docs/system: Extend PPC section

This moves the current documentation in files specific to each
platform family. PowerNV machine is updated, the other machines need
to be done.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20210222133956.156001-1-clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
[dwg: Trivial capitalization fix]
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

docs/system/target-ppc.rst

@@ -3,45 +3,22 @@
 PowerPC System emulator
 -----------------------
 
-Use the executable ``qemu-system-ppc`` to simulate a complete 40P (PREP)
-or PowerMac PowerPC system.
+Board-specific documentation
+============================
 
-QEMU emulates the following PowerMac peripherals:
+You can get a complete list by running ``qemu-system-ppc64 --machine
+help``.
 
--  UniNorth or Grackle PCI Bridge
+..
+   This table of contents should be kept sorted alphabetically
+   by the title text of each file, which isn't the same ordering
+   as an alphabetical sort by filename.
 
--  PCI VGA compatible card with VESA Bochs Extensions
+.. toctree::
+   :maxdepth: 1
 
--  2 PMAC IDE interfaces with hard disk and CD-ROM support
-
--  NE2000 PCI adapters
-
--  Non Volatile RAM
-
--  VIA-CUDA with ADB keyboard and mouse.
-
-QEMU emulates the following 40P (PREP) peripherals:
-
--  PCI Bridge
-
--  PCI VGA compatible card with VESA Bochs Extensions
-
--  2 IDE interfaces with hard disk and CD-ROM support
-
--  Floppy disk
-
--  PCnet network adapters
-
--  Serial port
-
--  PREP Non Volatile RAM
-
--  PC compatible keyboard and mouse.
-
-Since version 0.9.1, QEMU uses OpenBIOS https://www.openbios.org/ for
-the g3beige and mac99 PowerMac and the 40p machines. OpenBIOS is a free
-(GPL v2) portable firmware implementation. The goal is to implement a
-100% IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.
-
-More information is available at
-http://perso.magic.fr/l_indien/qemu-ppc/.
+   ppc/embedded
+   ppc/powermac
+   ppc/powernv
+   ppc/prep
+   ppc/pseries