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Bochs/bochs/iodev/pic.cc
Volker Ruppert d47cdb919a - fixed detection of single mode and level senistive mode in ICW1 
- fixed handling of rotate_on_autoeoi for master PIC in in IAC()
- removed old IRQ handling functions (trigger_irq / untrigger_irq)
- replaced BX_INFO in case of bx_dbg.pic by BX_DEBUG calls
2002-03-29 09:13:02 +00:00

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29 KiB
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/////////////////////////////////////////////////////////////////////////
// $Id: pic.cc,v 1.25 2002-03-29 09:13:02 vruppert Exp $
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2002 MandrakeSoft S.A.
//
// MandrakeSoft S.A.
// 43, rue d'Aboukir
// 75002 Paris - France
// http://www.linux-mandrake.com/
// http://www.mandrakesoft.com/
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
#include "bochs.h"
#define LOG_THIS bx_pic.
bx_pic_c bx_pic;
#if BX_USE_PIC_SMF
#define this (&bx_pic)
#endif
bx_pic_c::bx_pic_c(void)
{
put("PIC");
settype(PICLOG);
}
bx_pic_c::~bx_pic_c(void)
{
// nothing for now
}
void
bx_pic_c::init(bx_devices_c *d)
{
BX_PIC_THIS devices = d;
/* 8259 PIC (Programmable Interrupt Controller) */
BX_PIC_THIS devices->register_io_read_handler(this, read_handler, 0x0020, "8259 PIC");
BX_PIC_THIS devices->register_io_read_handler(this, read_handler, 0x0021, "8259 PIC");
BX_PIC_THIS devices->register_io_read_handler(this, read_handler, 0x00A0, "8259 PIC");
BX_PIC_THIS devices->register_io_read_handler(this, read_handler, 0x00A1, "8259 PIC");
BX_PIC_THIS devices->register_io_write_handler(this, write_handler, 0x0020, "8259 PIC");
BX_PIC_THIS devices->register_io_write_handler(this, write_handler, 0x0021, "8259 PIC");
BX_PIC_THIS devices->register_io_write_handler(this, write_handler, 0x00A0, "8259 PIC");
BX_PIC_THIS devices->register_io_write_handler(this, write_handler, 0x00A1, "8259 PIC");
BX_PIC_THIS s.master_pic.single_PIC = 0;
BX_PIC_THIS s.master_pic.interrupt_offset = 0x08; /* IRQ0 = INT 0x08 */
/* slave PIC connected to IRQ2 of master */
BX_PIC_THIS s.master_pic.u.slave_connect_mask = 0x04;
BX_PIC_THIS s.master_pic.sfnm = 0; /* normal nested mode */
BX_PIC_THIS s.master_pic.buffered_mode = 0; /* unbuffered mode */
BX_PIC_THIS s.master_pic.master_slave = 0; /* no meaning, buffered_mode=0 */
BX_PIC_THIS s.master_pic.auto_eoi = 0; /* manual EOI from CPU */
BX_PIC_THIS s.master_pic.imr = 0xFF; /* all IRQ's initially masked */
BX_PIC_THIS s.master_pic.isr = 0x00; /* no IRQ's in service */
BX_PIC_THIS s.master_pic.irr = 0x00; /* no IRQ's requested */
BX_PIC_THIS s.master_pic.read_reg_select = 0; /* IRR */
BX_PIC_THIS s.master_pic.irq = 0;
BX_PIC_THIS s.master_pic.INT = 0;
BX_PIC_THIS s.master_pic.init.in_init = 0;
BX_PIC_THIS s.master_pic.init.requires_4 = 0;
BX_PIC_THIS s.master_pic.init.byte_expected = 0;
BX_PIC_THIS s.master_pic.special_mask = 0;
BX_PIC_THIS s.master_pic.lowest_priority = 7;
BX_PIC_THIS s.master_pic.polled = 0;
BX_PIC_THIS s.master_pic.rotate_on_autoeoi = 0;
BX_PIC_THIS s.slave_pic.single_PIC = 0;
