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