...

makefile

@@ -6,8 +6,8 @@ CFLAGS 	= -m64 -ffreestanding -fno-builtin -Wall -Wextra -Wshadow -std=c23 -g
 LDFLAGS	= -g
 ASFLAGS	= -f elf64 -g -F dwarf
 
-SRC_C   := src/kernel.c src/string.c src/vga.c src/idt.c src/keyboard.c
+SRC_C   := src/kernel.c src/string.c src/vga.c src/interrupts.c src/keyboard.c
-SRC_ASM := src/boot.asm src/idt_stub.asm
+SRC_ASM := src/boot.asm src/idt.asm
 
 OBJ_C   := $(SRC_C:src/%.c=.build/%.o)
 OBJ_ASM := $(SRC_ASM:src/%.asm=.build/%.o)
@@ -28,7 +28,7 @@ build-dir:
 	cp .build/kernel .build/nub-os/boot/
 	grub-mkrescue -o .build/nub-os.iso .build/nub-os/
 
-.build/kernel: $(OBJS) | linker.ld
+.build/kernel: $(OBJS)
 	$(LD) $(LDFLAGS) -T linker.ld -o $@ $^
 
 .build/%.o: src/%.c | build-dir

src/boot.asm

@@ -26,17 +26,6 @@ section .bss
     pd:
         resb 4096
 
-section .bss
-    align 8
-    idt64:
-        resb 4096
-
-section .data
-    align 8
-    idt64_descriptor:
-        dw 4095     ; IDT size (256 entries * 16 bytes - 1)
-        dq idt64    ; IDT base address
-
 section .data
     align 8
     gdt64:
@@ -154,8 +143,6 @@ section .text
         mov ss, ax
 
         call setup_idt
-        sti
-
         call kernel_main
     .hang:
         hlt

src/idt.asm

@@ -14,17 +14,37 @@ isr_stub_%1:
     jmp isr_common
 %endmacro
 
-%macro GENERATE_NUB_ISR_NOERR 2
+section .bss
-    %assign i %1
+    align 4096
-    %rep (%2 - %1 + 1)
+    idt64:
-        ISR_NOERR i
+        resb 4096
-        %assign i i+1
+
-    %endrep
+section .data
-%endmacro
+    idt64_descriptor:
+        dw 4095
+        dq idt64
 
 section .text
     bits 64
     setup_idt:
+        mov rdi, idt64
+        mov rsi, isr_stub_table
+        mov rcx, 256
+    .loop:
+        mov rax, [rsi]
+        mov [rdi], ax
+        mov word [rdi + 2], 0x08
+        mov word [rdi + 4], 0x8E00
+        shr rax, 16
+        mov [rdi + 6], ax
+        shr rax, 16
+        mov [rdi + 8], eax
+        mov dword [rdi + 12], 0
+        add rdi, 16
+        add rsi, 8
+        loop .loop
+        lidt [idt64_descriptor]
+        sti
         ret
 
     isr_common:
@@ -43,8 +63,10 @@ section .text
         push r13
         push r14
         push r15
+
         mov rdi, rsp
         call handle_isr
+
         pop r15
         pop r14
         pop r13
@@ -60,10 +82,11 @@ section .text
         pop rcx
         pop rbx
         pop rax
+
         add rsp, 16
         iretq
 
-    ; CPU exceptions 0-31. Some of there contain error codes, so we define them manually
+    ; CPU exceptions 0-31. Some of these contain error codes, so we define them manually
     ISR_NOERR   0
     ISR_NOERR   1
     ISR_NOERR   2
@@ -97,18 +120,17 @@ section .text
     ISR_ERR     30
     ISR_NOERR   31
 
-    ; The remaining isr-s does not have an error code
+    ; Hardware interrupts and user-defined interrupts (32-255). These don't have error codes
-    GENERATE_ISRS 32, 255
+    %assign i 32
-
+    %rep 224
-%macro GENERATE_ISR_TABLE 2
+        ISR_NOERR i
-    %assign i %1
-    %rep (%2 - %1 + 1)
-        dq isr_stub_%[i]
         %assign i i+1
     %endrep
-%endmacro
 
 section .data
-    global isr_stub_table
     isr_stub_table:
-    GENERATE_ISR_TABLE 0, 255
+        %assign i 0
+        %rep 256
+            dq isr_stub_%[i]
+            %assign i i+1
+        %endrep