BX_PIC_THIS s.slave_pic.interrupt_offset = 0x70; /* IRQ8 = INT 0x70 */
BX_PIC_THIS s.slave_pic.u.slave_id = 0x02; /* slave PIC connected to IRQ2 of master */
BX_PIC_THIS s.slave_pic.sfnm = 0; /* normal nested mode */
BX_PIC_THIS s.slave_pic.buffered_mode = 0; /* unbuffered mode */
BX_PIC_THIS s.slave_pic.master_slave = 0; /* no meaning, buffered_mode=0 */
BX_PIC_THIS s.slave_pic.auto_eoi = 0; /* manual EOI from CPU */
BX_PIC_THIS s.slave_pic.imr = 0xFF; /* all IRQ's initially masked */
BX_PIC_THIS s.slave_pic.isr = 0x00; /* no IRQ's in service */
BX_PIC_THIS s.slave_pic.irr = 0x00; /* no IRQ's requested */
BX_PIC_THIS s.slave_pic.read_reg_select = 0; /* IRR */
BX_PIC_THIS s.slave_pic.irq = 0;
BX_PIC_THIS s.slave_pic.INT = 0;
BX_PIC_THIS s.slave_pic.init.in_init = 0;
BX_PIC_THIS s.slave_pic.init.requires_4 = 0;
BX_PIC_THIS s.slave_pic.init.byte_expected = 0;
BX_PIC_THIS s.slave_pic.special_mask = 0;
BX_PIC_THIS s.slave_pic.lowest_priority = 7;
BX_PIC_THIS s.slave_pic.polled = 0;
BX_PIC_THIS s.slave_pic.rotate_on_autoeoi = 0;
for (unsigned i=0; i<8; i++) { /* all IRQ lines low */
BX_PIC_THIS s.master_pic.IRQ_line[i] = 0;
BX_PIC_THIS s.slave_pic.IRQ_line[i] = 0;
}
}
// static IO port read callback handler
// redirects to non-static class handler to avoid virtual functions
Bit32u
bx_pic_c::read_handler(void *this_ptr, Bit32u address, unsigned io_len)
{
#if !BX_USE_PIC_SMF
bx_pic_c *class_ptr = (bx_pic_c *) this_ptr;
return( class_ptr->read(address, io_len) );
}
Bit32u
bx_pic_c::read(Bit32u address, unsigned io_len)
{
#else
UNUSED(this_ptr);
#endif // !BX_USE_PIC_SMF
if (io_len > 1)
BX_PANIC(("io read from port %04x, len=%u", (unsigned) address,
(unsigned) io_len));
BX_DEBUG(("IO read from %04x", (unsigned) address));
/*
8259A PIC
*/
if((address == 0x20 || address == 0x21) && BX_PIC_THIS s.master_pic.polled) {
// In polled mode. Treat this as an interrupt acknowledge
clear_highest_interrupt(& BX_PIC_THIS s.master_pic);
BX_PIC_THIS s.master_pic.polled = 0;
service_master_pic();
return BX_PIC_THIS s.master_pic.irq; // Return the current irq requested
}
if((address == 0xa0 || address == 0xa1) && BX_PIC_THIS s.slave_pic.polled) {
// In polled mode. Treat this as an interrupt acknowledge
clear_highest_interrupt(& BX_PIC_THIS s.slave_pic);
BX_PIC_THIS s.slave_pic.polled = 0;
service_slave_pic();
return BX_PIC_THIS s.slave_pic.irq; // Return the current irq requested
}
switch (address) {
case 0x20:
if (BX_PIC_THIS s.master_pic.read_reg_select) { /* ISR */
BX_DEBUG(("read master ISR = %02x",
(unsigned) BX_PIC_THIS s.master_pic.isr));
return(BX_PIC_THIS s.master_pic.isr);
}
else { /* IRR */
BX_DEBUG(("read master IRR = %02x",
(unsigned) BX_PIC_THIS s.master_pic.irr));
return(BX_PIC_THIS s.master_pic.irr);
}
break;
case 0x21:
BX_DEBUG(("read master IMR = %02x",
(unsigned) BX_PIC_THIS s.master_pic.imr));
return(BX_PIC_THIS s.master_pic.imr);
break;
case 0xA0:
if (BX_PIC_THIS s.slave_pic.read_reg_select) { /* ISR */
BX_DEBUG(("read slave ISR = %02x",
(unsigned) BX_PIC_THIS s.slave_pic.isr));
return(BX_PIC_THIS s.slave_pic.isr);
}
