IO: Add in/out declarations/definitions

I've forgotten to commit this when working on interrupts. The OS
won't build without these helpers.

They are used for now mostly to setup PICs.

Signed-off-by: Carlos Maiolino <[email protected]>

1 files changed, 56 insertions, 0 deletions

diff --git a/src/io/io.asm b/src/io/io.asm
new file mode 100644
index 0000000..37ad7eb
--- /dev/null
+++ b/src/io/io.asm
@@ -0,0 +1,56 @@
+section .asm
+
+global insb
+global insw
+global outb
+global outw
+
+insb:
+	push ebp
+	mov ebp, esp
+
+	xor eax, eax	; Zero out eax
+	mov dx, [ebp+8]
+	in al, dx
+
+	mov esp, ebp
+	pop ebp
+	ret
+
+insw:
+	push ebp
+	mov ebp, esp
+
+	xor eax, eax	; Zero out eax
+	mov dx, [ebp+8]
+	in ax, dx
+
+	mov esp, ebp
+	pop ebp
+	ret
+
+outb:
+	push ebp
+	mov ebp, esp
+
+	xor eax, eax
+	mov ax, [ebp+12]	; val to write
+	mov dx, [ebp+8]		; to this port
+	out dx, al
+
+	mov esp, ebp
+	pop ebp
+	ret
+
+outw:
+	push ebp
+	mov ebp, esp
+
+	xor eax, eax
+	mov ax, [ebp+12]	; val to write
+	mov dx, [ebp+8]		; to this port
+	out dx, ax
+
+	mov esp, ebp
+	pop ebp
+	ret