summaryrefslogtreecommitdiff
path: root/arch/s390/boot/compressed/misc.c
blob: 57cbaff1f39778b98b1de870e34f99cc14043687 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
/*
 * Definitions and wrapper functions for kernel decompressor
 *
 * Copyright IBM Corp. 2010
 *
 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
 */

#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/ipl.h>
#include "sizes.h"

/*
 * gzip declarations
 */
#define STATIC static

#undef memset
#undef memcpy
#undef memmove
#define memmove memmove
#define memzero(s, n) memset((s), 0, (n))

/* Symbols defined by linker scripts */
extern char input_data[];
extern int input_len;
extern char _text, _end;
extern char _bss, _ebss;

static void error(char *m);

static unsigned long free_mem_ptr;
static unsigned long free_mem_end_ptr;

#ifdef CONFIG_HAVE_KERNEL_BZIP2
#define HEAP_SIZE	0x400000
#else
#define HEAP_SIZE	0x10000
#endif

#ifdef CONFIG_KERNEL_GZIP
#include "../../../../lib/decompress_inflate.c"
#endif

#ifdef CONFIG_KERNEL_BZIP2
#include "../../../../lib/decompress_bunzip2.c"
#endif

#ifdef CONFIG_KERNEL_LZ4
#include "../../../../lib/decompress_unlz4.c"
#endif

#ifdef CONFIG_KERNEL_LZMA
#include "../../../../lib/decompress_unlzma.c"
#endif

#ifdef CONFIG_KERNEL_LZO
#include "../../../../lib/decompress_unlzo.c"
#endif

#ifdef CONFIG_KERNEL_XZ
#include "../../../../lib/decompress_unxz.c"
#endif

extern _sclp_print_early(const char *);

static int puts(const char *s)
{
	_sclp_print_early(s);
	return 0;
}

void *memset(void *s, int c, size_t n)
{
	char *xs;

	xs = s;
	while (n--)
		*xs++ = c;
	return s;
}

void *memcpy(void *dest, const void *src, size_t n)
{
	const char *s = src;
	char *d = dest;

	while (n--)
		*d++ = *s++;
	return dest;
}

void *memmove(void *dest, const void *src, size_t n)
{
	const char *s = src;
	char *d = dest;

	if (d <= s) {
		while (n--)
			*d++ = *s++;
	} else {
		d += n;
		s += n;
		while (n--)
			*--d = *--s;
	}
	return dest;
}

static void error(char *x)
{
	unsigned long long psw = 0x000a0000deadbeefULL;

	puts("\n\n");
	puts(x);
	puts("\n\n -- System halted");

	asm volatile("lpsw %0" : : "Q" (psw));
}

/*
 * Safe guard the ipl parameter block against a memory area that will be
 * overwritten. The validity check for the ipl parameter block is complex
 * (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to
 * the ipl parameter block intersects with the passed memory area we can
 * safely assume that we can read from that memory. In that case just copy
 * the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter
 * block.
 */
static void check_ipl_parmblock(void *start, unsigned long size)
{
	void *src, *dst;

	src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
	if (src + PAGE_SIZE <= start || src >= start + size)
		return;
	dst = (void *) IPL_PARMBLOCK_ORIGIN;
	memmove(dst, src, PAGE_SIZE);
	S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
}

unsigned long decompress_kernel(void)
{
	unsigned long output_addr;
	unsigned char *output;

	output_addr = ((unsigned long) &_end + HEAP_SIZE + 4095UL) & -4096UL;
	check_ipl_parmblock((void *) 0, output_addr + SZ__bss_start);
	memset(&_bss, 0, &_ebss - &_bss);
	free_mem_ptr = (unsigned long)&_end;
	free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
	output = (unsigned char *) output_addr;

#ifdef CONFIG_BLK_DEV_INITRD
	/*
	 * Move the initrd right behind the end of the decompressed
	 * kernel image.
	 */
	if (INITRD_START && INITRD_SIZE &&
	    INITRD_START < (unsigned long) output + SZ__bss_start) {
		check_ipl_parmblock(output + SZ__bss_start,
				    INITRD_START + INITRD_SIZE);
		memmove(output + SZ__bss_start,
			(void *) INITRD_START, INITRD_SIZE);
		INITRD_START = (unsigned long) output + SZ__bss_start;
	}
#endif

	puts("Uncompressing Linux... ");
	decompress(input_data, input_len, NULL, NULL, output, NULL, error);
	puts("Ok, booting the kernel.\n");
	return (unsigned long) output;
}