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 static void putstr(const char *);
  97
  98 extern int end;
  99 static long free_mem_ptr = (long)&end;
 100 static long free_mem_end_ptr;
 101
 102 #define INPLACE_MOVE_ROUTINE  0x1000
 103 #define LOW_BUFFER_START      0x2000
 104 #define LOW_BUFFER_MAX       0x90000
 105 #define HEAP_SIZE             0x3000
 106 static unsigned int low_buffer_end, low_buffer_size;
 107 static int high_loaded =0;
 108 static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/;
 109
 110 static char *vidmem = (char *)0xb8000;
 111 static int vidport;
 112 static int lines, cols;
 113
 114 #include "../../../../lib/inflate.c"
 115
 116 static void *malloc(int size)
 117 {
 118         void *p;
 119
 120         if (size <0) error("Malloc error");
 121         if (free_mem_ptr <= 0) error("Memory error");
 122
 123         free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
 124
 125         p = (void *)free_mem_ptr;
 126         free_mem_ptr += size;
 127
 128         if (free_mem_ptr >= free_mem_end_ptr)
 129                 error("Out of memory");
 130
 131         return p;
 132 }
 133
 134 static void free(void *where)
 135 {       /* Don't care */
 136 }
 137
 138 static void gzip_mark(void **ptr)
 139 {
 140         *ptr = (void *) free_mem_ptr;
 141 }
 142
 143 static void gzip_release(void **ptr)
 144 {
 145         free_mem_ptr = (long) *ptr;
 146 }
 147
 148 static void scroll(void)
 149 {
 150         int i;
 151
 152         memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
 153         for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
 154                 vidmem[i] = ' ';
 155 }
 156
 157 static void putstr(const char *s)
 158 {
 159         int x,y,pos;
 160         char c;
 161
 162         x = SCREEN_INFO.orig_x;
 163         y = SCREEN_INFO.orig_y;
 164
 165         while ( ( c = *s++ ) != '\0' ) {
 166                 if ( c == '\n' ) {
 167                         x = 0;
 168                         if ( ++y >= lines ) {
 169                                 scroll();
 170                                 y--;
 171                         }
 172                 } else {
 173                         vidmem [ ( x + cols * y ) * 2 ] = c;
 174                         if ( ++x >= cols ) {
 175                                 x = 0;
 176                                 if ( ++y >= lines ) {
 177                                         scroll();
 178                                         y--;
 179                                 }
 180                         }
 181                 }
 182         }
 183
 184         SCREEN_INFO.orig_x = x;
 185         SCREEN_INFO.orig_y = y;
 186
 187         pos = (x + cols * y) * 2;       /* Update cursor position */
 188         outb_p(14, vidport);
 189         outb_p(0xff & (pos >> 9), vidport+1);
 190         outb_p(15, vidport);
 191         outb_p(0xff & (pos >> 1), vidport+1);
 192 }
 193
 194 void* memset(void* s, int c, unsigned n)
 195 {
 196         int i;
 197         char *ss = (char*)s;
 198
 199         for (i=0;i<n;i++) ss[i] = c;
 200         return s;
 201 }
 202
 203 void* memcpy(void* dest, const void* src, unsigned n)
 204 {
 205         int i;
 206         char *d = (char *)dest, *s = (char *)src;
 207
 208         for (i=0;i<n;i++) d[i] = s[i];
 209         return dest;
 210 }
 211
 212 /* ===========================================================================
 213  * Fill the input buffer. This is called only when the buffer is empty
 214  * and at least one byte is really needed.
 215  */
 216 static int fill_inbuf(void)
 217 {
 218         if (insize != 0) {
 219                 error("ran out of input data");
 220         }
 221
 222         inbuf = input_data;
 223         insize = input_len;
 224         inptr = 1;
 225         return inbuf[0];
 226 }
 227
 228 /* ===========================================================================
 229  * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 230  * (Used for the decompressed data only.)
