Date: Wed, 21 May 1997 14:17:04 -0400 (CDT) From: Eliezer Rodriguez Gonzalez <elie@intranet.one.gov.cu> To: questions@freebsd.org Subject: A question concerning a networking issue. (fwd) Message-ID: <Pine.BSF.3.91.970521141649.17780B-100000@intranet.one.gov.cu>
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Greetings from Havana: I have a no-name PCI network interface card (NIC). By saying no-name I mean it is not from one of the well known brands but it is from a so called SURECOM (of Taiwan), it is jumperless. I also have a FreeBSD 2.1.5 box, it is a AMD 486DX4 100 MHz with 16 RAM, an SCSI-II PCI controller Adaptec 2940, a SCSI-II Seagate Hard Disk (1 GB) and a SCSI-II Nec CDROM. Everything works very well but I have some doubts. My new PCI NIC (the one depected above) features popular Ethernet adapter emulation modes such as Novell NE2000, SMC/WD 8013EBT and 3Com EtherLink II/16 share memory access. It also features a mode called Surecom, after the name of the brand. FreeBSD 2.1.5 is not aware of this so called Surecom modes, it also knows certain types of well know PCI NIC's, that's why when probing for devices on pci bus the systems "sees" the NIC but there is no a proper driver to handle it. That's why I reconfigure the NIC to emulate a NE2000, the system then "saw" the NIC but just when probing for devices on the ISA bus, of course using the ed0 driver, it printed out the MAC address and the "type NE2000 (16 bit)".Apparently everything should work fine so far but it did not. So I decided to make a second test and for twice I ran the configuration utility of the NIC to reconfigure the working mode as a SMC/WD 8013 EBT, but with the same IRQ and I/O as before ( 11 & 340h). This time the system also "saw" the card as an ISA device (although it is a PCI ?) and the system printed out the MAC address once again and "type WD 8013 (8 bits)". Finally this time everything worked fine since I was able to ping hosts on my network. But it happens that all these tests achieved confused me a lot. So here you are the quetions I'm asking now: Why although the NIC features a PCI bus, when emulating NE2000 etc the system "sees" the card as an ISA device and not as a PCI ? Does it means that althoug it is inserted in a PCI slot it is no using the 32 bits bandwith of the bus when transferring data to the PC ? I'm sure there are certain knowledge concerning emulation modes I need to know in order to anderstand what happened here. I also would like to know a little bit more about the different techniques use by NIC's in order to transfer data from itself to the computer so is there is any "paper" in the internet covering that issue I would like to know where it is in order to obtain a copy. My apologies for bothering you with such questions but since I'm running FreeBSD I don't have any one else to ask them instead. Thanks in advance. Bye. ======================================= Ing. Eliezer Rodriguez Gonzalez Grupo de Redes ONERED Oficina Nacional de Estadisticas E-mail: elie@intranet.one.gov.cu Voz: 30-00-75; 30-50-21 ext: 254 =======================================
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