else { /* IRR */
BX_DEBUG(("read slave IRR = %02x",
(unsigned) BX_PIC_THIS s.slave_pic.irr));
return(BX_PIC_THIS s.slave_pic.irr);
}
break;
case 0xA1:
BX_DEBUG(("read slave IMR = %02x",
(unsigned) BX_PIC_THIS s.slave_pic.imr));
return(BX_PIC_THIS s.slave_pic.imr);
break;
}
BX_PANIC(("io read to address %04x", (unsigned) address));
return(0); /* default if not found above */
}
// static IO port write callback handler
// redirects to non-static class handler to avoid virtual functions
void
bx_pic_c::write_handler(void *this_ptr, Bit32u address, Bit32u value, unsigned io_len)
{
#if !BX_USE_PIC_SMF
bx_pic_c *class_ptr = (bx_pic_c *) this_ptr;
class_ptr->write(address, value, io_len);
}
void
bx_pic_c::write(Bit32u address, Bit32u value, unsigned io_len)
{
#else
UNUSED(this_ptr);
#endif // !BX_USE_PIC_SMF
if (io_len > 1)
BX_PANIC(("io write to port %04x, len=%u", (unsigned) address,
(unsigned) io_len));
BX_DEBUG(("IO write to %04x = %02x", (unsigned) address, (unsigned) value));
/*
8259A PIC
*/
switch (address) {
case 0x20:
if (value & 0x10) { /* initialization command 1 */
BX_DEBUG(("master: init command 1 found"));
BX_DEBUG((" requires 4 = %u", (unsigned) (value & 0x01) ));
BX_DEBUG((" cascade mode: [0=cascade,1=single] %u",
(unsigned) ((value & 0x02) >> 1)));
BX_PIC_THIS s.master_pic.init.in_init = 1;
BX_PIC_THIS s.master_pic.init.requires_4 = (value & 0x01);
BX_PIC_THIS s.master_pic.init.byte_expected = 2; /* operation command 2 */
BX_PIC_THIS s.master_pic.imr = 0xFF; /* all IRQ's initially masked */
BX_PIC_THIS s.master_pic.isr = 0x00; /* no IRQ's in service */
BX_PIC_THIS s.master_pic.irr = 0x00; /* no IRQ's requested */
BX_PIC_THIS s.master_pic.lowest_priority = 7;
BX_PIC_THIS s.master_pic.INT = 0; /* reprogramming clears previous INTR request */
BX_PIC_THIS s.master_pic.auto_eoi = 0;
BX_PIC_THIS s.master_pic.rotate_on_autoeoi = 0;
if (value & 0x02)
BX_PANIC(("master: ICW1: single mode not supported"));
if (value & 0x08) {
BX_PANIC(("master: ICW1: level sensitive mode not supported"));
}
else {
BX_DEBUG(("master: ICW1: edge triggered mode selected"));
}
BX_SET_INTR(0);
return;
}
if ( (value & 0x18) == 0x08 ) { /* OCW3 */
Bit8u special_mask, poll, read_op;
special_mask = (value & 0x60) >> 5;
poll = (value & 0x04) >> 2;
read_op = (value & 0x03);
if (poll) {
BX_PIC_THIS s.master_pic.polled = 1;
return;
}
if (read_op == 0x02) /* read IRR */
BX_PIC_THIS s.master_pic.read_reg_select = 0;
else if (read_op == 0x03) /* read ISR */
BX_PIC_THIS s.master_pic.read_reg_select = 1;
if (special_mask == 0x02) { /* cancel special mask */
BX_PIC_THIS s.master_pic.special_mask = 0;
}
else if (special_mask == 0x03) { /* set specific mask */
BX_PIC_THIS s.master_pic.special_mask = 1;
service_master_pic();
}
return;
}
/* OCW2 */
switch (value) {
case 0x00: // Rotate in auto eoi mode clear
case 0x80: // Rotate in auto eoi mode set
BX_PIC_THIS s.master_pic.rotate_on_autoeoi = (value != 0);
break;
case 0x0A: /* select read interrupt request register */
BX_PIC_THIS s.master_pic.read_reg_select = 0;
break;
case 0x0B: /* select read interrupt in-service register */
