Messages in this thread | | | Subject | Re: Booting a modular kernel through a multiple streams file / Making Linux multiboot capable and grub loading kernel modules at boot time. | From | (Eric W. Biederman) | Date | 19 Dec 2001 02:12:31 -0700 |
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"H. Peter Anvin" <hpa@zytor.com> writes:
> Eric W. Biederman wrote: > > > I have a personally dislike for using firmware calls to drive hardware > > devices, so I won't be picking that up. But I am interested in what > > it requires to not burn bridges. So I can make certain a linux kernel > > loaded with a linux booting linux patch can requery the firmware. > > > > > My impression is that the linux kernel already does the important > > things by not smashing firmware reserved memory, (assuming you aren't > > loaded with loadlin). So all that is required is to switch the idt > > back to address 0, and switch the cpu back to 16bit real mode. > > But if you know of other cases that need to be handled I would be > > happy to hear about it. > > > > > Unfortunately that's not the case. The big issue is "who owns the interrupt > controller", and "who owns the interrupts." [snip]
> You can check out the BIOS extender I wrote for genesis at > ftp://ftp.zytor.com/pub/linux/genesis/
Thanks. I've got genesis-1.10 now looking and digesting to see if you have any unexpected tricks takes a little longer.
For my purposes I intend to fully disable the BIOS and then after I have done all of my work, reenable the BIOS. Which should be a little easier and have a slightly different set of issues.
>From the 10,000 foot level it looks like I am pretty safe already except for those BIOS functions that drive the hardware. For those I need to setup the legacy PIC back to it's default setting, and possibly a few other hardware things. I wonder just how sensitive the an x86 BIOS really is to changing those things...
For the most part I find it perfectly acceptable if I break all of the firmware hardware drivers. As long as the information callbacks are preserved. But preserver enough so I could load dos from linux would be nice.
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