Subversion Repositories HelenOS

Rev

Rev 1780 | Rev 2000 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
854 bondari 1
/*
2
 * Copyright (C) 2006 Sergey Bondari
1424 jermar 3
 * Copyright (C) 2006 Jakub Jermar
854 bondari 4
 * All rights reserved.
5
 *
6
 * Redistribution and use in source and binary forms, with or without
7
 * modification, are permitted provided that the following conditions
8
 * are met:
9
 *
10
 * - Redistributions of source code must retain the above copyright
11
 *   notice, this list of conditions and the following disclaimer.
12
 * - Redistributions in binary form must reproduce the above copyright
13
 *   notice, this list of conditions and the following disclaimer in the
14
 *   documentation and/or other materials provided with the distribution.
15
 * - The name of the author may not be used to endorse or promote products
16
 *   derived from this software without specific prior written permission.
17
 *
18
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28
 */
29
 
1757 jermar 30
/** @addtogroup generic
1702 cejka 31
 * @{
32
 */
33
 
1264 jermar 34
/**
1702 cejka 35
 * @file
1264 jermar 36
 * @brief   Kernel ELF loader.
37
 */
38
 
910 bondari 39
#include <elf.h>
938 jermar 40
#include <debug.h>
41
#include <arch/types.h>
42
#include <typedefs.h>
43
#include <mm/as.h>
44
#include <mm/frame.h>
952 jermar 45
#include <mm/slab.h>
938 jermar 46
#include <align.h>
952 jermar 47
#include <memstr.h>
48
#include <macros.h>
1409 jermar 49
#include <arch.h>
854 bondari 50
 
938 jermar 51
static char *error_codes[] = {
52
    "no error",
53
    "invalid image",
54
    "address space error",
55
    "incompatible image",
56
    "unsupported image type",
57
    "irrecoverable error"
58
};
59
 
952 jermar 60
static int segment_header(elf_segment_header_t *entry, elf_header_t *elf, as_t *as);
61
static int section_header(elf_section_header_t *entry, elf_header_t *elf, as_t *as);
62
static int load_segment(elf_segment_header_t *entry, elf_header_t *elf, as_t *as);
938 jermar 63
 
64
/** ELF loader
854 bondari 65
 *
66
 * @param header Pointer to ELF header in memory
67
 * @param as Created and properly mapped address space
68
 * @return EE_OK on success
69
 */
938 jermar 70
int elf_load(elf_header_t *header, as_t * as)
71
{
72
    int i, rc;
910 bondari 73
 
74
    /* Identify ELF */
938 jermar 75
    if (header->e_ident[EI_MAG0] != ELFMAG0 || header->e_ident[EI_MAG1] != ELFMAG1 ||
76
        header->e_ident[EI_MAG2] != ELFMAG2 || header->e_ident[EI_MAG3] != ELFMAG3) {
910 bondari 77
        return EE_INVALID;
78
    }
79
 
80
    /* Identify ELF compatibility */
938 jermar 81
    if (header->e_ident[EI_DATA] != ELF_DATA_ENCODING || header->e_machine != ELF_MACHINE ||
82
        header->e_ident[EI_VERSION] != EV_CURRENT || header->e_version != EV_CURRENT ||
83
        header->e_ident[EI_CLASS] != ELF_CLASS) {
84
        return EE_INCOMPATIBLE;
85
    }
86
 
952 jermar 87
    if (header->e_phentsize != sizeof(elf_segment_header_t))
938 jermar 88
        return EE_INCOMPATIBLE;
89
 
952 jermar 90
    if (header->e_shentsize != sizeof(elf_section_header_t))
91
        return EE_INCOMPATIBLE;
92
 
938 jermar 93
    /* Check if the object type is supported. */
94
    if (header->e_type != ET_EXEC)
910 bondari 95
        return EE_UNSUPPORTED;
938 jermar 96
 
952 jermar 97
    /* Walk through all segment headers and process them. */
938 jermar 98
    for (i = 0; i < header->e_phnum; i++) {
1780 jermar 99
        rc = segment_header(&((elf_segment_header_t *)(((uint8_t *) header) + header->e_phoff))[i], header, as);
938 jermar 100
        if (rc != EE_OK)
101
            return rc;
910 bondari 102
    }
938 jermar 103
 
