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Bochs/bochs/patches/patch.pic-priorities
Volker Ruppert 790bcfc3fe - this patch adds some PIC features
2002-02-12 11:42:57 +00:00

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----------------------------------------------------------------------
Patch name: patch.pic-prioities
Author: Volker Ruppert <Volker.Ruppert@t-online.de>
Date: Tue Feb 12 12:02:25 2002
Detailed description:
This is a patch from Jonathan Hunt <jhuntnz@users.sourceforge.net>
that adds some PIC features. I have modified the patch to make it work
with the current CVS version of the PIC. The standard features are working
without problems, but I don't know how to test the new ones. Please report
if you have tested one of these new features:
* polled mode
* auto EOI mode
* priority rotation
* rotate and auto EOI
Patch was created with:
diff -u
Apply patch to what version:
cvs checked out on DATE
Instructions:
To patch, go to main bochs directory.
Type "patch -p0 < THIS_PATCH_FILE".
----------------------------------------------------------------------
--- ../bochs/iodev/pic.cc Mon Feb 11 09:50:28 2002
+++ iodev/pic.cc Tue Feb 12 12:02:25 2002
@@ -85,6 +85,9 @@
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 */
@@ -103,6 +106,10 @@
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;
@@ -141,6 +148,23 @@
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 */
@@ -201,7 +225,6 @@
#else
UNUSED(this_ptr);
#endif // !BX_USE_PIC_SMF
- int irq;
if (io_len > 1)
BX_PANIC(("io write to port %04x, len=%u", (unsigned) address,
@@ -233,7 +256,10 @@
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) == 1 )
BX_PANIC(("master: ICW1: single mode not supported"));
if ( (value & 0x08) == 1 ) {
@@ -252,8 +278,10 @@
special_mask = (value & 0x60) >> 5;
poll = (value & 0x04) >> 2;
read_op = (value & 0x03);
- if (poll)
- BX_PANIC(("master: OCW3: poll bit set"));
+ 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 */
@@ -270,8 +298,10 @@
/* OCW2 */
switch (value) {
- case 0x00: // Rotate in Auto-EOI mode
- BX_PANIC(("Rotate in Auto-EOI mode command received."));
+ 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;
@@ -279,16 +309,23 @@
BX_PIC_THIS s.master_pic.read_reg_select = 1;
break;
- case 0x20: /* end of interrupt command */
- /* clear highest current in service bit */
- for (irq=0; irq<=7; irq++) {
- if (BX_PIC_THIS s.master_pic.isr & (1 << irq)) {
- BX_PIC_THIS s.master_pic.isr &= ~(1 << irq);
- break; /* out of for loop */
- }
- }
+ 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;
+ 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 */
@@ -300,7 +337,7 @@
case 0x67: /* specific EOI 7 */
BX_PIC_THIS s.master_pic.isr &= ~(1 << (value-0x60));
service_master_pic();
- break;
+ break;
// IRQ lowest priority commands
case 0xC0: // 0 7 6 5 4 3 2 1
@@ -311,8 +348,22 @@
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
- // ignore for now
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:
@@ -346,11 +397,15 @@
return;
break;
case 4:
- if (bx_dbg.pic) {
- BX_INFO(("master: init command 4 = %02x", (unsigned) value));
- if (value & 0x02) BX_INFO((" auto EOI"));
- else BX_INFO(("normal EOI interrupt"));
- }
+ 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) {
if (bx_dbg.pic)
BX_INFO((" 80x86 mode"));
@@ -385,7 +440,10 @@
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.INT = 0; /* reprogramming clears previous INTR request */
+ 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) == 1 )
BX_PANIC(("slave: ICW1: single mode not supported"));
if ( (value & 0x08) == 1 ) {
@@ -403,8 +461,10 @@
special_mask = (value & 0x60) >> 5;
poll = (value & 0x04) >> 2;
read_op = (value & 0x03);
- if (poll)
- BX_PANIC(("slave:OCW3: poll bit set"));
+ 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 */
@@ -420,22 +480,35 @@
}
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 0x20: /* end of interrupt command */
- /* clear highest current in service bit */
- for (irq=0; irq<=7; irq++) {
- if (BX_PIC_THIS s.slave_pic.isr & (1 << irq)) {
- BX_PIC_THIS s.slave_pic.isr &= ~(1 << irq);
- break; /* out of for loop */
- }
- }
+
+ 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;
+ 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 */
@@ -447,7 +520,7 @@
case 0x67: /* specific EOI 7 */
BX_PIC_THIS s.slave_pic.isr &= ~(1 << (value-0x60));
service_slave_pic();
- break;
+ break;
// IRQ lowest priority commands
case 0xC0: // 0 7 6 5 4 3 2 1
@@ -458,8 +531,22 @@
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
- // ignore for now
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:
@@ -491,15 +578,20 @@
return;
break;
case 4:
- if (bx_dbg.pic) {
- BX_DEBUG(("slave: init command 4 = %02x", (unsigned) value));
- if (value & 0x02) BX_INFO((" auto EOI"));
- else BX_DEBUG(("normal EOI interrupt"));
- }
- if (value & 0x01) {
- if (bx_dbg.pic)
- BX_INFO((" 80x86 mode"));
- } else BX_PANIC(("not 80x86 mode"));
+ 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) {
+ if (bx_dbg.pic)
+ BX_INFO((" 80x86 mode"));
+ } else
+ BX_PANIC((" not 80x86 mode"));
BX_PIC_THIS s.slave_pic.init.in_init = 0;
return;
break;
@@ -572,6 +664,32 @@
}
}
+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);
+
+}
+
// old IRQ handling routines (disabled)
#if 0
@@ -641,6 +759,9 @@
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;
@@ -650,28 +771,31 @@
/* all priorities may be enabled. check all IRR bits except ones
* which have corresponding ISR bits set
*/
- max_irq = 7;
+ 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 = 0;
- while ( (isr & 0x01) == 0 ) {
- isr >>= 1;
+ max_irq = highest_priority;
+ while ( (isr & (1 << max_irq)) == 0) {
max_irq++;
+ if(max_irq > 7)
+ max_irq = 0;
}
- if (max_irq == 0 ) return; /* IRQ0 in-service, no other priorities allowed */
+ 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 = 7; /* 0..7 bits in ISR are cleared */
+ 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)) ) {
- for (irq=0; irq<=max_irq; irq++) {
+ irq = highest_priority;
+ do {
/* for special mode, since we're looking at all IRQ's, skip if
* current IRQ is already in-service
*/
@@ -684,7 +808,11 @@
BX_PIC_THIS s.master_pic.irq = irq;
return;
} /* if (unmasked_requests & ... */
- } /* for (irq=7 ... */
+
+ irq ++;
+ if(irq > 7)
+ irq = 0;
+ } while(irq != max_irq); /* do ... */
} /* if (unmasked_requests = ... */
}
@@ -694,7 +822,10 @@
{
Bit8u unmasked_requests;
int irq;
- Bit8u isr, lowest_priority_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;
@@ -704,42 +835,49 @@
/* all priorities may be enabled. check all IRR bits except ones
* which have corresponding ISR bits set
*/
- lowest_priority_irq = 8;
- }
- else {
- /* Find the highest priority IRQ that is enabled due to current ISR */
- isr = BX_PIC_THIS s.slave_pic.isr;
- if (isr) {
- lowest_priority_irq = 0;
- while ( !(isr & 0x01) ) {
- isr >>= 1;
- lowest_priority_irq++;
+ 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()"));
}
- if (lowest_priority_irq > 7) BX_PANIC(("error in service_slave_pic()"));
- }
- else
- lowest_priority_irq = 8;
+ 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)) ) {
- for (irq=0; irq<lowest_priority_irq; irq++) {
+ 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)) {
- if (bx_dbg.pic)
- BX_DEBUG(("slave: signalling IRQ(%u)",
- (unsigned) 8 + irq));
+ BX_DEBUG(("slave: signalling IRQ(%u)", (unsigned) 8 + irq));
+
BX_PIC_THIS s.slave_pic.INT = 1;
- raise_irq(2); /* request IRQ 2 on master pic */
BX_PIC_THIS s.slave_pic.irq = irq;
+ raise_irq(2); /* request IRQ 2 on master pic */
return;
} /* if (unmasked_requests & ... */
- } /* for (irq=7 ... */
+
+ irq ++;
+ if(irq > 7)
+ irq = 0;
+ } while(irq != max_irq); /* do ... */
} /* if (unmasked_requests = ... */
}
@@ -753,8 +891,12 @@
BX_SET_INTR(0);
BX_PIC_THIS s.master_pic.INT = 0;
- BX_PIC_THIS s.master_pic.isr |= (1 << BX_PIC_THIS s.master_pic.irq);
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.slave_pic.rotate_on_autoeoi)
+ BX_PIC_THIS s.slave_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;
@@ -765,8 +907,12 @@
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.isr |= (1 << BX_PIC_THIS s.slave_pic.irq);
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
}
--- ../bochs/iodev/pic.h Mon Feb 11 09:50:28 2002
+++ iodev/pic.h Mon Feb 11 13:43:25 2002
@@ -52,6 +52,7 @@
Bit8u irr; /* interrupt request register */
Bit8u read_reg_select; /* 0=IRR, 1=ISR */
Bit8u irq; /* current IRQ number */
+ Bit8u lowest_priority; /* current lowest priority irq */
Boolean INT; /* INT request pin of PIC */
Boolean IRQ_line[8]; /* IRQ pins of PIC */
struct {
@@ -60,6 +61,8 @@
int byte_expected;
} init;
Boolean special_mask;
+ Boolean polled; /* Set when poll command is issued. */
+ Boolean rotate_on_autoeoi; /* Set when should rotate in auto-eoi mode. */
} bx_pic_t;
@@ -91,6 +94,7 @@
BX_PIC_SMF void service_master_pic(void);
BX_PIC_SMF void service_slave_pic(void);
BX_PIC_SMF void show_pic_state(void);
+ BX_PIC_SMF void clear_highest_interrupt(bx_pic_t *pic);
};
extern bx_pic_c bx_pic;
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