xref: /openbmc/linux/arch/arm/boot/compressed/misc.c (revision b6bec26c)
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 #ifdef CONFIG_ARCH_MULTIPLATFORM
29 static inline void putc(int c) {}
30 static inline void flush(void) {}
31 static inline void arch_decomp_setup(void) {}
32 #else
33 #include <mach/uncompress.h>
34 #endif
35 
36 #ifdef CONFIG_DEBUG_ICEDCC
37 
38 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
39 
40 static void icedcc_putc(int ch)
41 {
42 	int status, i = 0x4000000;
43 
44 	do {
45 		if (--i < 0)
46 			return;
47 
48 		asm volatile ("mrc p14, 0, %0, c0, c1, 0" : "=r" (status));
49 	} while (status & (1 << 29));
50 
51 	asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
52 }
53 
54 
55 #elif defined(CONFIG_CPU_XSCALE)
56 
57 static void icedcc_putc(int ch)
58 {
59 	int status, i = 0x4000000;
60 
61 	do {
62 		if (--i < 0)
63 			return;
64 
65 		asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
66 	} while (status & (1 << 28));
67 
68 	asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
69 }
70 
71 #else
72 
73 static void icedcc_putc(int ch)
74 {
75 	int status, i = 0x4000000;
76 
77 	do {
78 		if (--i < 0)
79 			return;
80 
81 		asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
82 	} while (status & 2);
83 
84 	asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
85 }
86 
87 #endif
88 
89 #define putc(ch)	icedcc_putc(ch)
90 #endif
91 
92 static void putstr(const char *ptr)
93 {
94 	char c;
95 
96 	while ((c = *ptr++) != '\0') {
97 		if (c == '\n')
98 			putc('\r');
99 		putc(c);
100 	}
101 
102 	flush();
103 }
104 
105 /*
106  * gzip declarations
107  */
108 extern char input_data[];
109 extern char input_data_end[];
110 
111 unsigned char *output_data;
112 
113 unsigned long free_mem_ptr;
114 unsigned long free_mem_end_ptr;
115 
116 #ifndef arch_error
117 #define arch_error(x)
118 #endif
119 
120 void error(char *x)
121 {
122 	arch_error(x);
123 
124 	putstr("\n\n");
125 	putstr(x);
126 	putstr("\n\n -- System halted");
127 
128 	while(1);	/* Halt */
129 }
130 
131 asmlinkage void __div0(void)
132 {
133 	error("Attempting division by 0!");
134 }
135 
136 extern int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));
137 
138 
139 void
140 decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
141 		unsigned long free_mem_ptr_end_p,
142 		int arch_id)
143 {
144 	int ret;
145 
146 	output_data		= (unsigned char *)output_start;
147 	free_mem_ptr		= free_mem_ptr_p;
148 	free_mem_end_ptr	= free_mem_ptr_end_p;
149 	__machine_arch_type	= arch_id;
150 
151 	arch_decomp_setup();
152 
153 	putstr("Uncompressing Linux...");
154 	ret = do_decompress(input_data, input_data_end - input_data,
155 			    output_data, error);
156 	if (ret)
157 		error("decompressor returned an error");
158 	else
159 		putstr(" done, booting the kernel.\n");
160 }
161