Bootable kernel skeleton

bootloader/x86/interrupts-i386.asm

@@ -0,0 +1,105 @@
+struc IDTEntry
+    .offsetl resw 1
+    .selector resw 1
+    .zero resb 1
+    .attribute resb 1
+    .offseth resw 1
+endstruc
+
+SECTION .text
+USE32
+
+interrupts:
+.first:
+    mov [.entry], byte 0
+    jmp dword .handle
+.second:
+%assign i 1
+%rep 255
+    mov [.entry], byte i
+    jmp dword .handle
+%assign i i+1
+%endrep
+.handle:
+    push ebp
+    push esi
+    push edi
+    push edx
+    push ecx
+    push ebx
+    push eax
+
+    push esp
+    push dword [.entry]
+
+    mov eax, gdt.kernel_data
+    mov ds, eax
+    mov es, eax
+    mov fs, eax
+    mov gs, eax
+
+    	call dword [.handler]
+
+    mov eax, gdt.user_data | 3
+    mov ds, eax
+    mov es, eax
+    mov fs, eax
+    mov eax, gdt.user_tls | 3
+    mov gs, eax
+
+    add esp, 8 ; Skip interrupt code and reg pointer
+
+    pop eax
+    pop ebx
+    pop ecx
+    pop edx
+    pop edi
+    pop esi
+    pop ebp
+
+    iretd
+
+.handler: dd 0
+.entry: dd 0
+
+idtr:
+    dw (idt.end - idt) + 1
+    dd idt
+
+idt:
+%assign i 0
+
+;Below system call
+%rep 128
+    istruc IDTEntry
+        at IDTEntry.offsetl, dw interrupts+(interrupts.second-interrupts.first)*i
+        at IDTEntry.selector, dw gdt.kernel_code
+        at IDTEntry.zero, db 0
+        at IDTEntry.attribute, db attrib.present | attrib.interrupt32
+        at IDTEntry.offseth, dw 0
+    iend
+%assign i i+1
+%endrep
+
+;System call
+istruc IDTEntry
+    at IDTEntry.offsetl, dw interrupts+(interrupts.second-interrupts.first)*i
+    at IDTEntry.selector, dw gdt.kernel_code
+    at IDTEntry.zero, db 0
+    at IDTEntry.attribute, db attrib.present | attrib.ring3 | attrib.interrupt32
+    at IDTEntry.offseth, dw 0
+iend
+%assign i i+1
+
+;Above system call
+%rep 127
+    istruc IDTEntry
+        at IDTEntry.offsetl, dw interrupts+(interrupts.second-interrupts.first)*i
+        at IDTEntry.selector, dw gdt.kernel_code
+        at IDTEntry.zero, db 0
+        at IDTEntry.attribute, db attrib.present | attrib.interrupt32
+        at IDTEntry.offseth, dw 0
+    iend
+%assign i i+1
+%endrep
+.end: