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 *
9 * Modified for ARM Linux by Russell King
10 *
11 * Nicolas Pitre <nico@visuaide.com>  1999/04/14 :
12 *  For this code to run directly from Flash, all constant variables must
13 *  be marked with 'const' and all other variables initialized at run-time
14 *  only.  This way all non constant variables will end up in the bss segment,
15 *  which should point to addresses in RAM and cleared to 0 on start.
16 *  This allows for a much quicker boot time.
17 *
18 * Modified for Alpha, from the ARM version, by Jay Estabrook 2003.
19 */
20
21#include <linux/kernel.h>
22#include <linux/slab.h>
23
24#include <asm/uaccess.h>
25
26#define memzero(s,n)	memset ((s),0,(n))
27#define puts		srm_printk
28extern long srm_printk(const char *, ...)
29     __attribute__ ((format (printf, 1, 2)));
30
31/*
32 * gzip delarations
33 */
34#define OF(args)  args
35#define STATIC static
36
37typedef unsigned char  uch;
38typedef unsigned short ush;
39typedef unsigned long  ulg;
40
41#define WSIZE 0x8000		/* Window size must be at least 32k, */
42				/* and a power of two */
43
44static uch *inbuf;		/* input buffer */
45static uch *window;		/* Sliding window buffer */
46
47static unsigned insize;		/* valid bytes in inbuf */
48static unsigned inptr;		/* index of next byte to be processed in inbuf */
49static unsigned outcnt;		/* bytes in output buffer */
50
51/* gzip flag byte */
52#define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
53#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
54#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
55#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
56#define COMMENT      0x10 /* bit 4 set: file comment present */
57#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
58#define RESERVED     0xC0 /* bit 6,7:   reserved */
59
60#define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())
61
62/* Diagnostic functions */
63#ifdef DEBUG
64#  define Assert(cond,msg) {if(!(cond)) error(msg);}
65#  define Trace(x) fprintf x
66#  define Tracev(x) {if (verbose) fprintf x ;}
67#  define Tracevv(x) {if (verbose>1) fprintf x ;}
68#  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
69#  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
70#else
71#  define Assert(cond,msg)
72#  define Trace(x)
73#  define Tracev(x)
74#  define Tracevv(x)
75#  define Tracec(c,x)
76#  define Tracecv(c,x)
77#endif
78
79static int  fill_inbuf(void);
80static void flush_window(void);
81static void error(char *m);
82
83static char *input_data;
84static int  input_data_size;
85
86static uch *output_data;
87static ulg output_ptr;
88static ulg bytes_out;
89
90static void error(char *m);
91static void gzip_mark(void **);
92static void gzip_release(void **);
93
94extern int end;
95static ulg free_mem_ptr;
96static ulg free_mem_end_ptr;
97
98#define HEAP_SIZE 0x3000
99
100#include "../../../lib/inflate.c"
101
102/* ===========================================================================
103 * Fill the input buffer. This is called only when the buffer is empty
104 * and at least one byte is really needed.
105 */
106int fill_inbuf(void)
107{
108	if (insize != 0)
109		error("ran out of input data");
110
111	inbuf = input_data;
112	insize = input_data_size;
113
114	inptr = 1;
115	return inbuf[0];
116}
117
118/* ===========================================================================
119 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
120 * (Used for the decompressed data only.)
121 */
122void flush_window(void)
123{
124	ulg c = crc;
125	unsigned n;
126	uch *in, *out, ch;
127
128	in = window;
129	out = &output_data[output_ptr];
130	for (n = 0; n < outcnt; n++) {
131		ch = *out++ = *in++;
132		c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
133	}
134	crc = c;
135	bytes_out += (ulg)outcnt;
136	output_ptr += (ulg)outcnt;
137	outcnt = 0;
138/*	puts("."); */
139}
140
141static void error(char *x)
142{
143	puts("\n\n");
144	puts(x);
145	puts("\n\n -- System halted");
146
147	while(1);	/* Halt */
148}
149
150unsigned int
151decompress_kernel(void *output_start,
152		  void *input_start,
153		  size_t ksize,
154		  size_t kzsize)
155{
156	output_data		= (uch *)output_start;
157	input_data		= (uch *)input_start;
158	input_data_size		= kzsize; /* use compressed size */
159
160	/* FIXME FIXME FIXME */
161	free_mem_ptr		= (ulg)output_start + ksize;
162	free_mem_end_ptr	= (ulg)output_start + ksize + 0x200000;
163	/* FIXME FIXME FIXME */
164
165	/* put in temp area to reduce initial footprint */
166	window = malloc(WSIZE);
167
168	makecrc();
169/*	puts("Uncompressing Linux..."); */
170	gunzip();
171/*	puts(" done, booting the kernel.\n"); */
172	return output_ptr;
173}
174