IRQ and C++ ...

[xyjamepa]

Hi guys...
when i was trying to rewrite my os using C++
and at function "void irq_handler(struct regs *r)"
i got this error:

invalid conversion from 'void*' to 'void (*)(regs*)'

it was working in my c file,and i know its problem about types
i tryied everything but nothing work.

Code: Select all

void *irq_routines[16] =
{
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0
};

void irq_handler(struct regs *r)
{
    /* This is a blank function pointer */
    void (*handler)(struct regs *r);

    /* Find out if we have a custom handler to run for this
    *  IRQ, and then finally, run it */
    handler = irq_routines[r->int_no - 32];
    if (handler)
    {
        handler(r);
    }


    /* If the IDT entry that was invoked was greater than 40
    *  (meaning IRQ8 - 15), then we need to send an EOI to
    *  the slave controller */
    if (r->int_no >= 40)
    {
        outportb(0xA0, 0x20);
    }

    /* In either case, we need to send an EOI to the master
    *  interrupt controller too */
    outportb(0x20, 0x20);
}

i'm using DJGPP and nasm
Thanx.

[Tyler]

i beleive the problem lies in the line

/* This is a blank function pointer */
void (*handler)(struct regs *r);

and though i not very good at conversion in C as of yet... it clearly reads the first part as void* and it u are converting to a pointer of handle i think it should be handler*... if that conversion is possible.. i am not sure struct can become function pointers.

Then again how can you declare somethign a void and then conver it to a handler... i don't understand that line so you are best ignoring my advice.... except the bit about trying to change it to handler* then some better programmer can come and correct us both

[Mikae]

The problem is that you declared array of pointers to void, not array of pointers to a function.

If you want an array of pointers to a function, you have to write the following declaration:

Code: Select all

void (*irq_routines[16])(struct regs *r);

[Tyler]

The problem is that you declared array of pointers to void, not array of pointers to a function.

If you want an array of pointers to a function, you have to write the following declaration:

Code: Select all

void (*irq_routines[16])(struct regs *r);

hey i was close in my ramblings... i will be dammed...

[gaf]

Some time ago there was a quite similar thread in the general programming section (link). Maybe it could also help you with your current problem.

void (*irq_routines[16])(struct regs *r);

Better use a typedef as the C declarator syntax for function-pointers can be quite obscure:

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typedef void (*function)();  // "function" is a datatype 
function stubs[0x20];       // Array of function-pointers

regards,
gaf

[xyjamepa]

thank you Mikae and all of you guys my IRQ works fine now,
i used Mikae advice

Code: Select all

void (*irq_routines[16])(struct regs *r);