xref: /openbmc/qemu/tests/qtest/boot-sector.c (revision 93d7620c)
1 /*
2  * QEMU boot sector testing helpers.
3  *
4  * Copyright (c) 2016 Red Hat Inc.
5  *
6  * Authors:
7  *  Michael S. Tsirkin <mst@redhat.com>
8  *  Victor Kaplansky <victork@redhat.com>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
11  * See the COPYING file in the top-level directory.
12  */
13 #include "qemu/osdep.h"
14 #include "boot-sector.h"
15 #include "libqtest.h"
16 
17 #define LOW(x) ((x) & 0xff)
18 #define HIGH(x) ((x) >> 8)
19 
20 #define SIGNATURE 0xdead
21 #define SIGNATURE_OFFSET 0x10
22 #define BOOT_SECTOR_ADDRESS 0x7c00
23 #define SIGNATURE_ADDR (BOOT_SECTOR_ADDRESS + SIGNATURE_OFFSET)
24 
25 /* x86 boot sector code: write SIGNATURE into memory,
26  * then halt.
27  */
28 static uint8_t x86_boot_sector[512] = {
29     /* The first sector will be placed at RAM address 00007C00, and
30      * the BIOS transfers control to 00007C00
31      */
32 
33     /* Data Segment register should be initialized, since pxe
34      * boot loader can leave it dirty.
35      */
36 
37     /* 7c00: move $0000,%ax */
38     [0x00] = 0xb8,
39     [0x01] = 0x00,
40     [0x02] = 0x00,
41     /* 7c03: move %ax,%ds */
42     [0x03] = 0x8e,
43     [0x04] = 0xd8,
44 
45     /* 7c05: mov $0xdead,%ax */
46     [0x05] = 0xb8,
47     [0x06] = LOW(SIGNATURE),
48     [0x07] = HIGH(SIGNATURE),
49     /* 7c08:  mov %ax,0x7c10 */
50     [0x08] = 0xa3,
51     [0x09] = LOW(SIGNATURE_ADDR),
52     [0x0a] = HIGH(SIGNATURE_ADDR),
53 
54     /* 7c0b cli */
55     [0x0b] = 0xfa,
56     /* 7c0c: hlt */
57     [0x0c] = 0xf4,
58     /* 7c0e: jmp 0x7c07=0x7c0f-3 */
59     [0x0d] = 0xeb,
60     [0x0e] = LOW(-3),
61     /* We mov 0xdead here: set value to make debugging easier */
62     [SIGNATURE_OFFSET] = LOW(0xface),
63     [SIGNATURE_OFFSET + 1] = HIGH(0xface),
64     /* End of boot sector marker */
65     [0x1FE] = 0x55,
66     [0x1FF] = 0xAA,
67 };
68 
69 /* For s390x, use a mini "kernel" with the appropriate signature */
70 static const uint8_t s390x_psw_and_magic[] = {
71     0x00, 0x08, 0x00, 0x00, 0x80, 0x01, 0x00, 0x00,  /* Program status word  */
72     0x02, 0x00, 0x00, 0x18, 0x60, 0x00, 0x00, 0x50,  /* Magic:               */
73     0x02, 0x00, 0x00, 0x68, 0x60, 0x00, 0x00, 0x50,  /* see linux_s390_magic */
74     0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40   /* in the s390-ccw bios */
75 };
76 static const uint8_t s390x_code[] = {
77     0xa7, 0xf4, 0x00, 0x08,                                /* j 0x10010 */
78     0x00, 0x00, 0x00, 0x00,
79     'S', '3', '9', '0',
80     'E', 'P', 0x00, 0x01,
81     0xa7, 0x39, HIGH(SIGNATURE_ADDR), LOW(SIGNATURE_ADDR), /* lghi r3,0x7c10 */
82     0xa7, 0x48, LOW(SIGNATURE), HIGH(SIGNATURE),           /* lhi r4,0xadde */
83     0x40, 0x40, 0x30, 0x00,                                /* sth r4,0(r3) */
84     0xa7, 0xf4, 0xff, 0xfa                                 /* j 0x10010 */
85 };
86 
87 /* Create boot disk file.  */
88 int boot_sector_init(char *fname)
89 {
90     int fd, ret;
91     size_t len;
92     char *boot_code;
93     const char *arch = qtest_get_arch();
94 
95     fd = mkstemp(fname);
