rollover to nodma when DMA fails

[ampoliros]

Since I've seen many posts across the forums complaining about Knoppix failing to boot from CD where the answer has been to append "nodma" to the boot command line, please alter miniroot to rollover to nodma behavior (at least for the CD drive) if mounting the cd image via DMA fails. Obviously the CD drive works... the syslinux boot prompt loaded and Knoppix began loading.

BTW, I'm also experiencing the nodma issue. Our old computers, Gateway 2000 Pentium 166 and IBM 300GL, work just fine with DMA enabled, but our new computers, IBM NetVista A60, do not work with DMA enabled.

We're trying to make a one-size-fits-all NX-Kiosk CD so our end users can just stick it in and go. As is, we'll have to have 2 versions, one with DMA for the older slower computers and one without DMA for the new computers. We're probably not going to do it because it'll be too confusing for our computer unsavvy users.

Please get the DMA to rollover when it fails to load the CD image.

Thank you.

[Harry Kuhman]

I would think that for a live CD that is intended to work for the largest number of users, the default should always be the one that does the least harm. In this case nodma would be a nice default, with DMA a cheat code that users could try if they wanted to boost their system after they got their first taste.

[mzilikazi]

Here I go with another Kanotix recommendation. It already has the so-called 'cheatcodes' in an easy to select manner including a line w/ nodma. You just have to see it to understand what I mean so please check this link.
http://osdir.com/shots/slideshows/sl...se=154&slide=1

[Fabianx]

This is quite a nice idea. However there is a problem:

Sometimes knoppix does boot, but you get many read errors with dma on.

Why don't you just set dma off and are done?

You can set it up on the old machines later one from your NX-startup scripts.

Like that:

        # Enable DMA for all IDE drives now if requested (if not already done by linuxrc).
        # This is already done by linuxrc now.
        # However, for a harddisk-installed version, we are doing it again here.
        # Please use hda=dma or similar in the lilo.conf append= line.
        for d in $(cd /proc/ide 2>/dev/null && echo hd[a-z])
        do
                if test -d /proc/ide/$d; then
                if egrep -q 'using_dma[ \t]+0' /proc/ide/$d/settings 2>/dev/null
                then
                        MODEL="$(cat /proc/ide/$d/model 2>/dev/null)"
                        test -z "$MODEL" && MODEL="[GENERIC IDE DEVICE]"
                        echo "${BLUE}Enabling DMA acceleration for: ${MAGENTA}$d        ${YELLOW}[${MODEL}]${NORMAL}"
                        echo "using_dma:1" >/proc/ide/$d/settings
                fi
                fi
        done

cu

Fabian

[firebyrd10]

Possible adding a message apon too many error or not being able to mount the image telling that user to try nodma