BX_PIC_THIS s.master_pic.read_reg_select = 1;
break;
case 0xA0: // Rotate on non-specific end of interrupt
case 0x20: /* end of interrupt command */
clear_highest_interrupt(& BX_PIC_THIS s.master_pic);
if(value == 0xA0) {// Rotate in Auto-EOI mode
BX_PIC_THIS s.master_pic.lowest_priority ++;
if(BX_PIC_THIS s.master_pic.lowest_priority > 7)
BX_PIC_THIS s.master_pic.lowest_priority = 0;
}
service_master_pic();
break;
case 0x40: // Intel PIC spec-sheet seems to indicate this should be ignored
BX_INFO(("IRQ no-op"));
break;
case 0x60: /* specific EOI 0 */
case 0x61: /* specific EOI 1 */
case 0x62: /* specific EOI 2 */
case 0x63: /* specific EOI 3 */
case 0x64: /* specific EOI 4 */
case 0x65: /* specific EOI 5 */
case 0x66: /* specific EOI 6 */
case 0x67: /* specific EOI 7 */
BX_PIC_THIS s.master_pic.isr &= ~(1 << (value-0x60));
service_master_pic();
break;
// IRQ lowest priority commands
case 0xC0: // 0 7 6 5 4 3 2 1
case 0xC1: // 1 0 7 6 5 4 3 2
case 0xC2: // 2 1 0 7 6 5 4 3
case 0xC3: // 3 2 1 0 7 6 5 4
case 0xC4: // 4 3 2 1 0 7 6 5
case 0xC5: // 5 4 3 2 1 0 7 6
case 0xC6: // 6 5 4 3 2 1 0 7
case 0xC7: // 7 6 5 4 3 2 1 0
BX_INFO(("IRQ lowest command 0x%x", value));
BX_PIC_THIS s.master_pic.lowest_priority = value - 0xC0;
break;
case 0xE0: // specific EOI and rotate 0
case 0xE1: // specific EOI and rotate 1
case 0xE2: // specific EOI and rotate 2
case 0xE3: // specific EOI and rotate 3
case 0xE4: // specific EOI and rotate 4
case 0xE5: // specific EOI and rotate 5
case 0xE6: // specific EOI and rotate 6
case 0xE7: // specific EOI and rotate 7
BX_PIC_THIS s.master_pic.isr &= ~(1 << (value-0xE0));
BX_PIC_THIS s.master_pic.lowest_priority = (value - 0xE0);
service_master_pic();
break;
default:
BX_PANIC(("write to port 20h = %02x", value));
} /* switch (value) */
break;
case 0x21:
/* initialization mode operation */
if (BX_PIC_THIS s.master_pic.init.in_init) {
switch (BX_PIC_THIS s.master_pic.init.byte_expected) {
case 2:
BX_PIC_THIS s.master_pic.interrupt_offset = value & 0xf8;
BX_PIC_THIS s.master_pic.init.byte_expected = 3;
BX_DEBUG(("master: init command 2 = %02x", (unsigned) value));
BX_DEBUG((" offset = INT %02x",
BX_PIC_THIS s.master_pic.interrupt_offset));
return;
break;
case 3:
BX_DEBUG(("master: init command 3 = %02x", (unsigned) value));
if (BX_PIC_THIS s.master_pic.init.requires_4) {
BX_PIC_THIS s.master_pic.init.byte_expected = 4;
}
else {
BX_PIC_THIS s.master_pic.init.in_init = 0;
}
return;
break;
case 4:
BX_DEBUG(("master: init command 4 = %02x", (unsigned) value));
if (value & 0x02) {
BX_DEBUG((" auto EOI"));
BX_PIC_THIS s.master_pic.auto_eoi = 1;
}
else {
BX_DEBUG(("normal EOI interrupt"));
BX_PIC_THIS s.master_pic.auto_eoi = 0;
}
if (value & 0x01) {
BX_DEBUG((" 80x86 mode"));
} else
BX_PANIC((" not 80x86 mode"));
BX_PIC_THIS s.master_pic.init.in_init = 0;
return;
break;
default:
BX_PANIC(("master expecting bad init command"));
}
}
/* normal operation */
BX_DEBUG(("setting master pic IMR to %02x", value));
BX_PIC_THIS s.master_pic.imr = value;
service_master_pic();
return;
break;
case 0xA0:
