root/arch/alpha/boot/misc.c

DEFINITIONS

1. fill_inbuf
2. flush_window
3. error
4. decompress_kernel

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * misc.c
   4  * 
   5  * This is a collection of several routines from gzip-1.0.3 
   6  * adapted for Linux.
   7  *
   8  * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
   9  *
  10  * Modified for ARM Linux by Russell King
  11  *
  12  * Nicolas Pitre <nico@visuaide.com>  1999/04/14 :
  13  *  For this code to run directly from Flash, all constant variables must
  14  *  be marked with 'const' and all other variables initialized at run-time 
  15  *  only.  This way all non constant variables will end up in the bss segment,
  16  *  which should point to addresses in RAM and cleared to 0 on start.
  17  *  This allows for a much quicker boot time.
  18  *
  19  * Modified for Alpha, from the ARM version, by Jay Estabrook 2003.
  20  */
  21 
  22 #include <linux/kernel.h>
  23 #include <linux/slab.h>
  24 
  25 #include <linux/uaccess.h>
  26 
  27 #define memzero(s,n)    memset ((s),0,(n))
  28 #define puts            srm_printk
  29 extern long srm_printk(const char *, ...)
  30      __attribute__ ((format (printf, 1, 2)));
  31 
  32 /*
  33  * gzip delarations
  34  */
  35 #define OF(args)  args
  36 #define STATIC static
  37 
  38 typedef unsigned char  uch;
  39 typedef unsigned short ush;
  40 typedef unsigned long  ulg;
  41 
  42 #define WSIZE 0x8000            /* Window size must be at least 32k, */
  43                                 /* and a power of two */
  44 
  45 static uch *inbuf;              /* input buffer */
  46 static uch *window;             /* Sliding window buffer */
  47 
  48 static unsigned insize;         /* valid bytes in inbuf */
  49 static unsigned inptr;          /* index of next byte to be processed in inbuf */
  50 static unsigned outcnt;         /* bytes in output buffer */
  51 
  52 /* gzip flag byte */
  53 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
  54 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
  55 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
  56 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
  57 #define COMMENT      0x10 /* bit 4 set: file comment present */
  58 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
  59 #define RESERVED     0xC0 /* bit 6,7:   reserved */
  60 
  61 #define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())
  62 
  63 /* Diagnostic functions */
  64 #ifdef DEBUG
  65 #  define Assert(cond,msg) {if(!(cond)) error(msg);}
  66 #  define Trace(x) fprintf x
  67 #  define Tracev(x) {if (verbose) fprintf x ;}
  68 #  define Tracevv(x) {if (verbose>1) fprintf x ;}
  69 #  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
  70 #  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
  71 #else
  72 #  define Assert(cond,msg)
  73 #  define Trace(x)
  74 #  define Tracev(x)
  75 #  define Tracevv(x)
  76 #  define Tracec(c,x)
  77 #  define Tracecv(c,x)
  78 #endif
  79 
  80 static int  fill_inbuf(void);
  81 static void flush_window(void);
  82 static void error(char *m);
  83 
  84 static char *input_data;
  85 static int  input_data_size;
  86 
  87 static uch *output_data;
  88 static ulg output_ptr;
  89 static ulg bytes_out;
  90 
  91 static void error(char *m);
  92 static void gzip_mark(void **);
  93 static void gzip_release(void **);
  94 
  95 extern int end;
  96 static ulg free_mem_ptr;
  97 static ulg free_mem_end_ptr;
  98 
  99 #define HEAP_SIZE 0x3000
 100 
 101 #include "../../../lib/inflate.c"
 102 
 103 /* ===========================================================================
 104  * Fill the input buffer. This is called only when the buffer is empty
 105  * and at least one byte is really needed.
 106  */
 107 int fill_inbuf(void)
 108 {
 109         if (insize != 0)
 110                 error("ran out of input data");
 111 
 112         inbuf = input_data;
 113         insize = input_data_size;
 114 
 115         inptr = 1;
 116         return inbuf[0];
 117 }
 118 
 119 /* ===========================================================================
 120  * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 121  * (Used for the decompressed data only.)
 122  */
 123 void flush_window(void)
 124 {
 125         ulg c = crc;
 126         unsigned n;
 127         uch *in, *out, ch;
 128 
 129         in = window;
 130         out = &output_data[output_ptr];
 131         for (n = 0; n < outcnt; n++) {
 132                 ch = *out++ = *in++;
 133                 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 134         }
 135         crc = c;
 136         bytes_out += (ulg)outcnt;
 137         output_ptr += (ulg)outcnt;
 138         outcnt = 0;
 139 /*      puts("."); */
 140 }
 141 
 142 static void error(char *x)
 143 {
 144         puts("\n\n");
 145         puts(x);
 146         puts("\n\n -- System halted");
 147 
 148         while(1);       /* Halt */
 149 }
 150 
 151 unsigned int
 152 decompress_kernel(void *output_start,
 153                   void *input_start,
 154                   size_t ksize,
 155                   size_t kzsize)
 156 {
 157         output_data             = (uch *)output_start;
 158         input_data              = (uch *)input_start;
 159         input_data_size         = kzsize; /* use compressed size */
 160 
 161         /* FIXME FIXME FIXME */
 162         free_mem_ptr            = (ulg)output_start + ksize;
 163         free_mem_end_ptr        = (ulg)output_start + ksize + 0x200000;
 164         /* FIXME FIXME FIXME */
 165 
 166         /* put in temp area to reduce initial footprint */
 167         window = malloc(WSIZE);
 168 
 169         makecrc();
 170 /*      puts("Uncompressing Linux..."); */
 171         gunzip();
 172 /*      puts(" done, booting the kernel.\n"); */
 173         return output_ptr;
 174 }