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IRQ and C++ ...
Posted: Sat Nov 25, 2006 7:39 am
by 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.
Posted: Sat Nov 25, 2006 9:22 am
by 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
Posted: Sat Nov 25, 2006 9:40 am
by 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);
Posted: Sat Nov 25, 2006 9:54 am
by Tyler
Mikae wrote: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...
Posted: Sat Nov 25, 2006 9:56 am
by 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:
Code: Select all
typedef void (*function)(); // "function" is a datatype
function stubs[0x20]; // Array of function-pointers
regards,
gaf
Posted: Sun Nov 26, 2006 4:20 am
by 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);