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authorGerd Hoffmann <kraxel@redhat.com>2014-09-23 12:45:56 +0200
committerGerd Hoffmann <kraxel@redhat.com>2014-10-15 11:08:35 +0200
commitb5682aa4ca790dbcce16de6dc991c72bc298019a (patch)
treead12a987ca308ceced6296b0a4583927746d2bcd /docs
parentb1d28ec6a7dbdaadda39d29322f0de694aeb0b74 (diff)
vga-pci: add qext region to mmio
Add a qemu extented register range to the standard vga mmio bar. Right nowe there are two registers: One readonly register returning the size of the region (so we can easily add more registers there if needed) and one endian control register, so guests (especially ppc) can flip the framebuffer endianness as they need it. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'docs')
-rw-r--r--docs/specs/standard-vga.txt9
1 files changed, 9 insertions, 0 deletions
diff --git a/docs/specs/standard-vga.txt b/docs/specs/standard-vga.txt
index f82773e677..19d2a74509 100644
--- a/docs/specs/standard-vga.txt
+++ b/docs/specs/standard-vga.txt
@@ -70,3 +70,12 @@ Likewise applies to the pci variant only for obvious reasons.
0500 - 0515 : bochs dispi interface registers, mapped flat
without index/data ports. Use (index << 1)
as offset for (16bit) register access.
+
+0600 - 0607 : qemu extended registers. qemu 2.2+ only.
+ The pci revision is 2 (or greater) when
+ these registers are present. The registers
+ are 32bit.
+ 0600 : qemu extended register region size, in bytes.
+ 0604 : framebuffer endianness register.
+ - 0xbebebebe indicates big endian.
+ - 0x1e1e1e1e indicates little endian.