aboutsummaryrefslogtreecommitdiff
path: root/hw/acpi/bios-linker-loader.c
blob: 5cc4d90c1666d1c7fdd736eae36a4a2ab1c6a6b1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
/* Dynamic linker/loader of ACPI tables
 *
 * Copyright (C) 2013 Red Hat Inc
 *
 * Author: Michael S. Tsirkin <mst@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.

 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.

 * You should have received a copy of the GNU General Public License along
 * with this program; if not, see <http://www.gnu.org/licenses/>.
 */

#include "qemu-common.h"
#include "hw/acpi/bios-linker-loader.h"
#include "hw/nvram/fw_cfg.h"

#include "qemu/bswap.h"

#define BIOS_LINKER_LOADER_FILESZ FW_CFG_MAX_FILE_PATH

struct BiosLinkerLoaderEntry {
    uint32_t command;
    union {
        /*
         * COMMAND_ALLOCATE - allocate a table from @alloc.file
         * subject to @alloc.align alignment (must be power of 2)
         * and @alloc.zone (can be HIGH or FSEG) requirements.
         *
         * Must appear exactly once for each file, and before
         * this file is referenced by any other command.
         */
        struct {
            char file[BIOS_LINKER_LOADER_FILESZ];
            uint32_t align;
            uint8_t zone;
        } alloc;

        /*
         * COMMAND_ADD_POINTER - patch the table (originating from
         * @dest_file) at @pointer.offset, by adding a pointer to the table
         * originating from @src_file. 1,2,4 or 8 byte unsigned
         * addition is used depending on @pointer.size.
         */
        struct {
            char dest_file[BIOS_LINKER_LOADER_FILESZ];
            char src_file[BIOS_LINKER_LOADER_FILESZ];
            uint32_t offset;
            uint8_t size;
        } pointer;

        /*
         * COMMAND_ADD_CHECKSUM - calculate checksum of the range specified by
         * @cksum_start and @cksum_length fields,
         * and then add the value at @cksum.offset.
         * Checksum simply sums -X for each byte X in the range
         * using 8-bit math.
         */
        struct {
            char file[BIOS_LINKER_LOADER_FILESZ];
            uint32_t offset;
            uint32_t start;
            uint32_t length;
        } cksum;

        /* padding */
        char pad[124];
    };
} QEMU_PACKED;
typedef struct BiosLinkerLoaderEntry BiosLinkerLoaderEntry;

enum {
    BIOS_LINKER_LOADER_COMMAND_ALLOCATE     = 0x1,
    BIOS_LINKER_LOADER_COMMAND_ADD_POINTER  = 0x2,
    BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM = 0x3,
};

enum {
    BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH = 0x1,
    BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG = 0x2,
};

GArray *bios_linker_loader_init(void)
{
    return g_array_new(false, true /* clear */, 1);
}

/* Free linker wrapper and return the linker array. */
void *bios_linker_loader_cleanup(GArray *linker)
{
    return g_array_free(linker, false);
}

void bios_linker_loader_alloc(GArray *linker,
                              const char *file,
                              uint32_t alloc_align,
                              bool alloc_fseg)
{
    BiosLinkerLoaderEntry entry;

    memset(&entry, 0, sizeof entry);
    strncpy(entry.alloc.file, file, sizeof entry.alloc.file - 1);
    entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ALLOCATE);
    entry.alloc.align = cpu_to_le32(alloc_align);
    entry.alloc.zone = cpu_to_le32(alloc_fseg ?
                                    BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG :
                                    BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH);

    /* Alloc entries must come first, so prepend them */
    g_array_prepend_vals(linker, &entry, sizeof entry);
}

void bios_linker_loader_add_checksum(GArray *linker, const char *file,
                                     void *table,
                                     void *start, unsigned size,
                                     uint8_t *checksum)
{
    BiosLinkerLoaderEntry entry;

    memset(&entry, 0, sizeof entry);
    strncpy(entry.cksum.file, file, sizeof entry.cksum.file - 1);
    entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM);
    entry.cksum.offset = cpu_to_le32(checksum - (uint8_t *)table);
    entry.cksum.start = cpu_to_le32((uint8_t *)start - (uint8_t *)table);
    entry.cksum.length = cpu_to_le32(size);

    g_array_append_vals(linker, &entry, sizeof entry);
}

void bios_linker_loader_add_pointer(GArray *linker,
                                    const char *dest_file,
                                    const char *src_file,
                                    GArray *table, void *pointer,
                                    uint8_t pointer_size)
{
    BiosLinkerLoaderEntry entry;

    memset(&entry, 0, sizeof entry);
    strncpy(entry.pointer.dest_file, dest_file,
            sizeof entry.pointer.dest_file - 1);
    strncpy(entry.pointer.src_file, src_file,
            sizeof entry.pointer.src_file - 1);
    entry.command = cpu_to_le32(BIOS_LINKER_LOADER_COMMAND_ADD_POINTER);
    entry.pointer.offset = cpu_to_le32((gchar *)pointer - table->data);
    entry.pointer.size = pointer_size;
    assert(pointer_size == 1 || pointer_size == 2 ||
           pointer_size == 4 || pointer_size == 8);

    g_array_append_vals(linker, &entry, sizeof entry);
}