/*
 * Constants etc. for the Bochs/Etherboot pseudo-NIC
 * 
 * This header file must be valid C and C++.
 *
 * Operation of the pseudo-NIC (PNIC) is pretty simple.  To write a
 * command plus data, first write the length of the data to
 * PNIC_REG_LEN, then write the data a byte at a type to
 * PNIC_REG_DATA, then write the command code to PNIC_REG_CMD.  The
 * status will be available from PNIC_REG_STAT.  The length of any
 * data returned will be in PNIC_REG_LEN and can be read a byte at a
 * time from PNIC_REG_DATA.
 */

/*
 * PCI parameters
 */
#define PNIC_PCI_VENDOR 0xfefe  /* Hopefully these won't clash with */
#define PNIC_PCI_DEVICE 0xefef  /* any real PCI device IDs.         */

/*
 * 'Hardware' register addresses, offset from io_base
 */
#define PNIC_REG_CMD    0x00    /* Command register, 2 bytes, write only */
#define PNIC_REG_STAT   0x00    /* Status register, 2 bytes, read only */
#define PNIC_REG_LEN    0x02    /* Length register, 2 bytes, read-write */
#define PNIC_REG_DATA   0x04    /* Data port, 1 byte, read-write */
/*
 * PNIC_MAX_REG used in Bochs to claim i/o space
 */
#define PNIC_MAX_REG    0x04

/*
 * Command code definitions: write these into PNIC_REG_CMD
 */
#define PNIC_CMD_NOOP           0x0000
#define PNIC_CMD_API_VER        0x0001
#define PNIC_CMD_READ_MAC       0x0002
#define PNIC_CMD_RESET          0x0003
#define PNIC_CMD_XMIT           0x0004
#define PNIC_CMD_RECV           0x0005
#define PNIC_CMD_RECV_QLEN      0x0006
#define PNIC_CMD_MASK_IRQ       0x0007
#define PNIC_CMD_FORCE_IRQ      0x0008

/*
 * Status code definitions: read these from PNIC_REG_STAT
 *
 * We avoid using status codes that might be confused with
 * randomly-read data (e.g. 0x0000, 0xffff etc.)
 */
#define PNIC_STATUS_OK          0x4f4b          /* 'OK' */
#define PNIC_STATUS_UNKNOWN_CMD 0x3f3f          /* '??' */

/*
 * Other miscellaneous information
 */

#define PNIC_API_VERSION        0x0101          /* 1.1 */