Re: [Qemu-devel] [RFC v2 5/6] Add RTC test case

[Luiz Capitulino <lcapitulino@redhat.com>]

On Thu,  1 Dec 2011 12:43:31 -0600
Anthony Liguori <aliguori@us.ibm.com> wrote:

I think it's a good idea to use python's unittest module and write tests as
unit-tests (eg. using asserts instead of writing results as strings).

> ---
>  rtc-test.py |  105 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 105 insertions(+), 0 deletions(-)
>  create mode 100644 rtc-test.py
> 
> diff --git a/rtc-test.py b/rtc-test.py
> new file mode 100644
> index 0000000..3159795
> --- /dev/null
> +++ b/rtc-test.py
> @@ -0,0 +1,105 @@
> +from qtest import inb, outb
> +import qtest, time, calendar
> +
> +base = 0x70
> +
> +def bcd2dec(value):
> +    return (((value >> 4) & 0x0F) * 10) + (value & 0x0F)
> +
> +def dec2bcd(value):
> +    return ((value / 10) << 4) | (value % 10)
> +
> +def cmos_read(reg):
> +    outb(base + 0, reg)
> +    return inb(base + 1)
> +
> +def cmos_write(reg, val):
> +    outb(base + 0, reg)
> +    outb(base + 1, val)
> +
> +def cmos_get_date_time():
> +    base_year = 2000
> +
> +    sec = cmos_read(0x00)
> +    min = cmos_read(0x02)
> +    hour = cmos_read(0x04)
> +    mday = cmos_read(0x07)
> +    mon = cmos_read(0x08)
> +    year = cmos_read(0x09)
> +
> +    if (cmos_read(0x0B) & 4) == 0:
> +        sec = bcd2dec(sec)
> +        min = bcd2dec(min)
> +        hour = bcd2dec(hour)
> +        mday = bcd2dec(mday)
> +        mon = bcd2dec(mon)
> +        year = bcd2dec(year)
> +        hour_offset = 80
> +    else:
> +        hour_offset = 0x80
> +
> +    if (cmos_read(0x0B) & 2) == 0:
> +        if hour >= hour_offset:
> +            hour -= hour_offset
> +            hour += 12
> +
> +    return time.gmtime(calendar.timegm(((base_year + year), mon, mday, hour, min, sec)))
> +
> +def check_time():
> +    # This check assumes a few things.  First, we cannot guarantee that we get
> +    # a consistent reading from the wall clock because we may hit an edge of
> +    # the clock while reading.  To work around this, we read four clock readings
> +    # such that at least two of them should match.  We need to assume that one
> +    # reading is corrupt so we need four readings to ensure that we have at
> +    # least two consecutive identical readings
> +    #
> +    # It's also possible that we'll cross an edge reading the host clock so
> +    # simply check to make sure that the clock reading is within the period of
> +    # when we expect it to be.
> +
> +    start = time.gmtime()
> +    date1 = cmos_get_date_time()
> +    date2 = cmos_get_date_time()
> +    date3 = cmos_get_date_time()
> +    date4 = cmos_get_date_time()
> +    end = time.gmtime()
> +
> +    if date1 == date2:
> +        date = date1
> +    elif date2 == date3:
> +        date = date2
> +    elif date3 == date4:
> +        date = date4
> +    else:
> +        print 'Could not read RTC fast enough'
> +        return False
> +
> +    if not start <= date <= end:
> +        t = calendar.timegm(date)
> +        s = calendar.timegm(start)
> +        if t < s:
> +            print 'RTC is %d second(s) behind wall-clock' % (s - t)
> +        else:
> +            print 'RTC is %d second(s) ahead of wall-clock' % (t - s)
> +        return False
> +
> +    return True
> +
> +def main(args):
> +    qtest.init(args[0])
> +
> +    # Set BCD mode
> +    cmos_write(0x0B, cmos_read(0x0B) | 0x02)
> +    if not check_time():
> +        return 1
> +
> +    # Set DEC mode
> +    cmos_write(0x0B, cmos_read(0x0B) & ~0x02)
> +    if not check_time():
> +        return 1
> +
> +    return 0
> +
> +if __name__ == '__main__':
> +    import sys
> +    sys.exit(main(sys.argv[1:]))