Move AHCI driver into separate drivers/ directory

src/drivers/ahci/fis.h

@@ -0,0 +1,49 @@
+#pragma once
+/// \file fis.h
+/// Definitions for Frame Information Structure types. (Not for pescatarians.)
+#include <stdint.h>
+
+
+namespace ahci {
+
+enum class ata_cmd : uint8_t;
+
+enum class fis_type : uint8_t
+{
+	register_h2d	= 0x27,
+	register_d2h	= 0x34,
+	dma_activate	= 0x39,
+	dma_setup		= 0x41,
+	data			= 0x46,
+	bist			= 0x58,
+	pio_setup		= 0x5f,
+	device_bits		= 0xa1
+};
+
+
+struct fis_register_h2d
+{
+	fis_type type;
+	uint8_t pm_port;  // high bit (0x80) is set for the command register flag
+	ata_cmd command;
+	uint8_t features;
+
+	uint8_t lba0;
+	uint8_t lba1;
+	uint8_t lba2;
+	uint8_t device;
+
+	uint8_t lba3;
+	uint8_t lba4;
+	uint8_t lba5;
+	uint8_t features2;
+
+	uint8_t count0;
+	uint8_t count1;
+	uint8_t icc;
+	uint8_t control;
+
+	uint32_t reserved;
+};
+
+} // namespace ahci