4 * This is a collection of several routines from gzip-1.0.3
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
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
17 #undef CONFIG_PARAVIRT
18 #include <linux/linkage.h>
19 #include <linux/vmalloc.h>
20 #include <linux/screen_info.h>
26 * This code is compiled with -fPIC and it is relocated dynamically
27 * at run time, but no relocation processing is performed.
28 * This means that it is not safe to place pointers in static structures.
32 * Getting to provable safe in place decompression is hard.
33 * Worst case behaviours need to be analyzed.
34 * Background information:
43 * compressed data blocks[N]
46 * resulting in 18 bytes of non compressed data overhead.
48 * Files divided into blocks
49 * 1 bit (last block flag)
52 * 1 block occurs every 32K -1 bytes or when there 50% compression has been achieved.
53 * The smallest block type encoding is always used.
56 * 32 bits length in bytes.
63 * dynamic tree encoding.
67 * The buffer for decompression in place is the length of the
68 * uncompressed data, plus a small amount extra to keep the algorithm safe.
69 * The compressed data is placed at the end of the buffer. The output
70 * pointer is placed at the start of the buffer and the input pointer
71 * is placed where the compressed data starts. Problems will occur
72 * when the output pointer overruns the input pointer.
74 * The output pointer can only overrun the input pointer if the input
75 * pointer is moving faster than the output pointer. A condition only
76 * triggered by data whose compressed form is larger than the uncompressed
79 * The worst case at the block level is a growth of the compressed data
80 * of 5 bytes per 32767 bytes.
82 * The worst case internal to a compressed block is very hard to figure.
83 * The worst case can at least be boundined by having one bit that represents
84 * 32764 bytes and then all of the rest of the bytes representing the very
87 * All of which is enough to compute an amount of extra data that is required
88 * to be safe. To avoid problems at the block level allocating 5 extra bytes
89 * per 32767 bytes of data is sufficient. To avoind problems internal to a block
90 * adding an extra 32767 bytes (the worst case uncompressed block size) is
91 * sufficient, to ensure that in the worst case the decompressed data for
92 * block will stop the byte before the compressed data for a block begins.
93 * To avoid problems with the compressed data's meta information an extra 18
94 * bytes are needed. Leading to the formula:
96 * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
98 * Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
99 * Adding 32768 instead of 32767 just makes for round numbers.
100 * Adding the decompressor_size is necessary as it musht live after all
101 * of the data as well. Last I measured the decompressor is about 14K.
102 * 10K of actual data and 4K of bss.
110 #define OF(args) args
111 #define STATIC static
115 #define memzero(s, n) memset ((s), 0, (n))
117 typedef unsigned char uch;
118 typedef unsigned short ush;
119 typedef unsigned long ulg;
121 #define WSIZE 0x80000000 /* Window size must be at least 32k,
123 * We don't actually have a window just
124 * a huge output buffer so I report
125 * a 2G windows size, as that should
126 * always be larger than our output buffer.
129 static uch *inbuf; /* input buffer */
130 static uch *window; /* Sliding window buffer, (and final output buffer) */
132 static unsigned insize; /* valid bytes in inbuf */
133 static unsigned inptr; /* index of next byte to be processed in inbuf */
134 static unsigned outcnt; /* bytes in output buffer */
137 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
138 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
139 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
140 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
141 #define COMMENT 0x10 /* bit 4 set: file comment present */
142 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
143 #define RESERVED 0xC0 /* bit 6,7: reserved */
145 #define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf())
147 /* Diagnostic functions */
149 # define Assert(cond,msg) {if(!(cond)) error(msg);}
150 # define Trace(x) fprintf x
151 # define Tracev(x) {if (verbose) fprintf x ;}
152 # define Tracevv(x) {if (verbose>1) fprintf x ;}
