LXR qemu/tests/boot-sector.c

   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 "qemu-common.h"
  16#include "libqtest.h"
  17
  18#define LOW(x) ((x) & 0xff)
  19#define HIGH(x) ((x) >> 8)
  20
  21#define SIGNATURE 0xdead
  22#define SIGNATURE_OFFSET 0x10
  23#define BOOT_SECTOR_ADDRESS 0x7c00
  24#define SIGNATURE_ADDR (BOOT_SECTOR_ADDRESS + SIGNATURE_OFFSET)
  25
  26/* x86 boot sector code: write SIGNATURE into memory,
  27 * then halt.
  28 */
  29static uint8_t x86_boot_sector[512] = {
  30    /* The first sector will be placed at RAM address 00007C00, and
  31     * the BIOS transfers control to 00007C00
  32     */
  33
  34    /* Data Segment register should be initialized, since pxe
  35     * boot loader can leave it dirty.
  36     */
  37
  38    /* 7c00: move $0000,%ax */
  39    [0x00] = 0xb8,
  40    [0x01] = 0x00,
  41    [0x02] = 0x00,
  42    /* 7c03: move %ax,%ds */
  43    [0x03] = 0x8e,
  44    [0x04] = 0xd8,
  45
  46    /* 7c05: mov $0xdead,%ax */
  47    [0x05] = 0xb8,
  48    [0x06] = LOW(SIGNATURE),
  49    [0x07] = HIGH(SIGNATURE),
  50    /* 7c08:  mov %ax,0x7c10 */
  51    [0x08] = 0xa3,
  52    [0x09] = LOW(SIGNATURE_ADDR),
  53    [0x0a] = HIGH(SIGNATURE_ADDR),
  54
  55    /* 7c0b cli */
  56    [0x0b] = 0xfa,
  57    /* 7c0c: hlt */
  58    [0x0c] = 0xf4,
  59    /* 7c0e: jmp 0x7c07=0x7c0f-3 */
  60    [0x0d] = 0xeb,
  61    [0x0e] = LOW(-3),
  62    /* We mov 0xdead here: set value to make debugging easier */
  63    [SIGNATURE_OFFSET] = LOW(0xface),
  64    [SIGNATURE_OFFSET + 1] = HIGH(0xface),
  65    /* End of boot sector marker */
  66    [0x1FE] = 0x55,
  67    [0x1FF] = 0xAA,
  68};
  69
  70/* For s390x, use a mini "kernel" with the appropriate signature */
  71static const uint8_t s390x_psw_and_magic[] = {
  72    0x00, 0x08, 0x00, 0x00, 0x80, 0x01, 0x00, 0x00,  /* Program status word  */
  73    0x02, 0x00, 0x00, 0x18, 0x60, 0x00, 0x00, 0x50,  /* Magic:               */
  74    0x02, 0x00, 0x00, 0x68, 0x60, 0x00, 0x00, 0x50,  /* see linux_s390_magic */
  75    0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40   /* in the s390-ccw bios */
  76};
  77static const uint8_t s390x_code[] = {
  78    0xa7, 0xf4, 0x00, 0x0a,                                /* j 0x10010 */
  79    0x00, 0x00, 0x00, 0x00,
  80    'S', '3', '9', '0',
  81    'E', 'P', 0x00, 0x01,
  82    0xa7, 0x38, HIGH(SIGNATURE_ADDR), LOW(SIGNATURE_ADDR), /* lhi r3,0x7c10 */
  83    0xa7, 0x48, LOW(SIGNATURE), HIGH(SIGNATURE),           /* lhi r4,0xadde */
  84    0x40, 0x40, 0x30, 0x00,                                /* sth r4,0(r3) */
  85    0xa7, 0xf4, 0xff, 0xfa                                 /* j 0x10010 */
  86};
  87
  88/* Create boot disk file.  */
  89int boot_sector_init(char *fname)
  90{
  91    int fd, ret;
  92    size_t len;
  93    char *boot_code;
  94    const char *arch = qtest_get_arch();
  95
  96    fd = mkstemp(fname);
  97    if (fd < 0) {
  98        fprintf(stderr, "Couldn't open \"%s\": %s", fname, strerror(errno));
  99        return 1;
 100    }
 101
 102    if (g_str_equal(arch, "i386") || g_str_equal(arch, "x86_64")) {
 103        /* Q35 requires a minimum 0x7e000 bytes disk (bug or feature?) */
 104        len = MAX(0x7e000, sizeof(x86_boot_sector));
 105        boot_code = g_malloc0(len);
 106        memcpy(boot_code, x86_boot_sector, sizeof(x86_boot_sector));
 107    } else if (g_str_equal(arch, "ppc64")) {
 108        /* For Open Firmware based system, use a Forth script */
 109        boot_code = g_strdup_printf("\\ Bootscript\n%x %x c! %x %x c!\n",
 110                                    LOW(SIGNATURE), SIGNATURE_ADDR,
 111                                    HIGH(SIGNATURE), SIGNATURE_ADDR + 1);
 112        len = strlen(boot_code);
 113    } else if (g_str_equal(arch, "s390x")) {
 114        len = 0x10000 + sizeof(s390x_code);
 115        boot_code = g_malloc0(len);
 116        memcpy(boot_code, s390x_psw_and_magic, sizeof(s390x_psw_and_magic));
 117        memcpy(&boot_code[0x10000], s390x_code, sizeof(s390x_code));
 118    } else {
 119        g_assert_not_reached();
 120    }
 121
 122    ret = write(fd, boot_code, len);
 123    close(fd);
 124
 125    g_free(boot_code);
 126
 127    if (ret != len) {
 128        fprintf(stderr, "Could not write \"%s\"", fname);
 129        return 1;
 130    }
 131
 132    return 0;
 133}
 134
 135/* Loop until signature in memory is OK.  */
 136void boot_sector_test(QTestState *qts)
 137{
 138    uint8_t signature_low;
 139    uint8_t signature_high;
 140    uint16_t signature;
 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            break;
 157        }
 158        g_usleep(TEST_DELAY);
 159    }
 160
 161    g_assert_cmphex(signature, ==, SIGNATURE);
 162}
 163
 164/* unlink boot disk file.  */
 165void boot_sector_cleanup(const char *fname)
 166{
 167    unlink(fname);
 168}
 169