xref: /openbmc/linux/arch/arm/boot/compressed/misc.c (revision 9cfc5c90)
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 #include <linux/compiler.h>	/* for inline */
22 #include <linux/types.h>
23 #include <linux/linkage.h>
24 
25 static void putstr(const char *ptr);
26 extern void error(char *x);
27 
28 #include CONFIG_UNCOMPRESS_INCLUDE
29 
30 #ifdef CONFIG_DEBUG_ICEDCC
31 
32 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
33 
34 static void icedcc_putc(int ch)
35 {
36 	int status, i = 0x4000000;
37 
38 	do {
39 		if (--i < 0)
40 			return;
41 
42 		asm volatile ("mrc p14, 0, %0, c0, c1, 0" : "=r" (status));
43 	} while (status & (1 << 29));
44 
45 	asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
46 }
47 
48 
49 #elif defined(CONFIG_CPU_XSCALE)
50 
51 static void icedcc_putc(int ch)
52 {
53 	int status, i = 0x4000000;
54 
55 	do {
56 		if (--i < 0)
57 			return;
58 
59 		asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
60 	} while (status & (1 << 28));
61 
62 	asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
63 }
64 
65 #else
66 
67 static void icedcc_putc(int ch)
68 {
69 	int status, i = 0x4000000;
70 
71 	do {
72 		if (--i < 0)
73 			return;
74 
75 		asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
76 	} while (status & 2);
77 
78 	asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
79 }
80 
81 #endif
82 
83 #define putc(ch)	icedcc_putc(ch)
84 #endif
85 
86 static void putstr(const char *ptr)
87 {
88 	char c;
89 
90 	while ((c = *ptr++) != '\0') {
91 		if (c == '\n')
92 			putc('\r');
93 		putc(c);
94 	}
95 
96 	flush();
97 }
98 
99 /*
100  * gzip declarations
101  */
102 extern char input_data[];
103 extern char input_data_end[];
104 
105 unsigned char *output_data;
106 
107 unsigned long free_mem_ptr;
108 unsigned long free_mem_end_ptr;
109 
110 #ifndef arch_error
111 #define arch_error(x)
112 #endif
113 
114 void error(char *x)
115 {
116 	arch_error(x);
117 
118 	putstr("\n\n");
119 	putstr(x);
120 	putstr("\n\n -- System halted");
121 
122 	while(1);	/* Halt */
123 }
124 
125 asmlinkage void __div0(void)
126 {
127 	error("Attempting division by 0!");
128 }
129 
130 unsigned long __stack_chk_guard;
131 
132 void __stack_chk_guard_setup(void)
133 {
134 	__stack_chk_guard = 0x000a0dff;
135 }
136 
137 void __stack_chk_fail(void)
138 {
139 	error("stack-protector: Kernel stack is corrupted\n");
140 }
141 
142 extern int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));
143 
144 
145 void
146 decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
147 		unsigned long free_mem_ptr_end_p,
148 		int arch_id)
149 {
150 	int ret;
151 
152 	__stack_chk_guard_setup();
153 
154 	output_data		= (unsigned char *)output_start;
155 	free_mem_ptr		= free_mem_ptr_p;
156 	free_mem_end_ptr	= free_mem_ptr_end_p;
157 	__machine_arch_type	= arch_id;
158 
159 	arch_decomp_setup();
160 
161 	putstr("Uncompressing Linux...");
162 	ret = do_decompress(input_data, input_data_end - input_data,
163 			    output_data, error);
164 	if (ret)
165 		error("decompressor returned an error");
166 	else
167 		putstr(" done, booting the kernel.\n");
168 }
169