if (value & 0x10) { /* initialization command 1 */
BX_DEBUG(("slave: init command 1 found"));
BX_DEBUG((" requires 4 = %u",
(unsigned) (value & 0x01) ));
BX_DEBUG((" cascade mode: [0=cascade,1=single] %u",
(unsigned) ((value & 0x02) >> 1)));
BX_PIC_THIS s.slave_pic.init.in_init = 1;
BX_PIC_THIS s.slave_pic.init.requires_4 = (value & 0x01);
BX_PIC_THIS s.slave_pic.init.byte_expected = 2; /* operation command 2 */
BX_PIC_THIS s.slave_pic.imr = 0xFF; /* all IRQ's initially masked */
BX_PIC_THIS s.slave_pic.isr = 0x00; /* no IRQ's in service */
BX_PIC_THIS s.slave_pic.irr = 0x00; /* no IRQ's requested */
BX_PIC_THIS s.slave_pic.lowest_priority = 7;
BX_PIC_THIS s.slave_pic.INT = 0; /* reprogramming clears previous INTR request */
BX_PIC_THIS s.slave_pic.auto_eoi = 0;
BX_PIC_THIS s.slave_pic.rotate_on_autoeoi = 0;
if (value & 0x02)
BX_PANIC(("slave: ICW1: single mode not supported"));
if (value & 0x08) {
BX_PANIC(("slave: ICW1: level sensitive mode not supported"));
}
else {
BX_DEBUG(("slave: ICW1: edge triggered mode selected"));
}
return;
}
if ( (value & 0x18) == 0x08 ) { /* OCW3 */
Bit8u special_mask, poll, read_op;
special_mask = (value & 0x60) >> 5;
poll = (value & 0x04) >> 2;
read_op = (value & 0x03);
if (poll) {
BX_PIC_THIS s.slave_pic.polled = 1;
return;
}
if (read_op == 0x02) /* read IRR */
BX_PIC_THIS s.slave_pic.read_reg_select = 0;
else if (read_op == 0x03) /* read ISR */
BX_PIC_THIS s.slave_pic.read_reg_select = 1;
if (special_mask == 0x02) { /* cancel special mask */
BX_PIC_THIS s.slave_pic.special_mask = 0;
}
else if (special_mask == 0x03) { /* set specific mask */
BX_PIC_THIS s.slave_pic.special_mask = 1;
service_slave_pic();
}
return;
}
switch (value) {
case 0x00: // Rotate in auto eoi mode clear
case 0x80: // Rotate in auto eoi mode set
BX_PIC_THIS s.slave_pic.rotate_on_autoeoi = (value != 0);
break;
case 0x0A: /* select read interrupt request register */
BX_PIC_THIS s.slave_pic.read_reg_select = 0;
break;
case 0x0B: /* select read interrupt in-service register */
BX_PIC_THIS s.slave_pic.read_reg_select = 1;
break;
case 0xA0: // Rotate on non-specific end of interrupt
case 0x20: /* end of interrupt command */
clear_highest_interrupt(& BX_PIC_THIS s.slave_pic);
if(value == 0xA0) {// Rotate in Auto-EOI mode
BX_PIC_THIS s.slave_pic.lowest_priority ++;
if(BX_PIC_THIS s.slave_pic.lowest_priority > 7)
BX_PIC_THIS s.slave_pic.lowest_priority = 0;
}
service_slave_pic();
break;
case 0x40: // Intel PIC spec-sheet seems to indicate this should be ignored
BX_INFO(("IRQ no-op"));
break;
case 0x60: /* specific EOI 0 */
case 0x61: /* specific EOI 1 */
case 0x62: /* specific EOI 2 */
case 0x63: /* specific EOI 3 */
case 0x64: /* specific EOI 4 */
case 0x65: /* specific EOI 5 */
case 0x66: /* specific EOI 6 */
case 0x67: /* specific EOI 7 */
BX_PIC_THIS s.slave_pic.isr &= ~(1 << (value-0x60));
service_slave_pic();
break;
// IRQ lowest priority commands
case 0xC0: // 0 7 6 5 4 3 2 1
case 0xC1: // 1 0 7 6 5 4 3 2
case 0xC2: // 2 1 0 7 6 5 4 3
case 0xC3: // 3 2 1 0 7 6 5 4
case 0xC4: // 4 3 2 1 0 7 6 5
case 0xC5: // 5 4 3 2 1 0 7 6
case 0xC6: // 6 5 4 3 2 1 0 7
