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 xs = s;
75 while (n--)
76 *xs++ = c;
77 return s;
78 }
79
memcpy(void * dest,const void * src,size_t n)80 void *memcpy(void *dest, const void *src, size_t n)
81 {
82 const char *s = src;
83 char *d = dest;
84
85 while (n--)
86 *d++ = *s++;
87 return dest;
88 }
89
memmove(void * dest,const void * src,size_t n)90 void *memmove(void *dest, const void *src, size_t n)
91 {
92 const char *s = src;
93 char *d = dest;
94
95 if (d <= s) {
96 while (n--)
97 *d++ = *s++;
98 } else {
99 d += n;
100 s += n;
101 while (n--)
102 *--d = *--s;
103 }
104 return dest;
105 }
106
error(char * x)107 static void error(char *x)
108 {
109 unsigned long long psw = 0x000a0000deadbeefULL;
110
111 puts("\n\n");
112 puts(x);
113 puts("\n\n -- System halted");
114
115 asm volatile("lpsw %0" : : "Q" (psw));
116 }
117
118 /*
119 * Safe guard the ipl parameter block against a memory area that will be
120 * overwritten. The validity check for the ipl parameter block is complex
121 * (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to
122 * the ipl parameter block intersects with the passed memory area we can
123 * safely assume that we can read from that memory. In that case just copy
124 * the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter
125 * block.
126 */
check_ipl_parmblock(void * start,unsigned long size)127 static void check_ipl_parmblock(void *start, unsigned long size)
128 {
129 void *src, *dst;
130
131 src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
132 if (src + PAGE_SIZE <= start || src >= start + size)
133 return;
134 dst = (void *) IPL_PARMBLOCK_ORIGIN;
135 memmove(dst, src, PAGE_SIZE);
136 S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
137 }
138
decompress_kernel(void)139 unsigned long decompress_kernel(void)
140 {
141 unsigned long output_addr;
142 unsigned char *output;
143
144 output_addr = ((unsigned long) &_end + HEAP_SIZE + 4095UL) & -4096UL;
145 check_ipl_parmblock((void *) 0, output_addr + SZ__bss_start);
146 memset(&_bss, 0, &_ebss - &_bss);
147 free_mem_ptr = (unsigned long)&_end;
148 free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
149 output = (unsigned char *) output_addr;
150
151 #ifdef CONFIG_BLK_DEV_INITRD
152 /*
153 * Move the initrd right behind the end of the decompressed
154 * kernel image.
155 */
156 if (INITRD_START && INITRD_SIZE &&
157 INITRD_START < (unsigned long) output + SZ__bss_start) {
158 check_ipl_parmblock(output + SZ__bss_start,
159 INITRD_START + INITRD_SIZE);
160 memmove(output + SZ__bss_start,
161 (void *) INITRD_START, INITRD_SIZE);
162 INITRD_START = (unsigned long) output + SZ__bss_start;
163 }
164 #endif
165
166 puts("Uncompressing Linux... ");
167 decompress(input_data, input_len, NULL, NULL, output, NULL, error);
168 puts("Ok, booting the kernel.\n");
169 return (unsigned long) output;
170 }
171
172