 231  */
 232 static void flush_window_low(void)
 233 {
 234     ulg c = crc;         /* temporary variable */
 235     unsigned n;
 236     uch *in, *out, ch;
 237
 238     in = window;
 239     out = &output_data[output_ptr];
 240     for (n = 0; n < outcnt; n++) {
 241             ch = *out++ = *in++;
 242             c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 243     }
 244     crc = c;
 245     bytes_out += (ulg)outcnt;
 246     output_ptr += (ulg)outcnt;
 247     outcnt = 0;
 248 }
 249
 250 static void flush_window_high(void)
 251 {
 252     ulg c = crc;         /* temporary variable */
 253     unsigned n;
 254     uch *in,  ch;
 255     in = window;
 256     for (n = 0; n < outcnt; n++) {
 257         ch = *output_data++ = *in++;
 258         if ((ulg)output_data == low_buffer_end) output_data=high_buffer_start;
 259         c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 260     }
 261     crc = c;
 262     bytes_out += (ulg)outcnt;
 263     outcnt = 0;
 264 }
 265
 266 static void flush_window(void)
 267 {
 268         if (high_loaded) flush_window_high();
 269         else flush_window_low();
 270 }
 271
 272 static void error(char *x)
 273 {
 274         putstr("\n\n");
 275         putstr(x);
 276         putstr("\n\n -- System halted");
 277
 278         while(1);
 279 }
 280
 281 void setup_normal_output_buffer(void)
 282 {
 283 #ifdef STANDARD_MEMORY_BIOS_CALL
 284         if (EXT_MEM_K < 1024) error("Less than 2MB of memory");
 285 #else
 286         if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < 1024) error("Less than 2MB of memory");
 287 #endif
 288         output_data = (char *)__PHYSICAL_START; /* Normally Points to 1M */
 289         free_mem_end_ptr = (long)real_mode;
 290 }
 291
 292 struct moveparams {
 293         uch *low_buffer_start;  int lcount;
 294         uch *high_buffer_start; int hcount;
 295 };
 296
 297 void setup_output_buffer_if_we_run_high(struct moveparams *mv)
 298 {
 299         high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE);
 300 #ifdef STANDARD_MEMORY_BIOS_CALL
 301         if (EXT_MEM_K < (3*1024)) error("Less than 4MB of memory");
 302 #else
 303         if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < (3*1024)) error("Less than 4MB of memory");
 304 #endif
 305         mv->low_buffer_start = output_data = (char *)LOW_BUFFER_START;
 306         low_buffer_end = ((unsigned int)real_mode > LOW_BUFFER_MAX
 307           ? LOW_BUFFER_MAX : (unsigned int)real_mode) & ~0xfff;
 308         low_buffer_size = low_buffer_end - LOW_BUFFER_START;
 309         high_loaded = 1;
 310         free_mem_end_ptr = (long)high_buffer_start;
 311         if ( (__PHYSICAL_START + low_buffer_size) > ((ulg)high_buffer_start)) {
 312                 high_buffer_start = (uch *)(__PHYSICAL_START + low_buffer_size);
 313                 mv->hcount = 0; /* say: we need not to move high_buffer */
 314         }
 315         else mv->hcount = -1;
 316         mv->high_buffer_start = high_buffer_start;
 317 }
 318
 319 void close_output_buffer_if_we_run_high(struct moveparams *mv)
 320 {
 321         if (bytes_out > low_buffer_size) {
 322                 mv->lcount = low_buffer_size;
 323                 if (mv->hcount)
 324                         mv->hcount = bytes_out - low_buffer_size;
 325         } else {
 326                 mv->lcount = bytes_out;
 327                 mv->hcount = 0;
 328         }
 329 }
 330
 331 int decompress_kernel(struct moveparams *mv, void *rmode)
 332 {
 333         real_mode = rmode;
 334
 335         if (SCREEN_INFO.orig_video_mode == 7) {
 336                 vidmem = (char *) 0xb0000;
 337                 vidport = 0x3b4;
 338         } else {
 339                 vidmem = (char *) 0xb8000;
 340                 vidport = 0x3d4;
 341         }
 342
 343         lines = SCREEN_INFO.orig_video_lines;
 344         cols = SCREEN_INFO.orig_video_cols;
 345
 346         if (free_mem_ptr < 0x100000) setup_normal_output_buffer();
 347         else setup_output_buffer_if_we_run_high(mv);
 348
 349         makecrc();
 350         putstr(".\nDecompressing Linux...");
 351         gunzip();
 352         putstr("done.\nBooting the kernel.\n");
 353         if (high_loaded) close_output_buffer_if_we_run_high(mv);
 354         return high_loaded;
 355 }