X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=bootcensus;a=blobdiff_plain;f=src%2Fintr.c;h=2ec1f1b5eb311b02ddafe4281a01b7593e6dc3ad;hp=1ace71e53b19317dd330faea96705559774762d4;hb=81c11bdd80190ec319a82b0402173cfb65fcbf72;hpb=a2f94f569a4c99204de02814a20098a71527e913

diff --git a/src/intr.c b/src/intr.c
index 1ace71e..2ec1f1b 100644
--- a/src/intr.c
+++ b/src/intr.c
@@ -1,4 +1,22 @@
+/*
+pcboot - bootable PC demo/game kernel
+Copyright (C) 2018  John Tsiombikas <nuclear@member.fsf.org>
+
+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 3 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, see <https://www.gnu.org/licenses/>.
+*/
 #include <stdio.h>
+#include "config.h"
 #include "intr.h"
 #include "desc.h"
 #include "segm.h"
@@ -37,12 +55,14 @@
 #define OCW2_EOI	(1 << 5)
 
 
-static void init_pic(int offset);
+void init_pic(void);
 static void gate_desc(desc_t *desc, uint16_t sel, uint32_t addr, int dpl, int type);
 
 /* defined in intr_asm.S */
 void set_idt(uint32_t addr, uint16_t limit);
 void intr_entry_default(void);
+void irq7_entry_check_spurious(void);
+void irq15_entry_check_spurious(void);
 
 /* the IDT (interrupt descriptor table) */
 static desc_t idt[256] __attribute__((aligned(8)));
@@ -73,10 +93,16 @@ void init_intr(void)
 	 */
 #include "intrtab.h"
 
+	/* change irq7 and irq15 to special entry points which first
+	 * make sure we didn't get a spurious interrupt before proceeding
+	 */
+	set_intr_entry(IRQ_TO_INTR(7), irq7_entry_check_spurious);
+	set_intr_entry(IRQ_TO_INTR(15), irq15_entry_check_spurious);
+
 	/* initialize the programmable interrupt controller
 	 * setting up the maping of IRQs [0, 15] to interrupts [32, 47]
 	 */
-	init_pic(IRQ_OFFSET);
+	init_pic();
 	eoi_pending = 0;
 }
 
@@ -91,7 +117,10 @@ struct intr_frame *get_intr_frame(void)
 /* set an interrupt handler function for a particular interrupt */
 void interrupt(int intr_num, intr_func_t func)
 {
+	int iflag = get_intr_flag();
+	disable_intr();
 	intr_func[intr_num] = func;
+	set_intr_flag(iflag);
 }
 
 /* this function is called from all interrupt entry points
@@ -121,14 +150,19 @@ void dispatch_intr(struct intr_frame frm)
 	}
 }
 
-static void init_pic(int offset)
+void init_pic(void)
+{
+	prog_pic(IRQ_OFFSET);
+}
+
+void prog_pic(int offs)
 {
 	/* send ICW1 saying we'll follow with ICW4 later on */
 	outb(ICW1_INIT | ICW1_ICW4_NEEDED, PIC1_CMD);
 	outb(ICW1_INIT | ICW1_ICW4_NEEDED, PIC2_CMD);
 	/* send ICW2 with IRQ remapping */
-	outb(offset, PIC1_DATA);
-	outb(offset + 8, PIC2_DATA);
+	outb(offs, PIC1_DATA);
+	outb(offs + 8, PIC2_DATA);
 	/* send ICW3 to setup the master/slave relationship */
 	/* ... set bit3 = 3rd interrupt input has a slave */
 	outb(4, PIC1_DATA);
@@ -169,6 +203,49 @@ void set_intr_entry(int num, void (*handler)(void))
 	gate_desc(idt + num, selector(SEGM_KCODE, 0), (uint32_t)handler, dpl, type);
 }
 
+void set_pic_mask(int pic, unsigned char mask)
+{
+	outb(mask, pic > 0 ? PIC2_DATA : PIC1_DATA);
+}
+
+unsigned char get_pic_mask(int pic)
+{
+	return inb(pic > 0 ? PIC2_DATA : PIC1_DATA);
+}
+
+void mask_irq(int irq)
+{
+	int port;
+	unsigned char mask;
+
+	if(irq < 8) {
+		port = PIC1_DATA;
+	} else {
+		port = PIC2_DATA;
+		irq -= 8;
+	}
+
+	mask = inb(port) | (1 << irq);
+	outb(mask, port);
+}
+
+void unmask_irq(int irq)
+{
+	int port;
+	unsigned char mask;
+
+	if(irq < 8) {
+		port = PIC1_DATA;
+	} else {
+		port = PIC2_DATA;
+		irq -= 8;
+	}
+
+	mask = inb(port) & ~(1 << irq);
+	outb(mask, port);
+}
+
+
 void end_of_irq(int irq)
 {
 	int intr_state = get_intr_flag();
@@ -186,3 +263,10 @@ void end_of_irq(int irq)
 
 	set_intr_flag(intr_state);
 }
+
+#ifdef ENABLE_GDB_STUB
+void exceptionHandler(int id, void (*func)())
+{
+	set_intr_entry(id, func);
+}
+#endif