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>
28 * This code is compiled with -fPIC and it is relocated dynamically
29 * at run time, but no relocation processing is performed.
30 * This means that it is not safe to place pointers in static structures.
34 * Getting to provable safe in place decompression is hard.
35 * Worst case behaviours need to be analyzed.
36 * Background information:
45 * compressed data blocks[N]
48 * resulting in 18 bytes of non compressed data overhead.
50 * Files divided into blocks
51 * 1 bit (last block flag)
54 * 1 block occurs every 32K -1 bytes or when there 50% compression has been achieved.
55 * The smallest block type encoding is always used.
58 * 32 bits length in bytes.
65 * dynamic tree encoding.
69 * The buffer for decompression in place is the length of the
70 * uncompressed data, plus a small amount extra to keep the algorithm safe.
71 * The compressed data is placed at the end of the buffer. The output
72 * pointer is placed at the start of the buffer and the input pointer
73 * is placed where the compressed data starts. Problems will occur
74 * when the output pointer overruns the input pointer.
76 * The output pointer can only overrun the input pointer if the input
77 * pointer is moving faster than the output pointer. A condition only
78 * triggered by data whose compressed form is larger than the uncompressed
81 * The worst case at the block level is a growth of the compressed data
82 * of 5 bytes per 32767 bytes.
84 * The worst case internal to a compressed block is very hard to figure.
85 * The worst case can at least be boundined by having one bit that represents
86 * 32764 bytes and then all of the rest of the bytes representing the very
89 * All of which is enough to compute an amount of extra data that is required
90 * to be safe. To avoid problems at the block level allocating 5 extra bytes
91 * per 32767 bytes of data is sufficient. To avoind problems internal to a block
92 * adding an extra 32767 bytes (the worst case uncompressed block size) is
93 * sufficient, to ensure that in the worst case the decompressed data for
94 * block will stop the byte before the compressed data for a block begins.
95 * To avoid problems with the compressed data's meta information an extra 18
96 * bytes are needed. Leading to the formula:
98 * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size.
100 * Adding 8 bytes per 32K is a bit excessive but much easier to calculate.
101 * Adding 32768 instead of 32767 just makes for round numbers.
102 * Adding the decompressor_size is necessary as it musht live after all
103 * of the data as well. Last I measured the decompressor is about 14K.
104 * 10K of actual data and 4K of bss.
112 #define OF(args) args
113 #define STATIC static
117 #define memzero(s, n) memset ((s), 0, (n))
119 typedef unsigned char uch
;
120 typedef unsigned short ush
;
121 typedef unsigned long ulg
;
123 #define WSIZE 0x80000000 /* Window size must be at least 32k,
125 * We don't actually have a window just
126 * a huge output buffer so I report
127 * a 2G windows size, as that should
128 * always be larger than our output buffer.
131 static uch
*inbuf
; /* input buffer */
132 static uch
*window
; /* Sliding window buffer, (and final output buffer) */
134 static unsigned insize
; /* valid bytes in inbuf */
135 static unsigned inptr
; /* index of next byte to be processed in inbuf */
136 static unsigned outcnt
; /* bytes in output buffer */
139 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
140 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
141 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
142 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
143 #define COMMENT 0x10 /* bit 4 set: file comment present */
144 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
145 #define RESERVED 0xC0 /* bit 6,7: reserved */
147 #define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf())
149 /* Diagnostic functions */
151 # define Assert(cond,msg) {if(!(cond)) error(msg);}
152 # define Trace(x) fprintf x
153 # define Tracev(x) {if (verbose) fprintf x ;}
154 # define Tracevv(x) {if (verbose>1) fprintf x ;}
