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[mirror_ubuntu-artful-kernel.git] / arch / x86 / boot / compressed / misc.c
CommitLineData
1da177e4
LT
1/*
2 * misc.c
818a08f8
IC
3 *
4 * This is a collection of several routines from gzip-1.0.3
1da177e4
LT
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
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IC
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 */
d3561b7f 17#undef CONFIG_PARAVIRT
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IC
18#ifdef CONFIG_X86_32
19#define _ASM_DESC_H_ 1
20#endif
21
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IC
22#ifdef CONFIG_X86_64
23#define _LINUX_STRING_H_ 1
24#define __LINUX_BITMAP_H 1
25#endif
26
1da177e4 27#include <linux/linkage.h>
7e7f358c 28#include <linux/screen_info.h>
099e1377 29#include <linux/elf.h>
1da177e4 30#include <asm/io.h>
968de4f0 31#include <asm/page.h>
e69f202d 32#include <asm/boot.h>
23968f71 33#include <asm/bootparam.h>
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EB
34
35/* WARNING!!
36 * This code is compiled with -fPIC and it is relocated dynamically
37 * at run time, but no relocation processing is performed.
38 * This means that it is not safe to place pointers in static structures.
39 */
40
41/*
42 * Getting to provable safe in place decompression is hard.
27b46d76 43 * Worst case behaviours need to be analyzed.
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44 * Background information:
45 *
46 * The file layout is:
47 * magic[2]
48 * method[1]
49 * flags[1]
50 * timestamp[4]
51 * extraflags[1]
52 * os[1]
53 * compressed data blocks[N]
54 * crc[4] orig_len[4]
55 *
56 * resulting in 18 bytes of non compressed data overhead.
57 *
58 * Files divided into blocks
59 * 1 bit (last block flag)
60 * 2 bits (block type)
61 *
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IM
62 * 1 block occurs every 32K -1 bytes or when there 50% compression
63 * has been achieved. The smallest block type encoding is always used.
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64 *
65 * stored:
66 * 32 bits length in bytes.
67 *
68 * fixed:
69 * magic fixed tree.
70 * symbols.
71 *
72 * dynamic:
73 * dynamic tree encoding.
74 * symbols.
75 *
76 *
77 * The buffer for decompression in place is the length of the
78 * uncompressed data, plus a small amount extra to keep the algorithm safe.
79 * The compressed data is placed at the end of the buffer. The output
80 * pointer is placed at the start of the buffer and the input pointer
81 * is placed where the compressed data starts. Problems will occur
82 * when the output pointer overruns the input pointer.
83 *
84 * The output pointer can only overrun the input pointer if the input
85 * pointer is moving faster than the output pointer. A condition only
86 * triggered by data whose compressed form is larger than the uncompressed
87 * form.
88 *
89 * The worst case at the block level is a growth of the compressed data
90 * of 5 bytes per 32767 bytes.
91 *
92 * The worst case internal to a compressed block is very hard to figure.
93 * The worst case can at least be boundined by having one bit that represents
94 * 32764 bytes and then all of the rest of the bytes representing the very
95 * very last byte.
96 *
97 * All of which is enough to compute an amount of extra data that is required
98 * to be safe. To avoid problems at the block level allocating 5 extra bytes
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IM
99 * per 32767 bytes of data is sufficient. To avoind problems internal to a
100 * block adding an extra 32767 bytes (the worst case uncompressed block size)
101 * is sufficient, to ensure that in the worst case the decompressed data for
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EB
102 * block will stop the byte before the compressed data for a block begins.
103 * To avoid problems with the compressed data's meta information an extra 18
104 * bytes are needed. Leading to the formula:
105 *
106 * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
107 *
108 * Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
109 * Adding 32768 instead of 32767 just makes for round numbers.
110 * Adding the decompressor_size is necessary as it musht live after all
111 * of the data as well. Last I measured the decompressor is about 14K.
27b46d76 112 * 10K of actual data and 4K of bss.
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113 *
114 */
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115
116/*
117 * gzip declarations
118 */
119
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120#define OF(args) args
121#define STATIC static
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LT
122
123#undef memset
124#undef memcpy
1180e01d 125#define memzero(s, n) memset((s), 0, (n))
1da177e4 126
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IM
127typedef unsigned char uch;
128typedef unsigned short ush;
129typedef unsigned long ulg;
1da177e4 130
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IM
131/*
132 * Window size must be at least 32k, and a power of two.
