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
93 static void *malloc(int size);
94 static void free(void *where);
95 static void error(char *m);
96 static void gzip_mark(void **);
97 static void gzip_release(void **);
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
malloc(int size)119 static void *malloc(int size)
120 {
121 void *p;
122
123 if (size <0) error("Malloc error\n");
124 if (free_mem_ptr <= 0) error("Memory error\n");
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("\nOut of memory\n");
133
134 return p;
135 }
136
free(void * where)137 static void free(void *where)
138 { /* Don't care */
139 }
140
gzip_mark(void ** ptr)141 static void gzip_mark(void **ptr)
142 {
143 *ptr = (void *) free_mem_ptr;
144 }
145
gzip_release(void ** ptr)146 static void gzip_release(void **ptr)
147 {
148 free_mem_ptr = (long) *ptr;
149 }
150
scroll(void)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
putstr(const char * s)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
memset(void * s,int c,size_t n)197 void* memset(void* s, int c, size_t 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
memcpy(void * __dest,__const void * __src,size_t __n)206 void* memcpy(void* __dest, __const void* __src,
207 size_t __n)
208 {
209 int i;
210 char *d = (char *)__dest, *s = (char *)__src;
211
212 for (i=0;i<__n;i++) d[i] = s[i];
213 return __dest;
214 }
215
216 /* ===========================================================================
217 * Fill the input buffer. This is called only when the buffer is empty
218 * and at least one byte is really needed.
219 */
fill_inbuf(void)220 static int fill_inbuf(void)
221 {
222 if (insize != 0) {
223 error("ran out of input data\n");
224 }
225
226 inbuf = input_data;
227 insize = input_len;
228 inptr = 1;
229 return inbuf[0];
230 }
231
232 /* ===========================================================================
233 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
234 * (Used for the decompressed data only.)
235 */
flush_window_low(void)236 static void flush_window_low(void)
237 {
238 ulg c = crc; /* temporary variable */
239 unsigned n;
240 uch *in, *out, ch;
241
242 in = window;
243 out = &output_data[output_ptr];
244 for (n = 0; n < outcnt; n++) {
245 ch = *out++ = *in++;
246 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
247 }
248 crc = c;
249 bytes_out += (ulg)outcnt;
250 output_ptr += (ulg)outcnt;
251 outcnt = 0;
252 }
253
flush_window_high(void)254 static void flush_window_high(void)
255 {
256 ulg c = crc; /* temporary variable */
257 unsigned n;
258 uch *in, ch;
259 in = window;
260 for (n = 0; n < outcnt; n++) {
261 ch = *output_data++ = *in++;
262 if ((ulg)output_data == low_buffer_end) output_data=high_buffer_start;
263 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
264 }
265 crc = c;
266 bytes_out += (ulg)outcnt;
267 outcnt = 0;
268 }
269
flush_window(void)270 static void flush_window(void)
271 {
272 if (high_loaded) flush_window_high();
273 else flush_window_low();
274 }
275
error(char * x)276 static void error(char *x)
277 {
278 putstr("\n\n");
279 putstr(x);
280 putstr("\n\n -- System halted");
281
282 while(1);
283 }
284
setup_normal_output_buffer(void)285 void setup_normal_output_buffer(void)
286 {
287 #ifdef STANDARD_MEMORY_BIOS_CALL
288 if (EXT_MEM_K < 1024) error("Less than 2MB of memory.\n");
289 #else
290 if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < 1024) error("Less than 2MB of memory.\n");
291 #endif
292 output_data = (char *)0x100000; /* Points to 1M */
293 free_mem_end_ptr = (long)real_mode;
294 }
295
296 struct moveparams {
297 uch *low_buffer_start; int lcount;
298 uch *high_buffer_start; int hcount;
299 };
300
setup_output_buffer_if_we_run_high(struct moveparams * mv)301 void setup_output_buffer_if_we_run_high(struct moveparams *mv)
302 {
303 high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE);
304 #ifdef STANDARD_MEMORY_BIOS_CALL
305 if (EXT_MEM_K < (3*1024)) error("Less than 4MB of memory.\n");
306 #else
307 if ((ALT_MEM_K > EXT_MEM_K ? ALT_MEM_K : EXT_MEM_K) < (3*1024)) error("Less than 4MB of memory.\n");
308 #endif
309 mv->low_buffer_start = output_data = (char *)LOW_BUFFER_START;
310 low_buffer_end = ((unsigned int)real_mode > LOW_BUFFER_MAX
311 ? LOW_BUFFER_MAX : (unsigned int)real_mode) & ~0xfff;
312 low_buffer_size = low_buffer_end - LOW_BUFFER_START;
313 high_loaded = 1;
314 free_mem_end_ptr = (long)high_buffer_start;
315 if ( (0x100000 + low_buffer_size) > ((ulg)high_buffer_start)) {
316 high_buffer_start = (uch *)(0x100000 + low_buffer_size);
317 mv->hcount = 0; /* say: we need not to move high_buffer */
318 }
319 else mv->hcount = -1;
320 mv->high_buffer_start = high_buffer_start;
321 }
322
close_output_buffer_if_we_run_high(struct moveparams * mv)323 void close_output_buffer_if_we_run_high(struct moveparams *mv)
324 {
325 if (bytes_out > low_buffer_size) {
326 mv->lcount = low_buffer_size;
327 if (mv->hcount)
328 mv->hcount = bytes_out - low_buffer_size;
329 } else {
330 mv->lcount = bytes_out;
331 mv->hcount = 0;
332 }
333 }
334
decompress_kernel(struct moveparams * mv,void * rmode)335 int decompress_kernel(struct moveparams *mv, void *rmode)
336 {
337 real_mode = rmode;
338
339 if (SCREEN_INFO.orig_video_mode == 7) {
340 vidmem = (char *) 0xb0000;
341 vidport = 0x3b4;
342 } else {
343 vidmem = (char *) 0xb8000;
344 vidport = 0x3d4;
345 }
346
347 lines = SCREEN_INFO.orig_video_lines;
348 cols = SCREEN_INFO.orig_video_cols;
349
350 if (free_mem_ptr < 0x100000) setup_normal_output_buffer();
351 else setup_output_buffer_if_we_run_high(mv);
352
353 makecrc();
354 putstr(".\nDecompressing Linux...");
355 gunzip();
356 putstr("done.\nBooting the kernel.\n");
357 if (high_loaded) close_output_buffer_if_we_run_high(mv);
358 return high_loaded;
359 }
360