README: document CONFIG_BOARD_SIZE_LIMIT

CONFIG_BOARD_SIZE_LIMIT was introduced by f3a14d37 [Makefile: allow
boards to check file size limits] and is in use by several boards, but
never got documented.

Signed-off-by: Sascha Silbe <t-uboot@infra-silbe.de>

diff --git a/README b/README
index 4fd87949cd7d8c39936b916d4d5773ca5a87c4f8..5c85fe0f91cd0cb6014f87e5f14231da2e5f9c93 100644 (file)
--- a/README
+++ b/README
@@ -4371,6 +4371,11 @@ use the "saveenv" command to store a valid environment.
                later, once stdio is running and output goes to the LCD, if
                present.
 
+- CONFIG_BOARD_SIZE_LIMIT:
+               Maximum size of the U-Boot image. When defined, the
+               build system checks that the actual size does not
+               exceed it.
+
 Low Level (hardware related) configuration options:
 ---------------------------------------------------