xref: /linux/arch/arm/boot/compressed/misc.c (revision f850548ef88e5ff9e40bae9e1a7140bef0653e6b)
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 
19 unsigned int __machine_arch_type;
20 
21 #define _LINUX_STRING_H_
22 
23 #include <linux/compiler.h>	/* for inline */
24 #include <linux/types.h>	/* for size_t */
25 #include <linux/stddef.h>	/* for NULL */
26 #include <linux/linkage.h>
27 #include <asm/string.h>
28 
29 #include <asm/unaligned.h>
30 
31 
32 static void putstr(const char *ptr);
33 extern void error(char *x);
34 
35 #include <mach/uncompress.h>
36 
37 #ifdef CONFIG_DEBUG_ICEDCC
38 
39 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
40 
41 static void icedcc_putc(int ch)
42 {
43 	int status, i = 0x4000000;
44 
45 	do {
46 		if (--i < 0)
47 			return;
48 
49 		asm volatile ("mrc p14, 0, %0, c0, c1, 0" : "=r" (status));
50 	} while (status & (1 << 29));
51 
52 	asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
53 }
54 
55 
56 #elif defined(CONFIG_CPU_XSCALE)
57 
58 static void icedcc_putc(int ch)
59 {
60 	int status, i = 0x4000000;
61 
62 	do {
63 		if (--i < 0)
64 			return;
65 
66 		asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
67 	} while (status & (1 << 28));
68 
69 	asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
70 }
71 
72 #else
73 
74 static void icedcc_putc(int ch)
75 {
76 	int status, i = 0x4000000;
77 
78 	do {
79 		if (--i < 0)
80 			return;
81 
82 		asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
83 	} while (status & 2);
84 
85 	asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
86 }
87 
88 #endif
89 
90 #define putc(ch)	icedcc_putc(ch)
91 #endif
92 
93 static void putstr(const char *ptr)
94 {
95 	char c;
96 
97 	while ((c = *ptr++) != '\0') {
98 		if (c == '\n')
99 			putc('\r');
100 		putc(c);
101 	}
102 
103 	flush();
104 }
105 
106 
107 void *memcpy(void *__dest, __const void *__src, size_t __n)
108 {
109 	int i = 0;
110 	unsigned char *d = (unsigned char *)__dest, *s = (unsigned char *)__src;
111 
112 	for (i = __n >> 3; i > 0; i--) {
113 		*d++ = *s++;
114 		*d++ = *s++;
115 		*d++ = *s++;
116 		*d++ = *s++;
117 		*d++ = *s++;
118 		*d++ = *s++;
119 		*d++ = *s++;
120 		*d++ = *s++;
121 	}
122 
123 	if (__n & 1 << 2) {
124 		*d++ = *s++;
125 		*d++ = *s++;
126 		*d++ = *s++;
127 		*d++ = *s++;
128 	}
129 
130 	if (__n & 1 << 1) {
131 		*d++ = *s++;
132 		*d++ = *s++;
133 	}
134 
135 	if (__n & 1)
136 		*d++ = *s++;
137 
138 	return __dest;
139 }
140 
141 /*
142  * gzip delarations
143  */
144 extern char input_data[];
145 extern char input_data_end[];
146 
147 unsigned char *output_data;
148 unsigned long output_ptr;
149 
150 unsigned long free_mem_ptr;
151 unsigned long free_mem_end_ptr;
152 
153 #ifndef arch_error
154 #define arch_error(x)
155 #endif
156 
157 void error(char *x)
158 {
159 	arch_error(x);
160 
161 	putstr("\n\n");
162 	putstr(x);
163 	putstr("\n\n -- System halted");
164 
165 	while(1);	/* Halt */
166 }
167 
168 asmlinkage void __div0(void)
169 {
170 	error("Attempting division by 0!");
171 }
172 
173 extern void do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));
174 
175 
176 unsigned long
177 decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
178 		unsigned long free_mem_ptr_end_p,
179 		int arch_id)
180 {
181 	unsigned char *tmp;
182 
183 	output_data		= (unsigned char *)output_start;
184 	free_mem_ptr		= free_mem_ptr_p;
185 	free_mem_end_ptr	= free_mem_ptr_end_p;
186 	__machine_arch_type	= arch_id;
187 
188 	arch_decomp_setup();
189 
190 	tmp = (unsigned char *) (((unsigned long)input_data_end) - 4);
191 	output_ptr = get_unaligned_le32(tmp);
192 
193 	putstr("Uncompressing Linux...");
194 	do_decompress(input_data, input_data_end - input_data,
195 			output_data, error);
196 	putstr(" done, booting the kernel.\n");
197 	return output_ptr;
198 }
199