text: #ifndef PXE_H
  #define PXE_H
  
  FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  
  #include "pxe_types.h"
  #include "pxe_error.h"
  #include "pxe_api.h"
  #include <ipxe/device.h>
  #include <ipxe/tables.h>
  
  /** PXE API invalid function code */
  #define PXENV_UNKNOWN 0xffff
  
  /** Parameter block for pxenv_unknown() */
  struct s_PXENV_UNKNOWN {
  	PXENV_STATUS_t Status;			/**< PXE status code */
  } __attribute__ (( packed ));
  
  typedef struct s_PXENV_UNKNOWN PXENV_UNKNOWN_t;
  
  /* Union used for PXE API calls; we don't know the type of the
   * structure until we interpret the opcode.  Also, Status is available
   * in the same location for any opcode, and it's convenient to have
   * non-specific access to it.
   */
  union u_PXENV_ANY {
  	/* Make it easy to read status for any operation */
  	PXENV_STATUS_t				Status;
  	struct s_PXENV_UNKNOWN			unknown;
  	struct s_PXENV_UNLOAD_STACK		unload_stack;
  	struct s_PXENV_GET_CACHED_INFO		get_cached_info;
  	struct s_PXENV_TFTP_READ_FILE		restart_tftp;
  	struct s_PXENV_START_UNDI		start_undi;
  	struct s_PXENV_STOP_UNDI		stop_undi;
  	struct s_PXENV_START_BASE		start_base;
  	struct s_PXENV_STOP_BASE		stop_base;
  	struct s_PXENV_TFTP_OPEN		tftp_open;
  	struct s_PXENV_TFTP_CLOSE		tftp_close;
  	struct s_PXENV_TFTP_READ		tftp_read;
  	struct s_PXENV_TFTP_READ_FILE		tftp_read_file;
  	struct s_PXENV_TFTP_GET_FSIZE		tftp_get_fsize;
  	struct s_PXENV_UDP_OPEN			udp_open;
  	struct s_PXENV_UDP_CLOSE		udp_close;
  	struct s_PXENV_UDP_WRITE		udp_write;
  	struct s_PXENV_UDP_READ			udp_read;
  	struct s_PXENV_UNDI_STARTUP		undi_startup;
  	struct s_PXENV_UNDI_CLEANUP		undi_cleanup;
  	struct s_PXENV_UNDI_INITIALIZE		undi_initialize;
  	struct s_PXENV_UNDI_RESET		undi_reset_adapter;
  	struct s_PXENV_UNDI_SHUTDOWN		undi_shutdown;
  	struct s_PXENV_UNDI_OPEN		undi_open;
  	struct s_PXENV_UNDI_CLOSE		undi_close;
  	struct s_PXENV_UNDI_TRANSMIT		undi_transmit;
  	struct s_PXENV_UNDI_SET_MCAST_ADDRESS	undi_set_mcast_address;
  	struct s_PXENV_UNDI_SET_STATION_ADDRESS undi_set_station_address;
  	struct s_PXENV_UNDI_SET_PACKET_FILTER	undi_set_packet_filter;
  	struct s_PXENV_UNDI_GET_INFORMATION	undi_get_information;
  	struct s_PXENV_UNDI_GET_STATISTICS	undi_get_statistics;
  	struct s_PXENV_UNDI_CLEAR_STATISTICS	undi_clear_statistics;
  	struct s_PXENV_UNDI_INITIATE_DIAGS	undi_initiate_diags;
  	struct s_PXENV_UNDI_FORCE_INTERRUPT	undi_force_interrupt;
  	struct s_PXENV_UNDI_GET_MCAST_ADDRESS	undi_get_mcast_address;
  	struct s_PXENV_UNDI_GET_NIC_TYPE	undi_get_nic_type;
  	struct s_PXENV_UNDI_GET_IFACE_INFO	undi_get_iface_info;
  	struct s_PXENV_UNDI_GET_STATE		undi_get_state;
  	struct s_PXENV_UNDI_ISR			undi_isr;
  	struct s_PXENV_FILE_OPEN		file_open;
  	struct s_PXENV_FILE_CLOSE		file_close;
  	struct s_PXENV_FILE_SELECT		file_select;
  	struct s_PXENV_FILE_READ		file_read;
  	struct s_PXENV_GET_FILE_SIZE		get_file_size;
  	struct s_PXENV_FILE_EXEC		file_exec;
  	struct s_PXENV_FILE_API_CHECK		file_api_check;
  	struct s_PXENV_FILE_EXIT_HOOK		file_exit_hook;
  };
  
  typedef union u_PXENV_ANY PXENV_ANY_t;
  