case 0xC7: // 7 6 5 4 3 2 1 0
BX_INFO(("IRQ lowest command 0x%x", value));
BX_PIC_THIS s.slave_pic.lowest_priority = value - 0xC0;
break;
case 0xE0: // specific EOI and rotate 0
case 0xE1: // specific EOI and rotate 1
case 0xE2: // specific EOI and rotate 2
case 0xE3: // specific EOI and rotate 3
case 0xE4: // specific EOI and rotate 4
case 0xE5: // specific EOI and rotate 5
case 0xE6: // specific EOI and rotate 6
case 0xE7: // specific EOI and rotate 7
BX_PIC_THIS s.slave_pic.isr &= ~(1 << (value-0xE0));
BX_PIC_THIS s.slave_pic.lowest_priority = (value - 0xE0);
service_slave_pic();
break;
default:
BX_PANIC(("write to port A0h = %02x", value));
} /* switch (value) */
break;
case 0xA1:
/* initialization mode operation */
if (BX_PIC_THIS s.slave_pic.init.in_init) {
switch (BX_PIC_THIS s.slave_pic.init.byte_expected) {
case 2:
BX_PIC_THIS s.slave_pic.interrupt_offset = value & 0xf8;
BX_PIC_THIS s.slave_pic.init.byte_expected = 3;
BX_DEBUG(("slave: init command 2 = %02x", (unsigned) value));
BX_DEBUG((" offset = INT %02x",
BX_PIC_THIS s.slave_pic.interrupt_offset));
return;
break;
case 3:
BX_DEBUG(("slave: init command 3 = %02x", (unsigned) value));
if (BX_PIC_THIS s.slave_pic.init.requires_4) {
BX_PIC_THIS s.slave_pic.init.byte_expected = 4;
} else {
BX_PIC_THIS s.slave_pic.init.in_init = 0;
}
return;
break;
case 4:
BX_DEBUG(("slave: init command 4 = %02x", (unsigned) value));
if (value & 0x02) {
BX_DEBUG((" auto EOI"));
BX_PIC_THIS s.slave_pic.auto_eoi = 1;
}
else {
BX_DEBUG(("normal EOI interrupt"));
BX_PIC_THIS s.slave_pic.auto_eoi = 0;
}
if (value & 0x01) {
BX_DEBUG((" 80x86 mode"));
} else
BX_PANIC((" not 80x86 mode"));
BX_PIC_THIS s.slave_pic.init.in_init = 0;
return;
break;
default:
BX_PANIC(("slave: expecting bad init command"));
}
}
/* normal operation */
BX_DEBUG(("setting slave pic IMR to %02x", value));
BX_PIC_THIS s.slave_pic.imr = value;
service_slave_pic();
return;
break;
} /* switch (address) */
return;
}
// new IRQ signal handling routines
void
bx_pic_c::lower_irq(unsigned irq_no)
{
#if BX_SUPPORT_APIC
// forward this function call to the ioapic too
if ((BX_PIC_THIS devices) && (BX_PIC_THIS devices->ioapic))
BX_PIC_THIS devices->ioapic->untrigger_irq (irq_no, -1);
#endif
if ((irq_no <= 7) && (BX_PIC_THIS s.master_pic.IRQ_line[irq_no])) {
BX_DEBUG(("IRQ line %d now low", (unsigned) irq_no));
BX_PIC_THIS s.master_pic.IRQ_line[irq_no] = 0;
BX_PIC_THIS s.master_pic.irr &= ~(1 << irq_no);
if ((BX_PIC_THIS s.master_pic.irr & ~BX_PIC_THIS s.master_pic.imr) == 0) {
BX_SET_INTR(0);
BX_PIC_THIS s.master_pic.INT = 0;
}
} else if ((irq_no > 7) && (irq_no <= 15) &&
(BX_PIC_THIS s.slave_pic.IRQ_line[irq_no-8])) {
BX_DEBUG(("IRQ line %d now low", (unsigned) irq_no));
BX_PIC_THIS s.slave_pic.IRQ_line[irq_no - 8] = 0;
BX_PIC_THIS s.slave_pic.irr &= ~(1 << (irq_no - 8));
if ((BX_PIC_THIS s.slave_pic.irr & ~BX_PIC_THIS s.slave_pic.imr) == 0) {
BX_PIC_THIS s.slave_pic.INT = 0;
lower_irq(2);
}
}
}
void
bx_pic_c::raise_irq(unsigned irq_no)
{
#if BX_SUPPORT_APIC
// forward this function call to the ioapic too
