[SeaBIOS] [PATCH] docs: Add info on MODE16/MODESEGMENT compile time flags

[Kevin O'Connor]

Signed-off-by: Kevin O'Connor <kevin at koconnor.net>
---
 docs/Memory_Model.md | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/docs/Memory_Model.md b/docs/Memory_Model.md
index c77fc22..196b57b 100644
--- a/docs/Memory_Model.md
+++ b/docs/Memory_Model.md
@@ -108,6 +108,15 @@ assembled using ".code16gcc". SeaBIOS is careful to use segment
 registers properly so that the same code can run in the different
 16bit modes that it needs to support.
 
+C code mode flags
+=================
+
+Two compile time flags are available to determine the memory model the
+code is intended for: MODE16 and MODESEGMENT. When compiling for the
+16 bit modes, MODE16 is true and MODESEGMENT is true. In 32bit
+segmented mode, MODE16 is false and MODESEGMENT is true. In 32bit flat
+mode both MODE16 and MODESEGMENT are false.
+
 Common memory used at run-time
 ==============================
 
-- 
1.9.3