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 <nico@visuaide.com> 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
29 extern 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
38 typedef unsigned char uch;
39 typedef unsigned short ush;
40 typedef unsigned long ulg;
41
42 #define WSIZE 0x8000 /* Window size must be at least 32k, */
43 /* and a power of two */
44
45 static uch *inbuf; /* input buffer */
46 static uch *window; /* Sliding window buffer */
47
48 static unsigned insize; /* valid bytes in inbuf */
49 static unsigned inptr; /* index of next byte to be processed in inbuf */
50 static 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
80 static int fill_inbuf(void);
81 static void flush_window(void);
82 static void error(char *m);
83
84 static char *input_data;
85 static int input_data_size;
86
87 static uch *output_data;
88 static ulg output_ptr;
89 static ulg bytes_out;
90
91 static void error(char *m);
92
93 extern int end;
94 static ulg free_mem_ptr;
95 static 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 */
105 int 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 */
121 void 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
140 static 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
149 unsigned int
150 decompress_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 }
173
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