arch/i386/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 <linux/linkage.h>
  13 #include <linux/vmalloc.h>
  14 #include <linux/tty.h>
  15 #include <asm/io.h>
  16
  17 /*
  18  * gzip declarations
  19  */
  20
  21 #define OF(args)  args
  22 #define STATIC static
  23
  24 #undef memset
  25 #undef memcpy
  26
  27 /*
  28  * Why do we do this? Don't ask me..
  29  *
  30  * Incomprehensible are the ways of bootloaders.
  31  */
  32 static void* memset(void *, int, size_t);
  33 static void* memcpy(void *, __const void *, size_t);
  34 #define memzero(s, n)     memset ((s), 0, (n))
  35
  36 typedef unsigned char  uch;
  37 typedef unsigned short ush;
  38 typedef unsigned long  ulg;
  39
  40 #define WSIZE 0x8000            /* Window size must be at least 32k, */
  41                                 /* and a power of two */
  42
  43 static uch *inbuf;           /* input buffer */
  44 static uch window[WSIZE];    /* Sliding window buffer */
  45
  46 static unsigned insize = 0;  /* valid bytes in inbuf */
  47 static unsigned inptr = 0;   /* index of next byte to be processed in inbuf */
  48 static unsigned outcnt = 0;  /* bytes in output buffer */
  49
  50 /* gzip flag byte */
  51 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
  52 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
  53 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
  54 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
  55 #define COMMENT      0x10 /* bit 4 set: file comment present */
  56 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
  57 #define RESERVED     0xC0 /* bit 6,7:   reserved */
  58
  59 #define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())
  60
  61 /* Diagnostic functions */
  62 #ifdef DEBUG
  63 #  define Assert(cond,msg) {if(!(cond)) error(msg);}
  64 #  define Trace(x) fprintf x
  65 #  define Tracev(x) {if (verbose) fprintf x ;}
  66 #  define Tracevv(x) {if (verbose>1) fprintf x ;}
  67 #  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
  68 #  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
  69 #else
  70 #  define Assert(cond,msg)
  71 #  define Trace(x)
  72 #  define Tracev(x)
  73 #  define Tracevv(x)
  74 #  define Tracec(c,x)
  75 #  define Tracecv(c,x)
  76 #endif
  77
  78 static int  fill_inbuf(void);
  79 static void flush_window(void);
  80 static void error(char *m);
  81 static void gzip_mark(void **);
  82 static void gzip_release(void **);
  83
  84 /*
  85  * This is set up by the setup-routine at boot-time
  86  */
  87 static unsigned char *real_mode; /* Pointer to real-mode data */
  88
  89 #define RM_EXT_MEM_K   (*(unsigned short *)(real_mode + 0x2))
  90 #ifndef STANDARD_MEMORY_BIOS_CALL
  91 #define RM_ALT_MEM_K   (*(unsigned long *)(real_mode + 0x1e0))
  92 #endif
  93 #define RM_SCREEN_INFO (*(struct screen_info *)(real_mode+0))
  94
  95 extern char input_data[];
  96 extern int input_len;
  97
  98 static long bytes_out = 0;
  99 static uch *output_data;
 100 static unsigned long output_ptr = 0;
 101
 102 static void *malloc(int size);
 103 static void free(void *where);
 104
 105 static void putstr(const char *);
 106
 107 extern int end;
 108 static long free_mem_ptr = (long)&end;
 109 static long free_mem_end_ptr;
 110
 111 #define INPLACE_MOVE_ROUTINE  0x1000
 112 #define LOW_BUFFER_START      0x2000
 113 #define LOW_BUFFER_MAX       0x90000
 114 #define HEAP_SIZE             0x3000
 115 static unsigned int low_buffer_end, low_buffer_size;
 116 static int high_loaded =0;
 117 static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/;
 118
 119 static char *vidmem = (char *)0xb8000;
