mirror of https://gitee.com/openkylin/qemu.git
119 lines
3.0 KiB
C
119 lines
3.0 KiB
C
/*
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* QEMU boot sector testing helpers.
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*
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* Copyright (c) 2016 Red Hat Inc.
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*
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* Authors:
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* Michael S. Tsirkin <mst@redhat.com>
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* Victor Kaplansky <victork@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*/
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#include "qemu/osdep.h"
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#include "boot-sector.h"
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#include "qemu-common.h"
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#include "libqtest.h"
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#define LOW(x) ((x) & 0xff)
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#define HIGH(x) ((x) >> 8)
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#define SIGNATURE 0xdead
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#define SIGNATURE_OFFSET 0x10
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#define BOOT_SECTOR_ADDRESS 0x7c00
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/* Boot sector code: write SIGNATURE into memory,
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* then halt.
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* Q35 machine requires a minimum 0x7e000 bytes disk.
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* (bug or feature?)
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*/
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static uint8_t boot_sector[0x7e000] = {
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/* The first sector will be placed at RAM address 00007C00, and
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* the BIOS transfers control to 00007C00
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*/
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/* Data Segment register should be initialized, since pxe
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* boot loader can leave it dirty.
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*/
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/* 7c00: move $0000,%ax */
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[0x00] = 0xb8,
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[0x01] = 0x00,
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[0x02] = 0x00,
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/* 7c03: move %ax,%ds */
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[0x03] = 0x8e,
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[0x04] = 0xd8,
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/* 7c05: mov $0xdead,%ax */
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[0x05] = 0xb8,
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[0x06] = LOW(SIGNATURE),
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[0x07] = HIGH(SIGNATURE),
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/* 7c08: mov %ax,0x7c10 */
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[0x08] = 0xa3,
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[0x09] = LOW(BOOT_SECTOR_ADDRESS + SIGNATURE_OFFSET),
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[0x0a] = HIGH(BOOT_SECTOR_ADDRESS + SIGNATURE_OFFSET),
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/* 7c0b cli */
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[0x0b] = 0xfa,
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/* 7c0c: hlt */
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[0x0c] = 0xf4,
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/* 7c0e: jmp 0x7c07=0x7c0f-3 */
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[0x0d] = 0xeb,
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[0x0e] = LOW(-3),
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/* We mov 0xdead here: set value to make debugging easier */
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[SIGNATURE_OFFSET] = LOW(0xface),
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[SIGNATURE_OFFSET + 1] = HIGH(0xface),
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/* End of boot sector marker */
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[0x1FE] = 0x55,
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[0x1FF] = 0xAA,
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};
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/* Create boot disk file. */
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int boot_sector_init(const char *fname)
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{
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FILE *f = fopen(fname, "w");
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if (!f) {
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fprintf(stderr, "Couldn't open \"%s\": %s", fname, strerror(errno));
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return 1;
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}
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fwrite(boot_sector, 1, sizeof boot_sector, f);
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fclose(f);
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return 0;
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}
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/* Loop until signature in memory is OK. */
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void boot_sector_test(void)
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{
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uint8_t signature_low;
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uint8_t signature_high;
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uint16_t signature;
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int i;
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/* Wait at most 1 minute */
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#define TEST_DELAY (1 * G_USEC_PER_SEC / 10)
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#define TEST_CYCLES MAX((60 * G_USEC_PER_SEC / TEST_DELAY), 1)
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/* Poll until code has run and modified memory. Once it has we know BIOS
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* initialization is done. TODO: check that IP reached the halt
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* instruction.
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*/
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for (i = 0; i < TEST_CYCLES; ++i) {
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signature_low = readb(BOOT_SECTOR_ADDRESS + SIGNATURE_OFFSET);
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signature_high = readb(BOOT_SECTOR_ADDRESS + SIGNATURE_OFFSET + 1);
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signature = (signature_high << 8) | signature_low;
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if (signature == SIGNATURE) {
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break;
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}
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g_usleep(TEST_DELAY);
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}
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g_assert_cmphex(signature, ==, SIGNATURE);
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}
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/* unlink boot disk file. */
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void boot_sector_cleanup(const char *fname)
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{
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unlink(fname);
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}
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