155 # define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
156 # define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
158 # define Assert(cond,msg)
163 # define Tracecv(c,x)
166 static int fill_inbuf(void);
167 static void flush_window(void);
168 static void error(char *m
);
169 static void gzip_mark(void **);
170 static void gzip_release(void **);
173 * This is set up by the setup-routine at boot-time
175 static unsigned char *real_mode
; /* Pointer to real-mode data */
177 #define RM_EXT_MEM_K (*(unsigned short *)(real_mode + 0x2))
178 #ifndef STANDARD_MEMORY_BIOS_CALL
179 #define RM_ALT_MEM_K (*(unsigned long *)(real_mode + 0x1e0))
181 #define RM_SCREEN_INFO (*(struct screen_info *)(real_mode+0))
183 extern unsigned char input_data
[];
184 extern int input_len
;
186 static long bytes_out
= 0;
188 static void *malloc(int size
);
189 static void free(void *where
);
191 static void *memset(void *s
, int c
, unsigned n
);
192 static void *memcpy(void *dest
, const void *src
, unsigned n
);
194 static void putstr(const char *);
196 static long free_mem_ptr
;
197 static long free_mem_end_ptr
;
199 #define HEAP_SIZE 0x7000
201 static char *vidmem
= (char *)0xb8000;
203 static int lines
, cols
;
205 #include "../../../../lib/inflate.c"
207 static void *malloc(int size
)
211 if (size
<0) error("Malloc error");
212 if (free_mem_ptr
<= 0) error("Memory error");
214 free_mem_ptr
= (free_mem_ptr
+ 3) & ~3; /* Align */
216 p
= (void *)free_mem_ptr
;
217 free_mem_ptr
+= size
;
219 if (free_mem_ptr
>= free_mem_end_ptr
)
220 error("Out of memory");
225 static void free(void *where
)
229 static void gzip_mark(void **ptr
)
231 *ptr
= (void *) free_mem_ptr
;
234 static void gzip_release(void **ptr
)
236 free_mem_ptr
= (long) *ptr
;
239 static void scroll(void)
243 memcpy ( vidmem
, vidmem
+ cols
* 2, ( lines
- 1 ) * cols
* 2 );
244 for ( i
= ( lines
- 1 ) * cols
* 2; i
< lines
* cols
* 2; i
+= 2 )
248 static void putstr(const char *s
)
253 x
= RM_SCREEN_INFO
.orig_x
;
254 y
= RM_SCREEN_INFO
.orig_y
;
256 while ( ( c
= *s
++ ) != '\0' ) {
259 if ( ++y
>= lines
) {
264 vidmem
[(x
+ cols
* y
) * 2] = c
;
267 if ( ++y
>= lines
) {
275 RM_SCREEN_INFO
.orig_x
= x
;
276 RM_SCREEN_INFO
.orig_y
= y
;
278 pos
= (x
+ cols
* y
) * 2; /* Update cursor position */
280 outb(0xff & (pos
>> 9), vidport
+1);
282 outb(0xff & (pos
>> 1), vidport
+1);
285 static void* memset(void* s
, int c
, unsigned n
)
290 for (i
=0;i
<n
;i
++) ss
[i
] = c
;
294 static void* memcpy(void* dest
, const void* src
, unsigned n
)
300 for (i
=0;i
<n
;i
++) d
[i
] = s
[i
];
304 /* ===========================================================================
305 * Fill the input buffer. This is called only when the buffer is empty
306 * and at least one byte is really needed.
308 static int fill_inbuf(void)
310 error("ran out of input data");
314 /* ===========================================================================
315 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
316 * (Used for the decompressed data only.)
318 static void flush_window(void)
320 /* With my window equal to my output buffer
321 * I only need to compute the crc here.
323 ulg c
= crc
; /* temporary variable */
328 for (n
= 0; n
< outcnt
; n
++) {
330 c
= crc_32_tab
[((int)c
^ ch
) & 0xff] ^ (c
>> 8);
333 bytes_out
+= (ulg
)outcnt
;
337 static void error(char *x
)
341 putstr("\n\n -- System halted");
347 asmlinkage
void decompress_kernel(void *rmode
, unsigned long heap
,
348 uch
*input_data
, unsigned long input_len
,
353 if (RM_SCREEN_INFO
.orig_video_mode
== 7) {
354 vidmem
= (char *) 0xb0000;
357 vidmem
= (char *) 0xb8000;
361 lines
= RM_SCREEN_INFO
.orig_video_lines
;
362 cols
= RM_SCREEN_INFO
.orig_video_cols
;
364 window
= output
; /* Output buffer (Normally at 1M) */
365 free_mem_ptr
= heap
; /* Heap */
366 free_mem_end_ptr
= heap
+ HEAP_SIZE
;
367 inbuf
= input_data
; /* Input buffer */
371 if ((ulg
)output
& (__KERNEL_ALIGN
- 1))
372 error("Destination address not 2M aligned");
373 if ((ulg
)output
>= 0xffffffffffUL
)
374 error("Destination address too large");
377 putstr("\nDecompressing Linux... ");
379 putstr("done.\nBooting the kernel.\n");