gma pcode: Add Mailbox_Read procedure
Some chipsets may have data that they need to read from the PCode,
with no data in particular necessary, therefore add a `Mailbox_Read`
procedure to do this.
Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: Ic8505ef46661c291e6f0787279b32430669f7d14
Reviewed-on: https://review.coreboot.org/c/libgfxinit/+/65140
Tested-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Nico Huber <nico.h@gmx.de>
diff --git a/common/hw-gfx-gma-pcode.ads b/common/hw-gfx-gma-pcode.ads
index ef2564a..595fe5b 100644
--- a/common/hw-gfx-gma-pcode.ads
+++ b/common/hw-gfx-gma-pcode.ads
@@ -57,4 +57,15 @@
with
Pre => Mailbox_Ready or Wait_Ready;
+ -- For reading data from PCode
+ procedure Mailbox_Read
+ (MBox : in Word32;
+ Command : in Word64 := 0;
+ Wait_Ready : in Boolean := False;
+ Reply : out Word64;
+ Success : out Boolean)
+ with
+ Pre => Mailbox_Ready or Wait_Ready,
+ Post => (if Success then Mailbox_Ready);
+
end HW.GFX.GMA.PCode;