When i try out the code from the showkey applet in busybox it gives
me completely wrong scancodes.
The following code gives correct scancodes, but since i've never
read the kernel sources it may not get all cases correctly.
(It's from my own showkey.c that works on {Open,Free}BSD and Linux.
The "kernel sources" is still true though..)


static ssize_t
mode_keycode(unsigned char *buf, ssize_t len)
{
    unsigned char *cursor;

    for (cursor = buf; --len >= 0;) {
        unsigned int isplain = 1, kc = *cursor++, rc = kc, isdown;

        if ((rc & 0xF0) == 0xE0 || (rc & 0xF8) == 0xF0) {
            isplain = 0;
            if (--len < 0) {
                *buf = (unsigned char)rc;
                len = 1;
                break;
            }

            kc <<= 8;
            kc |= *cursor++;
            rc = kc;
            kc &= ((kc & 0xF000) == 0xE000) ? 0x0FFF : 0x00FF;
        }

        isdown = (0 == (kc & 0x80));
        kc &= ~0x0080;
        if (! isplain)
            kc |= 0x80;

        printf("keycode %3u %-7s (0x%04X: 0x%04X | %c)\r\n",
            kc, (isdown ? "press" : "release"),
            rc, kc, (isdown ? 'v' : '^'));
    }

    return ((len <= 0) ? 0 : len);
}