panic: invalid bcd 194

Hello,

I've got an older Acer C720 with r314251, which was not booted for some time,
and now panics on boot, also in single user mode, saying:

...
Dec 30 19:54:26 c720-r314251 kernel: ada0: Command Queueing enabled
Dec 30 19:54:26 c720-r314251 kernel: ada0: 244198MB (500118192 512 byte sectors)
Dec 30 19:54:26 c720-r314251 kernel: WARNING: WITNESS option enabled, expect reduced performance.
Dec 30 19:54:26 c720-r314251 kernel: Trying to mount root from ufs:/dev/ada0p2 [rw,noatime]...
panic: invalid bcd 194
...

The message comes from 

$ find * -type f -exec fgrep "invalid bcd" {} /dev/null \;
sys/sys/libkern.h:	    ("invalid bcd %d", bcd));

$ vim sys/sys/libkern.h
...
#define LIBKERN_LEN_BCD2BIN     154
#define LIBKERN_LEN_BIN2BCD     100
#define LIBKERN_LEN_HEX2ASCII   36

static inline u_char
bcd2bin(int bcd)
{

        KASSERT(bcd >= 0 && bcd < LIBKERN_LEN_BCD2BIN,
            ("invalid bcd %d", bcd));
        return (bcd2bin_data[bcd]);
}

Any idea what could be damaged the system and what to do or check before
re-setup?

Thanks

	matthias

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Matthias Apitz, ✉ guru_at_unixarea.de, ⌂ http://www.unixarea.de/  📱 +49-176-38902045
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