i386: paravirt boot sequence
[deliverable/linux.git] / arch / x86 / boot / compressed / misc_32.c
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1da177e4
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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
d3561b7f 12#undef CONFIG_PARAVIRT
1da177e4
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13#include <linux/linkage.h>
14#include <linux/vmalloc.h>
7e7f358c 15#include <linux/screen_info.h>
1da177e4 16#include <asm/io.h>
968de4f0 17#include <asm/page.h>
e69f202d 18#include <asm/boot.h>
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19
20/* WARNING!!
21 * This code is compiled with -fPIC and it is relocated dynamically
22 * at run time, but no relocation processing is performed.
23 * This means that it is not safe to place pointers in static structures.
24 */
25
26/*
27 * Getting to provable safe in place decompression is hard.
27b46d76 28 * Worst case behaviours need to be analyzed.
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29 * Background information:
30 *
31 * The file layout is:
32 * magic[2]
33 * method[1]
34 * flags[1]
35 * timestamp[4]
36 * extraflags[1]
37 * os[1]
38 * compressed data blocks[N]
39 * crc[4] orig_len[4]
40 *
41 * resulting in 18 bytes of non compressed data overhead.
42 *
43 * Files divided into blocks
44 * 1 bit (last block flag)
45 * 2 bits (block type)
46 *
47 * 1 block occurs every 32K -1 bytes or when there 50% compression has been achieved.
48 * The smallest block type encoding is always used.
49 *
50 * stored:
51 * 32 bits length in bytes.
52 *
53 * fixed:
54 * magic fixed tree.
55 * symbols.
56 *
57 * dynamic:
58 * dynamic tree encoding.
59 * symbols.
60 *
61 *
62 * The buffer for decompression in place is the length of the
63 * uncompressed data, plus a small amount extra to keep the algorithm safe.
64 * The compressed data is placed at the end of the buffer. The output
65 * pointer is placed at the start of the buffer and the input pointer
66 * is placed where the compressed data starts. Problems will occur
67 * when the output pointer overruns the input pointer.
68 *
69 * The output pointer can only overrun the input pointer if the input
70 * pointer is moving faster than the output pointer. A condition only
71 * triggered by data whose compressed form is larger than the uncompressed
72 * form.
73 *
74 * The worst case at the block level is a growth of the compressed data
75 * of 5 bytes per 32767 bytes.
76 *
77 * The worst case internal to a compressed block is very hard to figure.
78 * The worst case can at least be boundined by having one bit that represents
79 * 32764 bytes and then all of the rest of the bytes representing the very
80 * very last byte.
81 *
82 * All of which is enough to compute an amount of extra data that is required
83 * to be safe. To avoid problems at the block level allocating 5 extra bytes
84 * per 32767 bytes of data is sufficient. To avoind problems internal to a block
85 * adding an extra 32767 bytes (the worst case uncompressed block size) is
86 * sufficient, to ensure that in the worst case the decompressed data for
87 * block will stop the byte before the compressed data for a block begins.
88 * To avoid problems with the compressed data's meta information an extra 18
89 * bytes are needed. Leading to the formula:
90 *
91 * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
92 *
93 * Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
94 * Adding 32768 instead of 32767 just makes for round numbers.
95 * Adding the decompressor_size is necessary as it musht live after all
96 * of the data as well. Last I measured the decompressor is about 14K.
27b46d76 97 * 10K of actual data and 4K of bss.
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98 *
99 */
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100
101/*
102 * gzip declarations
103 */
104
105#define OF(args) args
106#define STATIC static
107
108#undef memset
109#undef memcpy
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110#define memzero(s, n) memset ((s), 0, (n))
111
112typedef unsigned char uch;
113typedef unsigned short ush;
114typedef unsigned long ulg;
115
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116#define WSIZE 0x80000000 /* Window size must be at least 32k,
117 * and a power of two
118 * We don't actually have a window just
119 * a huge output buffer so I report
120 * a 2G windows size, as that should
121 * always be larger than our output buffer.
