add some more Blackfin docs

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/README b/README
index a5ffbb5ad1..d4afcfafea 100644
--- a/README
+++ b/README
@@ -3517,6 +3517,11 @@ For PowerPC, the following registers have specific use:
     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