952 jermar 104
    /* Inspect all section headers and proccess them. */
105
    for (i = 0; i < header->e_shnum; i++) {
1780 jermar 106
        rc = section_header(&((elf_section_header_t *)(((uint8_t *) header) + header->e_shoff))[i], header, as);
952 jermar 107
        if (rc != EE_OK)
108
            return rc;
109
    }
110
 
938 jermar 111
    return EE_OK;
112
}
113
 
114
/** Print error message according to error code.
115
 *
116
 * @param rc Return code returned by elf_load().
117
 *
118
 * @return NULL terminated description of error.
119
 */
120
char *elf_error(int rc)
121
{
122
    ASSERT(rc < sizeof(error_codes)/sizeof(char *));
123
 
124
    return error_codes[rc];
125
}
126
 
952 jermar 127
/** Process segment header.
938 jermar 128
 *
952 jermar 129
 * @param entry Segment header.
130
 * @param elf ELF header.
938 jermar 131
 * @param as Address space into wich the ELF is being loaded.
132
 *
133
 * @return EE_OK on success, error code otherwise.
134
 */
952 jermar 135
static int segment_header(elf_segment_header_t *entry, elf_header_t *elf, as_t *as)
938 jermar 136
{
137
    switch (entry->p_type) {
138
        case PT_NULL:
139
        case PT_PHDR:
140
        break;
141
        case PT_LOAD:
952 jermar 142
        return load_segment(entry, elf, as);
938 jermar 143
        break;
144
        case PT_DYNAMIC:
145
        case PT_INTERP:
146
        case PT_SHLIB:
147
        case PT_NOTE:
148
        case PT_LOPROC:
149
        case PT_HIPROC:
150
        default:
151
        return EE_UNSUPPORTED;
152
        break;
153
    }
154
    return EE_OK;
155
}
156
 
157
/** Load segment described by program header entry.
158
 *
159
 * @param entry Program header entry describing segment to be loaded.
952 jermar 160
 * @param elf ELF header.
1248 jermar 161
 * @param as Address space into wich the ELF is being loaded.
938 jermar 162
 *
163
 * @return EE_OK on success, error code otherwise.
164
 */
952 jermar 165
int load_segment(elf_segment_header_t *entry, elf_header_t *elf, as_t *as)
938 jermar 166
{
167
    as_area_t *a;
1409 jermar 168
    int flags = 0;
1425 jermar 169
    mem_backend_data_t backend_data;
170
 
171
    backend_data.elf = elf;
172
    backend_data.segment = entry;
938 jermar 173
 
174
    if (entry->p_align > 1) {
175
        if ((entry->p_offset % entry->p_align) != (entry->p_vaddr % entry->p_align)) {
176
            return EE_INVALID;
177
        }
178
    }
179
 
1026 jermar 180
    if (entry->p_flags & PF_X)
181
        flags |= AS_AREA_EXEC;
182
    if (entry->p_flags & PF_W)
183
        flags |= AS_AREA_WRITE;
184
    if (entry->p_flags & PF_R)
185
        flags |= AS_AREA_READ;
1424 jermar 186
    flags |= AS_AREA_CACHEABLE;
910 bondari 187
 
952 jermar 188
    /*
189
     * Check if the virtual address starts on page boundary.
190
     */
191
    if (ALIGN_UP(entry->p_vaddr, PAGE_SIZE) != entry->p_vaddr)
192
        return EE_UNSUPPORTED;
193
 
1424 jermar 194
    a = as_area_create(as, flags, entry->p_memsz, entry->p_vaddr, AS_AREA_ATTR_NONE,
195
        &elf_backend, &backend_data);
938 jermar 196
    if (!a)
1070 jermar 197
        return EE_MEMORY;
938 jermar 198
 
1409 jermar 199
    /*
200
     * The segment will be mapped on demand by elf_page_fault().
201
     */
202
 
938 jermar 203
    return EE_OK;
854 bondari 204
}
952 jermar 205
 
206
/** Process section header.
207
 *
208
 * @param entry Segment header.
209
 * @param elf ELF header.
210
 * @param as Address space into wich the ELF is being loaded.
211
 *
212
 * @return EE_OK on success, error code otherwise.
213
 */
214
static int section_header(elf_section_header_t *entry, elf_header_t *elf, as_t *as)
215
{
216
    switch (entry->sh_type) {
217
        default:
218
        break;
219
    }
220
 
221
    return EE_OK;
222
}
1702 cejka 223
 
1757 jermar 224
/** @}
1702 cejka 225
 */