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 #include <asm/page.h>
  15
  16 /*
  17  * gzip declarations
  18  */
  19
  20 #define OF(args)  args
  21 #define STATIC static
  22
  23 #undef memset
  24 #undef memcpy
  25 #define memzero(s, n)     memset ((s), 0, (n))
  26
  27 typedef unsigned char  uch;
  28 typedef unsigned short ush;
  29 typedef unsigned long  ulg;
  30
  31 #define WSIZE 0x8000            /* Window size must be at least 32k, */
  32                                 /* and a power of two */
  33
  34 static uch *inbuf;           /* input buffer */
  35 static uch window[WSIZE];    /* Sliding window buffer */
  36
  37 static unsigned insize = 0;  /* valid bytes in inbuf */
  38 static unsigned inptr = 0;   /* index of next byte to be processed in inbuf */
  39 static unsigned outcnt = 0;  /* bytes in output buffer */
  40
  41 /* gzip flag byte */
  42 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
  43 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
  44 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
  45 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
  46 #define COMMENT      0x10 /* bit 4 set: file comment present */
  47 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
  48 #define RESERVED     0xC0 /* bit 6,7:   reserved */
  49
  50 #define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())
  51
  52 /* Diagnostic functions */
  53 #ifdef DEBUG
  54 #  define Assert(cond,msg) {if(!(cond)) error(msg);}
  55 #  define Trace(x) fprintf x
  56 #  define Tracev(x) {if (verbose) fprintf x ;}
  57 #  define Tracevv(x) {if (verbose>1) fprintf x ;}
  58 #  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
  59 #  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
  60 #else
  61 #  define Assert(cond,msg)
  62 #  define Trace(x)
  63 #  define Tracev(x)
  64 #  define Tracevv(x)
  65 #  define Tracec(c,x)
  66 #  define Tracecv(c,x)
  67 #endif
  68
  69 static int  fill_inbuf(void);
  70 static void flush_window(void);
  71 static void error(char *m);
  72 static void gzip_mark(void **);
  73 static void gzip_release(void **);
  74
  75 /*
  76  * This is set up by the setup-routine at boot-time
  77  */
  78 static unsigned char *real_mode; /* Pointer to real-mode data */
  79
  80 #define EXT_MEM_K   (*(unsigned short *)(real_mode + 0x2))
  81 #ifndef STANDARD_MEMORY_BIOS_CALL
  82 #define ALT_MEM_K   (*(unsigned long *)(real_mode + 0x1e0))
  83 #endif
  84 #define SCREEN_INFO (*(struct screen_info *)(real_mode+0))
  85
  86 extern char input_data[];
  87 extern int input_len;
  88
  89 static long bytes_out = 0;
  90 static uch *output_data;
  91 static unsigned long output_ptr = 0;
  92
  93 static void *malloc(int size);
  94 static void free(void *where);
  95
  96 void* memset(void* s, int c, unsigned n);
  97 void* memcpy(void* dest, const void* src, unsigned n);
  98
  99 static void putstr(const char *);
 100
 101 extern int end;
 102 static long free_mem_ptr = (long)&end;
 103 static long free_mem_end_ptr;
 104
 105 #define INPLACE_MOVE_ROUTINE  0x1000
 106 #define LOW_BUFFER_START      0x2000
 107 #define LOW_BUFFER_MAX       0x90000
 108 #define HEAP_SIZE             0x3000
 109 static unsigned int low_buffer_end, low_buffer_size;
 110 static int high_loaded =0;
 111 static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/;
 112
 113 static char *vidmem = (char *)0xb8000;
 114 static int vidport;
 115 static int lines, cols;
 116
 117 #include "../../../../lib/inflate.c"
 118
 119 static void *malloc(int size)
 120 {
 121         void *p;
 122
 123         if (size <0) error("Malloc error");
 124         if (free_mem_ptr <= 0) error("Memory error");
 125
 126         free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
 127
 128         p = (void *)free_mem_ptr;
 129         free_mem_ptr += size;
 130
 131         if (free_mem_ptr >= free_mem_end_ptr)
 132                 error("Out of memory");
 133
 134         return p;
 135 }
 136
 137 static void free(void *where)
 138 {       /* Don't care */
 139 }
 140
 141 static void gzip_mark(void **ptr)
 142 {
 143         *ptr = (void *) free_mem_ptr;
 144 }
 145
 146 static void gzip_release(void **ptr)
 147 {
 148         free_mem_ptr = (long) *ptr;
 149 }
 150
 151 static void scroll(void)
 152 {
 153         int i;
 154
 155         memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
 156         for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
 157                 vidmem[i] = ' ';
 158 }
 159
 160 static void putstr(const char *s)
 161 {
 162         int x,y,pos;
 163         char c;
 164
 165         x = SCREEN_INFO.orig_x;
 166         y = SCREEN_INFO.orig_y;
 167
 168         while ( ( c = *s++ ) != '\0' ) {
 169                 if ( c == '\n' ) {
 170                         x = 0;
 171                         if ( ++y >= lines ) {
 172                                 scroll();
 173                                 y--;
 174                         }
 175                 } else {
 176                         vidmem [ ( x + cols * y ) * 2 ] = c;
 177                         if ( ++x >= cols ) {
 178                                 x = 0;
 179                                 if ( ++y >= lines ) {
 180                                         scroll();
 181                                         y--;
 182                                 }
 183                         }
 184                 }
 185         }
 186
 187         SCREEN_INFO.orig_x = x;
 188         SCREEN_INFO.orig_y = y;
 189
 190         pos = (x + cols * y) * 2;       /* Update cursor position */
 191         outb_p(14, vidport);
 192         outb_p(0xff & (pos >> 9), vidport+1);
 193         outb_p(15, vidport);
 194         outb_p(0xff & (pos >> 1), vidport+1);
 195 }
 196
 197 void* memset(void* s, int c, unsigned n)
 198 {
 199         int i;
 200         char *ss = (char*)s;
 201
 202         for (i=0;i<n;i++) ss[i] = c;
 203         return s;
 204 }
 205
 206 void* memcpy(void* dest, const void* src, unsigned n)
 207 {
 208         int i;
 209         char *d = (char *)dest, *s = (char *)src;
 210
 211         for (i=0;i<n;i++) d[i] = s[i];
 212         return dest;
 213 }
 214
 215 /* ===========================================================================
 216  * Fill the input buffer. This is called only when the buffer is empty
 217  * and at least one byte is really needed.
