Alan Cox wrote:
>
> > | Reserved for BIOS | Do not use. Reserved for BIOS EBDA.
> > 09A000 +------------------------+
>
> 9A000 is not a guaranteed address. The EBDA is defined by reading a low memory
> value
I know, and I address that in the document. Boot protocol 2.02 plus
bzImage allows the boot loader the flexibility to set the memory ceiling
quite low. However, we needed a "drop dead" address for existing
kernels as well, and John, Hans and I came up with 0x9A000 as being
something we can reasonably do. It is not always sufficient -- when
using M-systems flash or PXE the EBDA is several hundred K in size.
There is no way to support this with the old kernels which require
mucking with the 0x90000 segment. Hence the revised protocol.
However, I'll see if I can add a note.
The problem is that most of these are hard limits for the boot loader --
doing INT 12h to find out the ceiling only allows you to print an error
message instead of crashing.
-hpa
-- <hpa@transmeta.com> at work, <hpa@zytor.com> in private! "Unix gives you enough rope to shoot yourself in the foot." http://www.zytor.com/~hpa/puzzle.txt- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Fri Jul 14 2000 - 20:21:00 EDT