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/sclp.h>
12 #include <asm/ipl.h>
13 #include "sizes.h"
14
15 /*
16 * gzip declarations
17 */
18 #define STATIC static
19
20 #undef memset
21 #undef memcpy
22 #undef memmove
23 #define memmove memmove
24 #define memzero(s, n) memset((s), 0, (n))
25
26 /* Symbols defined by linker scripts */
27 extern char input_data[];
28 extern int input_len;
29 extern char _text, _end;
30 extern char _bss, _ebss;
31
32 static void error(char *m);
33
34 static unsigned long free_mem_ptr;
35 static unsigned long free_mem_end_ptr;
36
37 #ifdef CONFIG_HAVE_KERNEL_BZIP2
38 #define HEAP_SIZE 0x400000
39 #else
40 #define HEAP_SIZE 0x10000
41 #endif
42
43 #ifdef CONFIG_KERNEL_GZIP
44 #include "../../../../lib/decompress_inflate.c"
45 #endif
46
47 #ifdef CONFIG_KERNEL_BZIP2
48 #include "../../../../lib/decompress_bunzip2.c"
49 #endif
50
51 #ifdef CONFIG_KERNEL_LZ4
52 #include "../../../../lib/decompress_unlz4.c"
53 #endif
54
55 #ifdef CONFIG_KERNEL_LZMA
56 #include "../../../../lib/decompress_unlzma.c"
57 #endif
58
59 #ifdef CONFIG_KERNEL_LZO
60 #include "../../../../lib/decompress_unlzo.c"
61 #endif
62
63 #ifdef CONFIG_KERNEL_XZ
64 #include "../../../../lib/decompress_unxz.c"
65 #endif
66
puts(const char * s)67 static int puts(const char *s)
68 {
69 _sclp_print_early(s);
70 return 0;
71 }
72
memset(void * s,int c,size_t n)73 void *memset(void *s, int c, size_t n)
74 {
75 char *xs;
76
77 xs = s;
78 while (n--)
79 *xs++ = c;
80 return s;
81 }
82
memcpy(void * dest,const void * src,size_t n)83 void *memcpy(void *dest, const void *src, size_t n)
84 {
85 const char *s = src;
86 char *d = dest;
87
88 while (n--)
89 *d++ = *s++;
90 return dest;
91 }
92
memmove(void * dest,const void * src,size_t n)93 void *memmove(void *dest, const void *src, size_t n)
94 {
95 const char *s = src;
96 char *d = dest;
97
98 if (d <= s) {
99 while (n--)
100 *d++ = *s++;
101 } else {
102 d += n;
103 s += n;
104 while (n--)
105 *--d = *--s;
106 }
107 return dest;
108 }
109
error(char * x)110 static void error(char *x)
111 {
112 unsigned long long psw = 0x000a0000deadbeefULL;
113
114 puts("\n\n");
115 puts(x);
116 puts("\n\n -- System halted");
117
118 asm volatile("lpsw %0" : : "Q" (psw));
119 }
120
121 /*
122 * Safe guard the ipl parameter block against a memory area that will be
123 * overwritten. The validity check for the ipl parameter block is complex
124 * (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to
125 * the ipl parameter block intersects with the passed memory area we can
126 * safely assume that we can read from that memory. In that case just copy
127 * the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter
128 * block.
129 */
check_ipl_parmblock(void * start,unsigned long size)130 static void check_ipl_parmblock(void *start, unsigned long size)
131 {
132 void *src, *dst;
133
134 src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
135 if (src + PAGE_SIZE <= start || src >= start + size)
136 return;
137 dst = (void *) IPL_PARMBLOCK_ORIGIN;
138 memmove(dst, src, PAGE_SIZE);
139 S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
140 }
141
decompress_kernel(void)142 unsigned long decompress_kernel(void)
143 {
144 unsigned long output_addr;
145 unsigned char *output;
146
147 output_addr = ((unsigned long) &_end + HEAP_SIZE + 4095UL) & -4096UL;
148 check_ipl_parmblock((void *) 0, output_addr + SZ__bss_start);
149 memset(&_bss, 0, &_ebss - &_bss);
150 free_mem_ptr = (unsigned long)&_end;
151 free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
152 output = (unsigned char *) output_addr;
153
154 #ifdef CONFIG_BLK_DEV_INITRD
155 /*
156 * Move the initrd right behind the end of the decompressed
157 * kernel image.
158 */
159 if (INITRD_START && INITRD_SIZE &&
160 INITRD_START < (unsigned long) output + SZ__bss_start) {
161 check_ipl_parmblock(output + SZ__bss_start,
162 INITRD_START + INITRD_SIZE);
163 memmove(output + SZ__bss_start,
164 (void *) INITRD_START, INITRD_SIZE);
165 INITRD_START = (unsigned long) output + SZ__bss_start;
166 }
167 #endif
168
169 puts("Uncompressing Linux... ");
170 __decompress(input_data, input_len, NULL, NULL, output, 0, NULL, error);
171 puts("Ok, booting the kernel.\n");
172 return (unsigned long) output;
173 }
174
175