amd64: barely boot into kernel code

1 files changed, 22 insertions, 0 deletions

diff --git a/src/kernel/arch/amd64/port_io.h b/src/kernel/arch/amd64/port_io.h
new file mode 100644
index 0000000..eac9331
--- /dev/null
+++ b/src/kernel/arch/amd64/port_io.h
@@ -0,0 +1,22 @@
+#include <stdint.h>
+
+static inline void port_out8(uint16_t port, uint8_t val) {
+	asm volatile("outb %0, %1" : : "a" (val), "Nd" (port));
+}
+
+static inline void port_out16(uint16_t port, uint16_t val) {
+	asm volatile("outw %0, %1" : : "a" (val), "Nd" (port));
+}
+
+static inline uint8_t port_in8(uint16_t port) {
+	uint8_t val;
+	asm volatile("inb %1, %0" : "=a" (val) : "Nd" (port));
+	return val;
+}
+
+static inline uint16_t port_in16(uint16_t port) {
+	uint16_t val;
+	asm volatile("inw %1, %0" : "=a" (val) : "Nd" (port));
+	return val;
+}
+