Messages in this thread | | | From | "H.Rosmanith (Kernel Mailing List)" <> | Subject | Re: emm386 hangs when booting from linux | Date | Sat, 1 Mar 2003 00:26:00 +0100 (MET) |
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> On Fri, 28 Feb 2003, H.Rosmanith (Kernel Mailing List) wrote: > > > > > hello, > > > > for some reason, I am using the "switch to 16 bit realmode" function > > present in the linux kernel to execute various 16bit code. One thing > > that I am doing is to read the mbr off a harddisk to 0x7c00 and then > > jump to there. This allows to e.g. "quickboot dos" from linux without > > having to go through bios startup. > > > > I got this working with *one* exception: as soon as I load emm386 > > in config.sys, the system hangs. It doesn't hang completely, e.g. > > the num-lock led changes light when pressing num-lock, and ctrlaltdel > > reboots the system. When I "REM"ark the emm386.exe, then dos will > > boot and display a "C:\>" prompt. > > So you are trying a "home-brew" DOS-EMU which already exists and works > well.
hm? I am trying to boot "real" DOS from linux.
> emm386.exe attempts to go to protected mode. That's how it works.
and when going into protected mode, it crashes. I wonder why. I can start DOS4GW, which does not crash, and I think that DOS4GW too works with the protected mode features of the CPU.
> That's how it's able to make "high-RAM" appear in "low-RAM" windows > for the emm386 specification. Of course it will fail when you > are in virtual 386 mode. The real DOS-EMU emulates the extended/expanded
after executing "machine_real_start", the system is in 16 bit real mode, not in vm86 mode.
> memory specification so you don't need this in 'config.sys'. I sometimes > boot real DOS usinf DOS-EMU and it works fine. You need to configure > it so it will look at, say config.emu, instead of the DOS config.sys. > That way, you can keep boot-specific configuration files.
the problem is not only with DOS. when booting M$-Windows (w2k), the boot-process will hang as soon as w2k tries to enter protected mode.
starting loadlin will hang the system too, as I just found out. hm, well, at least it's easier looking into loadlin than looking into emm386 !
> Cheers, > Dick Johnson > Penguin : Linux version 2.4.18 on an i686 machine (797.90 BogoMips). > Why is the government concerned about the lunatic fringe? Think about it. > >
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