Handout

kernel/interrupt/handlers.asm

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+[SECTION .text]
+[EXTERN handle_keyboard]
+[GLOBAL handle_keyboard_asm]
+
+; entry point for an interrupt to trigger a kernelpanic
+;
+align 16
+handle_keyboard_asm:
+	; The interrupt may be triggered asynchronously, therefore the whole context
+	; has to be saved and restored, or the interrupted code might not be able to
+	; continue. The C++ compiler will only generates code to preserve
+	; non-scratch registers in the high-level interrupt handler -- the scratch
+	; registers have to be saved (and restored later) manually!
+	push rax
+	push rcx
+	push rdx
+	push rsi
+	push rdi
+	push r8
+	push r9
+	push r10
+	push r11
+
+	; Clear direction flag for string operations
+	cld
+	; Call the high-level handler routine
+	call handle_keyboard
+
+	; Restore scratch registers
+	pop r11
+	pop r10
+	pop r9
+	pop r8
+	pop rdi
+	pop rsi
+	pop rdx
+	pop rcx
+	pop rax
+	iretq