153 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
154 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
156 # define Assert(cond,msg)
161 # define Tracecv(c,x)
164 static int fill_inbuf(void);
165 static void flush_window(void);
166 static void error(char *m);
167 static void gzip_mark(void **);
168 static void gzip_release(void **);
171 * This is set up by the setup-routine at boot-time
173 static unsigned char *real_mode; /* Pointer to real-mode data */
175 #define RM_EXT_MEM_K (*(unsigned short *)(real_mode + 0x2))
176 #ifndef STANDARD_MEMORY_BIOS_CALL
177 #define RM_ALT_MEM_K (*(unsigned long *)(real_mode + 0x1e0))
179 #define RM_SCREEN_INFO (*(struct screen_info *)(real_mode+0))
181 extern unsigned char input_data[];
182 extern int input_len;
184 static long bytes_out = 0;
186 static void *malloc(int size);
187 static void free(void *where);
189 static void *memset(void *s, int c, unsigned n);
190 static void *memcpy(void *dest, const void *src, unsigned n);
192 static void putstr(const char *);
194 static unsigned long free_mem_ptr;
195 static unsigned long free_mem_end_ptr;
197 #define HEAP_SIZE 0x4000
199 static char *vidmem = (char *)0xb8000;
201 static int lines, cols;
203 #ifdef CONFIG_X86_NUMAQ
207 #include "../../../../lib/inflate.c"
209 static void *malloc(int size)
213 if (size <0) error("Malloc error");
214 if (free_mem_ptr <= 0) error("Memory error");
216 free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
218 p = (void *)free_mem_ptr;
219 free_mem_ptr += size;
221 if (free_mem_ptr >= free_mem_end_ptr)
222 error("Out of memory");
227 static void free(void *where)
231 static void gzip_mark(void **ptr)
233 *ptr = (void *) free_mem_ptr;
236 static void gzip_release(void **ptr)
238 free_mem_ptr = (unsigned long) *ptr;
241 static void scroll(void)
245 memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
246 for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
250 static void putstr(const char *s)
255 if (RM_SCREEN_INFO.orig_video_mode == 0 && lines == 0 && cols == 0)
258 x = RM_SCREEN_INFO.orig_x;
259 y = RM_SCREEN_INFO.orig_y;
261 while ( ( c = *s++ ) != '\0' ) {
264 if ( ++y >= lines ) {
269 vidmem [(x + cols * y) * 2] = c;
272 if ( ++y >= lines ) {
280 RM_SCREEN_INFO.orig_x = x;
281 RM_SCREEN_INFO.orig_y = y;
283 pos = (x + cols * y) * 2; /* Update cursor position */
285 outb(0xff & (pos >> 9), vidport+1);
287 outb(0xff & (pos >> 1), vidport+1);
290 static void* memset(void* s, int c, unsigned n)
295 for (i=0;i<n;i++) ss[i] = c;
299 static void* memcpy(void* dest, const void* src, unsigned n)
305 for (i=0;i<n;i++) d[i] = s[i];
309 /* ===========================================================================
310 * Fill the input buffer. This is called only when the buffer is empty
311 * and at least one byte is really needed.
313 static int fill_inbuf(void)
315 error("ran out of input data");
319 /* ===========================================================================
320 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
321 * (Used for the decompressed data only.)
323 static void flush_window(void)
325 /* With my window equal to my output buffer
326 * I only need to compute the crc here.
328 ulg c = crc; /* temporary variable */
333 for (n = 0; n < outcnt; n++) {
335 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
338 bytes_out += (ulg)outcnt;
342 static void error(char *x)
346 putstr("\n\n -- System halted");
352 asmlinkage void decompress_kernel(void *rmode, unsigned long end,
353 uch *input_data, unsigned long input_len,
358 if (RM_SCREEN_INFO.orig_video_mode == 7) {
359 vidmem = (char *) 0xb0000;
362 vidmem = (char *) 0xb8000;
366 lines = RM_SCREEN_INFO.orig_video_lines;
367 cols = RM_SCREEN_INFO.orig_video_cols;
369 window = output; /* Output buffer (Normally at 1M) */
370 free_mem_ptr = end; /* Heap */
371 free_mem_end_ptr = end + HEAP_SIZE;
372 inbuf = input_data; /* Input buffer */
376 if ((u32)output & (CONFIG_PHYSICAL_ALIGN -1))
377 error("Destination address not CONFIG_PHYSICAL_ALIGN aligned");
378 if (end > ((-__PAGE_OFFSET-(512 <<20)-1) & 0x7fffffff))
379 error("Destination address too large");
380 #ifndef CONFIG_RELOCATABLE
381 if ((u32)output != LOAD_PHYSICAL_ADDR)
382 error("Wrong destination address");
386 putstr("\nDecompressing Linux... ");
388 putstr("done.\nBooting the kernel.\n");