Root/arch/s390/boot/compressed/misc.c

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

Archive Download this file



interactive