root/arch/i386/boot/compressed/misc.c

/* */

DEFINITIONS

1. malloc
2. free
3. gzip_mark
4. gzip_release
5. scroll
6. puts
7. memset
8. memcpy
9. fill_inbuf
10. flush_window_low
11. flush_window_high
12. flush_window
13. error
14. gzip_mark
15. gzip_release
16. main
17. setup_normal_output_buffer
18. setup_output_buffer_if_we_run_high
19. close_output_buffer_if_we_run_high
20. decompress_kernel

   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 <string.h>
  13 
  14 #include <asm/segment.h>
  15 #include <asm/io.h>
  16 
  17 /*
  18  * gzip declarations
  19  */
  20 
  21 #define OF(args)  args
  22 #define STATIC static
  23 
  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  * These are set up by the setup-routine at boot-time:
  76  */
  77 
  78 struct screen_info {
  79         unsigned char  orig_x;
  80         unsigned char  orig_y;
  81         unsigned char  unused1[2];
  82         unsigned short orig_video_page;
  83         unsigned char  orig_video_mode;
  84         unsigned char  orig_video_cols;
  85         unsigned short unused2;
  86         unsigned short orig_video_ega_bx;
  87         unsigned short unused3;
  88         unsigned char  orig_video_lines;
  89         unsigned char  orig_video_isVGA;
  90 };
  91 
  92 /*
  93  * This is set up by the setup-routine at boot-time
  94  */
  95 #define EXT_MEM_K (*(unsigned short *)0x90002)
  96 #define DRIVE_INFO (*(struct drive_info *)0x90080)
  97 #define SCREEN_INFO (*(struct screen_info *)0x90000)
  98 #define RAMDISK_SIZE (*(unsigned short *)0x901F8)
  99 #define ORIG_ROOT_DEV (*(unsigned short *)0x901FC)
 100 #define AUX_DEVICE_INFO (*(unsigned char *)0x901FF)
 101 
 102 extern char input_data[];
 103 extern int input_len;
 104 
 105 static long bytes_out = 0;
 106 static uch *output_data;
 107 static unsigned long output_ptr = 0;
 108 
 109  
 110 static void *malloc(int size);
 111 static void free(void *where);
 112 static void error(char *m);
 113 static void gzip_mark(void **);
 114 static void gzip_release(void **);
 115  
 116 #ifndef STANDALONE_DEBUG
 117 static void puts(const char *);
 118   
 119 extern int end;
 120 static long free_mem_ptr = (long)&end;
 121 static long free_mem_end_ptr = 0x90000;
 122  
 123 #define INPLACE_MOVE_ROUTINE  0x1000
 124 #define LOW_BUFFER_START      0x2000
 125 #define LOW_BUFFER_END       0x90000
 126 #define LOW_BUFFER_SIZE      ( LOW_BUFFER_END - LOW_BUFFER_START )
 127 #define HEAP_SIZE             0x2000
 128 static int high_loaded =0;
 129 static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/;
 130 
 131 static char *vidmem = (char *)0xb8000;
 132 static int vidport;
 133 static int lines, cols;
 134 
 135 #include "../../../../lib/inflate.c"
 136 
 137 static void *malloc(int size)
     /*  */
 138 {
 139         void *p;
 140 
 141         if (size <0) error("Malloc error\n");
 142         if (free_mem_ptr <= 0) error("Memory error\n");
 143 
 144         free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
 145 
 146         p = (void *)free_mem_ptr;
 147         free_mem_ptr += size;
 148 
 149         if (free_mem_ptr >= free_mem_end_ptr)
 150                 error("\nOut of memory\n");
 151 
 152         return p;
 153 }
 154 
 155 static void free(void *where)
     /*  */
 156 {       /* Don't care */
 157 }
 158 
 159 static void gzip_mark(void **ptr)
     /*  */
 160 {
 161         *ptr = (void *) free_mem_ptr;
 162 }
 163 
 164 static void gzip_release(void **ptr)
     /*  */
 165 {
 166         free_mem_ptr = (long) *ptr;
 167 }
 168  
 169 static void scroll()
