Initial AoE implementation. Limitations are:

Cannot yet handle reads of more than two sectors

  No retransmission

  No way to find out a target's MAC address (this proof of concept uses
  broadcasts)

These limitations shall not last long!  :)

src/include/gpxe/aoe.h

@@ -0,0 +1,124 @@
+#ifndef _GPXE_AOE_H
+#define _GPXE_AOE_H
+
+/** @file
+ *
+ * AoE protocol
+ *
+ */
+
+#include <stdint.h>
+#include <gpxe/list.h>
+#include <gpxe/if_ether.h>
+#include <gpxe/ata.h>
+
+/** An AoE ATA command */
+struct aoecmd {
+	/** AoE command flags */
+	uint8_t aflags;
+	/** ATA error/feature register */
+	uint8_t err_feat;
+	/** ATA sector count register */
+	uint8_t count;
+	/** ATA command/status register */
+	uint8_t cmd_stat;
+	/** Logical block address, in little-endian order */
+	union {
+		uint64_t u64;
+		uint8_t bytes[6];
+	} lba;
+	/** Data payload */
+	uint8_t data[0];
+} __attribute__ (( packed ));
+
+#define AOE_FL_EXTENDED	0x40	/**< LBA48 extended addressing */
+#define AOE_FL_DEV_HEAD	0x10	/**< Device/head flag */
+#define AOE_FL_ASYNC	0x02	/**< Asynchronous write */
+#define AOE_FL_WRITE	0x01	/**< Write command */
+
+/** An AoE header */
+struct aoehdr {
+	/** Protocol version number and flags */
+	uint8_t ver_flags;
+	/** Error code */
+	uint8_t error;
+	/** Major device number, in network byte order */
+	uint16_t major;
+	/** Minor device number */
+	uint8_t minor;
+	/** Command number */
+	uint8_t command;
+	/** Tag, in network byte order */
+	uint32_t tag;
+	/** Payload */
+	union {
+		/** ATA command */
+		struct aoecmd command[0];
+	} arg;
+} __attribute__ (( packed ));
+
+#define AOE_VERSION	0x10	/**< Version 1 */
+#define AOE_VERSION_MASK 0xf0	/**< Version part of ver_flags field */
+
+#define AOE_FL_RESPONSE	0x08	/**< Message is a response */
+#define AOE_FL_ERROR	0x04	/**< Command generated an error */
+
+#define AOE_MAJOR_BROADCAST 0xffff
+#define AOE_MINOR_BROADCAST 0xff
+
+#define AOE_CMD_ATA	0x00	/**< Issue ATA command */
+#define AOE_CMD_CONFIG	0x01	/**< Query Config Information */
+
+#define AOE_ERR_BAD_COMMAND	1 /**< Unrecognised command code */
+#define AOE_ERR_BAD_PARAMETER	2 /**< Bad argument parameter */
+#define AOE_ERR_UNAVAILABLE	3 /**< Device unavailable */
+#define AOE_ERR_CONFIG_EXISTS	4 /**< Config string present */
+#define AOE_ERR_BAD_VERSION	5 /**< Unsupported version */
+
+/** An AoE session */
+struct aoe_session {
+	/** List of all AoE sessions */
+	struct list_head list;
+
+	/** Network device */
+	struct net_device *netdev;
+	/** Major number */
+	uint16_t major;
+	/** Minor number */
+	uint8_t minor;
+	/** Target MAC address */
+	uint8_t target[ETH_ALEN];
+
+	/** Tag for current command */
+	uint32_t tag;
+	/** Current ATA command */
+	struct ata_command *command;
+	/** Status of the command */
+	int status;
+	/** Byte offset within command's data buffer */
+	unsigned int command_offset;
+};
+
+#define AOE_STATUS_ERR_MASK	0x0f /**< Error portion of status code */ 
+#define AOE_STATUS_PENDING	0x80 /**< Command pending */
+#define AOE_STATUS_UNDERRUN	0x40 /**< Buffer overrun */
+#define AOE_STATUS_OVERRUN	0x20 /**< Buffer underrun */
+
+/** Maximum number of sectors per packet */
+#define AOE_MAX_COUNT 2
+
+extern void aoe_open ( struct aoe_session *aoe );
+extern void aoe_close ( struct aoe_session *aoe );
+extern int aoe_issue ( struct aoe_session *aoe, struct ata_command *command );
+
+/** An AoE device */
+struct aoe_device {
+	/** ATA device interface */
+	struct ata_device ata;
+	/** AoE protocol instance */
+	struct aoe_session aoe;
+};
+
+extern int init_aoedev ( struct aoe_device *aoedev );
+
+#endif /* _GPXE_AOE_H */