Re: switching to real mode

2001-12-07 Thread Terry Lambert
Ian Dowse wrote: [ ... booting another OS that is either real mode or requires the use of a real mode bootstrap, at FreeBSD shutdown ... ] Yeah, I attempted something like this a few years ago without much success. I've just updated the code to compile on -stable, and it seems to

Re: switching to real mode

2001-12-06 Thread Terry Lambert
Dmitry Konyshev wrote: For some odd reason I need to load another OS (no matter which one, everything that known about it is its boot sector number) at the end of the reboot syscall. Could someone please explain how to switch processor to real mode and continue program execution from some

Re: switching to real mode

2001-12-06 Thread Bob Bishop
Hi, At 17:04 06/12/01 +0300, Dmitry Konyshev wrote: Hello! For some odd reason I need to load another OS (no matter which one, everything that known about it is its boot sector number) [etc] man boot0cfg, look at the -s option. eg something like: boot0cfg -s 2 ad0 reboot -- Bob Bishop

Re: switching to real mode

2001-12-06 Thread Ronald G Minnich
On Thu, 6 Dec 2001, Terry Lambert wrote: Dmitry Konyshev wrote: For some odd reason I need to load another OS (no matter which one, everything that known about it is its boot sector number) at the end of the reboot syscall. Could someone please explain how to switch processor to real

Re: switching to real mode

2001-12-06 Thread Terry Lambert
Dmitry Konyshev wrote: [ ... reboot with new active partition ... ] I thought of this way, but it might seem strange for a user if her computer would want to reboot without any obvious reason. I'll keep this way in mind for the case I fail to implement it in more user-friendly manner. :)

Re: switching to real mode

2001-12-06 Thread Terry Lambert
Ronald G Minnich wrote: I saw an example of switching in real mode in linux' sources (it looks pretty clear) and thouhgt it is possible to do the same under FreeBSD. The problem is I'm absolutely lost in FreeBSD's physical memory management implementation (page tables and directory and so

Re: switching to real mode

2001-12-06 Thread Ronald G Minnich
On Thu, 6 Dec 2001, Terry Lambert wrote: It isn't enough to do what he wants, though. He wants to effectively return to real mode and jump to a real mode boot strap loader, as if in the second stage of a boot manager, after the partition to boot has been selected (e.g. Reboot to Linux,

Re: switching to real mode

2001-12-06 Thread Ronald G Minnich
On Thu, 6 Dec 2001, Ronald G Minnich wrote: no, you are right. It's just that the freebsd code for this is a nice tutorial, then when he looks at bootimg or whatever it will be easier to ^^^ NOT a typo. bootimg is Werner Almesberger's (LILO guy)

Re: switching to real mode

2001-12-06 Thread Mike Smith
It's still there. See the code in /sys/boot, in particular, the bios code in boot2 and boot 3. You're thinking of the bioscall interface in BTX, I guess, which uses v86 mode, not real mode. As John said, actually, really going back to real mode is hard. It would be easier to just reboot

Re: switching to real mode

2001-12-06 Thread Ian Dowse
In message [EMAIL PROTECTED], John Baldwin writes: The short form is htat you need to hack the cpu_halt to call a function that puts a stub down in low memory, and calls it. This code needs to be mapped 1:1 so that the logical address == physical address. The first thing you will Yeah, I

Re: switching to real mode

2001-12-06 Thread Ronald G Minnich
On Thu, 6 Dec 2001, Mike Smith wrote: As John said, actually, really going back to real mode is hard. It would be easier to just reboot the system, especially since we have probably left hardware in odd states. True. For two kernel monte and LOBOS we never leave protected mode before