1 files changed, 140 insertions, 0 deletions
diff --git a/firmware/irq.c b/firmware/irq.c
new file mode 100644
index 0000000..9fc1735
--- /dev/null
+++ b/firmware/irq.c
@@ -0,0 +1,140 @@
+// This is free and unencumbered software released into the public domain.
+//
+// Anyone is free to copy, modify, publish, use, compile, sell, or
+// distribute this software, either in source code form or as a compiled
+// binary, for any purpose, commercial or non-commercial, and by any
+// means.
+
+#include "firmware.h"
+
+uint32_t *irq(uint32_t *regs, uint32_t irqs)
+{
+	static unsigned int ext_irq_4_count = 0;
+	static unsigned int ext_irq_5_count = 0;
+	static unsigned int timer_irq_count = 0;
+
+	// checking compressed isa q0 reg handling
+	if ((irqs & 6) != 0) {
+		uint32_t pc = (regs[0] & 1) ? regs[0] - 3 : regs[0] - 4;
+		uint32_t instr = *(uint16_t*)pc;
+
+		if ((instr & 3) == 3)
+			instr = instr | (*(uint16_t*)(pc + 2)) << 16;
+
+		if (((instr & 3) != 3) != (regs[0] & 1)) {
+			print_str("Mismatch between q0 LSB and decoded instruction word! q0=0x");
+			print_hex(regs[0], 8);
+			print_str(", instr=0x");
+			if ((instr & 3) == 3)
+				print_hex(instr, 8);
+			else
+				print_hex(instr, 4);
+			print_str("\n");
+			__asm__ volatile ("ebreak");
+		}
+	}
+
+	if ((irqs & (1<<4)) != 0) {
+		ext_irq_4_count++;
+		// print_str("[EXT-IRQ-4]");
+	}
+
+	if ((irqs & (1<<5)) != 0) {
+		ext_irq_5_count++;
+		// print_str("[EXT-IRQ-5]");
+	}
+
+	if ((irqs & 1) != 0) {
+		timer_irq_count++;
+		// print_str("[TIMER-IRQ]");
+	}
+
+	if ((irqs & 6) != 0)
+	{
+		uint32_t pc = (regs[0] & 1) ? regs[0] - 3 : regs[0] - 4;
+		uint32_t instr = *(uint16_t*)pc;
+
+		if ((instr & 3) == 3)
+			instr = instr | (*(uint16_t*)(pc + 2)) << 16;
+
+		print_str("\n");
+		print_str("------------------------------------------------------------\n");
+
+		if ((irqs & 2) != 0) {
+			if (instr == 0x00100073 || instr == 0x9002) {
+				print_str("EBREAK instruction at 0x");
+				print_hex(pc, 8);
+				print_str("\n");
+			} else {
+				print_str("Illegal Instruction at 0x");
+				print_hex(pc, 8);
+				print_str(": 0x");
+				print_hex(instr, ((instr & 3) == 3) ? 8 : 4);
+				print_str("\n");
+			}
+		}
+
+		if ((irqs & 4) != 0) {
+			print_str("Bus error in Instruction at 0x");
+			print_hex(pc, 8);
+			print_str(": 0x");
+			print_hex(instr, ((instr & 3) == 3) ? 8 : 4);
+			print_str("\n");
+		}
+
+		for (int i = 0; i < 8; i++)
+		for (int k = 0; k < 4; k++)
+		{
+			int r = i + k*8;
+
+			if (r == 0) {
+				print_str("pc  ");
+			} else
+			if (r < 10) {
+				print_chr('x');
+				print_chr('0' + r);
+				print_chr(' ');
+				print_chr(' ');
+			} else
+			if (r < 20) {
+				print_chr('x');
+				print_chr('1');
+				print_chr('0' + r - 10);
+				print_chr(' ');
+			} else
+			if (r < 30) {
+				print_chr('x');
+				print_chr('2');
+				print_chr('0' + r - 20);
+				print_chr(' ');
+			} else {
+				print_chr('x');
+				print_chr('3');
+				print_chr('0' + r - 30);
+				print_chr(' ');
+			}
+
+			print_hex(regs[r], 8);
+			print_str(k == 3 ? "\n" : "    ");
+		}
+
+		print_str("------------------------------------------------------------\n");
+
+		print_str("Number of fast external IRQs counted: ");
+		print_dec(ext_irq_4_count);
+		print_str("\n");
+
+		print_str("Number of slow external IRQs counted: ");
+		print_dec(ext_irq_5_count);
+		print_str("\n");
+
+		print_str("Number of timer IRQs counted: ");
+		print_dec(timer_irq_count);
+		print_str("\n");
+
+		__asm__ volatile ("ebreak");
+	}
+
+	return regs;
+}
+