arch/x86_64/boot/compressed/misc.c

   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  * puts by Nick Holloway 1993, better puts by Martin Mares 1995
   9  * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
  10  */
  11
  12 #include "miscsetup.h"
  13 #include <asm/io.h>
  14
  15 /*
  16  * gzip declarations
  17  */
  18
  19 #define OF(args)  args
  20 #define STATIC static
  21
  22 #undef memset
  23 #undef memcpy
  24 #define memzero(s, n)     memset ((s), 0, (n))
  25
  26 typedef unsigned char  uch;
  27 typedef unsigned short ush;
  28 typedef unsigned long  ulg;
  29
  30 #define WSIZE 0x8000            /* Window size must be at least 32k, */
  31                                 /* and a power of two */
  32
  33 static uch *inbuf;           /* input buffer */
  34 static uch window[WSIZE];    /* Sliding window buffer */
  35
  36 static unsigned insize = 0;  /* valid bytes in inbuf */
  37 static unsigned inptr = 0;   /* index of next byte to be processed in inbuf */
  38 static unsigned outcnt = 0;  /* bytes in output buffer */
  39
  40 /* gzip flag byte */
  41 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
  42 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
  43 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
  44 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
  45 #define COMMENT      0x10 /* bit 4 set: file comment present */
  46 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
  47 #define RESERVED     0xC0 /* bit 6,7:   reserved */
  48
  49 #define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())
  50
  51 /* Diagnostic functions */
  52 #ifdef DEBUG
  53 #  define Assert(cond,msg) {if(!(cond)) error(msg);}
  54 #  define Trace(x) fprintf x
  55 #  define Tracev(x) {if (verbose) fprintf x ;}
  56 #  define Tracevv(x) {if (verbose>1) fprintf x ;}
  57 #  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
  58 #  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
  59 #else
  60 #  define Assert(cond,msg)
  61 #  define Trace(x)
  62 #  define Tracev(x)
  63 #  define Tracevv(x)
  64 #  define Tracec(c,x)
  65 #  define Tracecv(c,x)
  66 #endif
  67
  68 static int  fill_inbuf(void);
  69 static void flush_window(void);
  70 static void error(char *m);
  71 static void gzip_mark(void **);
  72 static void gzip_release(void **);
  73
  74 /*
  75  * This is set up by the setup-routine at boot-time
  76  */
  77 static unsigned char *real_mode; /* Pointer to real-mode data */
  78
  79 #define EXT_MEM_K   (*(unsigned short *)(real_mode + 0x2))
  80 #ifndef STANDARD_MEMORY_BIOS_CALL
  81 #define ALT_MEM_K   (*(unsigned long *)(real_mode + 0x1e0))
  82 #endif
  83 #define SCREEN_INFO (*(struct screen_info *)(real_mode+0))
  84
  85 extern char input_data[];
  86 extern int input_len;
  87
  88 static long bytes_out = 0;
  89 static uch *output_data;
  90 static unsigned long output_ptr = 0;
  91
  92 static void *malloc(int size);
  93 static void free(void *where);
  94
  95 static void putstr(const char *);
  96
  97 extern int end;
  98 static long free_mem_ptr = (long)&end;
  99 static long free_mem_end_ptr;
 100
 101 #define INPLACE_MOVE_ROUTINE  0x1000
 102 #define LOW_BUFFER_START      0x2000
 103 #define LOW_BUFFER_MAX       0x90000
 104 #define HEAP_SIZE             0x3000
 105 static unsigned int low_buffer_end, low_buffer_size;
 106 static int high_loaded =0;
 107 static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/;
 108
 109 static char *vidmem = (char *)0xb8000;