BX_PIC_THIS devices->ioapic->trigger_irq (irq_no, -1);
#endif
if ((irq_no <= 7) && (!BX_PIC_THIS s.master_pic.IRQ_line[irq_no])) {
BX_DEBUG(("IRQ line %d now high", (unsigned) irq_no));
BX_PIC_THIS s.master_pic.IRQ_line[irq_no] = 1;
BX_PIC_THIS s.master_pic.irr |= (1 << irq_no);
service_master_pic();
} else if ((irq_no > 7) && (irq_no <= 15) &&
(!BX_PIC_THIS s.slave_pic.IRQ_line[irq_no-8])) {
BX_DEBUG(("IRQ line %d now high", (unsigned) irq_no));
BX_PIC_THIS s.slave_pic.IRQ_line[irq_no - 8] = 1;
BX_PIC_THIS s.slave_pic.irr |= (1 << (irq_no - 8));
service_slave_pic();
}
}
void bx_pic_c::clear_highest_interrupt(bx_pic_t *pic)
{
int irq;
int lowest_priority;
int highest_priority;
/* clear highest current in service bit */
lowest_priority = pic->lowest_priority;
highest_priority = lowest_priority + 1;
if(highest_priority > 7)
highest_priority = 0;
irq = highest_priority;
do {
if (pic->isr & (1 << irq)) {
pic->isr &= ~(1 << irq);
break; /* Return mask of bit cleared. */
}
irq ++;
if(irq > 7)
irq = 0;
} while(irq != highest_priority);
}
/* */
void
bx_pic_c::service_master_pic(void)
{
Bit8u unmasked_requests;
int irq;
Bit8u isr, max_irq;
Bit8u highest_priority = BX_PIC_THIS s.master_pic.lowest_priority + 1;
if(highest_priority > 7)
highest_priority = 0;
if (BX_PIC_THIS s.master_pic.INT) { /* last interrupt still not acknowleged */
return;
}
if (BX_PIC_THIS s.master_pic.special_mask) {
/* all priorities may be enabled. check all IRR bits except ones
* which have corresponding ISR bits set
*/
max_irq = highest_priority;
}
else { /* normal mode */
/* Find the highest priority IRQ that is enabled due to current ISR */
isr = BX_PIC_THIS s.master_pic.isr;
if (isr) {
max_irq = highest_priority;
while ( (isr & (1 << max_irq)) == 0) {
max_irq++;
if(max_irq > 7)
max_irq = 0;
}
if (max_irq == highest_priority ) return; /* Highest priority interrupt in-service,
* no other priorities allowed */
if (max_irq > 7) BX_PANIC(("error in service_master_pic()"));
}
else
max_irq = highest_priority; /* 0..7 bits in ISR are cleared */
}
/* now, see if there are any higher priority requests */
if ((unmasked_requests = (BX_PIC_THIS s.master_pic.irr & ~BX_PIC_THIS s.master_pic.imr)) ) {
irq = highest_priority;
do {
/* for special mode, since we're looking at all IRQ's, skip if
* current IRQ is already in-service
*/
if ( BX_PIC_THIS s.master_pic.special_mask && ((BX_PIC_THIS s.master_pic.isr >> irq) & 0x01) )
continue;
if (unmasked_requests & (1 << irq)) {
BX_DEBUG(("signalling IRQ(%u)", (unsigned) irq));
BX_PIC_THIS s.master_pic.INT = 1;
BX_SET_INTR(1);
BX_PIC_THIS s.master_pic.irq = irq;
return;
} /* if (unmasked_requests & ... */
irq ++;
if(irq > 7)
irq = 0;
} while(irq != max_irq); /* do ... */
} /* if (unmasked_requests = ... */
}
void
bx_pic_c::service_slave_pic(void)
{
Bit8u unmasked_requests;
int irq;
Bit8u isr, max_irq;
Bit8u highest_priority = BX_PIC_THIS s.slave_pic.lowest_priority + 1;
if(highest_priority > 7)
highest_priority = 0;
if (BX_PIC_THIS s.slave_pic.INT) { /* last interrupt still not acknowleged */
return;
}
if (BX_PIC_THIS s.slave_pic.special_mask) {
