xref: /openbmc/linux/arch/alpha/boot/misc.c (revision e105007c)
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 
23 #include <asm/uaccess.h>
24 
25 #define memzero(s,n)	memset ((s),0,(n))
26 #define puts		srm_printk
27 extern long srm_printk(const char *, ...)
28      __attribute__ ((format (printf, 1, 2)));
29 
30 /*
31  * gzip delarations
32  */
33 #define OF(args)  args
34 #define STATIC static
35 
36 typedef unsigned char  uch;
37 typedef unsigned short ush;
38 typedef unsigned long  ulg;
39 
40 #define WSIZE 0x8000		/* Window size must be at least 32k, */
41 				/* and a power of two */
42 
43 static uch *inbuf;		/* input buffer */
44 static uch *window;		/* Sliding window buffer */
45 
46 static unsigned insize;		/* valid bytes in inbuf */
47 static unsigned inptr;		/* index of next byte to be processed in inbuf */
48 static unsigned outcnt;		/* bytes in output buffer */
49 
50 /* gzip flag byte */
51 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
52 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
53 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
54 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
55 #define COMMENT      0x10 /* bit 4 set: file comment present */
56 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
57 #define RESERVED     0xC0 /* bit 6,7:   reserved */
58 
59 #define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf())
60 
61 /* Diagnostic functions */
62 #ifdef DEBUG
63 #  define Assert(cond,msg) {if(!(cond)) error(msg);}
64 #  define Trace(x) fprintf x
65 #  define Tracev(x) {if (verbose) fprintf x ;}
66 #  define Tracevv(x) {if (verbose>1) fprintf x ;}
67 #  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
68 #  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
69 #else
70 #  define Assert(cond,msg)
71 #  define Trace(x)
72 #  define Tracev(x)
73 #  define Tracevv(x)
74 #  define Tracec(c,x)
75 #  define Tracecv(c,x)
76 #endif
77 
78 static int  fill_inbuf(void);
79 static void flush_window(void);
80 static void error(char *m);
81 
82 static char *input_data;
83 static int  input_data_size;
84 
85 static uch *output_data;
86 static ulg output_ptr;
87 static ulg bytes_out;
88 
89 static void error(char *m);
90 static void gzip_mark(void **);
91 static void gzip_release(void **);
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