G5

[Peter Grehan]

Hi Suleiman,

> I just have a few quick questions regarding booting on the G5s: 
> How far does it get?

  The boot loader works, but I'm still trying to get pmap_bootstrap
sorted out. It's going to take a while :-(  The hash table for
the G5 is the 64-bit version, but if you run in 'bridge' mode,
segment registers can still be used.

  Check out the IBM doc for details:

http://www-306.ibm.com/chips/techlib/techlib.nsf/techdocs/F6153E213FDD912E87256D49006C6541

  Fortunately the work needed to abstract out the hash-table differences
can be used in PPC implementations that don't have a hash table,
such as the IBM 4xx and Motorola 8xx series, which I'm very interested
in.

  I think I'll set up a P4 depot to track the changes I'm doing
for this.

> Are you trying to boot in 32-bit mode or 64-bit mode?

  32-bit mode. 64-bit mode is a hell of a lot of work with
toolchain, ld.so, exec, openfirmware callbacks etc, whereas
32-bit mode is mainly vm/trap work. Plus, it should produce
a kernel that can run on G3/G4/G5, which I think is a better
place for the project than immediately starting a 64-bit port
before the 32-bit port is stable.

> Does 32-bit mode need a toolchain that supports ppc64 anyway?

  There might be some config mods needed, but yes, I think the
32-bit toolchain could support 64-bit mode as well.

later,

Peter.