/* all priorities may be enabled. check all IRR bits except ones
* which have corresponding ISR bits set
*/
max_irq = highest_priority;
}
else { /* normal mode */
/* Find the highest priority IRQ that is enabled due to current ISR */
isr = BX_PIC_THIS s.slave_pic.isr;
if (isr) {
max_irq = highest_priority;
while ( (isr & (1 << max_irq)) == 0) {
max_irq++;
if(max_irq > 7)
max_irq = 0;
}
if (max_irq == highest_priority ) return; /* Highest priority interrupt in-service,
* no other priorities allowed */
if (max_irq > 7) BX_PANIC(("error in service_master_pic()"));
}
else
max_irq = highest_priority; /* 0..7 bits in ISR are cleared */
}
/* now, see if there are any higher priority requests */
if ((unmasked_requests = (BX_PIC_THIS s.slave_pic.irr & ~BX_PIC_THIS s.slave_pic.imr)) ) {
irq = highest_priority;
do {
/* for special mode, since we're looking at all IRQ's, skip if
* current IRQ is already in-service
*/
if ( BX_PIC_THIS s.slave_pic.special_mask && ((BX_PIC_THIS s.slave_pic.isr >> irq) & 0x01) )
continue;
if (unmasked_requests & (1 << irq)) {
BX_DEBUG(("slave: signalling IRQ(%u)", (unsigned) 8 + irq));
BX_PIC_THIS s.slave_pic.INT = 1;
BX_PIC_THIS s.slave_pic.irq = irq;
raise_irq(2); /* request IRQ 2 on master pic */
return;
} /* if (unmasked_requests & ... */
irq ++;
if(irq > 7)
irq = 0;
} while(irq != max_irq); /* do ... */
} /* if (unmasked_requests = ... */
}
/* CPU handshakes with PIC after acknowledging interrupt */
Bit8u
bx_pic_c::IAC(void)
{
Bit8u vector;
Bit8u irq;
BX_SET_INTR(0);
BX_PIC_THIS s.master_pic.INT = 0;
BX_PIC_THIS s.master_pic.irr &= ~(1 << BX_PIC_THIS s.master_pic.irq);
// In autoeoi mode don't set the isr bit.
if(!BX_PIC_THIS s.master_pic.auto_eoi)
BX_PIC_THIS s.master_pic.isr |= (1 << BX_PIC_THIS s.master_pic.irq);
else if(BX_PIC_THIS s.master_pic.rotate_on_autoeoi)
BX_PIC_THIS s.master_pic.lowest_priority = BX_PIC_THIS s.master_pic.irq;
if (BX_PIC_THIS s.master_pic.irq != 2) {
irq = BX_PIC_THIS s.master_pic.irq;
vector = irq + BX_PIC_THIS s.master_pic.interrupt_offset;
}
else { /* IRQ2 = slave pic IRQ8..15 */
BX_PIC_THIS s.slave_pic.INT = 0;
BX_PIC_THIS s.master_pic.IRQ_line[2] = 0;
irq = BX_PIC_THIS s.slave_pic.irq;
vector = irq + BX_PIC_THIS s.slave_pic.interrupt_offset;
BX_PIC_THIS s.slave_pic.irr &= ~(1 << BX_PIC_THIS s.slave_pic.irq);
// In autoeoi mode don't set the isr bit.
if(!BX_PIC_THIS s.slave_pic.auto_eoi)
BX_PIC_THIS s.slave_pic.isr |= (1 << BX_PIC_THIS s.slave_pic.irq);
else if(BX_PIC_THIS s.slave_pic.rotate_on_autoeoi)
BX_PIC_THIS s.slave_pic.lowest_priority = BX_PIC_THIS s.slave_pic.irq;
service_slave_pic();
irq += 8; // for debug printing purposes
}
service_master_pic();
BX_DBG_IAC_REPORT(vector, irq);
return(vector);
}
void
bx_pic_c::show_pic_state(void)
{
BX_INFO(("s.master_pic.imr = %02x", BX_PIC_THIS s.master_pic.imr));
BX_INFO(("s.master_pic.isr = %02x", BX_PIC_THIS s.master_pic.isr));
BX_INFO(("s.master_pic.irr = %02x", BX_PIC_THIS s.master_pic.irr));
BX_INFO(("s.master_pic.irq = %02x", BX_PIC_THIS s.master_pic.irq));
}
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