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79 lines
2.2 KiB

/* Copyright (C) 2004 The KOS Team
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
USA.
*/
#include "ioports.h"
#include "i8259.h"
#define PIC_MASTER 0x20
#define PIC_SLAVE 0xa0
/** Setup the 8259 PIC */
sos_ret_t sos_i8259_subsystem_setup(void)
{
/* Send ICW1: 8086 mode + NOT Single ctrl + call address
interval=8 */
outb(0x11, PIC_MASTER);
outb(0x11, PIC_SLAVE);
/* Send ICW2: ctrl base address */
outb(0x20, PIC_MASTER+1);
outb(0x28, PIC_SLAVE+1);
/* Send ICW3 master: mask where slaves are connected */
outb(0x4, PIC_MASTER+1);
/* Send ICW3 slave: index where the slave is connected on master */
outb(0x2, PIC_SLAVE+1);
/* Send ICW4: 8086 mode, fully nested, not buffered, no implicit EOI */
outb(0x1, PIC_MASTER+1);
outb(0x1, PIC_SLAVE+1);
/* Send OCW1:
* Closing all IRQs : waiting for a correct handler The only IRQ
* enabled is the cascade (that's why we use 0xFB for the master) */
outb(0xFB, PIC_MASTER+1);
outb(0xFF, PIC_SLAVE+1);
return SOS_OK;
}
sos_ret_t sos_i8259_enable_irq_line(int numirq)
{
if(numirq < 8)
/* irq on master PIC */
outb((inb(PIC_MASTER+1) & ~(1 << numirq)), PIC_MASTER+1);
else
/* irq on slave PIC */
outb((inb(PIC_SLAVE+1) & ~(1 << (numirq-8))), PIC_SLAVE+1);
return SOS_OK;
}
sos_ret_t sos_i8259_disable_irq_line(int numirq)
{
if(numirq < 8)
/* irq on master PIC */
outb((inb(PIC_MASTER+1) | (1 << numirq)), PIC_MASTER+1);
else
/* irq on slave PIC */
outb((inb(PIC_SLAVE+1) | (1 << (numirq-8))), PIC_SLAVE+1);
return SOS_OK;
}