1 files changed, 80 insertions, 0 deletions
diff --git a/src/shared/io.rs b/src/shared/io.rs
new file mode 100644
index 0000000..16f641c
--- /dev/null
+++ b/src/shared/io.rs
@@ -0,0 +1,80 @@
+//! I/O port functionality.
+
+/// Write 8 bits to port
+pub unsafe fn outb(port: u16, val: u8) {
+    asm!("outb %al, %dx" :: "{dx}"(port), "{al}"(val));
+}
+
+/// Read 8 bits from port
+pub unsafe fn inb(port: u16) -> u8 {
+    let ret: u8;
+    asm!("inb %dx, %al" : "={ax}"(ret) : "{dx}"(port) :: "volatile");
+    ret
+}
+
+/// Write 16 bits to port
+pub unsafe fn outw(port: u16, val: u16) {
+    asm!("outw %ax, %dx" :: "{dx}"(port), "{al}"(val));
+}
+
+/// Read 16 bits from port
+pub unsafe fn inw(port: u16) -> u16 {
+    let ret: u16;
+    asm!("inw %dx, %ax" : "={ax}"(ret) : "{dx}"(port) :: "volatile");
+    ret
+}
+
+/// Write 32 bits to port
+pub unsafe fn outl(port: u16, val: u32) {
+    asm!("outl %eax, %dx" :: "{dx}"(port), "{al}"(val));
+}
+
+/// Read 32 bits from port
+pub unsafe fn inl(port: u16) -> u32 {
+    let ret: u32;
+    asm!("inl %dx, %eax" : "={ax}"(ret) : "{dx}"(port) :: "volatile");
+    ret
+}
+
+
+// Write 8-bit array to port
+pub unsafe fn outsb(port: u16, buf: &[u8]) {
+    asm!("rep outsb (%esi), %dx"
+         :: "{ecx}"(buf.len()), "{dx}"(port), "{esi}"(buf.as_ptr())
+         : "ecx", "edi");
+}
+
+// Read 8-bit array from port
+pub unsafe fn insb(port: u16, buf: &mut [u8]) {
+    asm!("rep insb %dx, (%edi)"
+         :: "{ecx}"(buf.len()), "{dx}"(port), "{edi}"(buf.as_ptr())
+         : "ecx", "edi" : "volatile");
+}
+
+// Write 16-bit array to port
+pub unsafe fn outsw(port: u16, buf: &[u16]) {
+    asm!("rep outsw (%esi), %dx"
+         :: "{ecx}"(buf.len()), "{dx}"(port), "{esi}"(buf.as_ptr())
+         : "ecx", "edi");
+}
+
+// Read 16-bit array from port
+pub unsafe fn insw(port: u16, buf: &mut [u16]) {
+    asm!("rep insw %dx, (%edi)"
+         :: "{ecx}"(buf.len()), "{dx}"(port), "{edi}"(buf.as_ptr())
+         : "ecx", "edi" : "volatile");
+}
+
+// Write 32-bit array to port
+pub unsafe fn outsl(port: u16, buf: &[u32]) {
+    asm!("rep outsl (%esi), %dx"
+         :: "{ecx}"(buf.len()), "{dx}"(port), "{esi}"(buf.as_ptr())
+         : "ecx", "edi");
+}
+
+// Read 32-bit array from port
+pub unsafe fn insl(port: u16, buf: &mut [u32]) {
+    asm!("rep insl %dx, (%edi)"
+         :: "{ecx}"(buf.len()), "{dx}"(port), "{edi}"(buf.as_ptr())
+         : "ecx", "edi" : "volatile");
+}