From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 19 Feb 1999 15:36:05 +0100 To: linuxppc-dev@lists.linuxppc.org From: Benjamin Herrenschmidt Subject: Serial port test Message-Id: <19990219153605.011726@mail.mipsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: owner-linuxppc-dev@lists.linuxppc.org List-Id: If you have an heathrow, paddington or ohare based machine, and especially if you have problems (garbage) with the serial port, please test the following with xmon or MacsBug: Test if there is a 1 byte register at (baseaddress + 0x80). baseaddress is the base of the escc itself, that is the base of channel B (f3013000 on heathrow based machines). test also baseaddress+0x60. On my machines, I have 0x08. If you have problems, try changing your value to 0x08 or higher. This is the recovery count value of the ESCC (the number of cycles to wait between each access) and it may not be correctly initialised by OF. I'm not sure yet, but I think one some models, MacOS will reinit it too late in the boot process for BootX Extension. Try this from linux booted via OF, BootX Extension and BootX App, tell me if you see different values. -- E-Mail: BenH. Web : [[ This message was sent via the linuxppc-dev mailing list. Replies are ]] [[ not forced back to the list, so be sure to Cc linuxppc-dev if your ]] [[ reply is of general interest. To unsubscribe from linuxppc-dev, send ]] [[ the message 'unsubscribe' to linuxppc-dev-request@lists.linuxppc.org ]]