 110 static int vidport;
 111 static int lines, cols;
 112
 113 #include "../../../../lib/inflate.c"
 114
 115 static void *malloc(int size)
 116 {
 117         void *p;
 118
 119         if (size <0) error("Malloc error");
 120         if (free_mem_ptr <= 0) error("Memory error");
 121
 122         free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
 123
 124         p = (void *)free_mem_ptr;
 125         free_mem_ptr += size;
 126
 127         if (free_mem_ptr >= free_mem_end_ptr)
 128                 error("Out of memory");
 129
 130         return p;
 131 }
 132
 133 static void free(void *where)
 134 {       /* Don't care */
 135 }
 136
 137 static void gzip_mark(void **ptr)
 138 {
 139         *ptr = (void *) free_mem_ptr;
 140 }
 141
 142 static void gzip_release(void **ptr)
 143 {
 144         free_mem_ptr = (long) *ptr;
 145 }
 146
 147 static void scroll(void)
 148 {
 149         int i;
 150
 151         memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
 152         for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
 153                 vidmem[i] = ' ';
 154 }
 155
 156 static void putstr(const char *s)
 157 {
 158         int x,y,pos;
 159         char c;
 160
 161         x = SCREEN_INFO.orig_x;
 162         y = SCREEN_INFO.orig_y;
 163
 164         while ( ( c = *s++ ) != '\0' ) {
 165                 if ( c == '\n' ) {
 166                         x = 0;
 167                         if ( ++y >= lines ) {
 168                                 scroll();
 169                                 y--;
 170                         }
 171                 } else {
 172                         vidmem [ ( x + cols * y ) * 2 ] = c;
 173                         if ( ++x >= cols ) {
 174                                 x = 0;
 175                                 if ( ++y >= lines ) {
 176                                         scroll();
 177                                         y--;
 178                                 }
 179                         }
 180                 }
 181         }
 182
 183         SCREEN_INFO.orig_x = x;
 184         SCREEN_INFO.orig_y = y;
 185
 186         pos = (x + cols * y) * 2;       /* Update cursor position */
 187         outb_p(14, vidport);
 188         outb_p(0xff & (pos >> 9), vidport+1);
 189         outb_p(15, vidport);
 190         outb_p(0xff & (pos >> 1), vidport+1);
 191 }
 192
 193 void* memset(void* s, int c, unsigned n)
 194 {
 195         int i;
 196         char *ss = (char*)s;
 197
 198         for (i=0;i<n;i++) ss[i] = c;
 199         return s;
 200 }
 201
 202 void* memcpy(void* dest, const void* src, unsigned n)
 203 {
 204         int i;
 205         char *d = (char *)dest, *s = (char *)src;
 206
 207         for (i=0;i<n;i++) d[i] = s[i];
 208         return dest;
 209 }
 210
 211 /* ===========================================================================
 212  * Fill the input buffer. This is called only when the buffer is empty
 213  * and at least one byte is really needed.
 214  */
 215 static int fill_inbuf(void)
 216 {
 217         if (insize != 0) {
 218                 error("ran out of input data");
 219         }
 220
 221         inbuf = input_data;
 222         insize = input_len;
 223         inptr = 1;
 224         return inbuf[0];
 225 }
 226
 227 /* ===========================================================================
 228  * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 229  * (Used for the decompressed data only.)
