[U-Boot] [PATCH v5] pico-imx7d: Increase the CONFIG_ENV_OFFSET size

[Fabio Estevam <festevam@gmail.com>]

U-Boot binary has grown in such a way that it goes beyond the reserved
area for the environment variables.

Running "saveenv" causes U-Boot to hang because of this overlap.

Fix this problem by increasing the CONFIG_ENV_OFFSET size.

Also, in order to prevent this same problem to happen again in
the future, use CONFIG_BOARD_SIZE_LIMIT, which will detect the overlap
in build-time.

CONFIG_BOARD_SIZE_LIMIT is CONFIG_ENV_OFFSET - 69 kB, as u-boot.img
is flashed into the 69 kB offset.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
---
Changes since v4:
- Use math expressions for better readability

Hi Stefano,

This one depends on Wolfgang's v2 patch:
https://lists.denx.de/pipermail/u-boot/2018-December/351138.html

 include/configs/pico-imx7d.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/configs/pico-imx7d.h b/include/configs/pico-imx7d.h
index 2bc42a0..333c0b4 100644
--- a/include/configs/pico-imx7d.h
+++ b/include/configs/pico-imx7d.h
@@ -134,7 +134,8 @@
 /* FLASH and environment organization */
 #define CONFIG_ENV_SIZE			SZ_8K
 
-#define CONFIG_ENV_OFFSET			(8 * SZ_64K)
+#define CONFIG_ENV_OFFSET			(768 * 1024)
+#define CONFIG_BOARD_SIZE_LIMIT			((768 - 69) * 1024)
 #define CONFIG_SYS_FSL_USDHC_NUM		2
 
 #define CONFIG_SYS_MMC_ENV_DEV			0
-- 
2.7.4