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
20unsigned 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
30static 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
38static 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
55static 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
71static 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
90static 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 */
106unsigned char *output_data;
107
108unsigned long free_mem_ptr;
109unsigned long free_mem_end_ptr;
110
111#ifndef arch_error
112#define arch_error(x)
113#endif
114
115void error(char *x)
116{
117 arch_error(x);
118
119 putstr(ptr: "\n\n");
120 putstr(ptr: x);
121 putstr(ptr: "\n\n -- System halted");
122
123 while(1); /* Halt */
124}
125
126asmlinkage void __div0(void)
127{
128 error(x: "Attempting division by 0!");
129}
130
131void
132decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
133 unsigned long free_mem_ptr_end_p,
134 int arch_id)
135{
136 int ret;
137
138 output_data = (unsigned char *)output_start;
139 free_mem_ptr = free_mem_ptr_p;
140 free_mem_end_ptr = free_mem_ptr_end_p;
141 __machine_arch_type = arch_id;
142
143#ifdef CONFIG_ARCH_EP93XX
144 ep93xx_decomp_setup();
145#endif
146 arch_decomp_setup();
147
148 putstr(ptr: "Uncompressing Linux...");
149 ret = do_decompress(input: input_data, len: input_data_end - input_data,
150 output: output_data, error);
151 if (ret)
152 error(x: "decompressor returned an error");
153 else
154 putstr(ptr: " done, booting the kernel.\n");
155}
156
157void __fortify_panic(const u8 reason, size_t avail, size_t size)
158{
159 error(x: "detected buffer overflow");
160}
161

source code of linux/arch/arm/boot/compressed/misc.c