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