Re: The Kernel for powermacs

[Stephen.Ma%jtec.com.au@localhost (Stephen Ma)]

>>>>> "ws" == Wolfgang Solfrank <ws%kurt.tools.de@localhost> writes:

ws> The PowerPC processor binding to IEEE1275 (i.e. OpenFirmware) is
ws> quite explicit that the firmware is required to copy itself from
ws> ROM to RAM and thus to change the trap vectors from 0xfff0#### to
ws> 0x0000#### (these are the only two possible values for the trap
ws> vector).

ws>  Since the Apple firmware doesn't do that and presumably keeps
ws> running from the ROM image, overwriting the trap vector for page
ws> faults with the ones needed by e.g. NetBSD isn't possible.

Can we get around this particular problem by copying a bunch of stub
handlers to the low memory vectors that simply jump to the high memory
vectors (for vectors that we don't want handled in the kernel), and
set MSR_IP to 0 in the kernel?

- S