xref: /openbmc/linux/arch/arm/boot/compressed/misc.c (revision cef69974)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * misc.c
4  *
5  * This is a collection of several routines from gzip-1.0.3
6  * adapted for Linux.
7  *
8  * malloc by Hannu Savolainen 1993 and Matthias Urlichs 1994
9  *
10  * Modified for ARM Linux by Russell King
11  *
12  * Nicolas Pitre <nico@visuaide.com>  1999/04/14 :
13  *  For this code to run directly from Flash, all constant variables must
14  *  be marked with 'const' and all other variables initialized at run-time
15  *  only.  This way all non constant variables will end up in the bss segment,
16  *  which should point to addresses in RAM and cleared to 0 on start.
17  *  This allows for a much quicker boot time.
18  */
19 
20 unsigned int __machine_arch_type;
21 
22 #include <linux/compiler.h>	/* for inline */
23 #include <linux/types.h>
24 #include <linux/linkage.h>
25 #include "misc.h"
26 
27 static void putstr(const char *ptr);
28 
29 #include CONFIG_UNCOMPRESS_INCLUDE
30 
31 #ifdef CONFIG_DEBUG_ICEDCC
32 
33 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
34 
35 static void icedcc_putc(int ch)
36 {
37 	int status, i = 0x4000000;
38 
39 	do {
40 		if (--i < 0)
41 			return;
42 
43 		asm volatile ("mrc p14, 0, %0, c0, c1, 0" : "=r" (status));
44 	} while (status & (1 << 29));
45 
46 	asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
47 }
48 
49 
50 #elif defined(CONFIG_CPU_XSCALE)
51 
52 static void icedcc_putc(int ch)
53 {
54 	int status, i = 0x4000000;
55 
56 	do {
57 		if (--i < 0)
58 			return;
59 
60 		asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
61 	} while (status & (1 << 28));
62 
63 	asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
64 }
65 
66 #else
67 
68 static void icedcc_putc(int ch)
69 {
70 	int status, i = 0x4000000;
71 
72 	do {
73 		if (--i < 0)
74 			return;
75 
76 		asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
77 	} while (status & 2);
78 
79 	asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
80 }
81 
82 #endif
83 
84 #define putc(ch)	icedcc_putc(ch)
85 #endif
86 
87 static void putstr(const char *ptr)
88 {
89 	char c;
90 
91 	while ((c = *ptr++) != '\0') {
92 		if (c == '\n')
93 			putc('\r');
94 		putc(c);
95 	}
96 
97 	flush();
98 }
99 
100 /*
101  * gzip declarations
102  */
103 extern char input_data[];
104 extern char input_data_end[];
105 
106 unsigned char *output_data;
107 
108 unsigned long free_mem_ptr;
109 unsigned long free_mem_end_ptr;
110 
111 #ifndef arch_error
112 #define arch_error(x)
113 #endif
114 
115 void error(char *x)
116 {
117 	arch_error(x);
118 
119 	putstr("\n\n");
120 	putstr(x);
121 	putstr("\n\n -- System halted");
122 
123 	while(1);	/* Halt */
124 }
125 
126 asmlinkage void __div0(void)
127 {
128 	error("Attempting division by 0!");
129 }
130 
131 extern int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));
132 
133 
134 void
135 decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
136 		unsigned long free_mem_ptr_end_p,
137 		int arch_id)
138 {
139 	int ret;
140 
141 	output_data		= (unsigned char *)output_start;
142 	free_mem_ptr		= free_mem_ptr_p;
143 	free_mem_end_ptr	= free_mem_ptr_end_p;
144 	__machine_arch_type	= arch_id;
145 
146 	arch_decomp_setup();
147 
148 	putstr("Uncompressing Linux...");
149 	ret = do_decompress(input_data, input_data_end - input_data,
150 			    output_data, error);
151 	if (ret)
152 		error("decompressor returned an error");
153 	else
154 		putstr(" done, booting the kernel.\n");
155 }
156 
157 void fortify_panic(const char *name)
158 {
159 	error("detected buffer overflow");
160 }
161