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 #define _LINUX_STRING_H_ 1
19 #define __LINUX_BITMAP_H 1
21 #include <linux/linkage.h>
22 #include <linux/screen_info.h>
27 * This code is compiled with -fPIC and it is relocated dynamically
28 * at run time, but no relocation processing is performed.
29 * This means that it is not safe to place pointers in static structures.
33 * Getting to provable safe in place decompression is hard.
34 * Worst case behaviours need to be analyzed.
35 * Background information:
44 * compressed data blocks[N]
47 * resulting in 18 bytes of non compressed data overhead.
49 * Files divided into blocks
50 * 1 bit (last block flag)
53 * 1 block occurs every 32K -1 bytes or when there 50% compression has been achieved.
54 * The smallest block type encoding is always used.
57 * 32 bits length in bytes.
64 * dynamic tree encoding.
68 * The buffer for decompression in place is the length of the
69 * uncompressed data, plus a small amount extra to keep the algorithm safe.
70 * The compressed data is placed at the end of the buffer. The output
71 * pointer is placed at the start of the buffer and the input pointer
72 * is placed where the compressed data starts. Problems will occur
73 * when the output pointer overruns the input pointer.
75 * The output pointer can only overrun the input pointer if the input
76 * pointer is moving faster than the output pointer. A condition only
77 * triggered by data whose compressed form is larger than the uncompressed
80 * The worst case at the block level is a growth of the compressed data
81 * of 5 bytes per 32767 bytes.
83 * The worst case internal to a compressed block is very hard to figure.
84 * The worst case can at least be boundined by having one bit that represents
85 * 32764 bytes and then all of the rest of the bytes representing the very
88 * All of which is enough to compute an amount of extra data that is required
89 * to be safe. To avoid problems at the block level allocating 5 extra bytes
90 * per 32767 bytes of data is sufficient. To avoind problems internal to a block
91 * adding an extra 32767 bytes (the worst case uncompressed block size) is
92 * sufficient, to ensure that in the worst case the decompressed data for
93 * block will stop the byte before the compressed data for a block begins.
94 * To avoid problems with the compressed data's meta information an extra 18
95 * bytes are needed. Leading to the formula:
97 * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
99 * Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
100 * Adding 32768 instead of 32767 just makes for round numbers.
101 * Adding the decompressor_size is necessary as it musht live after all
102 * of the data as well. Last I measured the decompressor is about 14K.
103 * 10K of actual data and 4K of bss.
111 #define OF(args) args
112 #define STATIC static
116 #define memzero(s, n) memset ((s), 0, (n))
118 typedef unsigned char uch;
119 typedef unsigned short ush;
120 typedef unsigned long ulg;
122 #define WSIZE 0x80000000 /* Window size must be at least 32k,
124 * We don't actually have a window just
125 * a huge output buffer so I report
126 * a 2G windows size, as that should
127 * always be larger than our output buffer.
130 static uch *inbuf; /* input buffer */
131 static uch *window; /* Sliding window buffer, (and final output buffer) */
133 static unsigned insize; /* valid bytes in inbuf */
134 static unsigned inptr; /* index of next byte to be processed in inbuf */
135 static unsigned outcnt; /* bytes in output buffer */
138 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
139 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
140 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
141 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
142 #define COMMENT 0x10 /* bit 4 set: file comment present */
143 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
144 #define RESERVED 0xC0 /* bit 6,7: reserved */
146 #define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf())
148 /* Diagnostic functions */
150 # define Assert(cond,msg) {if(!(cond)) error(msg);}
151 # define Trace(x) fprintf x
