From efb1cf0895d6c5019f5a88fa14b59afd030fefca Mon Sep 17 00:00:00 2001
From: Peter Mikkelsen <petermikkelsen10@gmail.com>
Date: Sun, 27 Jul 2025 15:33:22 +0200
Subject: Setup descriptor tables, and enable interrupts

---
 src/nasty.S | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 84 insertions(+), 1 deletion(-)

(limited to 'src/nasty.S')

diff --git a/src/nasty.S b/src/nasty.S
index 26732a3..3f1c569 100644
--- a/src/nasty.S
+++ b/src/nasty.S
@@ -1,7 +1,90 @@
 .intel_syntax noprefix
-
 .section .text
+
 .global halt
 halt:
 1:	hlt
 	jmp 1b
+
+
+.global set_gdt
+set_gdt:
+	lgdt [rdi]
+	push rsi
+	lea rax, 1f
+	push rax
+	retfq
+1:	mov ds, rdx
+	mov es, rdx
+	mov fs, rdx
+	mov gs, rdx
+	mov ss, rdx
+	ltr rcx
+	ret
+
+.global set_idt
+set_idt:
+	lidt [rdi]
+	ret
+
+.global disable_interrupts
+disable_interrupts:
+	cli
+	ret
+
+.global enable_interrupts
+enable_interrupts:
+	sti
+	ret
+
+#define DEFINE_ISRS \
+	ISR(0) \
+	ISR(1) \
+	ISR(2) \
+	ISR(3) \
+	ISR(4) \
+	ISR(5) \
+	ISR(6) \
+	ISR(7) \
+	ISR(8) \
+	ISR(9) \
+	ISR(10) \
+	ISR(11) \
+	ISR(12) \
+	ISR(13) \
+	ISR(14) \
+	ISR(15) \
+	ISR(16) \
+	ISR(17) \
+	ISR(18) \
+	ISR(19) \
+	ISR(20) \
+	ISR(21) \
+	ISR(22) \
+	ISR(23) \
+	ISR(24) \
+	ISR(25) \
+	ISR(26) \
+	ISR(27) \
+	ISR(28) \
+	ISR(29) \
+	ISR(30) \
+	ISR(31) 
+
+.extern interrupt_handler
+#define ISR(n)	\
+isr_stub_##n: \
+	mov rdi, n; \
+	call interrupt_handler; \
+	iretq;
+DEFINE_ISRS
+#undef ISR
+
+#define ISR(n) \
+	.quad isr_stub_##n;
+
+.section .data
+.global isr_stubs
+isr_stubs:
+DEFINE_ISRS
+#undef ISR
-- 
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