133 * We don't actually have a window just a huge output buffer,
134 * so we report a 2G window size, as that should always be
135 * larger than our output buffer:
136 */
137#define WSIZE 0x80000000
138
139/* Input buffer: */
140static unsigned char *inbuf;
141
142/* Sliding window buffer (and final output buffer): */
143static unsigned char *window;
144
145/* Valid bytes in inbuf: */
146static unsigned insize;
1da177e4 147
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148/* Index of next byte to be processed in inbuf: */
149static unsigned inptr;
1da177e4 150
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IM
151/* Bytes in output buffer: */
152static unsigned outcnt;
1da177e4
LT
153
154/* gzip flag byte */
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IM
155#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
156#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gz file */
157#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
158#define ORIG_NAM 0x08 /* bit 3 set: original file name present */
159#define COMMENT 0x10 /* bit 4 set: file comment present */
160#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
161#define RESERVED 0xC0 /* bit 6, 7: reserved */
1da177e4 162
1180e01d 163#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf())
fd77c7ca 164
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LT
165/* Diagnostic functions */
166#ifdef DEBUG
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IM
167# define Assert(cond, msg) do { if (!(cond)) error(msg); } while (0)
168# define Trace(x) do { fprintf x; } while (0)
169# define Tracev(x) do { if (verbose) fprintf x ; } while (0)
170# define Tracevv(x) do { if (verbose > 1) fprintf x ; } while (0)
171# define Tracec(c, x) do { if (verbose && (c)) fprintf x ; } while (0)
172# define Tracecv(c, x) do { if (verbose > 1 && (c)) fprintf x ; } while (0)
1da177e4 173#else
fd77c7ca 174# define Assert(cond, msg)
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LT
175# define Trace(x)
176# define Tracev(x)
177# define Tracevv(x)
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PC
178# define Tracec(c, x)
179# define Tracecv(c, x)
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LT
180#endif
181
182static int fill_inbuf(void);
183static void flush_window(void);
184static void error(char *m);
185static void gzip_mark(void **);
186static void gzip_release(void **);
fd77c7ca 187
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LT
188/*
189 * This is set up by the setup-routine at boot-time
190 */
23968f71 191static struct boot_params *real_mode; /* Pointer to real-mode data */
3b6b9293 192static int quiet;
1da177e4 193
b79c4df7 194extern unsigned char input_data[];
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195extern int input_len;
196
fd77c7ca 197static long bytes_out;
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198
199static void *malloc(int size);
200static void free(void *where);
201
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CDH
202static void *memset(void *s, int c, unsigned n);
203static void *memcpy(void *dest, const void *src, unsigned n);
204
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BC
205static void __putstr(int, const char *);
206#define putstr(__x) __putstr(0, __x)
1da177e4 207
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208#ifdef CONFIG_X86_64
209#define memptr long
210#else
211#define memptr unsigned
212#endif
213
214static memptr free_mem_ptr;
215static memptr free_mem_end_ptr;
1da177e4 216
03056c88 217static char *vidmem;
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LT
218static int vidport;
219static int lines, cols;
220
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LT
221#include "../../../../lib/inflate.c"
222
223static void *malloc(int size)
224{
225 void *p;
226