152 # define Tracev(x) {if (verbose) fprintf x ;}
153 # define Tracevv(x) {if (verbose>1) fprintf x ;}
154 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
155 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
157 # define Assert(cond,msg)
162 # define Tracecv(c,x)
165 static int fill_inbuf(void);
166 static void flush_window(void);
167 static void error(char *m);
168 static void gzip_mark(void **);
169 static void gzip_release(void **);
172 * This is set up by the setup-routine at boot-time
174 static unsigned char *real_mode; /* Pointer to real-mode data */
176 #define RM_EXT_MEM_K (*(unsigned short *)(real_mode + 0x2))
177 #ifndef STANDARD_MEMORY_BIOS_CALL
178 #define RM_ALT_MEM_K (*(unsigned long *)(real_mode + 0x1e0))
180 #define RM_SCREEN_INFO (*(struct screen_info *)(real_mode+0))
182 extern unsigned char input_data[];
183 extern int input_len;
185 static long bytes_out = 0;
187 static void *malloc(int size);
188 static void free(void *where);
190 static void *memset(void *s, int c, unsigned n);
191 static void *memcpy(void *dest, const void *src, unsigned n);
193 static void putstr(const char *);
195 static long free_mem_ptr;
196 static long free_mem_end_ptr;
198 #define HEAP_SIZE 0x7000
200 static char *vidmem = (char *)0xb8000;
202 static int lines, cols;
204 #include "../../../../lib/inflate.c"
206 static void *malloc(int size)
210 if (size <0) error("Malloc error");
211 if (free_mem_ptr <= 0) error("Memory error");
213 free_mem_ptr = (free_mem_ptr + 3) & ~3; /* Align */
215 p = (void *)free_mem_ptr;
216 free_mem_ptr += size;
218 if (free_mem_ptr >= free_mem_end_ptr)
219 error("Out of memory");
224 static void free(void *where)
228 static void gzip_mark(void **ptr)
230 *ptr = (void *) free_mem_ptr;
233 static void gzip_release(void **ptr)
235 free_mem_ptr = (long) *ptr;
238 static void scroll(void)
242 memcpy ( vidmem, vidmem + cols * 2, ( lines - 1 ) * cols * 2 );
243 for ( i = ( lines - 1 ) * cols * 2; i < lines * cols * 2; i += 2 )
247 static void putstr(const char *s)
252 x = RM_SCREEN_INFO.orig_x;
253 y = RM_SCREEN_INFO.orig_y;
255 while ( ( c = *s++ ) != '\0' ) {
258 if ( ++y >= lines ) {
263 vidmem [ ( x + cols * y ) * 2 ] = c;
266 if ( ++y >= lines ) {
274 RM_SCREEN_INFO.orig_x = x;
275 RM_SCREEN_INFO.orig_y = y;
277 pos = (x + cols * y) * 2; /* Update cursor position */
279 outb(0xff & (pos >> 9), vidport+1);
281 outb(0xff & (pos >> 1), vidport+1);
284 static void* memset(void* s, int c, unsigned n)
289 for (i=0;i<n;i++) ss[i] = c;
293 static void* memcpy(void* dest, const void* src, unsigned n)
299 for (i=0;i<n;i++) d[i] = s[i];
303 /* ===========================================================================
304 * Fill the input buffer. This is called only when the buffer is empty
305 * and at least one byte is really needed.
307 static int fill_inbuf(void)
309 error("ran out of input data");
313 /* ===========================================================================
314 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
315 * (Used for the decompressed data only.)
317 static void flush_window(void)
319 /* With my window equal to my output buffer
320 * I only need to compute the crc here.
322 ulg c = crc; /* temporary variable */
327 for (n = 0; n < outcnt; n++) {
329 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
332 bytes_out += (ulg)outcnt;
336 static void error(char *x)
340 putstr("\n\n -- System halted");
346 asmlinkage void decompress_kernel(void *rmode, unsigned long heap,
347 uch *input_data, unsigned long input_len, uch *output)
351 if (RM_SCREEN_INFO.orig_video_mode == 7) {
352 vidmem = (char *) 0xb0000;
355 vidmem = (char *) 0xb8000;
359 lines = RM_SCREEN_INFO.orig_video_lines;
360 cols = RM_SCREEN_INFO.orig_video_cols;
362 window = output; /* Output buffer (Normally at 1M) */
363 free_mem_ptr = heap; /* Heap */
364 free_mem_end_ptr = heap + HEAP_SIZE;
365 inbuf = input_data; /* Input buffer */
369 if ((ulg)output & (__KERNEL_ALIGN - 1))
370 error("Destination address not 2M aligned");
371 if ((ulg)output >= 0xffffffffffUL)
372 error("Destination address too large");
375 putstr(".\nDecompressing Linux...");
377 putstr("done.\nBooting the kernel.\n");