[C++]Wrong keyboard scancodes (set 2) + IRQ1 didn't call

[kubawal]

Hi!

My problem is like that: I'm writing my first OS and currently i'm writing keyboard driver. It works properly, but when I turn scancodes into ASCII codes using scancode set 2, it was wrong. E.g when I type

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asdfghjkl[Enter]

it displays

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~~cxde43~w

(~ is key that is not defined in set 2). My function:

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char mosKbdToASCII( Key k, unsigned st ) // st - keyboard state bit enum
{
    const int maxKeynum = 0x66; // max implemented key
    if( st &( unsigned ) KbdState::Shift )
    {
        // with shift
        static char shiftMp[ maxKeynum + 1 ] =
        {
            0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
            0, 0, 0, '\t', '~', 0, 0, 0, 0, 0,
            'Q', '!', 0, 0, 0, 'Z', 'S', 'A', 'W', '@',
            0, 0, 'C', 'X', 'D', 'E', '$', '#', 0, 0,
            ' ', 'V', 'F', 'T', 'R', '%', 0, 0, 'N',
            'B', 'H', 'G', 'Y', '^', 0, 0, 0, 'M', 'J',
            'U', '&', '*', 0, 0, '<', 'K', 'I', 'O', ')',
            '(', 0, 0, '>', '?', 'L', ':', 'P', '_', 0,
            0, 0, '\"', 0, '{', '+', 0, 0, 0, 0,
            '\n', '}', 0, '|', 0, 0, 0, 0, '\b'
        };
        if(( int ) k > maxKeynum + 1 )
             return 0;
        else
             return shiftMp[( int ) k ];
        
    }
    
    // normal   
    static char mp[ maxKeynum + 1 ] =
    {
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, '\t', '`', 0, 0, 0, 0, 0,
        'q', '1', 0, 0, 0, 'z', 's', 'a', 'w', '2',
        0, 0, 'c', 'x', 'd', 'e', '4', '3', 0, 0,
        ' ', 'v', 'f', 't', 'r', '5', 0, 0, 'n',
        'b', 'h', 'g', 'y', '6', 0, 0, 0, 'm', 'j',
        'u', '7', '8', 0, 0, ',', 'k', 'i', 'o', '0',
        '9', 0, 0, '.', '/', 'l', ';', 'p', '-', 0,
        0, 0, '\'', 0, '[', '=', 0, 0, 0, 0,
        '\n', ']', 0, '\\', 0, 0, 0, 0, '\b',
    };
    
    
    
    if(( int ) k > maxKeynum + 1 )
         return 0;
    else
         return mp[( int ) k ];
    
}

// funcs to reading keys
Key mosReadKey()
{
    // mosReadKbd() gets key form keyboard without timeout
    // kbdBuf is simple queue
    if( kbdBuf.empty() ) // buffer is empty
    {
        Key k = mosReadKbd(); // mosReadKbd() wait until is any key is pressed and returns it
        while( !processKey( k ) || k == Key::None ) // processKey() support 'break' codes and keyboard states (e.g shift pressed), returns true if key can be gived to user
             k = mosReadKbd();
        
        return k;
    }
    else
         return kbdBuf.pop();
    
}

char mosReadChar() // simply read key and translate it into ASCII
{
    Key k = mosReadKey();
    return mosKbdToASCII( k, kbdSt );
}

And I've got second problem: when I trying to enable keyboard IRQ1, it doesn't call.

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// add record to IDT
#define _set_gate(gate_addr,type,dpl,addr) \
      __asm__ __volatile__("movw %%dx,%%ax\n\t" \
            "movw %0,%%dx\n\t" \
            "movl %%eax,%1\n\t" \
            "movl %%edx,%2\n\t" \
            : :"i"((short)(0x8000+(dpl<<13)+(type<<8))), \
              "o"(*((char *)(gate_addr))), \
              "o"(*(4+(char *)(gate_addr))), \
              "d"((char *)(addr)),"a"(0x00080000)) \
 	

void mosSetIntGate( int n, void * p ) // register interrupt
{
    _set_gate( & mosIDT[ n ], 14, 0, p );
}

// enable IRQ
void mosEnableIRQ( unsigned int num )
{
    unsigned int mask = ~( 1 << num );
    cached_irq_mask &= mask;
    if( irq & 8 ) {
        mosWritePort( cached_A1, 0xA1 );
    } else {
        mosWritePort( cached_21, 0x21 );
    }
}

#define ASMCALL extern "C" // to avoid c++ compiler name conversation


ASMCALL void doIrq1() // keyboard interrupt code
{
    Key k =( Key ) mosReadPort( KBD_DATA_PORT );
    if( processKey( k ) ) kbdBuf.push( k );
}

ASMCALL void irq1(); // asm interrupt function

void mosInitKbd()
{
    kbdSt = 0;
    while( !kbdBuf.empty() ) kbdBuf.pop(); // clear buffer
    
    mosSetIntGate( 0x21,( void * ) irq1 ); // set interrupt to propely address
    mosEnableIRQ( 1 );
}

[Gigasoft]

You need to set the Controller Configuration Byte. It should be set to 7 to enable both IRQs and disable translation, which is what you probably want.

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_outp(0x64,0x60);
_outp(0x60,7);

By the way, having drivers install IDT entries directly might not be the best of ideas. In a multitasking system, an interrupt handler might wake up a higher priority thread, so you'll need to check for this after every interrupt, and you also need to keep track of whether you are already in an interrupt so you don't switch away from an executing interrupt handler, so there should be some system code that does all this without the involvement of driver code.

[kubawal]

I tried to this before i create this topic, and it's not working.
When I use this code i've got (for typing

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asdfghjkl

)

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wwaaeettyygguuii;;

(keys doubles)

[Combuster]

keys doubles

That sounds like you're not separating up events from down events.

[kubawal]

i seperate this in mosProcessKey() (it returns true if key is pressed)

[iansjack]

Are you sure? You don't show us that function so it's not possible to check but iut certainly sounds logical that you are processing both key down and key up events.

[Gigasoft]

Your tables are wrong. The buffer mechanism is also highly suspicious. Implement a proper interrupt safe and blocking queue, and don't use std::queue. It comes as no surprise that data is being read twice or in the wrong order.

[kubawal]

and don't use std::queue. It comes as no surprise that data is being read twice or in the wrong order.

I use my implmentation of queue

[iansjack]

Another potential source of error that we can't really comment on as you haven't shown us the code. As you seem fairly sure that you know where the error doesn't lie perhaps it's time to do some debugging? That way you can narrow down the possibilities. Once you start debugging and gather some evidence it should be fairly simple to see what is causing this sort of error.

[kubawal]

Now it's OK, I simply use set 1. But it works only for my keyboard...