 230  */
 231 static void flush_window_low(void)
 232 {
 233     ulg c = crc;         /* temporary variable */
 234     unsigned n;
 235     uch *in, *out, ch;
 236
 237     in = window;
 238     out = &output_data[output_ptr];
 239     for (n = 0; n < outcnt; n++) {
 240             ch = *out++ = *in++;
 241             c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 242     }
 243     crc = c;
 244     bytes_out += (ulg)outcnt;
 245     output_ptr += (ulg)outcnt;
 246     outcnt = 0;
 247 }
 248
 249 static void flush_window_high(void)
 250 {
 251     ulg c = crc;         /* temporary variable */
 252     unsigned n;
 253     uch *in,  ch;
 254     in = window;
 255     for (n = 0; n < outcnt; n++) {
 256         ch = *output_data++ = *in++;
 257         if ((ulg)output_data == low_buffer_end) output_data=high_buffer_start;
 258         c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 259     }
 260     crc = c;
 261     bytes_out += (ulg)outcnt;
 262     outcnt = 0;
 263 }
 264
 265 static void flush_window(void)
 266 {
 267         if (high_loaded) flush_window_high();
 268         else flush_window_low();
 269 }
 270
 271 static void error(char *x)
 272 {
 273         putstr("\n\n");
 274         putstr(x);
 275         putstr("\n\n -- System halted");
 276
 277         while(1);
 278 }
 279
 280 void setup_normal_output_buffer(void)
 281 {
 282 #ifdef STANDARD_MEMORY_BIOS_CALL
 283         if (EXT_MEM_K < 1024) error("Less than 2MB of memory");
 284 #else
 285         if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < 1024) error("Less than 2MB of memory");
 286 #endif
 287         output_data = (char *)0x100000; /* Points to 1M */
 288         free_mem_end_ptr = (long)real_mode;
 289 }
 290
 291 struct moveparams {
 292         uch *low_buffer_start;  int lcount;
 293         uch *high_buffer_start; int hcount;
 294 };
 295
 296 void setup_output_buffer_if_we_run_high(struct moveparams *mv)
 297 {
 298         high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE);
 299 #ifdef STANDARD_MEMORY_BIOS_CALL
 300         if (EXT_MEM_K < (3*1024)) error("Less than 4MB of memory");
 301 #else
 302         if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < (3*1024)) error("Less than 4MB of memory");
 303 #endif
 304         mv->low_buffer_start = output_data = (char *)LOW_BUFFER_START;
 305         low_buffer_end = ((unsigned int)real_mode > LOW_BUFFER_MAX
 306           ? LOW_BUFFER_MAX : (unsigned int)real_mode) & ~0xfff;
 307         low_buffer_size = low_buffer_end - LOW_BUFFER_START;
 308         high_loaded = 1;
 309         free_mem_end_ptr = (long)high_buffer_start;
 310         if ( (0x100000 + low_buffer_size) > ((ulg)high_buffer_start)) {
 311                 high_buffer_start = (uch *)(0x100000 + low_buffer_size);
 312                 mv->hcount = 0; /* say: we need not to move high_buffer */
 313         }
 314         else mv->hcount = -1;
 315         mv->high_buffer_start = high_buffer_start;
 316 }
 317
 318 void close_output_buffer_if_we_run_high(struct moveparams *mv)
 319 {
 320         if (bytes_out > low_buffer_size) {
 321                 mv->lcount = low_buffer_size;
 322                 if (mv->hcount)
 323                         mv->hcount = bytes_out - low_buffer_size;
 324         } else {
 325                 mv->lcount = bytes_out;
 326                 mv->hcount = 0;
 327         }
 328 }
 329
 330 int decompress_kernel(struct moveparams *mv, void *rmode)
 331 {
 332         real_mode = rmode;
 333
 334         if (SCREEN_INFO.orig_video_mode == 7) {
 335                 vidmem = (char *) 0xb0000;
 336                 vidport = 0x3b4;
 337         } else {
 338                 vidmem = (char *) 0xb8000;
 339                 vidport = 0x3d4;
 340         }
 341
 342         lines = SCREEN_INFO.orig_video_lines;
 343         cols = SCREEN_INFO.orig_video_cols;
 344
 345         if (free_mem_ptr < 0x100000) setup_normal_output_buffer();
 346         else setup_output_buffer_if_we_run_high(mv);
 347
 348         makecrc();
 349         putstr(".\nDecompressing Linux...");
 350         gunzip();
 351         putstr("done.\nBooting the kernel.\n");
 352         if (high_loaded) close_output_buffer_if_we_run_high(mv);
 353         return high_loaded;
 354 }