summaryrefslogtreecommitdiffstats
path: root/tests/boot-sector.c
blob: be29d5bb9b965ccfbeaa751ba78c921588ebaaac (plain) (blame)
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
158
159
160
161
162
163
164
165
/*
 * QEMU boot sector testing helpers.
 *
 * Copyright (c) 2016 Red Hat Inc.
 *
 * Authors:
 *  Michael S. Tsirkin <mst@redhat.com>
 *  Victor Kaplansky <victork@redhat.com>    
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */
#include "qemu/osdep.h"
#include "boot-sector.h"
#include "qemu-common.h"
#include "libqtest.h"

#define LOW(x) ((x) & 0xff)
#define HIGH(x) ((x) >> 8)

#define SIGNATURE 0xdead
#define SIGNATURE_OFFSET 0x10
#define BOOT_SECTOR_ADDRESS 0x7c00
#define SIGNATURE_ADDR (BOOT_SECTOR_ADDRESS + SIGNATURE_OFFSET)

/* x86 boot sector code: write SIGNATURE into memory,
 * then halt.
 */
static uint8_t x86_boot_sector[512] = {
    /* The first sector will be placed at RAM address 00007C00, and
     * the BIOS transfers control to 00007C00
     */

    /* Data Segment register should be initialized, since pxe
     * boot loader can leave it dirty.
     */

    /* 7c00: move $0000,%ax */
    [0x00] = 0xb8,
    [0x01] = 0x00,
    [0x02] = 0x00,
    /* 7c03: move %ax,%ds */
    [0x03] = 0x8e,
    [0x04] = 0xd8,

    /* 7c05: mov $0xdead,%ax */
    [0x05] = 0xb8,
    [0x06] = LOW(SIGNATURE),
    [0x07] = HIGH(SIGNATURE),
    /* 7c08:  mov %ax,0x7c10 */
    [0x08] = 0xa3,
    [0x09] = LOW(SIGNATURE_ADDR),
    [0x0a] = HIGH(SIGNATURE_ADDR),

    /* 7c0b cli */
    [0x0b] = 0xfa,
    /* 7c0c: hlt */
    [0x0c] = 0xf4,
    /* 7c0e: jmp 0x7c07=0x7c0f-3 */
    [0x0d] = 0xeb,
    [0x0e] = LOW(-3),
    /* We mov 0xdead here: set value to make debugging easier */
    [SIGNATURE_OFFSET] = LOW(0xface),
    [SIGNATURE_OFFSET + 1] = HIGH(0xface),
    /* End of boot sector marker */
    [0x1FE] = 0x55,
    [0x1FF] = 0xAA,
};

/* For s390x, use a mini "kernel" with the appropriate signature */
static const uint8_t s390x_psw[] = {
    0x00, 0x08, 0x00, 0x00, 0x80, 0x01, 0x00, 0x00
};
static const uint8_t s390x_code[] = {
    0xa7, 0xf4, 0x00, 0x0a,                                /* j 0x10010 */
    0x00, 0x00, 0x00, 0x00,
    'S', '3', '9', '0',
    'E', 'P', 0x00, 0x01,
    0xa7, 0x38, HIGH(SIGNATURE_ADDR), LOW(SIGNATURE_ADDR), /* lhi r3,0x7c10 */
    0xa7, 0x48, LOW(SIGNATURE), HIGH(SIGNATURE),           /* lhi r4,0xadde */
    0x40, 0x40, 0x30, 0x00,                                /* sth r4,0(r3) */
    0xa7, 0xf4, 0xff, 0xfa                                 /* j 0x10010 */
};

/* Create boot disk file.  */
int boot_sector_init(char *fname)
{
    int fd, ret;
    size_t len;
    char *boot_code;
    const char *arch = qtest_get_arch();

    fd = mkstemp(fname);
    if (fd < 0) {
        fprintf(stderr, "Couldn't open \"%s\": %s", fname, strerror(errno));
        return 1;
    }

    if (g_str_equal(arch, "i386") || g_str_equal(arch, "x86_64")) {
        /* Q35 requires a minimum 0x7e000 bytes disk (bug or feature?) */
        len = MAX(0x7e000, sizeof(x86_boot_sector));
        boot_code = g_malloc0(len);
        memcpy(boot_code, x86_boot_sector, sizeof(x86_boot_sector));
    } else if (g_str_equal(arch, "ppc64")) {
        /* For Open Firmware based system, use a Forth script */
        boot_code = g_strdup_printf("\\ Bootscript\n%x %x c! %x %x c!\n",
                                    LOW(SIGNATURE), SIGNATURE_ADDR,
                                    HIGH(SIGNATURE), SIGNATURE_ADDR + 1);
        len = strlen(boot_code);
    } else if (g_str_equal(arch, "s390x")) {
        len = 0x10000 + sizeof(s390x_code);
        boot_code = g_malloc0(len);
        memcpy(boot_code, s390x_psw, sizeof(s390x_psw));
        memcpy(&boot_code[0x10000], s390x_code, sizeof(s390x_code));
    } else {
        g_assert_not_reached();
    }

    ret = write(fd, boot_code, len);
    close(fd);

    g_free(boot_code);

    if (ret != len) {
        fprintf(stderr, "Could not write \"%s\"", fname);
        return 1;
    }

    return 0;
}

/* Loop until signature in memory is OK.  */
void boot_sector_test(void)
{
    uint8_t signature_low;
    uint8_t signature_high;
    uint16_t signature;
    int i;

    /* Wait at most 600 seconds (test is slow with TCI and --enable-debug) */
#define TEST_DELAY (1 * G_USEC_PER_SEC / 10)
#define TEST_CYCLES MAX((600 * G_USEC_PER_SEC / TEST_DELAY), 1)

    /* Poll until code has run and modified memory.  Once it has we know BIOS
     * initialization is done.  TODO: check that IP reached the halt
     * instruction.
     */
    for (i = 0; i < TEST_CYCLES; ++i) {
        signature_low = readb(SIGNATURE_ADDR);
        signature_high = readb(SIGNATURE_ADDR + 1);
        signature = (signature_high << 8) | signature_low;
        if (signature == SIGNATURE) {
            break;
        }
        g_usleep(TEST_DELAY);
    }

    g_assert_cmphex(signature, ==, SIGNATURE);
}

/* unlink boot disk file.  */
void boot_sector_cleanup(const char *fname)
{
    unlink(fname);
}