Feat: Keyboard strokes working and in buffer

boot/elevator.asm

@@ -1,6 +1,10 @@
 ; File: elevator.asm
 ; Stage 2 Bootloader - No size limit!
 ; Job: Load kernel, set up GDT, switch to 64-bit mode, jump to kernel
+%ifndef KERNEL_SECTORS
+%define KERNEL_SECTORS 10   ; fallback default if build.sh doesn't override it
+%endif
+
 [org 0x7e00]
 [bits 16]
 
@@ -104,7 +108,7 @@ load_kernel:
     
     ; Set up DAP (Disk Address Packet)
     mov word [dap_size], 0x10
-    mov word [dap_sectors], 10
+    mov word [dap_sectors], KERNEL_SECTORS
     mov word [dap_offset], 0x0000
     mov word [dap_segment], 0x1000
     mov dword [dap_lba_low], 6      ; LBA 6 = bytes 3072+ (sector 7 in CHS)
@@ -136,7 +140,7 @@ load_kernel:
     
     ; Read using CHS
     mov ah, 0x02           ; Read function
-    mov al, 10             ; Number of sectors
+    mov al, KERNEL_SECTORS             ; Number of sectors
     mov ch, 0              ; Cylinder 0
     mov cl, 7              ; Sector 7
     mov dh, 0              ; Head 0
@@ -490,7 +494,6 @@ pm_msg: db '[PM32] Setting up Long Mode...', 0
 ; 64-BIT LONG MODE
 ; ============================================================
 [bits 64]
-[extern __keyboard_buffer_push] ; External function to push key into keyboard buffer
 long_mode:
     ; Set up segments
     mov ax, 0x20
@@ -518,8 +521,6 @@ long_mode:
     mov rsi, before_kernel_msg
     call print_64
 
-    sti ; Enable interrupts before jumping to kernel
-
     ; JUMP TO KERNEL!
     call KERNEL_OFFSET
 
@@ -624,32 +625,6 @@ setup_pic:
 
     ret 
 
-; keyboard handler - Catch PIC interrupt
-keyboard_handler:
-    push rax
-    push rdx
-    push rdi
-    push r8
-
-    mov dx, 0x60
-    in al, dx
-
-    ; convert ASCII
-    ; assuming output on r8 (as an example)
-
-    ; Acording to x86_64 SystemV
-    mov rdi, r8
-    call __keyboard_buffer_push
-
-    mov al, 0x20
-    out 0x20, al
-
-    pop r8
-    pop rdi
-    pop rdx
-    pop rax
-    iretq
-
 ; Exception handler - shows what went wrong
 exception_handler:
     ; Save registers
@@ -707,6 +682,8 @@ exception_handler:
 
 ; Dummy interrupt handler for IRQs (not CPU exceptions)
 dummy_handler:
+    mov al, 0x20 
+    out 0x20, al  ; Send EOI to PIC 
     iretq
 
 idt_descriptor:

boot/kernel.asm

@@ -2,14 +2,79 @@
 ; Assembly entry point for the kernel
 [bits 64]
 [extern kmain]      ; kmain is defined in kernel.c
+[extern __keyboard_handle_scancode]
+[extern __bss_start]
+[extern __bss_end]
 
 global _start       ; Make _start visible to linker
 
 _start:
+    call fill_idt
+
+; IMPORTANT
+    ; Zero out the .bss section
+    cld
+    mov rdi, __bss_start
+    mov rcx, __bss_end
+    sub rcx, rdi
+    xor rax, rax
+    rep stosb
+
     ; We're already in 64-bit mode with stack set up
     ; Just call the C kernel
+    sti
     call kmain
     
     ; If kmain returns, hang
     jmp $
+    hlt
 
+
+; Set up a minimal IDT
+fill_idt:
+    ; Fill IDT with different handlers for different exceptions
+    mov rdi, 0x4210         ; IDT location
+    mov rax, keyboard_handler
+
+    mov word [rdi], ax              ; Offset low
+    mov word [rdi + 2], 0x18        ; Code segment
+    mov byte [rdi + 4], 0           ; IST
+    mov byte [rdi + 5], 0x8E        ; Present, interrupt gate
+    shr rax, 16
+    mov word [rdi + 6], ax          ; Offset middle
+    shr rax, 16
+    mov dword [rdi + 8], eax        ; Offset high
+    mov dword [rdi + 12], 0         ; Reserved
+    ret
+
+; keyboard handler - Catch PIC interrupt
+keyboard_handler:
+    push rax
+    push rdx
+    push rdi
+    push rcx
+    push rsi
+    push r8
+    push r9
+    push r10
+    push r11
+
+    mov dx, 0x60
+    in al, dx
+
+    mov dil, al
+    call __keyboard_handle_scancode
+
+    mov al, 0x20
+    out 0x20, al
+
+    pop r11
+    pop r10
+    pop r9
+    pop r8
+    pop rsi
+    pop rcx
+    pop rdi
+    pop rdx
+    pop rax
+    iretq