  /** A PXE API call */
  struct pxe_api_call {
  	/** Entry point
  	 *
  	 * @v params		PXE API call parameters
  	 * @ret exit		PXE API call exit code
  	 */
  	PXENV_EXIT_t ( * entry ) ( union u_PXENV_ANY *params );
  	/** Length of parameters */
  	uint16_t params_len;
  	/** Opcode */
  	uint16_t opcode;
  };
  
  /** PXE API call table */
  #define PXE_API_CALLS __table ( struct pxe_api_call, "pxe_api_calls" )
  
  /** Declare a PXE API call */
  #define __pxe_api_call __table_entry ( PXE_API_CALLS, 01 )
  
  /**
   * Define a PXE API call
   *
   * @v _opcode		Opcode
   * @v _entry		Entry point
   * @v _params_type	Type of parameter structure
   * @ret call		PXE API call
   */
  #define PXE_API_CALL( _opcode, _entry, _params_type ) {			      \
  	.entry = ( ( ( ( PXENV_EXIT_t ( * ) ( _params_type *params ) ) NULL ) \
  		    == ( ( typeof ( _entry ) * ) NULL ) )		      \
  		   ? ( ( PXENV_EXIT_t ( * )				      \
  			 ( union u_PXENV_ANY *params ) ) _entry )	      \
  		   : ( ( PXENV_EXIT_t ( * )				      \
  			 ( union u_PXENV_ANY *params ) ) _entry ) ),	      \
  	.params_len = sizeof ( _params_type ),				      \
  	.opcode = _opcode,						      \
  	}
  
  /** An UNDI expansion ROM header */
  struct undi_rom_header {
  	/** Signature
  	 *
  	 * Must be equal to @c ROM_SIGNATURE
  	 */
  	UINT16_t Signature;
  	/** ROM length in 512-byte blocks */
  	UINT8_t ROMLength;
  	/** Unused */
  	UINT8_t unused[0x13];
  	/** Offset of the PXE ROM ID structure */
  	UINT16_t PXEROMID;
  	/** Offset of the PCI ROM structure */
  	UINT16_t PCIRHeader;
  } __attribute__ (( packed ));
  
  /** Signature for an expansion ROM */
  #define ROM_SIGNATURE 0xaa55
  
  /** An UNDI ROM ID structure */
  struct undi_rom_id {
  	/** Signature
  	 *
  	 * Must be equal to @c UNDI_ROM_ID_SIGNATURE
  	 */
  	UINT32_t Signature;
  	/** Length of structure */
  	UINT8_t StructLength;
  	/** Checksum */
  	UINT8_t StructCksum;
  	/** Structure revision
  	 *
  	 * Must be zero.
  	 */
  	UINT8_t StructRev;
  	/** UNDI revision
  	 *
  	 * Version 2.1.0 is encoded as the byte sequence 0x00, 0x01, 0x02.
  	 */
  	UINT8_t UNDIRev[3];
  	/** Offset to UNDI loader */
  	UINT16_t UNDILoader;
  	/** Minimum required stack segment size */
  	UINT16_t StackSize;
  	/** Minimum required data segment size */
  	UINT16_t DataSize;
  	/** Minimum required code segment size */
  	UINT16_t CodeSize;
  } __attribute__ (( packed ));
  
  /** Signature for an UNDI ROM ID structure */
  #define UNDI_ROM_ID_SIGNATURE \
  	( ( 'U' << 0 ) + ( 'N' << 8 ) + ( 'D' << 16 ) + ( 'I' << 24 ) )
  
  /** A PCI expansion header */
  struct pcir_header {
  	/** Signature
  	 *
  	 * Must be equal to @c PCIR_SIGNATURE
  	 */
  	uint32_t signature;
  	/** PCI vendor ID */
  	uint16_t vendor_id;
  	/** PCI device ID */
  	uint16_t device_id;
  } __attribute__ (( packed ));
  
  /** Signature for an UNDI ROM ID structure */
  #define PCIR_SIGNATURE \
  	( ( 'P' << 0 ) + ( 'C' << 8 ) + ( 'I' << 16 ) + ( 'R' << 24 ) )
  
  extern struct net_device *pxe_netdev;
  extern const char *pxe_cmdline;
  
  extern void pxe_set_netdev ( struct net_device *netdev );
  extern PXENV_EXIT_t pxenv_tftp_read_file ( struct s_PXENV_TFTP_READ_FILE
  					   *tftp_read_file );
  extern PXENV_EXIT_t undi_loader ( struct s_UNDI_LOADER *undi_loader );
  
  #endif /* PXE_H */
  