
This is an Etherboot option ROM for the rtl8139 NIC.  It has a few
non-standard settings, most to do with timeouts and when to give up,
and for stricter DHCP spec compliance.

Rom-o-matic.net will provide this image at the following URL:

http://rom-o-matic.net/5.4.3/build.php?version=5.4.3&F=ignore&nic=rtl8139%3Artl8139+--+%5B0x10ec%2C0x8139%5D&ofmt=Binary+ROM+Image%28.zrom%29&arch=i386&ASK_BOOT=-1&BOOT_FIRST=BOOT_NIC&BOOT_SECOND=BOOT_NOTHING&BOOT_THIRD=BOOT_NOTHING&BOOT_INDEX=0&STATIC_CLIENT_IP=&STATIC_SUBNET_MASK=&STATIC_SERVER_IP=&STATIC_GATEWAY_IP=&STATIC_BOOTFILE=&EXIT_ON_FILE_LOAD_ERROR=on&DHCP_CLIENT_ID=&DHCP_CLIENT_ID_LEN=&DHCP_CLIENT_ID_TYPE=&DHCP_USER_CLASS=&DHCP_USER_CLASS_LEN=&ALLOW_ONLY_ENCAPSULATED=on&DEFAULT_BOOTFILE=&CONGESTED=on&BACKOFF_LIMIT=7&TIMEOUT=180&TRY_FLOPPY_FIRST=0&EXIT_IF_NO_OFFER=on&TAGGED_IMAGE=on&ELF_IMAGE=on&PXE_IMAGE=on&DOWNLOAD_PROTO_TFTP=on&COMCONSOLE=0x3F8&CONSPEED=9600&COMPARM=0x03&PXE_EXPORT=on&CONFIG_PCI=on&CONFIG_ISA=on&BUILD_ID=&PCBIOS=on&PXE_DHCP_STRICT=on&A=Get+ROM

and the mkhex script in tools/firmware/hvmloader will make the header 
file from the downloaded image.
