add some more Blackfin docs
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/README b/README
index a5ffbb5..d4afcfa 100644
--- a/README
+++ b/README
@@ -3517,6 +3517,11 @@
average for all boards 752 bytes for the whole U-Boot image,
624 text + 127 data).
+On Blackfin, the normal C ABI (except for P5) is followed as documented here:
+ http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
+
+ ==> U-Boot will use P5 to hold a pointer to the global data
+
On ARM, the following registers are used:
R0: function argument word/integer result