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Diffstat (limited to 'bsps/powerpc/mpc8260ads/net/README')
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diff --git a/bsps/powerpc/mpc8260ads/net/README b/bsps/powerpc/mpc8260ads/net/README deleted file mode 100644 index d5722557c3..0000000000 --- a/bsps/powerpc/mpc8260ads/net/README +++ /dev/null @@ -1,55 +0,0 @@ -Networking with HDLC -==================== - -Author: Andy Dachs <a.dachs@sstl.co.uk> -Date: 31st August 2001 -Surrey Satellite Technology Limited - - -The network support in this BSP is not Ethernet support. The -"network" referred to here is a point to point HDLC communication link. -The ADS board does have a 10/100 ethernet port and it would be nice to -get support for that added. - -My requirement is for a WAN so I need the ability to send IP frames over -HDLC. Ultimately this will end up as frame relay support but in the meantime -I'm simply wrapping up the IP packet inside an HDLC frame. There is no -addressing mechanism or mac address attached to the start of the frame. - -This is what is physically transmitted: -<FLAG><IP Frame><CRC><FLAG> - - -The physical link consists of four lines, -TX DATA : Data transmitted -TX CLOCK: Clock for transmitted data. Data source provides clock. -RX DATA : Received data -RX CLOCK: Clock for received data. Data sink accepts clock. - -To connect two entities you require a NULL modem arrangement, i.e. TX data -and Tx clock from one end go into RX data and Rx clock on the other end. - -The MPC8260ADS side of the link is implemented using SCC3 in HDLC mode. The -TX clock is generated by BRG4. The RX clock in input to the board on the CLK5 -input. I built a LVTTL to RS422 converter. - -The other end of the link is a Windows NT PC with WANic400 synchronous -communication card. We bought the card from ImageStream -(http://www.imagestream.com/WANic400.html). You also need the NT -drivers and a cable. There are other distributors but I found these -guys helpful - and they also do Linux drivers. - -The NT WANic driver has a number of modes, one of which is ethernet emulation. -This mode is what is needed to transport IP packets in HDLC frames. - -In libnetworking/net you will find a file called if_hdlcsubr.c containing -the hdlc_input and hdlc_output routines required by network.c. This file was -created by taking out the addressing mechanisms from if_ethersubr.c in the -same directory. There are probably neater ways to do this <any -contributions welcome here>. - - - - - - |