3 files changed, 154 insertions, 0 deletions
diff --git a/kernel/boot/idt/exceptions.cc b/kernel/boot/idt/exceptions.cc
new file mode 100644
index 0000000..79ffd68
--- /dev/null
+++ b/kernel/boot/idt/exceptions.cc
@@ -0,0 +1,36 @@
+/*
+ * bubbl
+ * Copyright (C) 2025  Raghuram Subramani <raghus2247@gmail.com>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include <boot/idt.h>
+#include <common.h>
+#include <kernel/halt.h>
+#include <libk/stdio.h>
+#include <stdbool.h>
+
+namespace IDT
+{
+
+void
+exception_handler(void)
+{
+  ASSERT_NOT_REACHED();
+  while (true)
+    __asm__ volatile("cli; hlt");
+}
+
+}
diff --git a/kernel/boot/idt/idt.cc b/kernel/boot/idt/idt.cc
new file mode 100644
index 0000000..e640fd5
--- /dev/null
+++ b/kernel/boot/idt/idt.cc
@@ -0,0 +1,46 @@
+/*
+ * bubbl
+ * Copyright (C) 2025  Raghuram Subramani <raghus2247@gmail.com>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include <boot/idt.h>
+#include <kernel/io.h>
+
+namespace IDT
+{
+
+extern "C" void *isr_stub_table[];
+
+entry_t l_entries[256];
+descriptor_t descriptor = { sizeof(l_entries) - 1, l_entries };
+
+void
+load(void)
+{
+  for (uint16_t i = 0; i < 256; i++)
+    l_entries[i] = (entry_t) { 0 };
+
+  /* The first 32 entries are exceptions */
+  for (uint8_t i = 0; i < 32; i++) {
+    entry_t idt_entry = IDT_ENTRY((uint32_t) isr_stub_table[i], 0x8E);
+    l_entries[i] = idt_entry;
+  }
+
+  __asm__ volatile("lidt %0" ::"m"(descriptor));
+  __asm__ volatile("sti");
+}
+
+}
diff --git a/kernel/boot/idt/isr.s b/kernel/boot/idt/isr.s
new file mode 100644
index 0000000..925bb27
--- /dev/null
+++ b/kernel/boot/idt/isr.s
@@ -0,0 +1,72 @@
+;;
+;; bubbl
+;; Copyright (C) 2025  Raghuram Subramani <raghus2247@gmail.com>
+;;
+;; 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 <http://www.gnu.org/licenses/>.
+;;
+
+extern exception_handler;
+
+global isr_stub_table
+isr_stub_table:
+%assign i 0
+%rep 32
+dd ISR_%+i
+%assign i i+1
+%endrep
+
+%macro ISR_WITH_ERROR 1
+ISR_%+%1:
+  call exception_handler
+  iret
+%endmacro
+
+%macro ISR_NO_ERROR 1
+ISR_%+%1:
+  call exception_handler
+  iret
+%endmacro
+
+ISR_NO_ERROR 0
+ISR_NO_ERROR 1
+ISR_NO_ERROR 2
+ISR_NO_ERROR 3
+ISR_NO_ERROR 4
+ISR_NO_ERROR 5
+ISR_NO_ERROR 6
+ISR_NO_ERROR 7
+ISR_WITH_ERROR 8
+ISR_NO_ERROR 9
+ISR_WITH_ERROR 10
+ISR_WITH_ERROR 11
+ISR_WITH_ERROR 12
+ISR_WITH_ERROR 13
+ISR_WITH_ERROR 14
+ISR_NO_ERROR 15
+ISR_NO_ERROR 16
+ISR_WITH_ERROR 17
+ISR_NO_ERROR 18
+ISR_NO_ERROR 19
+ISR_NO_ERROR 20
+ISR_NO_ERROR 21
+ISR_NO_ERROR 22
+ISR_NO_ERROR 23
+ISR_NO_ERROR 24
+ISR_NO_ERROR 25
+ISR_NO_ERROR 26
+ISR_NO_ERROR 27
+ISR_NO_ERROR 28
+ISR_NO_ERROR 29
+ISR_WITH_ERROR 30
+ISR_NO_ERROR 31