Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 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 | } |