src/idt_stub.asm

@@ -1,109 +0,0 @@
-extern handle_isr
-
-isr_common:
-    push rax
-    push rbx
-    push rcx
-    push rdx
-    push rsi
-    push rdi
-    push rbp
-    push r8
-    push r9
-    push r10
-    push r11
-    push r12
-    push r13
-    push r14
-    push r15
-
-    mov rdi, rsp
-    call handle_isr
-
-    pop r15
-    pop r14
-    pop r13
-    pop r12
-    pop r11
-    pop r10
-    pop r9
-    pop r8
-    pop rbp
-    pop rdi
-    pop rsi
-    pop rdx
-    pop rcx
-    pop rbx
-    pop rax
-
-    add rsp, 16
-    iretq
-
-%macro ISR_NOERR 1
-isr_stub_%1:
-    push qword 0
-    push qword %1
-    jmp isr_common
-%endmacro
-
-%macro ISR_ERR 1
-isr_stub_%1:
-    push qword %1
-    jmp isr_common
-%endmacro
-
-; CPU exceptions 0-31
-ISR_NOERR   0
-ISR_NOERR   1
-ISR_NOERR   2
-ISR_NOERR   3
-ISR_NOERR   4
-ISR_NOERR   5
-ISR_NOERR   6
-ISR_NOERR   7
-ISR_ERR     8
-ISR_NOERR   9
-ISR_ERR     10
-ISR_ERR     11
-ISR_ERR     12
-ISR_ERR     13
-ISR_ERR     14
-ISR_NOERR   15
-ISR_NOERR   16
-ISR_ERR     17
-ISR_NOERR   18
-ISR_NOERR   19
-ISR_NOERR   20
-ISR_NOERR   21
-ISR_NOERR   22
-ISR_NOERR   23
-ISR_NOERR   24
-ISR_NOERR   25
-ISR_NOERR   26
-ISR_NOERR   27
-ISR_NOERR   28
-ISR_NOERR   29
-ISR_ERR     30
-ISR_NOERR   31
-
-%macro GENERATE_ISRS 2
-    %assign i %1
-    %rep (%2 - %1 + 1)
-        ISR_NOERR i
-        %assign i i+1
-    %endrep
-%endmacro
-
-GENERATE_ISRS 32, 255
-
-%macro GENERATE_ISR_TABLE 2
-    %assign i %1
-    %rep (%2 - %1 + 1)
-        dq isr_stub_%[i]
-        %assign i i+1
-    %endrep
-%endmacro
-
-global isr_stub_table
-isr_stub_table:
-GENERATE_ISR_TABLE 0, 255

src/interrupts.c

@@ -1,4 +1,4 @@
-#include "idt.h"
+#include "interrupts.h"
 #include "vga.h"
 #include "kernel.h"
 
@@ -7,12 +7,6 @@
 #define PIC2_COMMAND 0xA0
 #define PIC2_DATA 0xA1
 
-typedef struct
-{
-    u16 limit;
-    u64 base;
-} __attribute__((packed)) idtr_t;
-
 static irq_handler_t irq_handlers[16] = {0};
 
 static const char* exception_messages[32] = {
@@ -84,7 +78,11 @@ void handle_isr(isr_frame_t* frame)
         vga_print_uint(frame->err_code);
         vga_print("\n");
 
-        __asm__ volatile("cli; hlt");
+        while (true)
+        {
+            __asm__ volatile ("cli");
+            __asm__ volatile ("hlt");
+        }
     }
     else if (frame->int_no < 48)
     {

src/kernel.c

@@ -1,5 +1,5 @@
 #include "kernel.h"
-#include "idt.h"
+#include "interrupts.h"
 #include "keyboard.h"
 #include "vga.h"
 
@@ -17,11 +17,17 @@ void kernel_main()
 
     while (true)
     {
+        __asm__ volatile ("cli");
+        __asm__ volatile ("hlt");
     }
 }
 
 void kernel_panic()
 {
     vga_print("Kernel panic!\n");
-    __asm__ volatile("cli; hlt");
+    while (true)
+    {
+        __asm__ volatile ("cli");
+        __asm__ volatile ("hlt");
+    }
 }

src/keyboard.c

@@ -1,5 +1,5 @@
 #include "keyboard.h"
-#include "idt.h"
+#include "interrupts.h"
 #include "kernel.h"
 #include "vga.h"