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PC
227 if (size < 0)
228 error("Malloc error");
229 if (free_mem_ptr <= 0)
230 error("Memory error");
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LT
231
232 free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
233
234 p = (void *)free_mem_ptr;
235 free_mem_ptr += size;
236
237 if (free_mem_ptr >= free_mem_end_ptr)
238 error("Out of memory");
239
240 return p;
241}
242
243static void free(void *where)
244{ /* Don't care */
245}
246
247static void gzip_mark(void **ptr)
248{
249 *ptr = (void *) free_mem_ptr;
250}
251
252static void gzip_release(void **ptr)
253{
778cb929 254 free_mem_ptr = (memptr) *ptr;
1da177e4 255}
fd77c7ca 256
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LT
257static void scroll(void)
258{
259 int i;
260
fd77c7ca
PC
261 memcpy(vidmem, vidmem + cols * 2, (lines - 1) * cols * 2);
262 for (i = (lines - 1) * cols * 2; i < lines * cols * 2; i += 2)
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LT
263 vidmem[i] = ' ';
264}
265
6bcb13b3 266static void __putstr(int error, const char *s)
1da177e4 267{
fd77c7ca 268 int x, y, pos;
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LT
269 char c;
270
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BC
271#ifndef CONFIG_X86_VERBOSE_BOOTUP
272 if (!error)
273 return;
274#endif
275
778cb929 276#ifdef CONFIG_X86_32
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KH
277 if (real_mode->screen_info.orig_video_mode == 0 &&
278 lines == 0 && cols == 0)
a24e7851 279 return;
778cb929 280#endif
a24e7851 281
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KH
282 x = real_mode->screen_info.orig_x;
283 y = real_mode->screen_info.orig_y;
1da177e4 284
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PC
285 while ((c = *s++) != '\0') {
286 if (c == '\n') {
1da177e4 287 x = 0;
fd77c7ca 288 if (++y >= lines) {
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LT
289 scroll();
290 y--;
291 }
292 } else {
818a08f8 293 vidmem [(x + cols * y) * 2] = c;
fd77c7ca 294 if (++x >= cols) {
1da177e4 295 x = 0;
fd77c7ca 296 if (++y >= lines) {
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LT
297 scroll();
298 y--;
299 }
300 }
301 }
302 }
303
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KH
304 real_mode->screen_info.orig_x = x;
305 real_mode->screen_info.orig_y = y;
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LT
306
307 pos = (x + cols * y) * 2; /* Update cursor position */
b02aae9c
RH
308 outb(14, vidport);
309 outb(0xff & (pos >> 9), vidport+1);
310 outb(15, vidport);
311 outb(0xff & (pos >> 1), vidport+1);
1da177e4
LT
312}
313
fd77c7ca 314static void *memset(void *s, int c, unsigned n)
1da177e4
LT
315{
316 int i;
ade1af77 317 char *ss = s;
1da177e4 318
fd77c7ca 319 for (i = 0; i < n; i++) ss[i] = c;
1da177e4
LT
320 return s;
321}
322
fd77c7ca 323static void *memcpy(void *dest, const void *src, unsigned n)
1da177e4
LT
324{
325 int i;
ade1af77
JE
326 const char *s = src;
327 char *d = dest;
1da177e4 328
fd77c7ca 329 for (i = 0; i < n; i++) d[i] = s[i];
b79c4df7 330 return dest;
1da177e4
LT
331}
332
333/* ===========================================================================
334 * Fill the input buffer. This is called only when the buffer is empty
335 * and at least one byte is really needed.
336 */
337static int fill_inbuf(void)
338{
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EB
339 error("ran out of input data");
340 return 0;
1da177e4
LT
341}
342
343/* ===========================================================================
344 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
345 * (Used for the decompressed data only.)
346 */
1da177e4
LT
347static void flush_window(void)
348{
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EB
349 /* With my window equal to my output buffer
350 * I only need to compute the crc here.
