PPC: Make all e500 CPUs SVR aware

Our pre-e500mc e500 CPU types didn't get instanciated with SVR information,
even though those systems do support the SVR register.

Spawn them with the SVR tag so that they don't get confused when someone tries
to read SPR_SVR.

Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: Add definitions for GIVORs

We're missing SPR definitions for GIVORs. Add them to the list of SPRs.

Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: Fix SPR access control of L1CFG0

The L1CFG0 register on e200 and e500 is "User RO" according to the
specifications. So let's make it user readable and world unwritable.

Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: Add L1CFG1 SPR emulation

In addition to the L1 data cache configuration register L1CFG0 there is
also another one for the L1 instruction cache called L1CFG1.

Emulate that one with the same values as the data one.

Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: Properly emulate L1CSR0 and L1CSR1

There are 2 L1 cache control registers - one for data (L1CSR0) and
one for instructions (L1CSR1).

Emulate both of them well enough to give the guest the illusion that
it could actually do anything about its caches.

Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: Add dcbtls emulation

The dcbtls instruction is able to lock data inside the L1 cache.

Unfortunately we don't emulate any caches, so we have to tell the guest
that its locking attempt failed.

However, by implementing the instruction we at least don't give the
guest a program exception which it definitely does not expect.

Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: e500: Expose kernel load address in dt

We want to move to a model where firmware loads our kernel. To achieve
this we need to be able to tell firmware where the kernel lies.

Let's copy the mechanism we already use for -M pseries and expose the
kernel load address and size through the device tree.

Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: Add u-boot firmware for e500

This adds a special build of u-boot tailored for the e500 platforms we
emulate. It is based on the current version of upstream u-boot which
contains all the code necessary to drive our QEMU provided machines.

Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: e500: Move to u-boot as firmware

Almost all platforms QEMU emulates have some sort of firmware they can load
to expose a guest environment that closely resembles the way it would look
like on real hardware.

This patch introduces such a firmware on our e500 platforms. U-boot is the
default firmware for most of these systems and as such our preferred choice.

For backwards compatibility reasons (and speed and simplicity) we skip u-boot
when you use -kernel and don't pass in -bios. For all other combinations like
-kernel and -bios or no -kernel you get u-boot as firmware.

This allows you to modify the boot environment, execute a networked boot through
the e1000 emulation and execute u-boot payloads.

Signed-off-by: Alexander Graf <agraf@suse.de>