Feat: Starting of ACTUALL keyboard inturruptions with PIC

boot/elevator.asm

@@ -1,8 +1,6 @@
 ; File: elevator.asm
 ; Stage 2 Bootloader - No size limit!
 ; Job: Load kernel, set up GDT, switch to 64-bit mode, jump to kernel
-
-
 [org 0x7e00]
 [bits 16]
 
@@ -492,6 +490,7 @@ 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
@@ -506,6 +505,9 @@ long_mode:
     ; Point all interrupts to a dummy handler
     call setup_idt
 
+    ; Set up PIC to avoid spurious interrupts
+    call setup_pics
+
     ; Print message on line 3
     mov rdi, 0xb8000 + (160 * 2)
     mov rsi, lm_msg
@@ -516,6 +518,8 @@ long_mode:
     mov rsi, before_kernel_msg
     call print_64
 
+    sti ; Enable interrupts before jumping to kernel
+
     ; JUMP TO KERNEL!
     call KERNEL_OFFSET
 
@@ -572,6 +576,80 @@ setup_idt:
     lidt [idt_descriptor]
     ret
 
+setup_pics:
+    ; Loads master values into rdi/rsi/rdx/rcx
+    mov rdi, 0x20        ; Master command port 
+    mov rsi, 0x21        ; Master data port 
+    mov rdx, 0x20        ; Master offset 
+    mov rcx, 0x04        ; Master ICW3 value 
+    call setup_pic
+
+    ; Loads slave values into rdi/rsi/rdx/rcx
+    mov rdi, 0xA0        ; Slave command port
+    mov rsi, 0xA1        ; Slave data port
+    mov rdx, 0x28        ; Slave offset
+    mov rcx, 0x02        ; Slave ICW3 values
+    call setup_pic
+
+    ret
+; Set up PIC
+;   input:
+;       rdi - command port
+;       rsi - data port
+;       rdx - offset
+;       rcx - ICW3 value
+;  Master: 0x11, 0x20, 0x04, 0x01 
+;  Slave:  0x11, 0x28, 0x02, 0x01
+setup_pic:
+    ; Step 0: rescue the offset FIRST, before dx gets reused for ports
+    mov r8b, dl        ; r8b now safely holds the offset byte, forever
+
+    ; Step 1: ICW1 -> command port
+    mov dx, di
+    mov al, 0x11
+    out dx, al
+
+    ; Step 2: ICW2 (offset) -> data port
+    mov dx, si        
+    mov al, r8b
+    out dx, al
+
+    ; Step 3: ICW3 -> data port (dx is UNCHANGED since step 2 — no reload needed)
+    mov al, cl        
+    out dx, al
+
+    ; Step 4: ICW4 -> data port (still no reload needed)
+    mov al, 0x01
+    out dx, al
+
+    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