Date: Mon, 23 Nov 1998 10:44:52 +0200 (SAT) From: Robert Nordier <rnordier@nordier.com> To: freebsd-hackers@FreeBSD.ORG Cc: mike@smith.net.au Subject: Re: Changing the load address of the kernel? Message-ID: <199811230844.KAA12135@ceia.nordier.com> In-Reply-To: <199811222351.AAA18256@dorifer.heim3.tu-clausthal.de> from Oliver Fromme at "Nov 23, 98 00:51:59 am"
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Oliver Fromme wrote: > Mike Smith wrote in list.freebsd-hackers: > > > Background of the problem: I'm trying to boot a diskless > > > computer with a network boot ROM by LanWorks > > > (www.lanworks.com). They require to make a bootable floppy > > > first, then put an image of that floppy on a tftp server. > > > The ROM loads that image, makes a RAM disk from it and boots > > > it. The problem is: That RAM disks seems to overlap with the > > > kernel at 00100000. There doesn't seem to be a way to change > > > the location of the RAM disk. > > > > That's ugly. 8( > > Yes. Meanwhile I found out that the overlapping memory > locations are only half of the problem. Thanks to Lanworks > tech support, I got a new version of their image loader stub > that relocates the RAM disk to a different location. But > there's still the same problem. > > I tracked it down to some strange and subtl interference > between the 2nd stage bootloader and the RAM disk's INT 0x13 > interface. It occurs as soon as the bootloader switches to > protected mode. > > After some dirty hacking, it works now -- I created a modified > version of rawboot (I called it ramboot) which reads the kernel > directly from the RAM disk in memory. > > Should I give the code to someone who can commit it? On the > other hand, it's really ugly code, and (AFAIK) there will be a > new ELF-based bootloader soon, so it might not be worth > bothering. We do need a more capable netboot replacement, and if Lanworks is as responsive as they appear to be, then supporting their product may be an easy route to satisfying this requirement. It might be a reasonable solution to make something like this available as a port; after all, the boot blocks are *expected* to be somewhat out of sync with kernel development. Though I'd quite like to see it working with the new boot1/boot2 and boot/loader code, in some form, now that Oliver has shown the way. > Anyway, if someone needs some code to boot his/her FreeBSD box > with a Lanworks ROM, I've put the "ramboot" stuff on the web: > http://dorifer.heim3.tu-clausthal.de/~olli/ramboot.tar.gz Thanks. I've just fetched a copy. -- Robert Nordier To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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