96     if (fd < 0) {
97         fprintf(stderr, "Couldn't open \"%s\": %s", fname, strerror(errno));
98         return 1;
99     }
100 
101     if (g_str_equal(arch, "i386") || g_str_equal(arch, "x86_64")) {
102         /* Q35 requires a minimum 0x7e000 bytes disk (bug or feature?) */
103         len = MAX(0x7e000, sizeof(x86_boot_sector));
104         boot_code = g_malloc0(len);
105         memcpy(boot_code, x86_boot_sector, sizeof(x86_boot_sector));
106     } else if (g_str_equal(arch, "ppc64")) {
107         /* For Open Firmware based system, use a Forth script */
108         boot_code = g_strdup_printf("\\ Bootscript\n%x %x c! %x %x c!\n",
109                                     LOW(SIGNATURE), SIGNATURE_ADDR,
110                                     HIGH(SIGNATURE), SIGNATURE_ADDR + 1);
111         len = strlen(boot_code);
112     } else if (g_str_equal(arch, "s390x")) {
113         len = 0x10000 + sizeof(s390x_code);
114         boot_code = g_malloc0(len);
115         memcpy(boot_code, s390x_psw_and_magic, sizeof(s390x_psw_and_magic));
116         memcpy(&boot_code[0x10000], s390x_code, sizeof(s390x_code));
117     } else {
118         g_assert_not_reached();
119     }
120 
121     ret = write(fd, boot_code, len);
122     close(fd);
123 
124     g_free(boot_code);
125 
126     if (ret != len) {
127         fprintf(stderr, "Could not write \"%s\"", fname);
128         return 1;
129     }
130 
131     return 0;
132 }
133 
134 /* Loop until signature in memory is OK.  */
135 void boot_sector_test(QTestState *qts)
136 {
137     uint8_t signature_low;
138     uint8_t signature_high;
139     uint16_t signature;
140     QDict *qrsp, *qret;
141     int i;
142 
143     /* Wait at most 600 seconds (test is slow with TCI and --enable-debug) */
144 #define TEST_DELAY (1 * G_USEC_PER_SEC / 10)
145 #define TEST_CYCLES MAX((600 * G_USEC_PER_SEC / TEST_DELAY), 1)
146 
147     /* Poll until code has run and modified memory.  Once it has we know BIOS
148      * initialization is done.  TODO: check that IP reached the halt
149      * instruction.
150      */
151     for (i = 0; i < TEST_CYCLES; ++i) {
152         signature_low = qtest_readb(qts, SIGNATURE_ADDR);
153         signature_high = qtest_readb(qts, SIGNATURE_ADDR + 1);
154         signature = (signature_high << 8) | signature_low;
155         if (signature == SIGNATURE) {
156             /* wipe signature */
157             qtest_writeb(qts, SIGNATURE_ADDR, 0x00);
158             break;
159         }
160 
161         /* check that guest is still in "running" state and did not panic */
162         qrsp = qtest_qmp(qts, "{ 'execute': 'query-status' }");
163         qret = qdict_get_qdict(qrsp, "return");
164         g_assert_nonnull(qret);
165         if (qdict_get_try_str(qret, "status")) {
166             g_assert_cmpstr(qdict_get_try_str(qret, "status"), ==, "running");
167         }
168         qobject_unref(qrsp);
169 
170         g_usleep(TEST_DELAY);
171     }
172 
173     g_assert_cmphex(signature, ==, SIGNATURE);
174 }
175 
176 /* unlink boot disk file.  */
177 void boot_sector_cleanup(const char *fname)
178 {
179     unlink(fname);
180 }
181