text: /*
   * 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_and_magic[] = {
      0x00, 0x08, 0x00, 0x00, 0x80, 0x01, 0x00, 0x00,  /* Program status word  */
      0x02, 0x00, 0x00, 0x18, 0x60, 0x00, 0x00, 0x50,  /* Magic:               */
      0x02, 0x00, 0x00, 0x68, 0x60, 0x00, 0x00, 0x50,  /* see linux_s390_magic */
      0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x40   /* in the s390-ccw bios */
  };
  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_and_magic, sizeof(s390x_psw_and_magic));
          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(QTestState *qts)
  {
      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 = qtest_readb(qts, SIGNATURE_ADDR);
          signature_high = qtest_readb(qts, 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);
  }
  