     /*  */
 170 {
 171         int i;
 172 
 173         memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
 174         for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
 175                 vidmem[i] = ' ';
 176 }
 177 
 178 static void puts(const char *s)
     /*  */
 179 {
 180         int x,y,pos;
 181         char c;
 182 
 183         x = SCREEN_INFO.orig_x;
 184         y = SCREEN_INFO.orig_y;
 185 
 186         while ( ( c = *s++ ) != '\0' ) {
 187                 if ( c == '\n' ) {
 188                         x = 0;
 189                         if ( ++y >= lines ) {
 190                                 scroll();
 191                                 y--;
 192                         }
 193                 } else {
 194                         vidmem [ ( x + cols * y ) * 2 ] = c; 
 195                         if ( ++x >= cols ) {
 196                                 x = 0;
 197                                 if ( ++y >= lines ) {
 198                                         scroll();
 199                                         y--;
 200                                 }
 201                         }
 202                 }
 203         }
 204 
 205         SCREEN_INFO.orig_x = x;
 206         SCREEN_INFO.orig_y = y;
 207 
 208         pos = (x + cols * y) * 2;       /* Update cursor position */
 209         outb_p(14, vidport);
 210         outb_p(0xff & (pos >> 9), vidport+1);
 211         outb_p(15, vidport);
 212         outb_p(0xff & (pos >> 1), vidport+1);
 213 }
 214 
 215 __ptr_t memset(__ptr_t s, int c, size_t n)
     /*  */
 216 {
 217         int i;
 218         char *ss = (char*)s;
 219 
 220         for (i=0;i<n;i++) ss[i] = c;
 221 }
 222 
 223 __ptr_t memcpy(__ptr_t __dest, __const __ptr_t __src,
     /*  */
 224                             size_t __n)
 225 {
 226         int i;
 227         char *d = (char *)__dest, *s = (char *)__src;
 228 
 229         for (i=0;i<__n;i++) d[i] = s[i];
 230 }
 231 #endif
 232 
 233 /* ===========================================================================
 234  * Fill the input buffer. This is called only when the buffer is empty
 235  * and at least one byte is really needed.
 236  */
 237 static int fill_inbuf()
     /*  */
 238 {
 239         if (insize != 0) {
 240                 error("ran out of input data\n");
 241         }
 242 
 243         inbuf = input_data;
 244         insize = input_len;
 245         inptr = 1;
 246         return inbuf[0];
 247 }
 248 
 249 /* ===========================================================================
 250  * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 251  * (Used for the decompressed data only.)
 252  */
 253 static void flush_window_low()
     /*  */
 254 {
 255     ulg c = crc;         /* temporary variable */
 256     unsigned n;
 257     uch *in, *out, ch;
 258     
 259     in = window;
 260     out = &output_data[output_ptr]; 
 261     for (n = 0; n < outcnt; n++) {
 262             ch = *out++ = *in++;
 263             c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 264     }
 265     crc = c;
 266     bytes_out += (ulg)outcnt;
 267     output_ptr += (ulg)outcnt;
 268     outcnt = 0;
 269 }
 270 
 271 static void flush_window_high()
     /*  */
 272 {
 273     ulg c = crc;         /* temporary variable */
 274     unsigned n;
 275     uch *in,  ch;
 276     in = window;
 277     for (n = 0; n < outcnt; n++) {
 278         ch = *output_data++ = *in++;
 279         if ((ulg)output_data == LOW_BUFFER_END) output_data=high_buffer_start;
 280         c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 281     }
