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 */
19unsigned int __machine_arch_type;
20
21#include <linux/compiler.h>	/* for inline */
22#include <linux/types.h>
23#include <linux/linkage.h>
24#include "misc.h"
25
26static void putstr(const char *ptr);
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
34static 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
51static 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
67static 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
86static 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 */
102extern char input_data[];
103extern char input_data_end[];
104
105unsigned char *output_data;
106
107unsigned long free_mem_ptr;
108unsigned long free_mem_end_ptr;
109
110#ifndef arch_error
111#define arch_error(x)
112#endif
113
114void 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
125asmlinkage void __div0(void)
126{
127	error("Attempting division by 0!");
128}
129
130const unsigned long __stack_chk_guard = 0x000a0dff;
131
132void __stack_chk_fail(void)
133{
134	error("stack-protector: Kernel stack is corrupted\n");
135}
136
137extern int do_decompress(u8 *input, int len, u8 *output, void (*error)(char *x));
138
139
140void
141decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p,
142		unsigned long free_mem_ptr_end_p,
143		int arch_id)
144{
145	int ret;
146
147	output_data		= (unsigned char *)output_start;
148	free_mem_ptr		= free_mem_ptr_p;
149	free_mem_end_ptr	= free_mem_ptr_end_p;
150	__machine_arch_type	= arch_id;
151
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
163void fortify_panic(const char *name)
164{
165	error("detected buffer overflow");
166}
167