 218  */
 219 static int fill_inbuf(void)
 220 {
 221         if (insize != 0) {
 222                 error("ran out of input data");
 223         }
 224
 225         inbuf = input_data;
 226         insize = input_len;
 227         inptr = 1;
 228         return inbuf[0];
 229 }
 230
 231 /* ===========================================================================
 232  * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 233  * (Used for the decompressed data only.)
 234  */
 235 static void flush_window_low(void)
 236 {
 237     ulg c = crc;         /* temporary variable */
 238     unsigned n;
 239     uch *in, *out, ch;
 240
 241     in = window;
 242     out = &output_data[output_ptr];
 243     for (n = 0; n < outcnt; n++) {
 244             ch = *out++ = *in++;
 245             c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 246     }
 247     crc = c;
 248     bytes_out += (ulg)outcnt;
 249     output_ptr += (ulg)outcnt;
 250     outcnt = 0;
 251 }
 252
 253 static void flush_window_high(void)
 254 {
 255     ulg c = crc;         /* temporary variable */
 256     unsigned n;
 257     uch *in,  ch;
 258     in = window;
 259     for (n = 0; n < outcnt; n++) {
 260         ch = *output_data++ = *in++;
 261         if ((ulg)output_data == low_buffer_end) output_data=high_buffer_start;
 262         c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 263     }
 264     crc = c;
 265     bytes_out += (ulg)outcnt;
 266     outcnt = 0;
 267 }
 268
 269 static void flush_window(void)
 270 {
 271         if (high_loaded) flush_window_high();
 272         else flush_window_low();
 273 }
 274
 275 static void error(char *x)
 276 {
 277         putstr("\n\n");
 278         putstr(x);
 279         putstr("\n\n -- System halted");
 280
 281         while(1);
 282 }
 283
 284 void setup_normal_output_buffer(void)
 285 {
 286 #ifdef STANDARD_MEMORY_BIOS_CALL
 287         if (EXT_MEM_K < 1024) error("Less than 2MB of memory");
 288 #else
 289         if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < 1024) error("Less than 2MB of memory");
 290 #endif
 291         output_data = (char *)__PHYSICAL_START; /* Normally Points to 1M */
 292         free_mem_end_ptr = (long)real_mode;
 293 }
 294
 295 struct moveparams {
 296         uch *low_buffer_start;  int lcount;
 297         uch *high_buffer_start; int hcount;
 298 };
 299
 300 void setup_output_buffer_if_we_run_high(struct moveparams *mv)
 301 {
 302         high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE);
 303 #ifdef STANDARD_MEMORY_BIOS_CALL
 304         if (EXT_MEM_K < (3*1024)) error("Less than 4MB of memory");
 305 #else
 306         if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < (3*1024)) error("Less than 4MB of memory");
 307 #endif
 308         mv->low_buffer_start = output_data = (char *)LOW_BUFFER_START;
 309         low_buffer_end = ((unsigned int)real_mode > LOW_BUFFER_MAX
 310           ? LOW_BUFFER_MAX : (unsigned int)real_mode) & ~0xfff;
 311         low_buffer_size = low_buffer_end - LOW_BUFFER_START;
 312         high_loaded = 1;
 313         free_mem_end_ptr = (long)high_buffer_start;
 314         if ( (__PHYSICAL_START + low_buffer_size) > ((ulg)high_buffer_start)) {
 315                 high_buffer_start = (uch *)(__PHYSICAL_START + low_buffer_size);
 316                 mv->hcount = 0; /* say: we need not to move high_buffer */
 317         }
 318         else mv->hcount = -1;
 319         mv->high_buffer_start = high_buffer_start;
 320 }
 321
 322 void close_output_buffer_if_we_run_high(struct moveparams *mv)
 323 {
 324         if (bytes_out > low_buffer_size) {
 325                 mv->lcount = low_buffer_size;
 326                 if (mv->hcount)
 327                         mv->hcount = bytes_out - low_buffer_size;
 328         } else {
 329                 mv->lcount = bytes_out;
 330                 mv->hcount = 0;
 331         }
 332 }
 333
 334 int decompress_kernel(struct moveparams *mv, void *rmode)
 335 {
 336         real_mode = rmode;
 337
 338         if (SCREEN_INFO.orig_video_mode == 7) {
 339                 vidmem = (char *) 0xb0000;
 340                 vidport = 0x3b4;
 341         } else {
 342                 vidmem = (char *) 0xb8000;
 343                 vidport = 0x3d4;
 344         }
 345
 346         lines = SCREEN_INFO.orig_video_lines;
 347         cols = SCREEN_INFO.orig_video_cols;
 348
 349         if (free_mem_ptr < 0x100000) setup_normal_output_buffer();
 350         else setup_output_buffer_if_we_run_high(mv);
 351
 352         makecrc();
 353         putstr(".\nDecompressing Linux...");
 354         gunzip();
 355         putstr("done.\nBooting the kernel.\n");
 356         if (high_loaded) close_output_buffer_if_we_run_high(mv);
 357         return high_loaded;
 358 }