linux/arch/alpha/boot/misc.c
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   1/*
   2 * misc.c
   3 * 
   4 * This is a collection of several routines from gzip-1.0.3 
   5 * adapted for Linux.
   6 *
   7 * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
   8 *
   9 * Modified for ARM Linux by Russell King
  10 *
  11 * Nicolas Pitre <nico@visuaide.com>  1999/04/14 :
  12 *  For this code to run directly from Flash, all constant variables must
  13 *  be marked with 'const' and all other variables initialized at run-time 
  14 *  only.  This way all non constant variables will end up in the bss segment,
  15 *  which should point to addresses in RAM and cleared to 0 on start.
  16 *  This allows for a much quicker boot time.
  17 *
  18 * Modified for Alpha, from the ARM version, by Jay Estabrook 2003.
  19 */
  20
  21#include <linux/kernel.h>
  22#include <linux/slab.h>
  23
  24#include <asm/uaccess.h>
  25
  26#define memzero(s,n)    memset ((s),0,(n))
  27#define puts            srm_printk
  28extern long srm_printk(const char *, ...)
  29     __attribute__ ((format (printf, 1, 2)));
  30
  31/*
  32 * gzip delarations
  33 */
  34#define OF(args)  args
  35#define STATIC static
  36
  37typedef unsigned char  uch;
  38typedef unsigned short ush;
  39typedef unsigned long  ulg;
  40
  41#define WSIZE 0x8000            /* Window size must be at least 32k, */
  42                                /* and a power of two */
  43
  44static uch *inbuf;              /* input buffer */
  45static uch *window;             /* Sliding window buffer */
  46
  47static unsigned insize;         /* valid bytes in inbuf */
  48static unsigned inptr;          /* index of next byte to be processed in inbuf */
  49static unsigned outcnt;         /* bytes in output buffer */
  50
  51/* gzip flag byte */
  52#define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
  53#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
  54#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
  55#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
  56#define COMMENT      0x10 /* bit 4 set: file comment present */
  57#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
  58#define RESERVED     0xC0 /* bit 6,7:   reserved */
  59
  60#define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())
  61
  62/* Diagnostic functions */
  63#ifdef DEBUG
  64#  define Assert(cond,msg) {if(!(cond)) error(msg);}
  65#  define Trace(x) fprintf x
  66#  define Tracev(x) {if (verbose) fprintf x ;}
  67#  define Tracevv(x) {if (verbose>1) fprintf x ;}
  68#  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
  69#  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
  70#else
  71#  define Assert(cond,msg)
  72#  define Trace(x)
  73#  define Tracev(x)
  74#  define Tracevv(x)
  75#  define Tracec(c,x)
  76#  define Tracecv(c,x)
  77#endif
  78
  79static int  fill_inbuf(void);
  80static void flush_window(void);
  81static void error(char *m);
  82
  83static char *input_data;
  84static int  input_data_size;
  85
  86static uch *output_data;
  87static ulg output_ptr;
  88static ulg bytes_out;
  89
  90static void error(char *m);
  91static void gzip_mark(void **);
  92static void gzip_release(void **);
  93
  94extern int end;
  95static ulg free_mem_ptr;
  96static ulg free_mem_end_ptr;
  97
  98#define HEAP_SIZE 0x3000
  99
 100#include "../../../lib/inflate.c"
 101
 102/* ===========================================================================
 103 * Fill the input buffer. This is called only when the buffer is empty
 104 * and at least one byte is really needed.
 105 */
 106int fill_inbuf(void)
 107{
 108        if (insize != 0)
 109                error("ran out of input data");
 110
 111        inbuf = input_data;
 112        insize = input_data_size;
 113
 114        inptr = 1;
 115        return inbuf[0];
 116}
 117
 118/* ===========================================================================
 119 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 120 * (Used for the decompressed data only.)
 121 */
 122void flush_window(void)
 123{
 124        ulg c = crc;
 125        unsigned n;
 126        uch *in, *out, ch;
 127
 128        in = window;
 129        out = &output_data[output_ptr];
 130        for (n = 0; n < outcnt; n++) {
 131                ch = *out++ = *in++;
 132                c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 133        }
 134        crc = c;
 135        bytes_out += (ulg)outcnt;
 136        output_ptr += (ulg)outcnt;
 137        outcnt = 0;
 138/*      puts("."); */
 139}
 140
 141static void error(char *x)
 142{
 143        puts("\n\n");
 144        puts(x);
 145        puts("\n\n -- System halted");
 146
 147        while(1);       /* Halt */
 148}
 149
 150unsigned int
 151decompress_kernel(void *output_start,
 152                  void *input_start,
 153                  size_t ksize,
 154                  size_t kzsize)
 155{
 156        output_data             = (uch *)output_start;
 157        input_data              = (uch *)input_start;
 158        input_data_size         = kzsize; /* use compressed size */
 159
 160        /* FIXME FIXME FIXME */
 161        free_mem_ptr            = (ulg)output_start + ksize;
 162        free_mem_end_ptr        = (ulg)output_start + ksize + 0x200000;
 163        /* FIXME FIXME FIXME */
 164
 165        /* put in temp area to reduce initial footprint */
 166        window = malloc(WSIZE);
 167
 168        makecrc();
 169/*      puts("Uncompressing Linux..."); */
 170        gunzip();
 171/*      puts(" done, booting the kernel.\n"); */
 172        return output_ptr;
 173}
 174
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