Linux kernel mirror (for testing)
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linux
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/screen_info.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
27typedef unsigned char uch;
28typedef unsigned short ush;
29typedef unsigned long ulg;
30
31#define WSIZE 0x8000 /* Window size must be at least 32k, */
32 /* and a power of two */
33
34static uch *inbuf; /* input buffer */
35static uch window[WSIZE]; /* Sliding window buffer */
36
37static unsigned insize = 0; /* valid bytes in inbuf */
38static unsigned inptr = 0; /* index of next byte to be processed in inbuf */
39static 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
69static int fill_inbuf(void);
70static void flush_window(void);
71static void error(char *m);
72static void gzip_mark(void **);
73static void gzip_release(void **);
74
75/*
76 * This is set up by the setup-routine at boot-time
77 */
78static unsigned char *real_mode; /* Pointer to real-mode data */
79
80#define RM_EXT_MEM_K (*(unsigned short *)(real_mode + 0x2))
81#ifndef STANDARD_MEMORY_BIOS_CALL
82#define RM_ALT_MEM_K (*(unsigned long *)(real_mode + 0x1e0))
83#endif
84#define RM_SCREEN_INFO (*(struct screen_info *)(real_mode+0))
85
86extern unsigned char input_data[];
87extern int input_len;
88
89static long bytes_out = 0;
90static uch *output_data;
91static unsigned long output_ptr = 0;
92
93static void *malloc(int size);
94static void free(void *where);
95
96static void *memset(void *s, int c, unsigned n);
97static void *memcpy(void *dest, const void *src, unsigned n);
98
99static void putstr(const char *);
100
101extern int end;
102static long free_mem_ptr = (long)&end;
103static 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
109static unsigned int low_buffer_end, low_buffer_size;
110static int high_loaded =0;
111static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/;
112
113static char *vidmem = (char *)0xb8000;
114static int vidport;
115static int lines, cols;
116
117#include "../../../../lib/inflate.c"
118
119static void *malloc(int size)
120{
121 void *p;
122
123 if (size <0) error("Malloc error");
124 if (free_mem_ptr <= 0) error("Memory error");
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("Out of memory");
133
134 return p;
135}
136
137static void free(void *where)
138{ /* Don't care */
139}
140
141static void gzip_mark(void **ptr)
142{
143 *ptr = (void *) free_mem_ptr;
144}
145
146static void gzip_release(void **ptr)
147{
148 free_mem_ptr = (long) *ptr;
149}
150
151static 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
160static void putstr(const char *s)
161{
162 int x,y,pos;
163 char c;
164
165 x = RM_SCREEN_INFO.orig_x;
166 y = RM_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 RM_SCREEN_INFO.orig_x = x;
188 RM_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
197static void* memset(void* s, int c, unsigned 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
206static void* memcpy(void* dest, const void* src, unsigned n)
207{
208 int i;
209 char *d = (char *)dest, *s = (char *)src;
210
211 for (i=0;i<n;i++) d[i] = s[i];
212 return dest;
213}
214
215/* ===========================================================================
216 * Fill the input buffer. This is called only when the buffer is empty
217 * and at least one byte is really needed.
218 */
219static int fill_inbuf(void)
220{
221 if (insize != 0) {
222 error("ran out of input data");
223 }
224
225 inbuf = input_data;
226 insize = input_len;
227 inptr = 1;
228 return inbuf[0];
229}
230
231/* ===========================================================================
232 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
233 * (Used for the decompressed data only.)
