On 28 Jun 2001, Eric W. Biederman wrote:
> > Another question, which seems to be the only problem I have with my
> > code, is regarding x86. When I do protected mode with linuxbios code,
> > what could be missing if a "lss" instruction causes an exception ?
> > (this lss comes from arch/i386/boot/compressed/head.S)
>
> There are some ugly connections between the linux boot code and
> segments, and global descriptor tables.
>
> Basicaly if lss is failing it means you don't have a valid global
> descriptor table setup, or it doesn't have the segments that linux
> expect to be there.
>
> My memory is that linuxBIOS was getting this right, but I suspect
> there is something you changed in your code that invalidates this.
I found the problem, it was my fault. The lss
instruction loads from the memory location pointed by the given
value and this location didn't have the correct values.
When I checked the loaded image, I only checked what was read
from the IDE device and not what was stored in memory.
The whole problem was only a miscalculated pointer, sorry for that.
Now my image starts, but linux doesn't start up correctly, so
some init of my hardware seems to be missing, which is my next job.
When I want to add the code to the standard linuxbios, is it okay
to use the cvs version as a base to make patches ?
Are there any efforts yet to add IDE boot to linuxbios ?
Armin