122 */
1da177e4 123
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124static uch *inbuf; /* input buffer */
125static uch *window; /* Sliding window buffer, (and final output buffer) */
1da177e4 126
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127static unsigned insize; /* valid bytes in inbuf */
128static unsigned inptr; /* index of next byte to be processed in inbuf */
129static unsigned outcnt; /* bytes in output buffer */
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130
131/* gzip flag byte */
132#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
133#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
134#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
135#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
136#define COMMENT 0x10 /* bit 4 set: file comment present */
137#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
138#define RESERVED 0xC0 /* bit 6,7: reserved */
139
140#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf())
141
142/* Diagnostic functions */
143#ifdef DEBUG
144# define Assert(cond,msg) {if(!(cond)) error(msg);}
145# define Trace(x) fprintf x
146# define Tracev(x) {if (verbose) fprintf x ;}
147# define Tracevv(x) {if (verbose>1) fprintf x ;}
148# define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
149# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
150#else
151# define Assert(cond,msg)
152# define Trace(x)
153# define Tracev(x)
154# define Tracevv(x)
155# define Tracec(c,x)
156# define Tracecv(c,x)
157#endif
158
159static int fill_inbuf(void);
160static void flush_window(void);
161static void error(char *m);
162static void gzip_mark(void **);
163static void gzip_release(void **);
164
165/*
166 * This is set up by the setup-routine at boot-time
167 */
168static unsigned char *real_mode; /* Pointer to real-mode data */
169
170#define RM_EXT_MEM_K (*(unsigned short *)(real_mode + 0x2))
171#ifndef STANDARD_MEMORY_BIOS_CALL
172#define RM_ALT_MEM_K (*(unsigned long *)(real_mode + 0x1e0))
173#endif
174#define RM_SCREEN_INFO (*(struct screen_info *)(real_mode+0))
175
b79c4df7 176extern unsigned char input_data[];
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177extern int input_len;
178
179static long bytes_out = 0;
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180
181static void *malloc(int size);
182static void free(void *where);
183
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184static void *memset(void *s, int c, unsigned n);
185static void *memcpy(void *dest, const void *src, unsigned n);
186
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187static void putstr(const char *);
188
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189static unsigned long free_mem_ptr;
190static unsigned long free_mem_end_ptr;
1da177e4 191
35c74226 192#define HEAP_SIZE 0x4000
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193
194static char *vidmem = (char *)0xb8000;
195static int vidport;
196static int lines, cols;
197
198#ifdef CONFIG_X86_NUMAQ
d5d2448d 199void *xquad_portio;
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200#endif
201
202#include "../../../../lib/inflate.c"
203
204static void *malloc(int size)
205{
206 void *p;
207
208 if (size <0) error("Malloc error");
209 if (free_mem_ptr <= 0) error("Memory error");
210
211 free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
212
213 p = (void *)free_mem_ptr;
214 free_mem_ptr += size;
215
216 if (free_mem_ptr >= free_mem_end_ptr)
217 error("Out of memory");
218
219 return p;
220}
221
222static void free(void *where)
223{ /* Don't care */
224}
225
226static void gzip_mark(void **ptr)
227{
228 *ptr = (void *) free_mem_ptr;
229}
230
231static void gzip_release(void **ptr)
232{
968de4f0 233 free_mem_ptr = (unsigned long) *ptr;
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234}
235
236static void scroll(void)
237{
238 int i;
239
240 memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
241 for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
242 vidmem[i] = ' ';
243}
244
245static void putstr(const char *s)
246{
247 int x,y,pos;
248 char c;
249
a24e7851
RR
250 if (RM_SCREEN_INFO.orig_video_mode == 0 && lines == 0 && cols == 0)
251 return;
252
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253 x = RM_SCREEN_INFO.orig_x;
254 y = RM_SCREEN_INFO.orig_y;
255
256 while ( ( c = *s++ ) != '\0' ) {
257 if ( c == '\n' ) {
258 x = 0;
259 if ( ++y >= lines ) {
260 scroll();
261 y--;
262 }
263 } else {
968de4f0 264 vidmem [ ( x + cols * y ) * 2 ] = c;
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265 if ( ++x >= cols ) {
266 x = 0;
267 if ( ++y >= lines ) {
268 scroll();
269 y--;
270 }
271 }
272 }
273 }
274
275 RM_SCREEN_INFO.orig_x = x;
276 RM_SCREEN_INFO.orig_y = y;
277
278 pos = (x + cols * y) * 2; /* Update cursor position */
279 outb_p(14, vidport);
280 outb_p(0xff & (pos >> 9), vidport+1);
281 outb_p(15, vidport);
282 outb_p(0xff & (pos >> 1), vidport+1);
283}
284
b79c4df7 285static void* memset(void* s, int c, unsigned n)
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286{
287 int i;
288 char *ss = (char*)s;
289
290 for (i=0;i<n;i++) ss[i] = c;
291 return s;
292}
293
b79c4df7 294static void* memcpy(void* dest, const void* src, unsigned n)
1da177e4
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295{
296 int i;
b79c4df7 297 char *d = (char *)dest, *s = (char *)src;
1da177e4 298
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CDH
299 for (i=0;i<n;i++) d[i] = s[i];
300 return dest;
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301}
302
303/* ===========================================================================
304 * Fill the input buffer. This is called only when the buffer is empty
305 * and at least one byte is really needed.
306 */
307static int fill_inbuf(void)
308{
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309 error("ran out of input data");
310 return 0;
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311}
312
313/* ===========================================================================
314 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
315 * (Used for the decompressed data only.)
316 */
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317static void flush_window(void)
318{
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319 /* With my window equal to my output buffer
320 * I only need to compute the crc here.
321 */
322 ulg c = crc; /* temporary variable */
323 unsigned n;
324 uch *in, ch;
325
326 in = window;
327 for (n = 0; n < outcnt; n++) {
328 ch = *in++;
329 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
330 }
331 crc = c;
332 bytes_out += (ulg)outcnt;
333 outcnt = 0;
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334}
335
336static void error(char *x)
337{
338 putstr("\n\n");
339 putstr(x);
340 putstr("\n\n -- System halted");
341
342 while(1); /* Halt */
343}
344
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345asmlinkage void decompress_kernel(void *rmode, unsigned long end,
346 uch *input_data, unsigned long input_len, uch *output)
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347{
348 real_mode = rmode;
349
350 if (RM_SCREEN_INFO.orig_video_mode == 7) {
351 vidmem = (char *) 0xb0000;
352 vidport = 0x3b4;
353 } else {
354 vidmem = (char *) 0xb8000;
355 vidport = 0x3d4;
356 }
357
358 lines = RM_SCREEN_INFO.orig_video_lines;
359 cols = RM_SCREEN_INFO.orig_video_cols;
360
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361 window = output; /* Output buffer (Normally at 1M) */
362 free_mem_ptr = end; /* Heap */
363 free_mem_end_ptr = end + HEAP_SIZE;
364 inbuf = input_data; /* Input buffer */
365 insize = input_len;
366 inptr = 0;
367
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368 if ((u32)output & (CONFIG_PHYSICAL_ALIGN -1))
369 error("Destination address not CONFIG_PHYSICAL_ALIGN aligned");
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370 if (end > ((-__PAGE_OFFSET-(512 <<20)-1) & 0x7fffffff))
371 error("Destination address too large");
372#ifndef CONFIG_RELOCATABLE
e69f202d 373 if ((u32)output != LOAD_PHYSICAL_ADDR)
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374 error("Wrong destination address");
375#endif
1da177e4
LT
376
377 makecrc();
378 putstr("Uncompressing Linux... ");
379 gunzip();
380 putstr("Ok, booting the kernel.\n");
968de4f0 381 return;
1da177e4 382}
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