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1 /*
2  * Definitions and wrapper functions for kernel decompressor
3  *
4  * Copyright IBM Corp. 2010
5  *
6  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
7  */
8 
9 #include <asm/uaccess.h>
10 #include <asm/page.h>
11 #include <asm/ipl.h>
12 #include "sizes.h"
13 
14 /*
15  * gzip declarations
16  */
17 #define STATIC static
18 
19 #undef memset
20 #undef memcpy
21 #undef memmove
22 #define memmove memmove
23 #define memzero(s, n) memset((s), 0, (n))
24 
25 /* Symbols defined by linker scripts */
26 extern char input_data[];
27 extern int input_len;
28 extern char _text, _end;
29 extern char _bss, _ebss;
30 
31 static void error(char *m);
32 
33 static unsigned long free_mem_ptr;
34 static unsigned long free_mem_end_ptr;
35 
36 #ifdef CONFIG_HAVE_KERNEL_BZIP2
37 #define HEAP_SIZE	0x400000
38 #else
39 #define HEAP_SIZE	0x10000
40 #endif
41 
42 #ifdef CONFIG_KERNEL_GZIP
43 #include "../../../../lib/decompress_inflate.c"
44 #endif
45 
46 #ifdef CONFIG_KERNEL_BZIP2
47 #include "../../../../lib/decompress_bunzip2.c"
48 #endif
49 
50 #ifdef CONFIG_KERNEL_LZMA
51 #include "../../../../lib/decompress_unlzma.c"
52 #endif
53 
54 #ifdef CONFIG_KERNEL_LZO
55 #include "../../../../lib/decompress_unlzo.c"
56 #endif
57 
58 #ifdef CONFIG_KERNEL_XZ
59 #include "../../../../lib/decompress_unxz.c"
60 #endif
61 
62 extern _sclp_print_early(const char *);
63 
puts(const char * s)64 static int puts(const char *s)
65 {
66 	_sclp_print_early(s);
67 	return 0;
68 }
69 
memset(void * s,int c,size_t n)70 void *memset(void *s, int c, size_t n)
71 {
72 	char *xs;
73 
74 	if (c == 0)
75 		return __builtin_memset(s, 0, n);
76 
77 	xs = (char *) s;
78 	if (n > 0)
79 		do {
80 			*xs++ = c;
81 		} while (--n > 0);
82 	return s;
83 }
84 
memcpy(void * __dest,__const void * __src,size_t __n)85 void *memcpy(void *__dest, __const void *__src, size_t __n)
86 {
87 	return __builtin_memcpy(__dest, __src, __n);
88 }
89 
memmove(void * __dest,__const void * __src,size_t __n)90 void *memmove(void *__dest, __const void *__src, size_t __n)
91 {
92 	char *d;
93 	const char *s;
94 
95 	if (__dest <= __src)
96 		return __builtin_memcpy(__dest, __src, __n);
97 	d = __dest + __n;
98 	s = __src + __n;
99 	while (__n--)
100 		*--d = *--s;
101 	return __dest;
102 }
103 
error(char * x)104 static void error(char *x)
105 {
106 	unsigned long long psw = 0x000a0000deadbeefULL;
107 
108 	puts("\n\n");
109 	puts(x);
110 	puts("\n\n -- System halted");
111 
112 	asm volatile("lpsw %0" : : "Q" (psw));
113 }
114 
115 /*
116  * Safe guard the ipl parameter block against a memory area that will be
117  * overwritten. The validity check for the ipl parameter block is complex
118  * (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to
119  * the ipl parameter block intersects with the passed memory area we can
120  * safely assume that we can read from that memory. In that case just copy
121  * the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter
122  * block.
123  */
check_ipl_parmblock(void * start,unsigned long size)124 static void check_ipl_parmblock(void *start, unsigned long size)
125 {
126 	void *src, *dst;
127 
128 	src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
129 	if (src + PAGE_SIZE <= start || src >= start + size)
130 		return;
131 	dst = (void *) IPL_PARMBLOCK_ORIGIN;
132 	memmove(dst, src, PAGE_SIZE);
133 	S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
134 }
135 
decompress_kernel(void)136 unsigned long decompress_kernel(void)
137 {
138 	unsigned long output_addr;
139 	unsigned char *output;
140 
141 	output_addr = ((unsigned long) &_end + HEAP_SIZE + 4095UL) & -4096UL;
142 	check_ipl_parmblock((void *) 0, output_addr + SZ__bss_start);
143 	memset(&_bss, 0, &_ebss - &_bss);
144 	free_mem_ptr = (unsigned long)&_end;
145 	free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
146 	output = (unsigned char *) output_addr;
147 
148 #ifdef CONFIG_BLK_DEV_INITRD
149 	/*
150 	 * Move the initrd right behind the end of the decompressed
151 	 * kernel image.
152 	 */
153 	if (INITRD_START && INITRD_SIZE &&
154 	    INITRD_START < (unsigned long) output + SZ__bss_start) {
155 		check_ipl_parmblock(output + SZ__bss_start,
156 				    INITRD_START + INITRD_SIZE);
157 		memmove(output + SZ__bss_start,
158 			(void *) INITRD_START, INITRD_SIZE);
159 		INITRD_START = (unsigned long) output + SZ__bss_start;
160 	}
161 #endif
162 
163 	puts("Uncompressing Linux... ");
164 	decompress(input_data, input_len, NULL, NULL, output, NULL, error);
165 	puts("Ok, booting the kernel.\n");
166 	return (unsigned long) output;
167 }
168 
169