sandbox: Add instructions about building on 32-bit machines

[people/ms/u-boot.git] / board / sandbox / README.sandbox

diff --git a/board/sandbox/README.sandbox b/board/sandbox/README.sandbox
index 9fe3bf171a22d64d18f64892b4f4fdb156214957..ed820d338e586bb9dba9d491152d2325f9757b2a 100644 (file)
--- a/board/sandbox/README.sandbox
+++ b/board/sandbox/README.sandbox
@@ -44,6 +44,9 @@ Note:
       make sandbox_defconfig all NO_SDL=1
       ./u-boot
 
+   If you are building on a 32-bit machine you may get errors from __ffs.h
+   about shifting more than the machine word size. Edit the config file
+   include/configs/sandbox.h and change CONFIG_SANDBOX_BITS_PER_LONG to 32.
 
 U-Boot will start on your computer, showing a sandbox emulation of the serial
 console: