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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
12/*
13 * we have to be careful, because no indirections are allowed here, and
14 * paravirt_ops is a kind of one. As it will only run in baremetal anyway,
15 * we just keep it from happening
16 */
17#undef CONFIG_PARAVIRT
18#ifdef CONFIG_X86_64
19#define _LINUX_STRING_H_ 1
20#define __LINUX_BITMAP_H 1
21#endif
22
23#include <linux/linkage.h>
24#include <linux/screen_info.h>
25#include <asm/io.h>
26#include <asm/page.h>
27#include <asm/boot.h>
28
29/* WARNING!!
30 * This code is compiled with -fPIC and it is relocated dynamically
31 * at run time, but no relocation processing is performed.
32 * This means that it is not safe to place pointers in static structures.
33 */
34
35/*
36 * Getting to provable safe in place decompression is hard.
37 * Worst case behaviours need to be analyzed.
38 * Background information:
39 *
40 * The file layout is:
41 * magic[2]
42 * method[1]
43 * flags[1]
44 * timestamp[4]
45 * extraflags[1]
46 * os[1]
47 * compressed data blocks[N]
48 * crc[4] orig_len[4]
49 *
50 * resulting in 18 bytes of non compressed data overhead.
51 *
52 * Files divided into blocks
53 * 1 bit (last block flag)
54 * 2 bits (block type)
55 *
56 * 1 block occurs every 32K -1 bytes or when there 50% compression has been achieved.
57 * The smallest block type encoding is always used.
58 *
59 * stored:
60 * 32 bits length in bytes.
61 *
62 * fixed:
63 * magic fixed tree.
64 * symbols.
65 *
66 * dynamic:
67 * dynamic tree encoding.
68 * symbols.
69 *
70 *
71 * The buffer for decompression in place is the length of the
72 * uncompressed data, plus a small amount extra to keep the algorithm safe.
73 * The compressed data is placed at the end of the buffer. The output
74 * pointer is placed at the start of the buffer and the input pointer
75 * is placed where the compressed data starts. Problems will occur
76 * when the output pointer overruns the input pointer.
77 *
78 * The output pointer can only overrun the input pointer if the input
79 * pointer is moving faster than the output pointer. A condition only
80 * triggered by data whose compressed form is larger than the uncompressed
81 * form.
82 *
83 * The worst case at the block level is a growth of the compressed data
84 * of 5 bytes per 32767 bytes.
85 *
86 * The worst case internal to a compressed block is very hard to figure.
87 * The worst case can at least be boundined by having one bit that represents
88 * 32764 bytes and then all of the rest of the bytes representing the very
89 * very last byte.
90 *
91 * All of which is enough to compute an amount of extra data that is required
92 * to be safe. To avoid problems at the block level allocating 5 extra bytes
93 * per 32767 bytes of data is sufficient. To avoind problems internal to a block
94 * adding an extra 32767 bytes (the worst case uncompressed block size) is
95 * sufficient, to ensure that in the worst case the decompressed data for
96 * block will stop the byte before the compressed data for a block begins.
97 * To avoid problems with the compressed data's meta information an extra 18
98 * bytes are needed. Leading to the formula:
99 *
100 * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
101 *
102 * Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
103 * Adding 32768 instead of 32767 just makes for round numbers.
104 * Adding the decompressor_size is necessary as it musht live after all
105 * of the data as well. Last I measured the decompressor is about 14K.
106 * 10K of actual data and 4K of bss.
107 *
108 */
109
110/*
111 * gzip declarations
112 */
113
114#define OF(args) args
115#define STATIC static
116
117#undef memset
118#undef memcpy
119#define memzero(s, n) memset ((s), 0, (n))
120
121typedef unsigned char uch;
122typedef unsigned short ush;
123typedef unsigned long ulg;
124
125#define WSIZE 0x80000000 /* Window size must be at least 32k,
126 * and a power of two
127 * We don't actually have a window just
128 * a huge output buffer so I report
129 * a 2G windows size, as that should
130 * always be larger than our output buffer.
131 */
132
133static uch *inbuf; /* input buffer */
134static uch *window; /* Sliding window buffer, (and final output buffer) */
135
136static unsigned insize; /* valid bytes in inbuf */
137static unsigned inptr; /* index of next byte to be processed in inbuf */
138static unsigned outcnt; /* bytes in output buffer */
139
140/* gzip flag byte */
141#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
142#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
143#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
144#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
145#define COMMENT 0x10 /* bit 4 set: file comment present */
146#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
147#define RESERVED 0xC0 /* bit 6,7: reserved */
148
149#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf())
150
151/* Diagnostic functions */
152#ifdef DEBUG
153# define Assert(cond,msg) {if(!(cond)) error(msg);}
154# define Trace(x) fprintf x
155# define Tracev(x) {if (verbose) fprintf x ;}
156# define Tracevv(x) {if (verbose>1) fprintf x ;}
157# define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
158# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
159#else
160# define Assert(cond,msg)
161# define Trace(x)
162# define Tracev(x)
163# define Tracevv(x)
164# define Tracec(c,x)
165# define Tracecv(c,x)
166#endif
167
168static int fill_inbuf(void);
169static void flush_window(void);
170static void error(char *m);
171static void gzip_mark(void **);
172static void gzip_release(void **);
173
174/*
175 * This is set up by the setup-routine at boot-time
176 */
177static unsigned char *real_mode; /* Pointer to real-mode data */
178
179#define RM_EXT_MEM_K (*(unsigned short *)(real_mode + 0x2))
180#ifndef STANDARD_MEMORY_BIOS_CALL
181#define RM_ALT_MEM_K (*(unsigned long *)(real_mode + 0x1e0))
182#endif
183#define RM_SCREEN_INFO (*(struct screen_info *)(real_mode+0))
184
185extern unsigned char input_data[];
186extern int input_len;
187
188static long bytes_out = 0;
189
190static void *malloc(int size);
191static void free(void *where);
192
193static void *memset(void *s, int c, unsigned n);
194static void *memcpy(void *dest, const void *src, unsigned n);
195
196static void putstr(const char *);
197
198#ifdef CONFIG_X86_64
199#define memptr long
200#else
201#define memptr unsigned
202#endif
203
204static memptr free_mem_ptr;
205static memptr free_mem_end_ptr;
206
207#ifdef CONFIG_X86_64
208#define HEAP_SIZE 0x7000
209#else
210#define HEAP_SIZE 0x4000
211#endif
212
213static char *vidmem = (char *)0xb8000;
214static int vidport;
215static int lines, cols;
216
217#ifdef CONFIG_X86_NUMAQ
218void *xquad_portio;
219#endif
220
221#include "../../../../lib/inflate.c"
222
223static void *malloc(int size)
224{
225 void *p;
226
227 if (size <0) error("Malloc error");
228 if (free_mem_ptr <= 0) error("Memory error");
229
230 free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
231
232 p = (void *)free_mem_ptr;
233 free_mem_ptr += size;
234
235 if (free_mem_ptr >= free_mem_end_ptr)
236 error("Out of memory");
237
238 return p;
239}
240
241static void free(void *where)
242{ /* Don't care */
243}
244
245static void gzip_mark(void **ptr)
246{
247 *ptr = (void *) free_mem_ptr;
248}
249
250static void gzip_release(void **ptr)
251{
252 free_mem_ptr = (memptr) *ptr;
253}
254
255static void scroll(void)
256{
257 int i;
258
259 memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
260 for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
261 vidmem[i] = ' ';
262}
263
264static void putstr(const char *s)
265{
266 int x,y,pos;
267 char c;
268
269#ifdef CONFIG_X86_32
270 if (RM_SCREEN_INFO.orig_video_mode == 0 && lines == 0 && cols == 0)
271 return;
272#endif
273
274 x = RM_SCREEN_INFO.orig_x;
275 y = RM_SCREEN_INFO.orig_y;
276
277 while ( ( c = *s++ ) != '\0' ) {
278 if ( c == '\n' ) {
279 x = 0;
280 if ( ++y >= lines ) {
281 scroll();
282 y--;
283 }
284 } else {
285 vidmem [(x + cols * y) * 2] = c;
286 if ( ++x >= cols ) {
287 x = 0;
288 if ( ++y >= lines ) {
289 scroll();
290 y--;
291 }
292 }
293 }
294 }
295
296 RM_SCREEN_INFO.orig_x = x;
297 RM_SCREEN_INFO.orig_y = y;
298
299 pos = (x + cols * y) * 2; /* Update cursor position */
300 outb(14, vidport);
301 outb(0xff & (pos >> 9), vidport+1);
302 outb(15, vidport);
303 outb(0xff & (pos >> 1), vidport+1);
304}
305
306static void* memset(void* s, int c, unsigned n)
307{
308 int i;
309 char *ss = s;
310
311 for (i=0;i<n;i++) ss[i] = c;
312 return s;
313}
314
315static void* memcpy(void* dest, const void* src, unsigned n)
316{
317 int i;
318 const char *s = src;
319 char *d = dest;
320
321 for (i=0;i<n;i++) d[i] = s[i];
322 return dest;
323}
324
325/* ===========================================================================
326 * Fill the input buffer. This is called only when the buffer is empty
327 * and at least one byte is really needed.
328 */
329static int fill_inbuf(void)
330{
331 error("ran out of input data");
332 return 0;
333}
334
335/* ===========================================================================
336 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
337 * (Used for the decompressed data only.)
338 */
339static void flush_window(void)
340{
341 /* With my window equal to my output buffer
342 * I only need to compute the crc here.
343 */
344 ulg c = crc; /* temporary variable */
345 unsigned n;
346 uch *in, ch;
347
348 in = window;
349 for (n = 0; n < outcnt; n++) {
350 ch = *in++;
351 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
352 }
353 crc = c;
354 bytes_out += (ulg)outcnt;
355 outcnt = 0;
356}
357
358static void error(char *x)
359{
360 putstr("\n\n");
361 putstr(x);
362 putstr("\n\n -- System halted");
363
364 while (1)
365 asm("hlt");
366}
367
368asmlinkage void decompress_kernel(void *rmode, memptr heap,
369 uch *input_data, unsigned long input_len,
370 uch *output)
371{
372 real_mode = rmode;
373
374 if (RM_SCREEN_INFO.orig_video_mode == 7) {
375 vidmem = (char *) 0xb0000;
376 vidport = 0x3b4;
377 } else {
378 vidmem = (char *) 0xb8000;
379 vidport = 0x3d4;
380 }
381
382 lines = RM_SCREEN_INFO.orig_video_lines;
383 cols = RM_SCREEN_INFO.orig_video_cols;
384
385 window = output; /* Output buffer (Normally at 1M) */
386 free_mem_ptr = heap; /* Heap */
387 free_mem_end_ptr = heap + HEAP_SIZE;
388 inbuf = input_data; /* Input buffer */
389 insize = input_len;
390 inptr = 0;
391
392#ifdef CONFIG_X86_64
393 if ((ulg)output & (__KERNEL_ALIGN - 1))
394 error("Destination address not 2M aligned");
395 if ((ulg)output >= 0xffffffffffUL)
396 error("Destination address too large");
397#else
398 if ((u32)output & (CONFIG_PHYSICAL_ALIGN -1))
399 error("Destination address not CONFIG_PHYSICAL_ALIGN aligned");
400 if (heap > ((-__PAGE_OFFSET-(512<<20)-1) & 0x7fffffff))
401 error("Destination address too large");
402#ifndef CONFIG_RELOCATABLE
403 if ((u32)output != LOAD_PHYSICAL_ADDR)
404 error("Wrong destination address");
405#endif
406#endif
407
408 makecrc();
409 putstr("\nDecompressing Linux... ");
410 gunzip();
411 putstr("done.\nBooting the kernel.\n");
412 return;
413}