 282     crc = c;
 283     bytes_out += (ulg)outcnt;
 284     outcnt = 0;
 285 }
 286 
 287 static void flush_window()
     /*  */
 288 {
 289         if (high_loaded) flush_window_high();
 290         else flush_window_low();
 291 }
 292 
 293 static void error(char *x)
     /*  */
 294 {
 295         puts("\n\n");
 296         puts(x);
 297         puts("\n\n -- System halted");
 298 
 299         while(1);       /* Halt */
 300 }
 301 
 302 #define STACK_SIZE (4096)
 303 
 304 long user_stack [STACK_SIZE];
 305 
 306 struct {
 307         long * a;
 308         short b;
 309         } stack_start = { & user_stack [STACK_SIZE] , KERNEL_DS };
 310 
 311 #ifdef STANDALONE_DEBUG
 312 
 313 static void gzip_mark(void **ptr)
     /*  */
 314 {
 315 }
 316 
 317 static void gzip_release(void **ptr)
     /*  */
 318 {
 319 }
 320 
 321 char output_buffer[1024 * 800];
 322 
 323 int
 324 main(argc, argv)
     /*  */
 325         int     argc;
 326         char    **argv;
 327 {
 328         output_data = output_buffer;
 329 
 330         makecrc();
 331         puts("Uncompressing Linux...");
 332         gunzip();
 333         puts("done.\n");
 334         return 0;
 335 }
 336 
 337 #else
 338 
 339 void setup_normal_output_buffer()
     /*  */
 340 {
 341         if (EXT_MEM_K < 1024) error("Less than 2MB of memory.\n");
 342         output_data = (char *)0x100000; /* Points to 1M */
 343 }
 344 
 345 struct moveparams {
 346         uch *low_buffer_start;  int lcount;
 347         uch *high_buffer_start; int hcount;
 348 };
 349 
 350 void setup_output_buffer_if_we_run_high(struct moveparams *mv)
     /*  */
 351 {
 352         high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE);
 353         if (EXT_MEM_K < (4*1024)) error("Less than 4MB of memory.\n");
 354         mv->low_buffer_start = output_data = (char *)LOW_BUFFER_START;
 355         high_loaded = 1;
 356         free_mem_end_ptr = (long)high_buffer_start;
 357         if ( (0x100000 + LOW_BUFFER_SIZE) > ((ulg)high_buffer_start)) {
 358                 high_buffer_start = (uch *)(0x100000 + LOW_BUFFER_SIZE);
 359                 mv->hcount = 0; /* say: we need not to move high_buffer */
 360         }
 361         else mv->hcount = -1;
 362         mv->high_buffer_start = high_buffer_start;
 363 }
 364 
 365 void close_output_buffer_if_we_run_high(struct moveparams *mv)
     /*  */
 366 {
 367         mv->lcount = bytes_out;
 368         if (bytes_out > LOW_BUFFER_SIZE) {
 369                 mv->lcount = LOW_BUFFER_SIZE;
 370                 if (mv->hcount) mv->hcount = bytes_out - LOW_BUFFER_SIZE;
 371         }
 372         else mv->hcount = 0;
 373 }
 374 
 375 
 376 int decompress_kernel(struct moveparams *mv)
     /*  */
 377 {
 378         if (SCREEN_INFO.orig_video_mode == 7) {
 379                 vidmem = (char *) 0xb0000;
 380                 vidport = 0x3b4;
 381         } else {
 382                 vidmem = (char *) 0xb8000;
 383                 vidport = 0x3d4;
 384         }
 385 
 386         lines = SCREEN_INFO.orig_video_lines;
 387         cols = SCREEN_INFO.orig_video_cols;
 388 
 389         if (free_mem_ptr < 0x100000) setup_normal_output_buffer();
 390         else setup_output_buffer_if_we_run_high(mv);
 391 
 392         makecrc();
 393         puts("Uncompressing Linux...");
 394         gunzip();
 395         puts("done.\nNow booting the kernel\n");
 396         if (high_loaded) close_output_buffer_if_we_run_high(mv);
 397         return high_loaded;
 398 }
 399 #endif
 400 
 401 
 402 
 403 

/* */