xref: /linux/arch/alpha/boot/misc.c (revision c0c914eca7f251c70facc37dfebeaf176601918d)
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
28 extern 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 
37 typedef unsigned char  uch;
38 typedef unsigned short ush;
39 typedef unsigned long  ulg;
40 
41 #define WSIZE 0x8000		/* Window size must be at least 32k, */
42 				/* and a power of two */
43 
44 static uch *inbuf;		/* input buffer */
45 static uch *window;		/* Sliding window buffer */
46 
47 static unsigned insize;		/* valid bytes in inbuf */
48 static unsigned inptr;		/* index of next byte to be processed in inbuf */
49 static 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 
79 static int  fill_inbuf(void);
80 static void flush_window(void);
81 static void error(char *m);
82 
83 static char *input_data;
84 static int  input_data_size;
85 
86 static uch *output_data;
87 static ulg output_ptr;
88 static ulg bytes_out;
89 
90 static void error(char *m);
91 static void gzip_mark(void **);
92 static void gzip_release(void **);
93 
94 extern int end;
95 static ulg free_mem_ptr;
96 static 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  */
106 int 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  */
122 void 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 
141 static 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 
150 unsigned int
151 decompress_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