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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * misc.c
4 *
5 * This is a collection of several routines from gzip-1.0.3
6 * adapted for Linux.
7 *
8 * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
9 *
10 * Modified for ARM Linux by Russell King
11 *
12 * Nicolas Pitre <[email protected]> 1999/04/14 :
13 * For this code to run directly from Flash, all constant variables must
14 * be marked with 'const' and all other variables initialized at run-time
15 * only. This way all non constant variables will end up in the bss segment,
16 * which should point to addresses in RAM and cleared to 0 on start.
17 * This allows for a much quicker boot time.
18 *
19 * Modified for Alpha, from the ARM version, by Jay Estabrook 2003.
20 */
21
22#include <linux/kernel.h>
23#include <linux/slab.h>
24
25#include <linux/uaccess.h>
26
27#define memzero(s,n) memset ((s),0,(n))
28#define puts srm_printk
29extern long srm_printk(const char *, ...)
30 __attribute__ ((format (printf, 1, 2)));
31
32/*
33 * gzip declarations
34 */
35#define OF(args) args
36#define STATIC static
37
38typedef unsigned char uch;
39typedef unsigned short ush;
40typedef unsigned long ulg;
41
42#define WSIZE 0x8000 /* Window size must be at least 32k, */
43 /* and a power of two */
44
45static uch *inbuf; /* input buffer */
46static uch *window; /* Sliding window buffer */
47
48static unsigned insize; /* valid bytes in inbuf */
49static unsigned inptr; /* index of next byte to be processed in inbuf */
50static unsigned outcnt; /* bytes in output buffer */
51
52/* gzip flag byte */
53#define ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
54#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
55#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
56#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
57#define COMMENT 0x10 /* bit 4 set: file comment present */
58#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
59#define RESERVED 0xC0 /* bit 6,7: reserved */
60
61#define get_byte() (inptr < insize ? inbuf[inptr++] : fill_inbuf())
62
63/* Diagnostic functions */
64#ifdef DEBUG
65# define Assert(cond,msg) {if(!(cond)) error(msg);}
66# define Trace(x) fprintf x
67# define Tracev(x) {if (verbose) fprintf x ;}
68# define Tracevv(x) {if (verbose>1) fprintf x ;}
69# define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
70# define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
71#else
72# define Assert(cond,msg)
73# define Trace(x)
74# define Tracev(x)
75# define Tracevv(x)
76# define Tracec(c,x)
77# define Tracecv(c,x)
78#endif
79
80static int fill_inbuf(void);
81static void flush_window(void);
82static void error(char *m);
83
84static char *input_data;
85static int input_data_size;
86
87static uch *output_data;
88static ulg output_ptr;
89static ulg bytes_out;
90
91static void error(char *m);
92
93extern int end;
94static ulg free_mem_ptr;
95static ulg free_mem_end_ptr;
96
97#define HEAP_SIZE 0x3000
98
99#include "../../../lib/inflate.c"
100
101/* ===========================================================================
102 * Fill the input buffer. This is called only when the buffer is empty
103 * and at least one byte is really needed.
104 */
105int fill_inbuf(void)
106{
107 if (insize != 0)
108 error("ran out of input data");
109
110 inbuf = input_data;
111 insize = input_data_size;
112
113 inptr = 1;
114 return inbuf[0];
115}
116
117/* ===========================================================================
118 * Write the output window window[0..outcnt-1] and update crc and bytes_out.
119 * (Used for the decompressed data only.)
120 */
121void flush_window(void)
122{
123 ulg c = crc;
124 unsigned n;
125 uch *in, *out, ch;
126
127 in = window;
128 out = &output_data[output_ptr];
129 for (n = 0; n < outcnt; n++) {
130 ch = *out++ = *in++;
131 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
132 }
133 crc = c;
134 bytes_out += (ulg)outcnt;
135 output_ptr += (ulg)outcnt;
136 outcnt = 0;
137/* puts("."); */
138}
139
140static void error(char *x)
141{
142 puts("\n\n");
143 puts(x);
144 puts("\n\n -- System halted");
145
146 while(1); /* Halt */
147}
148
149unsigned int
150decompress_kernel(void *output_start,
151 void *input_start,
152 size_t ksize,
153 size_t kzsize)
154{
155 output_data = (uch *)output_start;
156 input_data = (uch *)input_start;
157 input_data_size = kzsize; /* use compressed size */
158
159 /* FIXME FIXME FIXME */
160 free_mem_ptr = (ulg)output_start + ksize;
161 free_mem_end_ptr = (ulg)output_start + ksize + 0x200000;
162 /* FIXME FIXME FIXME */
163
164 /* put in temp area to reduce initial footprint */
165 window = malloc(WSIZE);
166
167 makecrc();
168/* puts("Uncompressing Linux..."); */
169 gunzip();
170/* puts(" done, booting the kernel.\n"); */
171 return output_ptr;
172}