 120 static int vidport;
 121 static int lines, cols;
 122
 123 #ifdef CONFIG_X86_NUMAQ
 124 static void * xquad_portio = NULL;
 125 #endif
 126
 127 #include "../../../../lib/inflate.c"
 128
 129 static void *malloc(int size)
 130 {
 131         void *p;
 132
 133         if (size <0) error("Malloc error");
 134         if (free_mem_ptr <= 0) error("Memory error");
 135
 136         free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
 137
 138         p = (void *)free_mem_ptr;
 139         free_mem_ptr += size;
 140
 141         if (free_mem_ptr >= free_mem_end_ptr)
 142                 error("Out of memory");
 143
 144         return p;
 145 }
 146
 147 static void free(void *where)
 148 {       /* Don't care */
 149 }
 150
 151 static void gzip_mark(void **ptr)
 152 {
 153         *ptr = (void *) free_mem_ptr;
 154 }
 155
 156 static void gzip_release(void **ptr)
 157 {
 158         free_mem_ptr = (long) *ptr;
 159 }
 160
 161 static void scroll(void)
 162 {
 163         int i;
 164
 165         memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
 166         for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
 167                 vidmem[i] = ' ';
 168 }
 169
 170 static void putstr(const char *s)
 171 {
 172         int x,y,pos;
 173         char c;
 174
 175         x = RM_SCREEN_INFO.orig_x;
 176         y = RM_SCREEN_INFO.orig_y;
 177
 178         while ( ( c = *s++ ) != '\0' ) {
 179                 if ( c == '\n' ) {
 180                         x = 0;
 181                         if ( ++y >= lines ) {
 182                                 scroll();
 183                                 y--;
 184                         }
 185                 } else {
 186                         vidmem [ ( x + cols * y ) * 2 ] = c;
 187                         if ( ++x >= cols ) {
 188                                 x = 0;
 189                                 if ( ++y >= lines ) {
 190                                         scroll();
 191                                         y--;
 192                                 }
 193                         }
 194                 }
 195         }
 196
 197         RM_SCREEN_INFO.orig_x = x;
 198         RM_SCREEN_INFO.orig_y = y;
 199
 200         pos = (x + cols * y) * 2;       /* Update cursor position */
 201         outb_p(14, vidport);
 202         outb_p(0xff & (pos >> 9), vidport+1);
 203         outb_p(15, vidport);
 204         outb_p(0xff & (pos >> 1), vidport+1);
 205 }
 206
 207 static void* memset(void* s, int c, size_t n)
 208 {
 209         int i;
 210         char *ss = (char*)s;
 211
 212         for (i=0;i<n;i++) ss[i] = c;
 213         return s;
 214 }
 215
 216 static void* memcpy(void* __dest, __const void* __src,
 217                             size_t __n)
 218 {
 219         int i;
 220         char *d = (char *)__dest, *s = (char *)__src;
 221
 222         for (i=0;i<__n;i++) d[i] = s[i];
 223         return __dest;
 224 }
 225
 226 /* ===========================================================================
 227  * Fill the input buffer. This is called only when the buffer is empty
 228  * and at least one byte is really needed.
 229  */
 230 static int fill_inbuf(void)
 231 {
 232         if (insize != 0) {
 233                 error("ran out of input data");
 234         }
 235
 236         inbuf = input_data;
 237         insize = input_len;
 238         inptr = 1;
 239         return inbuf[0];
 240 }
 241
 242 /* ===========================================================================
 243  * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 244  * (Used for the decompressed data only.)