351 */
1180e01d 352 unsigned long c = crc; /* temporary variable */
968de4f0 353 unsigned n;
1180e01d 354 unsigned char *in, ch;
968de4f0
EB
355
356 in = window;
357 for (n = 0; n < outcnt; n++) {
358 ch = *in++;
359 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
360 }
361 crc = c;
1180e01d 362 bytes_out += (unsigned long)outcnt;
968de4f0 363 outcnt = 0;
1da177e4
LT
364}
365
366static void error(char *x)
367{
6bcb13b3
BC
368 __putstr(1, "\n\n");
369 __putstr(1, x);
370 __putstr(1, "\n\n -- System halted");
1da177e4 371
ff3cf856
IM
372 while (1)
373 asm("hlt");
1da177e4
LT
374}
375
099e1377
IC
376static void parse_elf(void *output)
377{
378#ifdef CONFIG_X86_64
379 Elf64_Ehdr ehdr;
380 Elf64_Phdr *phdrs, *phdr;
381#else
382 Elf32_Ehdr ehdr;
383 Elf32_Phdr *phdrs, *phdr;
384#endif
385 void *dest;
386 int i;
387
388 memcpy(&ehdr, output, sizeof(ehdr));
fd77c7ca 389 if (ehdr.e_ident[EI_MAG0] != ELFMAG0 ||
099e1377
IC
390 ehdr.e_ident[EI_MAG1] != ELFMAG1 ||
391 ehdr.e_ident[EI_MAG2] != ELFMAG2 ||
fd77c7ca 392 ehdr.e_ident[EI_MAG3] != ELFMAG3) {
099e1377
IC
393 error("Kernel is not a valid ELF file");
394 return;
395 }
396
3b6b9293
KH
397 if (!quiet)
398 putstr("Parsing ELF... ");
099e1377
IC
399
400 phdrs = malloc(sizeof(*phdrs) * ehdr.e_phnum);
401 if (!phdrs)
402 error("Failed to allocate space for phdrs");
403
404 memcpy(phdrs, output + ehdr.e_phoff, sizeof(*phdrs) * ehdr.e_phnum);
405
fd77c7ca 406 for (i = 0; i < ehdr.e_phnum; i++) {
099e1377
IC
407 phdr = &phdrs[i];
408
409 switch (phdr->p_type) {
410 case PT_LOAD:
411#ifdef CONFIG_RELOCATABLE
412 dest = output;
413 dest += (phdr->p_paddr - LOAD_PHYSICAL_ADDR);
414#else
fd77c7ca 415 dest = (void *)(phdr->p_paddr);
099e1377
IC
416#endif
417 memcpy(dest,
418 output + phdr->p_offset,
419 phdr->p_filesz);
420 break;
421 default: /* Ignore other PT_* */ break;
422 }
423 }
424}
425
778cb929 426asmlinkage void decompress_kernel(void *rmode, memptr heap,
1180e01d
IM
427 unsigned char *input_data,
428 unsigned long input_len,
429 unsigned char *output)
1da177e4
LT
430{
431 real_mode = rmode;
432
3b6b9293
KH
433 if (real_mode->hdr.loadflags & QUIET_FLAG)
434 quiet = 1;
435
23968f71 436 if (real_mode->screen_info.orig_video_mode == 7) {
1da177e4
LT
437 vidmem = (char *) 0xb0000;
438 vidport = 0x3b4;
439 } else {
440 vidmem = (char *) 0xb8000;
441 vidport = 0x3d4;
442 }
443
23968f71
KH
444 lines = real_mode->screen_info.orig_video_lines;
445 cols = real_mode->screen_info.orig_video_cols;
1da177e4 446
818a08f8 447 window = output; /* Output buffer (Normally at 1M) */
4c83d653 448 free_mem_ptr = heap; /* Heap */
7c539764 449 free_mem_end_ptr = heap + BOOT_HEAP_SIZE;
818a08f8 450 inbuf = input_data; /* Input buffer */
968de4f0
EB
451 insize = input_len;
452 inptr = 0;
453
778cb929 454#ifdef CONFIG_X86_64
1180e01d 455 if ((unsigned long)output & (__KERNEL_ALIGN - 1))
778cb929 456 error("Destination address not 2M aligned");
1180e01d 457 if ((unsigned long)output >= 0xffffffffffUL)
778cb929
IC
458 error("Destination address too large");
459#else
1180e01d 460 if ((u32)output & (CONFIG_PHYSICAL_ALIGN - 1))
e69f202d 461 error("Destination address not CONFIG_PHYSICAL_ALIGN aligned");
4c83d653 462 if (heap > ((-__PAGE_OFFSET-(512<<20)-1) & 0x7fffffff))
968de4f0
EB
463 error("Destination address too large");
464#ifndef CONFIG_RELOCATABLE
e69f202d 465 if ((u32)output != LOAD_PHYSICAL_ADDR)
968de4f0 466 error("Wrong destination address");
778cb929 467#endif
968de4f0 468#endif
1da177e4
LT
469
470 makecrc();
3b6b9293
KH
471 if (!quiet)
472 putstr("\nDecompressing Linux... ");
1da177e4 473 gunzip();
099e1377 474 parse_elf(output);
3b6b9293
KH
475 if (!quiet)
476 putstr("done.\nBooting the kernel.\n");
968de4f0 477 return;
1da177e4 478}