tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 */
26extern char input_data[];
27extern int input_len;
28extern char _text, _end;
29extern char _bss, _ebss;
30
31static void error(char *m);
32
33static unsigned long free_mem_ptr;
34static 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_LZ4
51#include "../../../../lib/decompress_unlz4.c"
52#endif
53
54#ifdef CONFIG_KERNEL_LZMA
55#include "../../../../lib/decompress_unlzma.c"
56#endif
57
58#ifdef CONFIG_KERNEL_LZO
59#include "../../../../lib/decompress_unlzo.c"
60#endif
61
62#ifdef CONFIG_KERNEL_XZ
63#include "../../../../lib/decompress_unxz.c"
64#endif
65
66extern _sclp_print_early(const char *);
67
68static int puts(const char *s)
69{
70 _sclp_print_early(s);
71 return 0;
72}
73
74void *memset(void *s, int c, size_t n)
75{
76 char *xs;
77
78 xs = s;
79 while (n--)
80 *xs++ = c;
81 return s;
82}
83
84void *memcpy(void *dest, const void *src, size_t n)
85{
86 const char *s = src;
87 char *d = dest;
88
89 while (n--)
90 *d++ = *s++;
91 return dest;
92}
93
94void *memmove(void *dest, const void *src, size_t n)
95{
96 const char *s = src;
97 char *d = dest;
98
99 if (d <= s) {
100 while (n--)
101 *d++ = *s++;
102 } else {
103 d += n;
104 s += n;
105 while (n--)
106 *--d = *--s;
107 }
108 return dest;
109}
110
111static void error(char *x)
112{
113 unsigned long long psw = 0x000a0000deadbeefULL;
114
115 puts("\n\n");
116 puts(x);
117 puts("\n\n -- System halted");
118
119 asm volatile("lpsw %0" : : "Q" (psw));
120}
121
122/*
123 * Safe guard the ipl parameter block against a memory area that will be
124 * overwritten. The validity check for the ipl parameter block is complex
125 * (see cio_get_iplinfo and ipl_save_parameters) but if the pointer to
126 * the ipl parameter block intersects with the passed memory area we can
127 * safely assume that we can read from that memory. In that case just copy
128 * the memory to IPL_PARMBLOCK_ORIGIN even if there is no ipl parameter
129 * block.
130 */
131static void check_ipl_parmblock(void *start, unsigned long size)
132{
133 void *src, *dst;
134
135 src = (void *)(unsigned long) S390_lowcore.ipl_parmblock_ptr;
136 if (src + PAGE_SIZE <= start || src >= start + size)
137 return;
138 dst = (void *) IPL_PARMBLOCK_ORIGIN;
139 memmove(dst, src, PAGE_SIZE);
140 S390_lowcore.ipl_parmblock_ptr = IPL_PARMBLOCK_ORIGIN;
141}
142
143unsigned long decompress_kernel(void)
144{
145 unsigned long output_addr;
146 unsigned char *output;
147
148 output_addr = ((unsigned long) &_end + HEAP_SIZE + 4095UL) & -4096UL;
149 check_ipl_parmblock((void *) 0, output_addr + SZ__bss_start);
150 memset(&_bss, 0, &_ebss - &_bss);
151 free_mem_ptr = (unsigned long)&_end;
152 free_mem_end_ptr = free_mem_ptr + HEAP_SIZE;
153 output = (unsigned char *) output_addr;
154
155#ifdef CONFIG_BLK_DEV_INITRD
156 /*
157 * Move the initrd right behind the end of the decompressed
158 * kernel image.
159 */
160 if (INITRD_START && INITRD_SIZE &&
161 INITRD_START < (unsigned long) output + SZ__bss_start) {
162 check_ipl_parmblock(output + SZ__bss_start,
163 INITRD_START + INITRD_SIZE);
164 memmove(output + SZ__bss_start,
165 (void *) INITRD_START, INITRD_SIZE);
166 INITRD_START = (unsigned long) output + SZ__bss_start;
167 }
168#endif
169
170 puts("Uncompressing Linux... ");
171 decompress(input_data, input_len, NULL, NULL, output, NULL, error);
172 puts("Ok, booting the kernel.\n");
173 return (unsigned long) output;
174}
175