 245  */
 246 static void flush_window_low(void)
 247 {
 248     ulg c = crc;         /* temporary variable */
 249     unsigned n;
 250     uch *in, *out, ch;
 251
 252     in = window;
 253     out = &output_data[output_ptr];
 254     for (n = 0; n < outcnt; n++) {
 255             ch = *out++ = *in++;
 256             c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 257     }
 258     crc = c;
 259     bytes_out += (ulg)outcnt;
 260     output_ptr += (ulg)outcnt;
 261     outcnt = 0;
 262 }
 263
 264 static void flush_window_high(void)
 265 {
 266     ulg c = crc;         /* temporary variable */
 267     unsigned n;
 268     uch *in,  ch;
 269     in = window;
 270     for (n = 0; n < outcnt; n++) {
 271         ch = *output_data++ = *in++;
 272         if ((ulg)output_data == low_buffer_end) output_data=high_buffer_start;
 273         c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 274     }
 275     crc = c;
 276     bytes_out += (ulg)outcnt;
 277     outcnt = 0;
 278 }
 279
 280 static void flush_window(void)
 281 {
 282         if (high_loaded) flush_window_high();
 283         else flush_window_low();
 284 }
 285
 286 static void error(char *x)
 287 {
 288         putstr("\n\n");
 289         putstr(x);
 290         putstr("\n\n -- System halted");
 291
 292         while(1);       /* Halt */
 293 }
 294
 295 #define STACK_SIZE (4096)
 296
 297 long user_stack [STACK_SIZE];
 298
 299 struct {
 300         long * a;
 301         short b;
 302         } stack_start = { & user_stack [STACK_SIZE] , __BOOT_DS };
 303
 304 static void setup_normal_output_buffer(void)
 305 {
 306 #ifdef STANDARD_MEMORY_BIOS_CALL
 307         if (RM_EXT_MEM_K < 1024) error("Less than 2MB of memory");
 308 #else
 309         if ((RM_ALT_MEM_K > RM_EXT_MEM_K ? RM_ALT_MEM_K : RM_EXT_MEM_K) < 1024) error("Less than 2MB of memory");
 310 #endif
 311         output_data = (char *)0x100000; /* Points to 1M */
 312         free_mem_end_ptr = (long)real_mode;
 313 }
 314
 315 struct moveparams {
 316         uch *low_buffer_start;  int lcount;
 317         uch *high_buffer_start; int hcount;
 318 };
 319
 320 static void setup_output_buffer_if_we_run_high(struct moveparams *mv)
 321 {
 322         high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE);
 323 #ifdef STANDARD_MEMORY_BIOS_CALL
 324         if (RM_EXT_MEM_K < (3*1024)) error("Less than 4MB of memory");
 325 #else
 326         if ((RM_ALT_MEM_K > RM_EXT_MEM_K ? RM_ALT_MEM_K : RM_EXT_MEM_K) <
 327                         (3*1024))
 328                 error("Less than 4MB of memory");
 329 #endif
 330         mv->low_buffer_start = output_data = (char *)LOW_BUFFER_START;
 331         low_buffer_end = ((unsigned int)real_mode > LOW_BUFFER_MAX
 332           ? LOW_BUFFER_MAX : (unsigned int)real_mode) & ~0xfff;
 333         low_buffer_size = low_buffer_end - LOW_BUFFER_START;
 334         high_loaded = 1;
 335         free_mem_end_ptr = (long)high_buffer_start;
 336         if ( (0x100000 + low_buffer_size) > ((ulg)high_buffer_start)) {
 337                 high_buffer_start = (uch *)(0x100000 + low_buffer_size);
 338                 mv->hcount = 0; /* say: we need not to move high_buffer */
 339         }
 340         else mv->hcount = -1;
 341         mv->high_buffer_start = high_buffer_start;
 342 }
 343
 344 static void close_output_buffer_if_we_run_high(struct moveparams *mv)
 345 {
 346         if (bytes_out > low_buffer_size) {
 347                 mv->lcount = low_buffer_size;
 348                 if (mv->hcount)
 349                         mv->hcount = bytes_out - low_buffer_size;
 350         } else {
 351                 mv->lcount = bytes_out;
 352                 mv->hcount = 0;
 353         }
 354 }
 355
 356
 357 asmlinkage int decompress_kernel(struct moveparams *mv, void *rmode)
 358 {
 359         real_mode = rmode;
 360
 361         if (RM_SCREEN_INFO.orig_video_mode == 7) {
 362                 vidmem = (char *) 0xb0000;
 363                 vidport = 0x3b4;
 364         } else {
 365                 vidmem = (char *) 0xb8000;
 366                 vidport = 0x3d4;
 367         }
 368
 369         lines = RM_SCREEN_INFO.orig_video_lines;
 370         cols = RM_SCREEN_INFO.orig_video_cols;
 371
 372         if (free_mem_ptr < 0x100000) setup_normal_output_buffer();
 373         else setup_output_buffer_if_we_run_high(mv);
 374
 375         makecrc();
 376         putstr("Uncompressing Linux... ");
 377         gunzip();
 378         putstr("Ok, booting the kernel.\n");
 379         if (high_loaded) close_output_buffer_if_we_run_high(mv);
 380         return high_loaded;
 381 }