234 */
235static void flush_window_low(void)
236{
237 ulg c = crc; /* temporary variable */
238 unsigned n;
239 uch *in, *out, ch;
240
241 in = window;
242 out = &output_data[output_ptr];
243 for (n = 0; n < outcnt; n++) {
244 ch = *out++ = *in++;
245 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
246 }
247 crc = c;
248 bytes_out += (ulg)outcnt;
249 output_ptr += (ulg)outcnt;
250 outcnt = 0;
251}
252
253static void flush_window_high(void)
254{
255 ulg c = crc; /* temporary variable */
256 unsigned n;
257 uch *in, ch;
258 in = window;
259 for (n = 0; n < outcnt; n++) {
260 ch = *output_data++ = *in++;
261 if ((ulg)output_data == low_buffer_end) output_data=high_buffer_start;
262 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
263 }
264 crc = c;
265 bytes_out += (ulg)outcnt;
266 outcnt = 0;
267}
268
269static void flush_window(void)
270{
271 if (high_loaded) flush_window_high();
272 else flush_window_low();
273}
274
275static void error(char *x)
276{
277 putstr("\n\n");
278 putstr(x);
279 putstr("\n\n -- System halted");
280
281 while(1); /* Halt */
282}
283
284static void setup_normal_output_buffer(void)
285{
286#ifdef STANDARD_MEMORY_BIOS_CALL
287 if (RM_EXT_MEM_K < 1024) error("Less than 2MB of memory");
288#else
289 if ((RM_ALT_MEM_K > RM_EXT_MEM_K ? RM_ALT_MEM_K : RM_EXT_MEM_K) < 1024) error("Less than 2MB of memory");
290#endif
291 output_data = (unsigned char *)__PHYSICAL_START; /* Normally Points to 1M */
292 free_mem_end_ptr = (long)real_mode;
293}
294
295struct moveparams {
296 uch *low_buffer_start; int lcount;
297 uch *high_buffer_start; int hcount;
298};
299
300static void setup_output_buffer_if_we_run_high(struct moveparams *mv)
301{
302 high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE);
303#ifdef STANDARD_MEMORY_BIOS_CALL
304 if (RM_EXT_MEM_K < (3*1024)) error("Less than 4MB of memory");
305#else
306 if ((RM_ALT_MEM_K > RM_EXT_MEM_K ? RM_ALT_MEM_K : RM_EXT_MEM_K) < (3*1024)) error("Less than 4MB of memory");
307#endif
308 mv->low_buffer_start = output_data = (unsigned char *)LOW_BUFFER_START;
309 low_buffer_end = ((unsigned int)real_mode > LOW_BUFFER_MAX
310 ? LOW_BUFFER_MAX : (unsigned int)real_mode) & ~0xfff;
311 low_buffer_size = low_buffer_end - LOW_BUFFER_START;
312 high_loaded = 1;
313 free_mem_end_ptr = (long)high_buffer_start;
314 if ( (__PHYSICAL_START + low_buffer_size) > ((ulg)high_buffer_start)) {
315 high_buffer_start = (uch *)(__PHYSICAL_START + low_buffer_size);
316 mv->hcount = 0; /* say: we need not to move high_buffer */
317 }
318 else mv->hcount = -1;
319 mv->high_buffer_start = high_buffer_start;
320}
321
322static void close_output_buffer_if_we_run_high(struct moveparams *mv)
323{
324 if (bytes_out > low_buffer_size) {
325 mv->lcount = low_buffer_size;
326 if (mv->hcount)
327 mv->hcount = bytes_out - low_buffer_size;
328 } else {
329 mv->lcount = bytes_out;
330 mv->hcount = 0;
331 }
332}
333
334int decompress_kernel(struct moveparams *mv, void *rmode)
335{
336 real_mode = rmode;
337
338 if (RM_SCREEN_INFO.orig_video_mode == 7) {
339 vidmem = (char *) 0xb0000;
340 vidport = 0x3b4;
341 } else {
342 vidmem = (char *) 0xb8000;
343 vidport = 0x3d4;
344 }
345
346 lines = RM_SCREEN_INFO.orig_video_lines;
347 cols = RM_SCREEN_INFO.orig_video_cols;
348
349 if (free_mem_ptr < 0x100000) setup_normal_output_buffer();
350 else setup_output_buffer_if_we_run_high(mv);
351
352 makecrc();
353 putstr(".\nDecompressing Linux...");
354 gunzip();
355 putstr("done.\nBooting the kernel.\n");
356 if (high_loaded) close_output_buffer_if_we_run_high(mv);
357 return high_loaded;
358}