tests/pflash-cfi02-test.c

/*
 * QTest testcase for parallel flash with AMD command set
 *
 * Copyright (c) 2019 Stephen Checkoway
 *
 * 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 "libqtest.h"

/*
 * To test the pflash_cfi02 device, we run QEMU with the musicpal machine with
 * a pflash drive. This enables us to test some flash configurations, but not
 * all. In particular, we're limited to a 16-bit wide flash device.
 */

#define MP_FLASH_SIZE_MAX (32 * 1024 * 1024)
#define BASE_ADDR (0x100000000ULL - MP_FLASH_SIZE_MAX)

#define FLASH_WIDTH 2
#define CFI_ADDR (FLASH_WIDTH * 0x55)
#define UNLOCK0_ADDR (FLASH_WIDTH * 0x555)
#define UNLOCK1_ADDR (FLASH_WIDTH * 0x2AA)

#define CFI_CMD 0x98
#define UNLOCK0_CMD 0xAA
#define UNLOCK1_CMD 0x55
#define AUTOSELECT_CMD 0x90
#define RESET_CMD 0xF0
#define PROGRAM_CMD 0xA0
#define SECTOR_ERASE_CMD 0x30
#define CHIP_ERASE_CMD 0x10
#define UNLOCK_BYPASS_CMD 0x20
#define UNLOCK_BYPASS_RESET_CMD 0x00

static char image_path[] = "/tmp/qtest.XXXXXX";

static inline void flash_write(uint64_t byte_addr, uint16_t data)
{
    qtest_writew(global_qtest, BASE_ADDR + byte_addr, data);
}

static inline uint16_t flash_read(uint64_t byte_addr)
{
    return qtest_readw(global_qtest, BASE_ADDR + byte_addr);
}

static void unlock(void)
{
    flash_write(UNLOCK0_ADDR, UNLOCK0_CMD);
    flash_write(UNLOCK1_ADDR, UNLOCK1_CMD);
}

static void reset(void)
{
    flash_write(0, RESET_CMD);
}

static void sector_erase(uint64_t byte_addr)
{
    unlock();
    flash_write(UNLOCK0_ADDR, 0x80);
    unlock();
    flash_write(byte_addr, SECTOR_ERASE_CMD);
}

static void wait_for_completion(uint64_t byte_addr)
{
    /* If DQ6 is toggling, step the clock and ensure the toggle stops. */
    if ((flash_read(byte_addr) & 0x40) ^ (flash_read(byte_addr) & 0x40)) {
        /* Wait for erase or program to finish. */
        clock_step_next();
        /* Ensure that DQ6 has stopped toggling. */
        g_assert_cmphex(flash_read(byte_addr), ==, flash_read(byte_addr));
    }
}

static void bypass_program(uint64_t byte_addr, uint16_t data)
{
    flash_write(UNLOCK0_ADDR, PROGRAM_CMD);
    flash_write(byte_addr, data);
    /*
     * Data isn't valid until DQ6 stops toggling. We don't model this as
     * writes are immediate, but if this changes in the future, we can wait
     * until the program is complete.
     */
    wait_for_completion(byte_addr);
}

static void program(uint64_t byte_addr, uint16_t data)
{
    unlock();
    bypass_program(byte_addr, data);
}

static void chip_erase(void)
{
    unlock();
    flash_write(UNLOCK0_ADDR, 0x80);
    unlock();
    flash_write(UNLOCK0_ADDR, SECTOR_ERASE_CMD);
}

static void test_flash(void)
{
    global_qtest = qtest_initf("-M musicpal,accel=qtest "
                               "-drive if=pflash,file=%s,format=raw,copy-on-read",
                               image_path);
    /* Check the IDs. */
    unlock();
    flash_write(UNLOCK0_ADDR, AUTOSELECT_CMD);
    g_assert_cmphex(flash_read(FLASH_WIDTH * 0x0000), ==, 0x00BF);
    g_assert_cmphex(flash_read(FLASH_WIDTH * 0x0001), ==, 0x236D);
    reset();

    /* Check the erase blocks. */
    flash_write(CFI_ADDR, CFI_CMD);
    g_assert_cmphex(flash_read(FLASH_WIDTH * 0x10), ==, 'Q');
    g_assert_cmphex(flash_read(FLASH_WIDTH * 0x11), ==, 'R');
    g_assert_cmphex(flash_read(FLASH_WIDTH * 0x12), ==, 'Y');
    /* Num erase regions. */
    g_assert_cmphex(flash_read(FLASH_WIDTH * 0x2C), >=, 1);
    uint32_t nb_sectors = flash_read(FLASH_WIDTH * 0x2D) +
                          (flash_read(FLASH_WIDTH * 0x2E) << 8) + 1;
    uint32_t sector_len = (flash_read(FLASH_WIDTH * 0x2F) << 8) +
                          (flash_read(FLASH_WIDTH * 0x30) << 16);
    reset();

