xref: /openbmc/linux/arch/arm/boot/compressed/misc.c (revision fb4a5dfc)
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 #ifdef CONFIG_ARCH_EP93XX
27 #include "misc-ep93xx.h"
28 #endif
29 
30 static void putstr(const char *ptr);
31 
32 #include CONFIG_UNCOMPRESS_INCLUDE
33 
34 #ifdef CONFIG_DEBUG_ICEDCC
35 
36 #if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V6K) || defined(CONFIG_CPU_V7)
37 
38 static void icedcc_putc(int ch)
39 {
40 	int status, i = 0x4000000;
41 
42 	do {
43 		if (--i < 0)
44 			return;
45 
46 		asm volatile ("mrc p14, 0, %0, c0, c1, 0" : "=r" (status));
47 	} while (status & (1 << 29));
48 
49 	asm("mcr p14, 0, %0, c0, c5, 0" : : "r" (ch));
50 }
51 
52 
53 #elif defined(CONFIG_CPU_XSCALE)
54 
55 static void icedcc_putc(int ch)
56 {
57 	int status, i = 0x4000000;
58 
59 	do {
60 		if (--i < 0)
61 			return;
62 
63 		asm volatile ("mrc p14, 0, %0, c14, c0, 0" : "=r" (status));
64 	} while (status & (1 << 28));
65 
66 	asm("mcr p14, 0, %0, c8, c0, 0" : : "r" (ch));
67 }
68 
69 #else
70 
71 static void icedcc_putc(int ch)
72 {
73 	int status, i = 0x4000000;
74 
75 	do {
76 		if (--i < 0)
77 			return;
78 
79 		asm volatile ("mrc p14, 0, %0, c0, c0, 0" : "=r" (status));
80 	} while (status & 2);
81 
82 	asm("mcr p14, 0, %0, c1, c0, 0" : : "r" (ch));
83 }
84 
85 #endif
86 
87 #define putc(ch)	icedcc_putc(ch)
88 #endif
89 
90 static void putstr(const char *ptr)
91 {
92 	char c;
93 
94 	while ((c = *ptr++) != '\0') {
95 		if (c == '\n')
96 			putc('\r');
97 		putc(c);
98 	}
99 
100 	flush();
101 }
102 
103 /*
104  * gzip declarations
105  */
106 extern char input_data[];
107 extern char input_data_end[];
108 
109 unsigned char *output_data;
110 
111 unsigned long free_mem_ptr;
112 unsigned long free_mem_end_ptr;
113 
114 #ifndef arch_error
115 #define arch_error(x)
116 #endif
117 
118 void error(char *x)
119 {
120 	arch_error(x);
121 
122 	putstr("\n\n");
123 	putstr(x);
124 	putstr("\n\n -- System halted");
125 
126 	while(1);	/* Halt */
127 }
128 
129 asmlinkage void __div0(void)
130 {
131 	error("Attempting division by 0!");
132 }
133 
134 extern int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));
135 
136 
137 void
138 decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
139 		unsigned long free_mem_ptr_end_p,
140 		int arch_id)
141 {
142 	int ret;
143 
144 	output_data		= (unsigned char *)output_start;
145 	free_mem_ptr		= free_mem_ptr_p;
146 	free_mem_end_ptr	= free_mem_ptr_end_p;
147 	__machine_arch_type	= arch_id;
148 
149 #ifdef CONFIG_ARCH_EP93XX
150 	ep93xx_decomp_setup();
151 #endif
152 	arch_decomp_setup();
153 
154 	putstr("Uncompressing Linux...");
155 	ret = do_decompress(input_data, input_data_end - input_data,
156 			    output_data, error);
157 	if (ret)
158 		error("decompressor returned an error");
159 	else
160 		putstr(" done, booting the kernel.\n");
161 }
162 
163 void fortify_panic(const char *name)
164 {
165 	error("detected buffer overflow");
166 }
167