Configure PS/2 only if it is present

Author: Ian Seyler

src/drivers/ps2.asm

@@ -8,6 +8,11 @@
 
 ; -----------------------------------------------------------------------------
 ps2_init:
+	; Check if PS/2 is present via ACPI IAPC_BOOT_ARCH
+	mov ax, [os_boot_arch]
+	bt ax, 1			; 8042
+	jnc ps2_init_error
+
 	call ps2_flush			; Read any pending data
 
 	; Disable keyboard
@@ -62,6 +67,7 @@ ps2_init:
 	call ps2_mouse_init
 
 	; Set flag that the PS/2 keyboard was enabled
+	; TODO - Move to a ps2_keyboard_init function
 	or qword [os_SysConfEn], 1 << 0
 
 ps2_init_error:

src/init/64.asm

@@ -55,6 +55,8 @@ init_64:
 	mov esi, 0x00005090		; PCIe bus count
 	lodsw
 	mov [os_pcie_count], ax
+	lodsw
+	mov [os_boot_arch], ax 
 	xor eax, eax
 	mov esi, 0x00005604		; IOAPIC
 	lodsd
@@ -101,13 +103,22 @@ make_interrupt_gate_stubs:
 	dec ecx
 	jnz make_interrupt_gate_stubs
 
-	; Set up the IRQ handlers (Network IRQ handler is configured in init_net)
+	; Set up the IRQ handlers on enabled PS/2 devices
+	mov rbx, [os_SysConfEn]
+	bt ebx, 0
+	jnc init_64_no_ps2keyboard
 	mov edi, 0x21
 	mov rax, int_keyboard
 	call create_gate
+init_64_no_ps2keyboard:
+	bt ebx, 0
+	jnc init_64_no_ps2mouse
 	mov edi, 0x2C
 	mov rax, int_mouse
 	call create_gate
+init_64_no_ps2mouse:
+
+	; Set up IRQ handlers for CPUs
 	mov edi, 0x80
 	mov rax, ap_wakeup
 	call create_gate

src/sysvar.asm

@@ -132,6 +132,7 @@ os_ps2_mouse_buttons:	equ os_SystemVariables + 0x0218 ; Button state, bit 0 - le
 os_ps2_mouse_x:		equ os_SystemVariables + 0x021A ; Cursor screen position on X axis
 os_ps2_mouse_y:		equ os_SystemVariables + 0x021C ; Cursor screen position on Y axis
 os_ps2_mouse_count:	equ os_SystemVariables + 0x021E ; Byte counter
+os_boot_arch:		equ os_SystemVariables + 0x0220 ; Bit 0 set for legacy ports, bit 1 set for 60/64 support
 
 
 ; DB - Starting at offset 768, increments by 1