    /* Erase and program sector. */
    for (uint32_t i = 0; i < nb_sectors; ++i) {
        uint64_t byte_addr = i * sector_len;
        sector_erase(byte_addr);
        /* Read toggle. */
        uint16_t status0 = flash_read(byte_addr);
        /* DQ7 is 0 during an erase. */
        g_assert_cmphex(status0 & 0x80, ==, 0);
        uint16_t status1 = flash_read(byte_addr);
        /* DQ6 toggles during an erase. */
        g_assert_cmphex(status0 & 0x40, !=, status1 & 0x40);
        /* Wait for erase to complete. */
        clock_step_next();
        /* Ensure DQ6 has stopped toggling. */
        g_assert_cmphex(flash_read(byte_addr), ==, flash_read(byte_addr));
        /* Now the data should be valid. */
        g_assert_cmphex(flash_read(byte_addr), ==, 0xFFFF);

        /* Program a bit pattern. */
        program(byte_addr, 0x5555);
        g_assert_cmphex(flash_read(byte_addr), ==, 0x5555);
        program(byte_addr, 0xAA55);
        g_assert_cmphex(flash_read(byte_addr), ==, 0x0055);
    }

    /* Erase the chip. */
    chip_erase();
    /* Read toggle. */
    uint16_t status0 = flash_read(0);
    /* DQ7 is 0 during an erase. */
    g_assert_cmphex(status0 & 0x80, ==, 0);
    uint16_t status1 = flash_read(0);
    /* DQ6 toggles during an erase. */
    g_assert_cmphex(status0 & 0x40, !=, status1 & 0x40);
    /* Wait for erase to complete. */
    clock_step_next();
    /* Ensure DQ6 has stopped toggling. */
    g_assert_cmphex(flash_read(0), ==, flash_read(0));
    /* Now the data should be valid. */
    g_assert_cmphex(flash_read(0), ==, 0xFFFF);

    /* Unlock bypass */
    unlock();
    flash_write(UNLOCK0_ADDR, UNLOCK_BYPASS_CMD);
    bypass_program(0, 0x0123);
    bypass_program(2, 0x4567);
    bypass_program(4, 0x89AB);
    /*
     * Test that bypass programming, unlike normal programming can use any
     * address for the PROGRAM_CMD.
     */
    flash_write(6, PROGRAM_CMD);
    flash_write(6, 0xCDEF);
    wait_for_completion(6);
    flash_write(0, UNLOCK_BYPASS_RESET_CMD);
    bypass_program(8, 0x55AA); /* Should fail. */
    g_assert_cmphex(flash_read(0), ==, 0x0123);
    g_assert_cmphex(flash_read(2), ==, 0x4567);
    g_assert_cmphex(flash_read(4), ==, 0x89AB);
    g_assert_cmphex(flash_read(6), ==, 0xCDEF);
    g_assert_cmphex(flash_read(8), ==, 0xFFFF);

    /* Test ignored high order bits of address. */
    flash_write(FLASH_WIDTH * 0x5555, UNLOCK0_CMD);
    flash_write(FLASH_WIDTH * 0x2AAA, UNLOCK1_CMD);
    flash_write(FLASH_WIDTH * 0x5555, AUTOSELECT_CMD);
    g_assert_cmpint(flash_read(FLASH_WIDTH * 0x0000), ==, 0x00BF);
    g_assert_cmpint(flash_read(FLASH_WIDTH * 0x0001), ==, 0x236D);
    reset();

    qtest_quit(global_qtest);
}

static void cleanup(void *opaque)
{
    unlink(image_path);
}

int main(int argc, char **argv)
{
    int fd = mkstemp(image_path);
    if (fd == -1) {
        g_printerr("Failed to create temporary file %s: %s\n", image_path,
                   strerror(errno));
        exit(EXIT_FAILURE);
    }
    if (ftruncate(fd, 8 * 1024 * 1024) < 0) {
        int error_code = errno;
        close(fd);
        unlink(image_path);
        g_printerr("Failed to truncate file %s to 8 MB: %s\n", image_path,
                   strerror(error_code));
        exit(EXIT_FAILURE);
    }
    close(fd);

    qtest_add_abrt_handler(cleanup, NULL);
    g_test_init(&argc, &argv, NULL);
    qtest_add_func("pflash-cfi02", test_flash);
    int result = g_test_run();
    cleanup(NULL);
    return result;
}