMDISK: error while reading compressed data");
+        else if (r == 0)
+                printk(KERN_ERR "RAMDISK: EOF while reading compressed data");
+        return r;
 }
 
-/* ===========================================================================
- * 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)
+static int __init compr_flush(void *window, unsigned int outcnt)
 {
-    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;
+        int written = sys_write(crd_outfd, window, outcnt);
+        if (written != outcnt) {
+                if (decompress_error == 0)
+                        printk(KERN_ERR
+                               "RAMDISK: incomplete write (%d != %d)\n",
+                               written, outcnt);
+                decompress_error = 1;
+                return -1;
+        }
+        return outcnt;
 }
 
 static void __init error(char *x)
 {
         printk(KERN_ERR "%s\n", x);
         exit_code = 1;
-        unzip_error = 1;
+        decompress_error = 1;
 }
 
-static int __init crd_load(int in_fd, int out_fd)
+static int __init crd_load(int in_fd, int out_fd, decompress_fn deco)
 {
         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 = deco(NULL, 0, compr_fill, compr_flush, NULL, NULL, error);
+        if (decompress_error)
                 result = 1;
-        kfree(inbuf);
-        kfree(window);
         return result;
 }
diff --git a/init/initramfs.c b/init/initramfs.c
index d9c941c0c3ca..f8241e832aa3 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -390,11 +390,14 @@ static int __init write_buffer(char *buf, unsigned len)
         return len - count;
 }
 
-static void __init flush_buffer(char *buf, unsigned len)
+#if defined CONFIG_RD_GZIP || defined CONFIG_RD_BZIP2 || defined CONFIG_RD_LZMA
+static int __init flush_buffer(void *bufv, unsigned len)
 {
+        char *buf = (char *) bufv;
         int written;
+        int origLen = len;
         if (message)
-                return;
+                return -1;
         while ((written = write_buffer(buf, len)) < len && !message) {
                 char c = buf[written];
                 if (c == '0') {
@@ -408,84 +411,27 @@ static void __init flush_buffer(char *buf, unsigned len)
                 } else
                         error("junk in compressed archive");
         }
+        return origLen;
 }
-
-/*
- * 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 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 long bytes_out;
-
-#define get_byte()  (inptr < insize ? inbuf[inptr++] : -1)
-                
-/* 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 void __init flush_window(void);
-static void __init error(char *m);
+static unsigned my_inptr;   /* index of next byte to be processed in inbuf */
 
-#define NO_INFLATE_MALLOC
-
-#include "../lib/inflate.c"
-
-/* ===========================================================================
- * 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;
-        uch *in, ch;
-
-        flush_buffer(window, outcnt);
-        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;
-}
+#include <linux/decompress/generic.h>
 
 static char * __init unpack_to_rootfs(char *buf, unsigned len, int check_only)
 {
         int written;
+        decompress_fn decompress;
+
         dry_run = check_only;
         header_buf = kmalloc(110, GFP_KERNEL);
         symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
         name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
-        window = kmalloc(WSIZE, GFP_KERNEL);
-        if (!window || !header_buf || !symlink_buf || !name_buf)
+
+        if (!header_buf || !symlink_buf || !name_buf)
                 panic("can't allocate buffers");
+
         state = Start;
         this_header = 0;
         message = NULL;
@@ -505,22 +451,17 @@ static char * __init unpack_to_rootfs(char *buf, unsigned len, int check_only)
                         continue;
                 }
                 this_header = 0;
-                insize = len;
-                inbuf = buf;
-                inptr = 0;
-                outcnt = 0;             /* bytes in output buffer */
-                bytes_out = 0;
-                crc = (ulg)0xffffffffL; /* shift register contents */
-                makecrc();
-                gunzip();
+                decompress = decompress_method(buf, len, NULL);
+                if (decompress)
+                        decompress(buf, len, NULL, flush_buffer, NULL,
+                                   &my_inptr, error);
                 if (state != Reset)
-                        error("junk in gzipped archive");
-                this_header = saved_offset + inptr;
-                buf += inptr;
-                len -= inptr;
+                        error("junk in compressed archive");
+                this_header = saved_offset + my_inptr;
+                buf += my_inptr;
+                len -= my_inptr;
         }
         dir_utime();
-        kfree(window);
         kfree(name_buf);
         kfree(symlink_buf);
         kfree(header_buf);